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pigweed / third_party / github / h2o / picotls / 163effd7afad94f01a0c1ffc944b9af0e33bce95 / . / lib / picotls.c
blob: ef72b2cf89efad6871a4548c7679785b97597734 [file] [log] [blame]
/*
* Copyright (c) 2016 DeNA Co., Ltd., Kazuho Oku
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifdef _WINDOWS
#include "wincompat.h"
#endif
#include <assert.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef _WINDOWS
#include <errno.h>
#include <pthread.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/time.h>
#endif
#include "picotls.h"
#if PICOTLS_USE_DTRACE
#include "picotls-probes.h"
#endif
#define PTLS_MAX_PLAINTEXT_RECORD_SIZE 16384
#define PTLS_MAX_ENCRYPTED_RECORD_SIZE (16384 + 256)
#define PTLS_RECORD_VERSION_MAJOR 3
#define PTLS_RECORD_VERSION_MINOR 3
#define PTLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC 20
#define PTLS_CONTENT_TYPE_ALERT 21
#define PTLS_CONTENT_TYPE_HANDSHAKE 22
#define PTLS_CONTENT_TYPE_APPDATA 23
#define PTLS_PSK_KE_MODE_PSK 0
#define PTLS_PSK_KE_MODE_PSK_DHE 1
#define PTLS_HANDSHAKE_HEADER_SIZE 4
#define PTLS_EXTENSION_TYPE_SERVER_NAME 0
#define PTLS_EXTENSION_TYPE_STATUS_REQUEST 5
#define PTLS_EXTENSION_TYPE_SUPPORTED_GROUPS 10
#define PTLS_EXTENSION_TYPE_SIGNATURE_ALGORITHMS 13
#define PTLS_EXTENSION_TYPE_ALPN 16
#define PTLS_EXTENSION_TYPE_SERVER_CERTIFICATE_TYPE 20
#define PTLS_EXTENSION_TYPE_COMPRESS_CERTIFICATE 27
#define PTLS_EXTENSION_TYPE_PRE_SHARED_KEY 41
#define PTLS_EXTENSION_TYPE_EARLY_DATA 42
#define PTLS_EXTENSION_TYPE_SUPPORTED_VERSIONS 43
#define PTLS_EXTENSION_TYPE_COOKIE 44
#define PTLS_EXTENSION_TYPE_PSK_KEY_EXCHANGE_MODES 45
#define PTLS_EXTENSION_TYPE_KEY_SHARE 51
#define PTLS_EXTENSION_TYPE_ECH_OUTER_EXTENSIONS 0xfd00
#define PTLS_EXTENSION_TYPE_ENCRYPTED_CLIENT_HELLO 0xfe0d
#define PTLS_SERVER_NAME_TYPE_HOSTNAME 0
#define PTLS_ECH_CONFIG_VERSION 0xfe0d
#define PTLS_ECH_CLIENT_HELLO_TYPE_OUTER 0
#define PTLS_ECH_CLIENT_HELLO_TYPE_INNER 1
#define PTLS_ECH_CONFIRM_LENGTH 8
static const char ech_info_prefix[8] = "tls ech";
#define PTLS_SERVER_CERTIFICATE_VERIFY_CONTEXT_STRING "TLS 1.3, server CertificateVerify"
#define PTLS_CLIENT_CERTIFICATE_VERIFY_CONTEXT_STRING "TLS 1.3, client CertificateVerify"
#define PTLS_MAX_CERTIFICATE_VERIFY_SIGNDATA_SIZE \
(64 + sizeof(PTLS_SERVER_CERTIFICATE_VERIFY_CONTEXT_STRING) + PTLS_MAX_DIGEST_SIZE * 2)
#define PTLS_EARLY_DATA_MAX_DELAY 10000 /* max. RTT (in msec) to permit early data */
#ifndef PTLS_MAX_EARLY_DATA_SKIP_SIZE
#define PTLS_MAX_EARLY_DATA_SKIP_SIZE 65536
#endif
#if defined(PTLS_DEBUG) && PTLS_DEBUG
#define PTLS_DEBUGF(...) fprintf(stderr, __VA_ARGS__)
#else
#define PTLS_DEBUGF(...)
#endif
#ifndef PTLS_MEMORY_DEBUG
#define PTLS_MEMORY_DEBUG 0
#endif
#if PICOTLS_USE_DTRACE
#define PTLS_SHOULD_PROBE(LABEL, tls) (PTLS_UNLIKELY(PICOTLS_##LABEL##_ENABLED()) && !(tls)->skip_tracing)
#define PTLS_PROBE0(LABEL, tls) \
do { \
ptls_t *_tls = (tls); \
if (PTLS_SHOULD_PROBE(LABEL, _tls)) \
PICOTLS_##LABEL(_tls); \
} while (0)
#define PTLS_PROBE(LABEL, tls, ...) \
do { \
ptls_t *_tls = (tls); \
if (PTLS_SHOULD_PROBE(LABEL, _tls)) \
PICOTLS_##LABEL(_tls, __VA_ARGS__); \
} while (0)
#else
#define PTLS_PROBE0(LABEL, tls)
#define PTLS_PROBE(LABEL, tls, ...)
#endif
/**
* list of supported versions in the preferred order
*/
static const uint16_t supported_versions[] = {PTLS_PROTOCOL_VERSION_TLS13};
static const uint8_t hello_retry_random[PTLS_HELLO_RANDOM_SIZE] = {0xCF, 0x21, 0xAD, 0x74, 0xE5, 0x9A, 0x61, 0x11, 0xBE, 0x1D, 0x8C,
0x02, 0x1E, 0x65, 0xB8, 0x91, 0xC2, 0xA2, 0x11, 0x16, 0x7A, 0xBB,
0x8C, 0x5E, 0x07, 0x9E, 0x09, 0xE2, 0xC8, 0xA8, 0x33, 0x9C};
struct st_ptls_traffic_protection_t {
uint8_t secret[PTLS_MAX_DIGEST_SIZE];
size_t epoch;
/* the following fields are not used if the key_change callback is set */
ptls_aead_context_t *aead;
uint64_t seq;
unsigned tls12 : 1;
uint64_t tls12_enc_record_iv;
};
struct st_ptls_record_message_emitter_t {
ptls_message_emitter_t super;
size_t rec_start;
};
struct st_ptls_signature_algorithms_t {
uint16_t list[16]; /* expand? */
size_t count;
};
struct st_ptls_certificate_request_t {
/**
* context.base becomes non-NULL when a CertificateRequest is pending for processing
*/
ptls_iovec_t context;
struct st_ptls_signature_algorithms_t signature_algorithms;
};
struct st_decoded_ech_config_t {
uint8_t id;
ptls_hpke_kem_t *kem;
ptls_iovec_t public_key;
ptls_hpke_cipher_suite_t *cipher;
uint8_t max_name_length;
ptls_iovec_t public_name;
ptls_iovec_t bytes;
};
/**
* Properties for ECH. Iff ECH is used and not rejected, `aead` is non-NULL.
*/
struct st_ptls_ech_t {
uint8_t offered : 1;
uint8_t offered_grease : 1;
uint8_t accepted : 1;
uint8_t config_id;
ptls_hpke_kem_t *kem;
ptls_hpke_cipher_suite_t *cipher;
ptls_aead_context_t *aead;
uint8_t inner_client_random[PTLS_HELLO_RANDOM_SIZE];
struct {
ptls_iovec_t enc;
uint8_t max_name_length;
char *public_name;
/**
* retains a copy of entire ECH extension so that it can be replayed in the 2nd CH when ECH is rejected via HRR
*/
ptls_iovec_t first_ech;
} client;
};
struct st_ptls_t {
/**
* the context
*/
ptls_context_t *ctx;
/**
* the state
*/
enum en_ptls_state_t {
PTLS_STATE_CLIENT_HANDSHAKE_START,
PTLS_STATE_CLIENT_EXPECT_SERVER_HELLO,
PTLS_STATE_CLIENT_EXPECT_SECOND_SERVER_HELLO,
PTLS_STATE_CLIENT_EXPECT_ENCRYPTED_EXTENSIONS,
PTLS_STATE_CLIENT_EXPECT_CERTIFICATE_REQUEST_OR_CERTIFICATE,
PTLS_STATE_CLIENT_EXPECT_CERTIFICATE,
PTLS_STATE_CLIENT_EXPECT_CERTIFICATE_VERIFY,
PTLS_STATE_CLIENT_EXPECT_FINISHED,
PTLS_STATE_SERVER_EXPECT_CLIENT_HELLO,
PTLS_STATE_SERVER_EXPECT_SECOND_CLIENT_HELLO,
PTLS_STATE_SERVER_GENERATING_CERTIFICATE_VERIFY,
PTLS_STATE_SERVER_EXPECT_CERTIFICATE,
PTLS_STATE_SERVER_EXPECT_CERTIFICATE_VERIFY,
/* ptls_send can be called if the state is below here */
PTLS_STATE_SERVER_EXPECT_END_OF_EARLY_DATA,
PTLS_STATE_SERVER_EXPECT_FINISHED,
PTLS_STATE_POST_HANDSHAKE_MIN,
PTLS_STATE_CLIENT_POST_HANDSHAKE = PTLS_STATE_POST_HANDSHAKE_MIN,
PTLS_STATE_SERVER_POST_HANDSHAKE
} state;
/**
* receive buffers
*/
struct {
ptls_buffer_t rec;
ptls_buffer_t mess;
} recvbuf;
/**
* key schedule
*/
ptls_key_schedule_t *key_schedule;
/**
* values used for record protection
*/
struct {
struct st_ptls_traffic_protection_t dec;
struct st_ptls_traffic_protection_t enc;
} traffic_protection;
/**
* server-name passed using SNI
*/
char *server_name;
/**
* result of ALPN
*/
char *negotiated_protocol;
/**
* selected key-exchange
*/
ptls_key_exchange_algorithm_t *key_share;
/**
* selected cipher-suite
*/
ptls_cipher_suite_t *cipher_suite;
/**
* ClientHello.random that appears on the wire. When ECH is used, that of inner CH is retained separately.
*/
uint8_t client_random[PTLS_HELLO_RANDOM_SIZE];
/**
* exporter master secret (either 0rtt or 1rtt)
*/
struct {
uint8_t *early;
uint8_t *one_rtt;
} exporter_master_secret;
/**
* ECH
*/
struct st_ptls_ech_t ech;
/* flags */
unsigned is_server : 1;
unsigned is_psk_handshake : 1;
unsigned send_change_cipher_spec : 1;
unsigned needs_key_update : 1;
unsigned key_update_send_request : 1;
unsigned skip_tracing : 1;
/**
* misc.
*/
union {
struct {
ptls_iovec_t legacy_session_id;
uint8_t legacy_session_id_buf[32];
ptls_key_exchange_context_t *key_share_ctx;
unsigned offered_psk : 1;
/**
* if 1-RTT write key is active
*/
unsigned using_early_data : 1;
struct st_ptls_certificate_request_t certificate_request;
} client;
struct {
uint8_t pending_traffic_secret[PTLS_MAX_DIGEST_SIZE];
uint32_t early_data_skipped_bytes; /* if not UINT32_MAX, the server is skipping early data */
unsigned can_send_session_ticket : 1;
ptls_async_job_t *async_job;
} server;
};
/**
* certificate verify; will be used by the client and the server (if require_client_authentication is set)
*/
struct {
int (*cb)(void *verify_ctx, uint16_t algo, ptls_iovec_t data, ptls_iovec_t signature);
void *verify_ctx;
} certificate_verify;
/**
* handshake traffic secret to be commisioned (an array of `uint8_t [PTLS_MAX_DIGEST_SIZE]` or NULL)
*/
uint8_t *pending_handshake_secret;
/**
* user data
*/
void *data_ptr;
};
struct st_ptls_record_t {
uint8_t type;
uint16_t version;
size_t length;
const uint8_t *fragment;
};
struct st_ptls_client_hello_psk_t {
ptls_iovec_t identity;
uint32_t obfuscated_ticket_age;
ptls_iovec_t binder;
};
#define MAX_UNKNOWN_EXTENSIONS 16
#define MAX_CERTIFICATE_TYPES 8
struct st_ptls_client_hello_t {
uint16_t legacy_version;
const uint8_t *random_bytes;
ptls_iovec_t legacy_session_id;
struct {
const uint8_t *ids;
size_t count;
} compression_methods;
uint16_t selected_version;
ptls_iovec_t cipher_suites;
ptls_iovec_t negotiated_groups;
ptls_iovec_t key_shares;
struct st_ptls_signature_algorithms_t signature_algorithms;
ptls_iovec_t server_name;
struct {
ptls_iovec_t list[16];
size_t count;
} alpn;
struct {
uint16_t list[16];
size_t count;
} cert_compression_algos;
struct {
ptls_iovec_t all;
ptls_iovec_t tbs;
ptls_iovec_t ch1_hash;
ptls_iovec_t signature;
unsigned sent_key_share : 1;
} cookie;
struct {
uint8_t list[MAX_CERTIFICATE_TYPES];
size_t count;
} server_certificate_types;
unsigned status_request : 1;
/**
* ECH: payload.base != NULL indicates that the extension was received
*/
struct {
uint8_t type;
uint8_t config_id;
ptls_hpke_cipher_suite_id_t cipher_suite;
ptls_iovec_t enc;
ptls_iovec_t payload;
} ech;
struct {
const uint8_t *hash_end;
struct {
struct st_ptls_client_hello_psk_t list[4];
size_t count;
} identities;
unsigned ke_modes;
unsigned early_data_indication : 1;
unsigned is_last_extension : 1;
} psk;
ptls_raw_extension_t unknown_extensions[MAX_UNKNOWN_EXTENSIONS + 1];
size_t first_extension_at;
};
struct st_ptls_server_hello_t {
uint8_t random_[PTLS_HELLO_RANDOM_SIZE];
ptls_iovec_t legacy_session_id;
int is_retry_request;
union {
ptls_iovec_t peerkey;
struct {
uint16_t selected_group;
ptls_iovec_t cookie;
const uint8_t *ech;
} retry_request;
};
};
struct st_ptls_key_schedule_t {
unsigned generation; /* early secret (1), hanshake secret (2), master secret (3) */
uint8_t secret[PTLS_MAX_DIGEST_SIZE];
size_t num_hashes;
struct {
ptls_hash_algorithm_t *algo;
ptls_hash_context_t *ctx, *ctx_outer;
} hashes[1];
};
struct st_ptls_extension_decoder_t {
uint16_t type;
int (*cb)(ptls_t *tls, void *arg, const uint8_t *src, const uint8_t *const end);
};
struct st_ptls_extension_bitmap_t {
uint64_t bits;
};
static const uint8_t zeroes_of_max_digest_size[PTLS_MAX_DIGEST_SIZE] = {0};
static ptls_aead_context_t *new_aead(ptls_aead_algorithm_t *aead, ptls_hash_algorithm_t *hash, int is_enc, const void *secret,
ptls_iovec_t hash_value, const char *label_prefix);
static int server_finish_handshake(ptls_t *tls, ptls_message_emitter_t *emitter, int send_cert_verify,
struct st_ptls_signature_algorithms_t *signature_algorithms);
static int is_supported_version(uint16_t v)
{
size_t i;
for (i = 0; i != PTLS_ELEMENTSOF(supported_versions); ++i)
if (supported_versions[i] == v)
return 1;
return 0;
}
static int extension_bitmap_testandset(struct st_ptls_extension_bitmap_t *bitmap, int hstype, uint16_t extid)
{
#define HSTYPE_TO_BIT(hstype) ((uint64_t)1 << ((hstype) + 1)) /* min(hstype) is -1 (PSEUDO_HRR) */
#define DEFINE_BIT(abbrev, hstype) static const uint64_t abbrev = HSTYPE_TO_BIT(PTLS_HANDSHAKE_TYPE_##hstype)
#define EXT(candext, allowed_bits) \
do { \
if (PTLS_UNLIKELY(extid == PTLS_EXTENSION_TYPE_##candext)) { \
allowed_hs_bits = allowed_bits; \
goto Found; \
} \
ext_bitmap_mask <<= 1; \
} while (0)
DEFINE_BIT(CH, CLIENT_HELLO);
DEFINE_BIT(SH, SERVER_HELLO);
DEFINE_BIT(HRR, PSEUDO_HRR);
DEFINE_BIT(EE, ENCRYPTED_EXTENSIONS);
DEFINE_BIT(CR, CERTIFICATE_REQUEST);
DEFINE_BIT(CT, CERTIFICATE);
DEFINE_BIT(NST, NEW_SESSION_TICKET);
uint64_t allowed_hs_bits, ext_bitmap_mask = 1;
/* clang-format off */
/* RFC 8446 section 4.2: "The table below indicates the messages where a given extension may appear... If an implementation
* receives an extension which it recognizes and which is not specified for the message in which it appears, it MUST abort the
* handshake with an "illegal_parameter" alert.
*
* +-------------------------+---------------+
* + Extension | Allowed |
* +-------------------------+---------------+ */
EXT( SERVER_NAME , CH + EE );
EXT( STATUS_REQUEST , CH + CR + CT );
EXT( SUPPORTED_GROUPS , CH + EE );
EXT( SIGNATURE_ALGORITHMS , CH + CR );
EXT( ALPN , CH + EE );
EXT( SERVER_CERTIFICATE_TYPE , CH + EE );
EXT( KEY_SHARE , CH + SH + HRR );
EXT( PRE_SHARED_KEY , CH + SH );
EXT( PSK_KEY_EXCHANGE_MODES , CH );
EXT( EARLY_DATA , CH + EE + NST );
EXT( COOKIE , CH + HRR );
EXT( SUPPORTED_VERSIONS , CH + SH + HRR );
EXT( COMPRESS_CERTIFICATE , CH + CR ); /* from RFC 8879 */
EXT( ENCRYPTED_CLIENT_HELLO , CH + HRR + EE ); /* from draft-ietf-tls-esni-15 */
EXT( ECH_OUTER_EXTENSIONS , 0 );
/* +-----------------------------------------+ */
/* clang-format on */
return 1;
Found:
if ((allowed_hs_bits & HSTYPE_TO_BIT(hstype)) == 0)
return 0;
if ((bitmap->bits & ext_bitmap_mask) != 0)
return 0;
bitmap->bits |= ext_bitmap_mask;
return 1;
#undef HSTYPE_TO_BIT
#undef DEFINE_ABBREV
#undef EXT
}
#ifndef ntoh16
static uint16_t ntoh16(const uint8_t *src)
{
return (uint16_t)src[0] << 8 | src[1];
}
#endif
#ifndef ntoh24
static uint32_t ntoh24(const uint8_t *src)
{
return (uint32_t)src[0] << 16 | (uint32_t)src[1] << 8 | src[2];
}
#endif
#ifndef ntoh32
static uint32_t ntoh32(const uint8_t *src)
{
return (uint32_t)src[0] << 24 | (uint32_t)src[1] << 16 | (uint32_t)src[2] << 8 | src[3];
}
#endif
#ifndef ntoh64
static uint64_t ntoh64(const uint8_t *src)
{
return (uint64_t)src[0] << 56 | (uint64_t)src[1] << 48 | (uint64_t)src[2] << 40 | (uint64_t)src[3] << 32 |
(uint64_t)src[4] << 24 | (uint64_t)src[5] << 16 | (uint64_t)src[6] << 8 | src[7];
}
#endif
static void encode64(uint8_t *dst, uint64_t v)
{
for (size_t i = 0; i < 8; ++i)
dst[i] = (uint8_t)(v >> (56 - 8 * i));
}
static char *duplicate_as_str(const void *src, size_t len)
{
char *dst;
if ((dst = malloc(len + 1)) == NULL)
return NULL;
memcpy(dst, src, len);
dst[len] = '\0';
return dst;
}
void ptls_buffer__release_memory(ptls_buffer_t *buf)
{
ptls_clear_memory(buf->base, buf->off);
if (buf->is_allocated) {
#ifdef _WINDOWS
if (buf->align_bits != 0) {
_aligned_free(buf->base);
} else {
free(buf->base);
}
#else
free(buf->base);
#endif
}
}
int ptls_buffer_reserve(ptls_buffer_t *buf, size_t delta)
{
return ptls_buffer_reserve_aligned(buf, delta, 0);
}
int ptls_buffer_reserve_aligned(ptls_buffer_t *buf, size_t delta, uint8_t align_bits)
{
if (buf->base == NULL)
return PTLS_ERROR_NO_MEMORY;
if (PTLS_MEMORY_DEBUG || buf->capacity < buf->off + delta ||
(buf->align_bits < align_bits && ((uintptr_t)buf->base & (((uintptr_t)1 << align_bits) - 1)) != 0)) {
void *newp;
size_t new_capacity = buf->capacity;
if (new_capacity < 1024)
new_capacity = 1024;
while (new_capacity < buf->off + delta) {
new_capacity *= 2;
}
if (align_bits != 0) {
#ifdef _WINDOWS
if ((newp = _aligned_malloc(new_capacity, (size_t)1 << align_bits)) == NULL)
return PTLS_ERROR_NO_MEMORY;
#else
if (posix_memalign(&newp, 1 << align_bits, new_capacity) != 0)
return PTLS_ERROR_NO_MEMORY;
#endif
} else {
if ((newp = malloc(new_capacity)) == NULL)
return PTLS_ERROR_NO_MEMORY;
}
memcpy(newp, buf->base, buf->off);
ptls_buffer__release_memory(buf);
buf->base = newp;
buf->capacity = new_capacity;
buf->is_allocated = 1;
buf->align_bits = align_bits;
}
return 0;
}
int ptls_buffer__do_pushv(ptls_buffer_t *buf, const void *src, size_t len)
{
int ret;
if (len == 0)
return 0;
if ((ret = ptls_buffer_reserve(buf, len)) != 0)
return ret;
memcpy(buf->base + buf->off, src, len);
buf->off += len;
return 0;
}
int ptls_buffer__adjust_quic_blocksize(ptls_buffer_t *buf, size_t body_size)
{
uint8_t sizebuf[PTLS_ENCODE_QUICINT_CAPACITY];
size_t sizelen = ptls_encode_quicint(sizebuf, body_size) - sizebuf;
/* adjust amount of space before body_size to `sizelen` bytes */
if (sizelen != 1) {
int ret;
if ((ret = ptls_buffer_reserve(buf, sizelen - 1)) != 0)
return ret;
memmove(buf->base + buf->off - body_size - 1 + sizelen, buf->base + buf->off - body_size, body_size);
buf->off += sizelen - 1;
}
/* write the size */
memcpy(buf->base + buf->off - body_size - sizelen, sizebuf, sizelen);
return 0;
}
int ptls_buffer__adjust_asn1_blocksize(ptls_buffer_t *buf, size_t body_size)
{
fprintf(stderr, "unimplemented\n");
abort();
}
int ptls_buffer_push_asn1_ubigint(ptls_buffer_t *buf, const void *bignum, size_t size)
{
const uint8_t *p = bignum, *const end = p + size;
int ret;
/* skip zeroes */
for (; end - p >= 1; ++p)
if (*p != 0)
break;
/* emit */
ptls_buffer_push(buf, 2);
ptls_buffer_push_asn1_block(buf, {
if (*p >= 0x80)
ptls_buffer_push(buf, 0);
if (p != end) {
ptls_buffer_pushv(buf, p, end - p);
} else {
ptls_buffer_pushv(buf, "", 1);
}
});
ret = 0;
Exit:
return ret;
}
#if PTLS_FUZZ_HANDSHAKE
static size_t aead_encrypt(struct st_ptls_traffic_protection_t *ctx, void *output, const void *input, size_t inlen,
uint8_t content_type)
{
memcpy(output, input, inlen);
memcpy(output + inlen, &content_type, 1);
return inlen + 1 + 16;
}
static int aead_decrypt(struct st_ptls_traffic_protection_t *ctx, void *output, size_t *outlen, const void *input, size_t inlen)
{
if (inlen < 16) {
return PTLS_ALERT_BAD_RECORD_MAC;
}
memcpy(output, input, inlen - 16);
*outlen = inlen - 16; /* removing the 16 bytes of tag */
return 0;
}
#else
static void build_aad(uint8_t aad[5], size_t reclen)
{
aad[0] = PTLS_CONTENT_TYPE_APPDATA;
aad[1] = PTLS_RECORD_VERSION_MAJOR;
aad[2] = PTLS_RECORD_VERSION_MINOR;
aad[3] = (uint8_t)(reclen >> 8);
aad[4] = (uint8_t)reclen;
}
static size_t aead_encrypt(struct st_ptls_traffic_protection_t *ctx, void *output, const void *input, size_t inlen,
uint8_t content_type)
{
ptls_iovec_t invec[2] = {ptls_iovec_init(input, inlen), ptls_iovec_init(&content_type, 1)};
uint8_t aad[5];
build_aad(aad, inlen + 1 + ctx->aead->algo->tag_size);
ptls_aead_encrypt_v(ctx->aead, output, invec, PTLS_ELEMENTSOF(invec), ctx->seq++, aad, sizeof(aad));
return inlen + 1 + ctx->aead->algo->tag_size;
}
static int aead_decrypt(struct st_ptls_traffic_protection_t *ctx, void *output, size_t *outlen, const void *input, size_t inlen)
{
uint8_t aad[5];
build_aad(aad, inlen);
if ((*outlen = ptls_aead_decrypt(ctx->aead, output, input, inlen, ctx->seq, aad, sizeof(aad))) == SIZE_MAX)
return PTLS_ALERT_BAD_RECORD_MAC;
++ctx->seq;
return 0;
}
#endif /* #if PTLS_FUZZ_HANDSHAKE */
static void build_tls12_aad(uint8_t *aad, uint8_t type, uint64_t seq, uint16_t length)
{
for (size_t i = 0; i < 8; ++i)
aad[i] = (uint8_t)(seq >> (56 - i * 8));
aad[8] = type;
aad[9] = PTLS_RECORD_VERSION_MAJOR;
aad[10] = PTLS_RECORD_VERSION_MINOR;
aad[11] = length >> 8;
aad[12] = (uint8_t)length;
}
#define buffer_push_record(buf, type, block) \
do { \
ptls_buffer_push((buf), (type), PTLS_RECORD_VERSION_MAJOR, PTLS_RECORD_VERSION_MINOR); \
ptls_buffer_push_block((buf), 2, block); \
} while (0)
static int buffer_push_encrypted_records(ptls_buffer_t *buf, uint8_t type, const uint8_t *src, size_t len,
struct st_ptls_traffic_protection_t *enc)
{
int ret = 0;
while (len != 0) {
size_t chunk_size = len;
if (chunk_size > PTLS_MAX_PLAINTEXT_RECORD_SIZE)
chunk_size = PTLS_MAX_PLAINTEXT_RECORD_SIZE;
if (enc->tls12) {
buffer_push_record(buf, type, {
/* reserve memory */
if ((ret = ptls_buffer_reserve_aligned(
buf, enc->aead->algo->tls12.record_iv_size + chunk_size + enc->aead->algo->tag_size,
enc->aead->algo->align_bits)) != 0)
goto Exit;
/* determine nonce, as well as prepending that walue as the record IV (AES-GCM) */
uint64_t nonce;
if (enc->aead->algo->tls12.record_iv_size != 0) {
assert(enc->aead->algo->tls12.record_iv_size == 8);
nonce = enc->tls12_enc_record_iv++;
encode64(buf->base + buf->off, nonce);
buf->off += 8;
} else {
nonce = enc->seq;
}
/* build AAD */
uint8_t aad[PTLS_TLS12_AAD_SIZE];
build_tls12_aad(aad, type, enc->seq, (uint16_t)chunk_size);
/* encrypt */
buf->off += ptls_aead_encrypt(enc->aead, buf->base + buf->off, src, chunk_size, nonce, aad, sizeof(aad));
++enc->seq;
});
} else {
buffer_push_record(buf, PTLS_CONTENT_TYPE_APPDATA, {
if ((ret = ptls_buffer_reserve_aligned(buf, chunk_size + enc->aead->algo->tag_size + 1,
enc->aead->algo->align_bits)) != 0)
goto Exit;
buf->off += aead_encrypt(enc, buf->base + buf->off, src, chunk_size, type);
});
}
src += chunk_size;
len -= chunk_size;
}
Exit:
return ret;
}
static int buffer_encrypt_record(ptls_buffer_t *buf, size_t rec_start, struct st_ptls_traffic_protection_t *enc)
{
size_t bodylen = buf->off - rec_start - 5;
uint8_t *tmpbuf, type = buf->base[rec_start];
int ret;
/* Fast path: do in-place encryption if only one record needs to be emitted. (For simplicity, do not take this path if TLS 1.2
* is used, as this function will be called no more than once per connection, for encrypting an alert.) */
if (!enc->tls12 && bodylen <= PTLS_MAX_PLAINTEXT_RECORD_SIZE) {
size_t overhead = 1 + enc->aead->algo->tag_size;
if ((ret = ptls_buffer_reserve_aligned(buf, overhead, enc->aead->algo->align_bits)) != 0)
return ret;
size_t encrypted_len = aead_encrypt(enc, buf->base + rec_start + 5, buf->base + rec_start + 5, bodylen, type);
assert(encrypted_len == bodylen + overhead);
buf->off += overhead;
buf->base[rec_start] = PTLS_CONTENT_TYPE_APPDATA;
buf->base[rec_start + 3] = (encrypted_len >> 8) & 0xff;
buf->base[rec_start + 4] = encrypted_len & 0xff;
return 0;
}
/* move plaintext to temporary buffer */
if ((tmpbuf = malloc(bodylen)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
memcpy(tmpbuf, buf->base + rec_start + 5, bodylen);
ptls_clear_memory(buf->base + rec_start, bodylen + 5);
buf->off = rec_start;
/* push encrypted records */
ret = buffer_push_encrypted_records(buf, type, tmpbuf, bodylen, enc);
Exit:
if (tmpbuf != NULL) {
ptls_clear_memory(tmpbuf, bodylen);
free(tmpbuf);
}
return ret;
}
static int begin_record_message(ptls_message_emitter_t *_self)
{
struct st_ptls_record_message_emitter_t *self = (void *)_self;
int ret;
self->rec_start = self->super.buf->off;
ptls_buffer_push(self->super.buf, PTLS_CONTENT_TYPE_HANDSHAKE, PTLS_RECORD_VERSION_MAJOR, PTLS_RECORD_VERSION_MINOR, 0, 0);
ret = 0;
Exit:
return ret;
}
static int commit_record_message(ptls_message_emitter_t *_self)
{
struct st_ptls_record_message_emitter_t *self = (void *)_self;
int ret;
if (self->super.enc->aead != NULL) {
ret = buffer_encrypt_record(self->super.buf, self->rec_start, self->super.enc);
} else {
/* TODO allow CH,SH,HRR above 16KB */
size_t sz = self->super.buf->off - self->rec_start - 5;
assert(sz <= PTLS_MAX_PLAINTEXT_RECORD_SIZE);
self->super.buf->base[self->rec_start + 3] = (uint8_t)(sz >> 8);
self->super.buf->base[self->rec_start + 4] = (uint8_t)(sz);
ret = 0;
}
return ret;
}
#define buffer_push_extension(buf, type, block) \
do { \
ptls_buffer_push16((buf), (type)); \
ptls_buffer_push_block((buf), 2, block); \
} while (0);
#define decode_open_extensions(src, end, hstype, exttype, block) \
do { \
struct st_ptls_extension_bitmap_t bitmap = {0}; \
ptls_decode_open_block((src), end, 2, { \
while ((src) != end) { \
if ((ret = ptls_decode16((exttype), &(src), end)) != 0) \
goto Exit; \
if (!extension_bitmap_testandset(&bitmap, (hstype), *(exttype))) { \
ret = PTLS_ALERT_ILLEGAL_PARAMETER; \
goto Exit; \
} \
ptls_decode_open_block((src), end, 2, block); \
} \
}); \
} while (0)
#define decode_extensions(src, end, hstype, exttype, block) \
do { \
decode_open_extensions((src), end, hstype, exttype, block); \
ptls_decode_assert_block_close((src), end); \
} while (0)
int ptls_decode8(uint8_t *value, const uint8_t **src, const uint8_t *end)
{
if (*src == end)
return PTLS_ALERT_DECODE_ERROR;
*value = *(*src)++;
return 0;
}
int ptls_decode16(uint16_t *value, const uint8_t **src, const uint8_t *end)
{
if (end - *src < 2)
return PTLS_ALERT_DECODE_ERROR;
*value = ntoh16(*src);
*src += 2;
return 0;
}
int ptls_decode24(uint32_t *value, const uint8_t **src, const uint8_t *end)
{
if (end - *src < 3)
return PTLS_ALERT_DECODE_ERROR;
*value = ((uint32_t)(*src)[0] << 16) | ((uint32_t)(*src)[1] << 8) | (*src)[2];
*src += 3;
return 0;
}
int ptls_decode32(uint32_t *value, const uint8_t **src, const uint8_t *end)
{
if (end - *src < 4)
return PTLS_ALERT_DECODE_ERROR;
*value = ntoh32(*src);
*src += 4;
return 0;
}
int ptls_decode64(uint64_t *value, const uint8_t **src, const uint8_t *end)
{
if (end - *src < 8)
return PTLS_ALERT_DECODE_ERROR;
*value = ntoh64(*src);
*src += 8;
return 0;
}
uint64_t ptls_decode_quicint(const uint8_t **src, const uint8_t *end)
{
if (PTLS_UNLIKELY(*src == end))
return UINT64_MAX;
uint8_t b = *(*src)++;
if (PTLS_LIKELY(b <= 0x3f))
return b;
uint64_t v = b & 0x3f;
unsigned bytes_left = (1 << (b >> 6)) - 1;
if (PTLS_UNLIKELY((size_t)(end - *src) < bytes_left))
return UINT64_MAX;
do {
v = (v << 8) | *(*src)++;
} while (--bytes_left != 0);
return v;
}
static void log_secret(ptls_t *tls, const char *type, ptls_iovec_t secret)
{
char hexbuf[PTLS_MAX_DIGEST_SIZE * 2 + 1];
PTLS_PROBE(NEW_SECRET, tls, type, ptls_hexdump(hexbuf, secret.base, secret.len));
PTLS_LOG_CONN(new_secret, tls, { PTLS_LOG_ELEMENT_SAFESTR(label, type); });
if (tls->ctx->log_event != NULL)
tls->ctx->log_event->cb(tls->ctx->log_event, tls, type, "%s", ptls_hexdump(hexbuf, secret.base, secret.len));
}
/**
* This function preserves the flags and modes (e.g., `offered`, `accepted`, `cipher`), they can be used afterwards.
*/
static void clear_ech(struct st_ptls_ech_t *ech, int is_server)
{
if (ech->aead != NULL) {
ptls_aead_free(ech->aead);
ech->aead = NULL;
}
ptls_clear_memory(ech->inner_client_random, PTLS_HELLO_RANDOM_SIZE);
if (!is_server) {
free(ech->client.enc.base);
ech->client.enc = ptls_iovec_init(NULL, 0);
if (ech->client.public_name != NULL) {
free(ech->client.public_name);
ech->client.public_name = NULL;
}
free(ech->client.first_ech.base);
ech->client.first_ech = ptls_iovec_init(NULL, 0);
}
}
/**
* Decodes one ECHConfigContents (tls-esni-15 section 4). `decoded->kem` and `cipher` may be NULL even when the function returns
* zero, if the corresponding entries are not found.
*/
static int decode_one_ech_config(ptls_hpke_kem_t **kems, ptls_hpke_cipher_suite_t **ciphers,
struct st_decoded_ech_config_t *decoded, const uint8_t **src, const uint8_t *const end)
{
char *public_name_buf = NULL;
int ret;
*decoded = (struct st_decoded_ech_config_t){0};
if ((ret = ptls_decode8(&decoded->id, src, end)) != 0)
goto Exit;
uint16_t kem_id;
if ((ret = ptls_decode16(&kem_id, src, end)) != 0)
goto Exit;
for (size_t i = 0; kems[i] != NULL; ++i) {
if (kems[i]->id == kem_id) {
decoded->kem = kems[i];
break;
}
}
ptls_decode_open_block(*src, end, 2, {
if (*src == end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
decoded->public_key = ptls_iovec_init(*src, end - *src);
*src = end;
});
ptls_decode_open_block(*src, end, 2, {
do {
uint16_t kdf_id;
uint16_t aead_id;
if ((ret = ptls_decode16(&kdf_id, src, end)) != 0)
goto Exit;
if ((ret = ptls_decode16(&aead_id, src, end)) != 0)
goto Exit;
if (decoded->cipher == NULL) {
for (size_t i = 0; ciphers[i] != NULL; ++i) {
if (ciphers[i]->id.kdf == kdf_id && ciphers[i]->id.aead == aead_id) {
decoded->cipher = ciphers[i];
break;
}
}
}
} while (*src != end);
});
if ((ret = ptls_decode8(&decoded->max_name_length, src, end)) != 0)
goto Exit;
#define SKIP_DECODED() \
do { \
decoded->kem = NULL; \
decoded->cipher = NULL; \
} while (0)
/* Decode public_name. The specification requires clients to ignore (upon parsing ESNIConfigList) or reject (upon handshake)
* public names that are not DNS names or IPv4 addresses. We ignore IPv4 and v6 addresses during parsing (IPv6 addresses never
* looks like DNS names), and delegate the responsibility of rejecting non-DNS names to the certificate verify callback. */
ptls_decode_open_block(*src, end, 1, {
if (*src == end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
if ((public_name_buf = duplicate_as_str(*src, end - *src)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
if (ptls_server_name_is_ipaddr(public_name_buf)) {
SKIP_DECODED();
} else {
decoded->public_name = ptls_iovec_init(*src, end - *src);
}
*src = end;
});
ptls_decode_block(*src, end, 2, {
while (*src < end) {
uint16_t type;
if ((ret = ptls_decode16(&type, src, end)) != 0)
goto Exit;
ptls_decode_open_block(*src, end, 2, { *src = end; });
/* if a critital extension is found, indicate that the config cannot be used */
if ((type & 0x8000) != 0)
SKIP_DECODED();
}
});
#undef SKIP_DECODED
Exit:
free(public_name_buf);
return ret;
}
static int client_decode_ech_config_list(ptls_context_t *ctx, struct st_decoded_ech_config_t *decoded, ptls_iovec_t config_list)
{
const uint8_t *src = config_list.base, *const end = src + config_list.len;
int match_found = 0, ret;
*decoded = (struct st_decoded_ech_config_t){0};
ptls_decode_block(src, end, 2, {
do {
const uint8_t *config_start = src;
uint16_t version;
if ((ret = ptls_decode16(&version, &src, end)) != 0)
goto Exit;
ptls_decode_open_block(src, end, 2, {
/* If the block is the one that we recognize, parse it, then adopt if if possible. Otherwise, skip. */
if (version == PTLS_ECH_CONFIG_VERSION) {
struct st_decoded_ech_config_t thisconf;
if ((ret = decode_one_ech_config(ctx->ech.client.kems, ctx->ech.client.ciphers, &thisconf, &src, end)) != 0)
goto Exit;
if (!match_found && thisconf.kem != NULL && thisconf.cipher != NULL) {
*decoded = thisconf;
decoded->bytes = ptls_iovec_init(config_start, end - config_start);
match_found = 1;
}
} else {
src = end;
}
});
} while (src != end);
});
ret = 0;
Exit:
if (ret != 0)
*decoded = (struct st_decoded_ech_config_t){0};
return ret;
}
static int client_setup_ech(struct st_ptls_ech_t *ech, struct st_decoded_ech_config_t *decoded,
void (*random_bytes)(void *, size_t))
{
ptls_buffer_t infobuf;
uint8_t infobuf_smallbuf[256];
int ret;
/* setup `enc` and `aead` by running HPKE */
ptls_buffer_init(&infobuf, infobuf_smallbuf, sizeof(infobuf_smallbuf));
ptls_buffer_pushv(&infobuf, ech_info_prefix, sizeof(ech_info_prefix));
ptls_buffer_pushv(&infobuf, decoded->bytes.base, decoded->bytes.len);
if ((ret = ptls_hpke_setup_base_s(decoded->kem, decoded->cipher, &ech->client.enc, &ech->aead, decoded->public_key,
ptls_iovec_init(infobuf.base, infobuf.off))) != 0)
goto Exit;
/* setup the rest */
ech->config_id = decoded->id;
ech->kem = decoded->kem;
ech->cipher = decoded->cipher;
random_bytes(ech->inner_client_random, PTLS_HELLO_RANDOM_SIZE);
ech->client.max_name_length = decoded->max_name_length;
if ((ech->client.public_name = duplicate_as_str(decoded->public_name.base, decoded->public_name.len)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
Exit:
if (ret != 0)
clear_ech(ech, 0);
return ret;
}
static void client_setup_ech_grease(struct st_ptls_ech_t *ech, void (*random_bytes)(void *, size_t), ptls_hpke_kem_t **kems,
ptls_hpke_cipher_suite_t **ciphers, const char *sni_name)
{
static const size_t x25519_key_size = 32;
uint8_t random_secret[PTLS_AES128_KEY_SIZE + PTLS_AES_IV_SIZE];
/* pick up X25519, AES-128-GCM or bail out */
for (size_t i = 0; kems[i] != NULL; ++i) {
if (kems[i]->id == PTLS_HPKE_KEM_X25519_SHA256) {
ech->kem = kems[i];
break;
}
}
for (size_t i = 0; ciphers[i] != NULL; ++i) {
if (ciphers[i]->id.kdf == PTLS_HPKE_HKDF_SHA256 && ciphers[i]->id.aead == PTLS_HPKE_AEAD_AES_128_GCM) {
ech->cipher = ciphers[i];
break;
}
}
if (ech->kem == NULL || ech->cipher == NULL)
goto Fail;
/* aead is generated from random */
random_bytes(random_secret, sizeof(random_secret));
ech->aead = ptls_aead_new_direct(ech->cipher->aead, 1, random_secret, random_secret + PTLS_AES128_KEY_SIZE);
/* `enc` is random bytes */
if ((ech->client.enc.base = malloc(x25519_key_size)) == NULL)
goto Fail;
ech->client.enc.len = x25519_key_size;
random_bytes(ech->client.enc.base, ech->client.enc.len);
/* setup the rest (inner_client_random is left zeros) */
random_bytes(&ech->config_id, sizeof(ech->config_id));
ech->client.max_name_length = 64;
if ((ech->client.public_name = duplicate_as_str(sni_name, strlen(sni_name))) == NULL)
goto Fail;
return;
Fail:
clear_ech(ech, 0);
}
#define ECH_CONFIRMATION_SERVER_HELLO "ech accept confirmation"
#define ECH_CONFIRMATION_HRR "hrr ech accept confirmation"
static int ech_calc_confirmation(ptls_key_schedule_t *sched, void *dst, const uint8_t *inner_random, const char *label,
ptls_iovec_t message)
{
ptls_hash_context_t *hash = NULL;
uint8_t secret[PTLS_MAX_DIGEST_SIZE], transcript_hash[PTLS_MAX_DIGEST_SIZE];
int ret;
/* calc transcript hash using the modified ServerHello / HRR */
if ((hash = sched->hashes[0].ctx->clone_(sched->hashes[0].ctx)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
hash->update(hash, message.base, message.len);
hash->final(hash, transcript_hash, PTLS_HASH_FINAL_MODE_FREE);
hash = NULL;
/* HKDF extract and expand */
if ((ret = ptls_hkdf_extract(sched->hashes[0].algo, secret, ptls_iovec_init(NULL, 0),
ptls_iovec_init(inner_random, PTLS_HELLO_RANDOM_SIZE))) != 0)
goto Exit;
if ((ret = ptls_hkdf_expand_label(sched->hashes[0].algo, dst, 8, ptls_iovec_init(secret, sched->hashes[0].algo->digest_size),
label, ptls_iovec_init(transcript_hash, sched->hashes[0].algo->digest_size), NULL)) != 0)
goto Exit;
Exit:
ptls_clear_memory(secret, sizeof(secret));
ptls_clear_memory(transcript_hash, sizeof(transcript_hash));
if (hash != NULL)
hash->final(hash, NULL, PTLS_HASH_FINAL_MODE_FREE);
return ret;
}
static void key_schedule_free(ptls_key_schedule_t *sched)
{
size_t i;
ptls_clear_memory(sched->secret, sizeof(sched->secret));
for (i = 0; i != sched->num_hashes; ++i) {
sched->hashes[i].ctx->final(sched->hashes[i].ctx, NULL, PTLS_HASH_FINAL_MODE_FREE);
if (sched->hashes[i].ctx_outer != NULL)
sched->hashes[i].ctx_outer->final(sched->hashes[i].ctx_outer, NULL, PTLS_HASH_FINAL_MODE_FREE);
}
free(sched);
}
static ptls_key_schedule_t *key_schedule_new(ptls_cipher_suite_t *preferred, ptls_cipher_suite_t **offered, int use_outer)
{
#define FOREACH_HASH(block) \
do { \
ptls_cipher_suite_t *cs; \
if ((cs = preferred) != NULL) { \
block \
} \
if (offered != NULL) { \
size_t i, j; \
for (i = 0; (cs = offered[i]) != NULL; ++i) { \
if (preferred == NULL || cs->hash != preferred->hash) { \
for (j = 0; j != i; ++j) \
if (cs->hash == offered[j]->hash) \
break; \
if (j == i) { \
block \
} \
} \
} \
} \
} while (0)
ptls_key_schedule_t *sched;
{ /* allocate */
size_t num_hashes = 0;
FOREACH_HASH({ ++num_hashes; });
if ((sched = malloc(offsetof(ptls_key_schedule_t, hashes) + sizeof(sched->hashes[0]) * num_hashes)) == NULL)
return NULL;
*sched = (ptls_key_schedule_t){0};
}
/* setup the hash algos and contexts */
FOREACH_HASH({
sched->hashes[sched->num_hashes].algo = cs->hash;
if ((sched->hashes[sched->num_hashes].ctx = cs->hash->create()) == NULL)
goto Fail;
if (use_outer) {
if ((sched->hashes[sched->num_hashes].ctx_outer = cs->hash->create()) == NULL)
goto Fail;
} else {
sched->hashes[sched->num_hashes].ctx_outer = NULL;
}
++sched->num_hashes;
});
return sched;
Fail:
key_schedule_free(sched);
return NULL;
#undef FOREACH_HASH
}
static int key_schedule_extract(ptls_key_schedule_t *sched, ptls_iovec_t ikm)
{
int ret;
if (ikm.base == NULL)
ikm = ptls_iovec_init(zeroes_of_max_digest_size, sched->hashes[0].algo->digest_size);
if (sched->generation != 0 &&
(ret = ptls_hkdf_expand_label(sched->hashes[0].algo, sched->secret, sched->hashes[0].algo->digest_size,
ptls_iovec_init(sched->secret, sched->hashes[0].algo->digest_size), "derived",
ptls_iovec_init(sched->hashes[0].algo->empty_digest, sched->hashes[0].algo->digest_size),
NULL)) != 0)
return ret;
++sched->generation;
ret = ptls_hkdf_extract(sched->hashes[0].algo, sched->secret,
ptls_iovec_init(sched->secret, sched->hashes[0].algo->digest_size), ikm);
PTLS_DEBUGF("%s: %u, %02x%02x\n", __FUNCTION__, sched->generation, (int)sched->secret[0], (int)sched->secret[1]);
return ret;
}
static int key_schedule_select_cipher(ptls_key_schedule_t *sched, ptls_cipher_suite_t *cs, int reset)
{
size_t found_slot = SIZE_MAX, i;
int ret;
assert(sched->generation == 1);
/* find the one, while freeing others */
for (i = 0; i != sched->num_hashes; ++i) {
if (sched->hashes[i].algo == cs->hash) {
assert(found_slot == SIZE_MAX);
found_slot = i;
} else {
sched->hashes[i].ctx->final(sched->hashes[i].ctx, NULL, PTLS_HASH_FINAL_MODE_FREE);
if (sched->hashes[i].ctx_outer != NULL)
sched->hashes[i].ctx_outer->final(sched->hashes[i].ctx_outer, NULL, PTLS_HASH_FINAL_MODE_FREE);
}
}
if (found_slot != 0) {
sched->hashes[0] = sched->hashes[found_slot];
reset = 1;
}
sched->num_hashes = 1;
/* recalculate the hash if a different hash as been selected than the one we used for calculating the early secrets */
if (reset) {
--sched->generation;
memset(sched->secret, 0, sizeof(sched->secret));
if ((ret = key_schedule_extract(sched, ptls_iovec_init(NULL, 0))) != 0)
goto Exit;
}
ret = 0;
Exit:
return ret;
}
static void key_schedule_select_outer(ptls_key_schedule_t *sched)
{
/* This function is called when receiving a cleartext message (Server Hello), after the cipher-suite is determined (and hence
* the hash also), if ECH was offered */
assert(sched->generation == 1);
assert(sched->num_hashes == 1);
assert(sched->hashes[0].ctx_outer != NULL);
sched->hashes[0].ctx->final(sched->hashes[0].ctx, NULL, PTLS_HASH_FINAL_MODE_FREE);
sched->hashes[0].ctx = sched->hashes[0].ctx_outer;
sched->hashes[0].ctx_outer = NULL;
}
void ptls__key_schedule_update_hash(ptls_key_schedule_t *sched, const uint8_t *msg, size_t msglen, int use_outer)
{
size_t i;
PTLS_DEBUGF("%s:%zu\n", __FUNCTION__, msglen);
for (i = 0; i != sched->num_hashes; ++i) {
ptls_hash_context_t *ctx = use_outer ? sched->hashes[i].ctx_outer : sched->hashes[i].ctx;
ctx->update(ctx, msg, msglen);
}
}
static void key_schedule_update_ch1hash_prefix(ptls_key_schedule_t *sched)
{
uint8_t prefix[4] = {PTLS_HANDSHAKE_TYPE_MESSAGE_HASH, 0, 0, (uint8_t)sched->hashes[0].algo->digest_size};
ptls__key_schedule_update_hash(sched, prefix, sizeof(prefix), 0);
}
static void key_schedule_extract_ch1hash(ptls_key_schedule_t *sched, uint8_t *hash)
{
assert(sched->hashes[0].ctx_outer == NULL);
sched->hashes[0].ctx->final(sched->hashes[0].ctx, hash, PTLS_HASH_FINAL_MODE_RESET);
}
static void key_schedule_transform_post_ch1hash(ptls_key_schedule_t *sched)
{
size_t digest_size = sched->hashes[0].algo->digest_size;
ptls_hash_context_t *hashes[3] = {sched->hashes[0].ctx, sched->hashes[0].ctx_outer, NULL};
uint8_t ch1hash[PTLS_MAX_DIGEST_SIZE];
uint8_t prefix[4] = {PTLS_HANDSHAKE_TYPE_MESSAGE_HASH, 0, 0, (uint8_t)digest_size};
for (size_t i = 0; hashes[i] != NULL; ++i) {
hashes[i]->final(hashes[i], ch1hash, PTLS_HASH_FINAL_MODE_RESET);
hashes[i]->update(hashes[i], prefix, sizeof(prefix));
hashes[i]->update(hashes[i], ch1hash, digest_size);
}
ptls_clear_memory(ch1hash, sizeof(ch1hash));
}
static int derive_secret_with_hash(ptls_key_schedule_t *sched, void *secret, const char *label, const uint8_t *hash)
{
int ret = ptls_hkdf_expand_label(sched->hashes[0].algo, secret, sched->hashes[0].algo->digest_size,
ptls_iovec_init(sched->secret, sched->hashes[0].algo->digest_size), label,
ptls_iovec_init(hash, sched->hashes[0].algo->digest_size), NULL);
PTLS_DEBUGF("%s: (label=%s, hash=%02x%02x) => %02x%02x\n", __FUNCTION__, label, hash[0], hash[1], ((uint8_t *)secret)[0],
((uint8_t *)secret)[1]);
return ret;
}
static int derive_secret(ptls_key_schedule_t *sched, void *secret, const char *label)
{
uint8_t hash_value[PTLS_MAX_DIGEST_SIZE];
sched->hashes[0].ctx->final(sched->hashes[0].ctx, hash_value, PTLS_HASH_FINAL_MODE_SNAPSHOT);
int ret = derive_secret_with_hash(sched, secret, label, hash_value);
ptls_clear_memory(hash_value, sizeof(hash_value));
return ret;
}
static int derive_secret_with_empty_digest(ptls_key_schedule_t *sched, void *secret, const char *label)
{
return derive_secret_with_hash(sched, secret, label, sched->hashes[0].algo->empty_digest);
}
static int derive_exporter_secret(ptls_t *tls, int is_early)
{
int ret;
if (!tls->ctx->use_exporter)
return 0;
uint8_t **slot = is_early ? &tls->exporter_master_secret.early : &tls->exporter_master_secret.one_rtt;
assert(*slot == NULL);
if ((*slot = malloc(tls->key_schedule->hashes[0].algo->digest_size)) == NULL)
return PTLS_ERROR_NO_MEMORY;
if ((ret = derive_secret(tls->key_schedule, *slot, is_early ? "e exp master" : "exp master")) != 0)
return ret;
log_secret(tls, is_early ? "EARLY_EXPORTER_SECRET" : "EXPORTER_SECRET",
ptls_iovec_init(*slot, tls->key_schedule->hashes[0].algo->digest_size));
return 0;
}
static void free_exporter_master_secret(ptls_t *tls, int is_early)
{
uint8_t *slot = is_early ? tls->exporter_master_secret.early : tls->exporter_master_secret.one_rtt;
if (slot == NULL)
return;
assert(tls->key_schedule != NULL);
ptls_clear_memory(slot, tls->key_schedule->hashes[0].algo->digest_size);
free(slot);
}
static int derive_resumption_secret(ptls_key_schedule_t *sched, uint8_t *secret, ptls_iovec_t nonce)
{
int ret;
if ((ret = derive_secret(sched, secret, "res master")) != 0)
goto Exit;
if ((ret = ptls_hkdf_expand_label(sched->hashes[0].algo, secret, sched->hashes[0].algo->digest_size,
ptls_iovec_init(secret, sched->hashes[0].algo->digest_size), "resumption", nonce, NULL)) != 0)
goto Exit;
Exit:
if (ret != 0)
ptls_clear_memory(secret, sched->hashes[0].algo->digest_size);
return ret;
}
static int decode_new_session_ticket(ptls_t *tls, uint32_t *lifetime, uint32_t *age_add, ptls_iovec_t *nonce, ptls_iovec_t *ticket,
uint32_t *max_early_data_size, const uint8_t *src, const uint8_t *const end)
{
uint16_t exttype;
int ret;
if ((ret = ptls_decode32(lifetime, &src, end)) != 0)
goto Exit;
if ((ret = ptls_decode32(age_add, &src, end)) != 0)
goto Exit;
ptls_decode_open_block(src, end, 1, {
*nonce = ptls_iovec_init(src, end - src);
src = end;
});
ptls_decode_open_block(src, end, 2, {
if (src == end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
*ticket = ptls_iovec_init(src, end - src);
src = end;
});
*max_early_data_size = 0;
decode_extensions(src, end, PTLS_HANDSHAKE_TYPE_NEW_SESSION_TICKET, &exttype, {
if (tls->ctx->on_extension != NULL &&
(ret = tls->ctx->on_extension->cb(tls->ctx->on_extension, tls, PTLS_HANDSHAKE_TYPE_NEW_SESSION_TICKET, exttype,
ptls_iovec_init(src, end - src)) != 0))
goto Exit;
switch (exttype) {
case PTLS_EXTENSION_TYPE_EARLY_DATA:
if ((ret = ptls_decode32(max_early_data_size, &src, end)) != 0)
goto Exit;
break;
default:
src = end;
break;
}
});
ret = 0;
Exit:
return ret;
}
static int decode_stored_session_ticket(ptls_t *tls, ptls_key_exchange_algorithm_t **key_share, ptls_cipher_suite_t **cs,
ptls_iovec_t *secret, uint32_t *obfuscated_ticket_age, ptls_iovec_t *ticket,
uint32_t *max_early_data_size, const uint8_t *src, const uint8_t *const end)
{
uint16_t kxid, csid;
uint32_t lifetime, age_add;
uint64_t obtained_at, now;
ptls_iovec_t nonce;
int ret;
/* decode */
if ((ret = ptls_decode64(&obtained_at, &src, end)) != 0)
goto Exit;
if ((ret = ptls_decode16(&kxid, &src, end)) != 0)
goto Exit;
if ((ret = ptls_decode16(&csid, &src, end)) != 0)
goto Exit;
ptls_decode_open_block(src, end, 3, {
if ((ret = decode_new_session_ticket(tls, &lifetime, &age_add, &nonce, ticket, max_early_data_size, src, end)) != 0)
goto Exit;
src = end;
});
ptls_decode_block(src, end, 2, {
*secret = ptls_iovec_init(src, end - src);
src = end;
});
{ /* determine the key-exchange */
ptls_key_exchange_algorithm_t **cand;
for (cand = tls->ctx->key_exchanges; *cand != NULL; ++cand)
if ((*cand)->id == kxid)
break;
if (*cand == NULL) {
ret = PTLS_ERROR_LIBRARY;
goto Exit;
}
*key_share = *cand;
}
{ /* determine the cipher-suite */
ptls_cipher_suite_t **cand;
for (cand = tls->ctx->cipher_suites; *cand != NULL; ++cand)
if ((*cand)->id == csid)
break;
if (*cand == NULL) {
ret = PTLS_ERROR_LIBRARY;
goto Exit;
}
*cs = *cand;
}
/* calculate obfuscated_ticket_age */
now = tls->ctx->get_time->cb(tls->ctx->get_time);
if (!(obtained_at <= now && now - obtained_at < 7 * 86400 * 1000)) {
ret = PTLS_ERROR_LIBRARY;
goto Exit;
}
*obfuscated_ticket_age = (uint32_t)(now - obtained_at) + age_add;
ret = 0;
Exit:
return ret;
}
static int get_traffic_key(ptls_hash_algorithm_t *algo, void *key, size_t key_size, int is_iv, const void *secret,
ptls_iovec_t hash_value, const char *label_prefix)
{
return ptls_hkdf_expand_label(algo, key, key_size, ptls_iovec_init(secret, algo->digest_size), is_iv ? "iv" : "key", hash_value,
label_prefix);
}
static int get_traffic_keys(ptls_aead_algorithm_t *aead, ptls_hash_algorithm_t *hash, void *key, void *iv, const void *secret,
ptls_iovec_t hash_value, const char *label_prefix)
{
int ret;
if ((ret = get_traffic_key(hash, key, aead->key_size, 0, secret, hash_value, label_prefix)) != 0 ||
(ret = get_traffic_key(hash, iv, aead->iv_size, 1, secret, hash_value, label_prefix)) != 0) {
ptls_clear_memory(key, aead->key_size);
ptls_clear_memory(iv, aead->iv_size);
}
return ret;
}
static int setup_traffic_protection(ptls_t *tls, int is_enc, const char *secret_label, size_t epoch, int skip_notify)
{
static const char *log_labels[2][4] = {
{NULL, "CLIENT_EARLY_TRAFFIC_SECRET", "CLIENT_HANDSHAKE_TRAFFIC_SECRET", "CLIENT_TRAFFIC_SECRET_0"},
{NULL, NULL, "SERVER_HANDSHAKE_TRAFFIC_SECRET", "SERVER_TRAFFIC_SECRET_0"}};
struct st_ptls_traffic_protection_t *ctx = is_enc ? &tls->traffic_protection.enc : &tls->traffic_protection.dec;
if (secret_label != NULL) {
int ret;
if ((ret = derive_secret(tls->key_schedule, ctx->secret, secret_label)) != 0)
return ret;
}
ctx->epoch = epoch;
log_secret(tls, log_labels[ptls_is_server(tls) == is_enc][epoch],
ptls_iovec_init(ctx->secret, tls->key_schedule->hashes[0].algo->digest_size));
/* special path for applications having their own record layer */
if (tls->ctx->update_traffic_key != NULL) {
if (skip_notify)
return 0;
return tls->ctx->update_traffic_key->cb(tls->ctx->update_traffic_key, tls, is_enc, epoch, ctx->secret);
}
if (ctx->aead != NULL)
ptls_aead_free(ctx->aead);
if ((ctx->aead = ptls_aead_new(tls->cipher_suite->aead, tls->cipher_suite->hash, is_enc, ctx->secret,
tls->ctx->hkdf_label_prefix__obsolete)) == NULL)
return PTLS_ERROR_NO_MEMORY; /* TODO obtain error from ptls_aead_new */
ctx->seq = 0;
PTLS_DEBUGF("[%s] %02x%02x,%02x%02x\n", log_labels[ptls_is_server(tls)][epoch], (unsigned)ctx->secret[0],
(unsigned)ctx->secret[1], (unsigned)ctx->aead->static_iv[0], (unsigned)ctx->aead->static_iv[1]);
return 0;
}
static int commission_handshake_secret(ptls_t *tls)
{
int is_enc = !ptls_is_server(tls);
assert(tls->pending_handshake_secret != NULL);
memcpy((is_enc ? &tls->traffic_protection.enc : &tls->traffic_protection.dec)->secret, tls->pending_handshake_secret,
PTLS_MAX_DIGEST_SIZE);
ptls_clear_memory(tls->pending_handshake_secret, PTLS_MAX_DIGEST_SIZE);
free(tls->pending_handshake_secret);
tls->pending_handshake_secret = NULL;
return setup_traffic_protection(tls, is_enc, NULL, 2, 1);
}
static void log_client_random(ptls_t *tls)
{
char buf[sizeof(tls->client_random) * 2 + 1];
PTLS_PROBE(CLIENT_RANDOM, tls, ptls_hexdump(buf, tls->client_random, sizeof(tls->client_random)));
PTLS_LOG_CONN(client_random, tls, { PTLS_LOG_ELEMENT_HEXDUMP(bytes, tls->client_random, sizeof(tls->client_random)); });
}
#define SESSION_IDENTIFIER_MAGIC "ptls0001" /* the number should be changed upon incompatible format change */
#define SESSION_IDENTIFIER_MAGIC_SIZE (sizeof(SESSION_IDENTIFIER_MAGIC) - 1)
static int encode_session_identifier(ptls_context_t *ctx, ptls_buffer_t *buf, uint32_t ticket_age_add, ptls_iovec_t ticket_nonce,
ptls_key_schedule_t *sched, const char *server_name, uint16_t key_exchange_id, uint16_t csid,
const char *negotiated_protocol)
{
int ret = 0;
ptls_buffer_push_block(buf, 2, {
/* format id */
ptls_buffer_pushv(buf, SESSION_IDENTIFIER_MAGIC, SESSION_IDENTIFIER_MAGIC_SIZE);
/* date */
ptls_buffer_push64(buf, ctx->get_time->cb(ctx->get_time));
/* resumption master secret */
ptls_buffer_push_block(buf, 2, {
if ((ret = ptls_buffer_reserve(buf, sched->hashes[0].algo->digest_size)) != 0)
goto Exit;
if ((ret = derive_resumption_secret(sched, buf->base + buf->off, ticket_nonce)) != 0)
goto Exit;
buf->off += sched->hashes[0].algo->digest_size;
});
/* key-exchange */
ptls_buffer_push16(buf, key_exchange_id);
/* cipher-suite */
ptls_buffer_push16(buf, csid);
/* ticket_age_add */
ptls_buffer_push32(buf, ticket_age_add);
/* server-name */
ptls_buffer_push_block(buf, 2, {
if (server_name != NULL)
ptls_buffer_pushv(buf, server_name, strlen(server_name));
});
/* alpn */
ptls_buffer_push_block(buf, 1, {
if (negotiated_protocol != NULL)
ptls_buffer_pushv(buf, negotiated_protocol, strlen(negotiated_protocol));
});
});
Exit:
return ret;
}
int decode_session_identifier(uint64_t *issued_at, ptls_iovec_t *psk, uint32_t *ticket_age_add, ptls_iovec_t *server_name,
uint16_t *key_exchange_id, uint16_t *csid, ptls_iovec_t *negotiated_protocol, const uint8_t *src,
const uint8_t *const end)
{
int ret = 0;
ptls_decode_block(src, end, 2, {
if (end - src < SESSION_IDENTIFIER_MAGIC_SIZE ||
memcmp(src, SESSION_IDENTIFIER_MAGIC, SESSION_IDENTIFIER_MAGIC_SIZE) != 0) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
src += SESSION_IDENTIFIER_MAGIC_SIZE;
if ((ret = ptls_decode64(issued_at, &src, end)) != 0)
goto Exit;
ptls_decode_open_block(src, end, 2, {
*psk = ptls_iovec_init(src, end - src);
src = end;
});
if ((ret = ptls_decode16(key_exchange_id, &src, end)) != 0)
goto Exit;
if ((ret = ptls_decode16(csid, &src, end)) != 0)
goto Exit;
if ((ret = ptls_decode32(ticket_age_add, &src, end)) != 0)
goto Exit;
ptls_decode_open_block(src, end, 2, {
*server_name = ptls_iovec_init(src, end - src);
src = end;
});
ptls_decode_open_block(src, end, 1, {
*negotiated_protocol = ptls_iovec_init(src, end - src);
src = end;
});
});
Exit:
return ret;
}
static size_t build_certificate_verify_signdata(uint8_t *data, ptls_key_schedule_t *sched, const char *context_string)
{
size_t datalen = 0;
memset(data + datalen, 32, 64);
datalen += 64;
memcpy(data + datalen, context_string, strlen(context_string) + 1);
datalen += strlen(context_string) + 1;
sched->hashes[0].ctx->final(sched->hashes[0].ctx, data + datalen, PTLS_HASH_FINAL_MODE_SNAPSHOT);
datalen += sched->hashes[0].algo->digest_size;
assert(datalen <= PTLS_MAX_CERTIFICATE_VERIFY_SIGNDATA_SIZE);
return datalen;
}
static int calc_verify_data(void *output, ptls_key_schedule_t *sched, const void *secret)
{
ptls_hash_context_t *hmac;
uint8_t digest[PTLS_MAX_DIGEST_SIZE];
int ret;
if ((ret = ptls_hkdf_expand_label(sched->hashes[0].algo, digest, sched->hashes[0].algo->digest_size,
ptls_iovec_init(secret, sched->hashes[0].algo->digest_size), "finished",
ptls_iovec_init(NULL, 0), NULL)) != 0)
return ret;
if ((hmac = ptls_hmac_create(sched->hashes[0].algo, digest, sched->hashes[0].algo->digest_size)) == NULL) {
ptls_clear_memory(digest, sizeof(digest));
return PTLS_ERROR_NO_MEMORY;
}
sched->hashes[0].ctx->final(sched->hashes[0].ctx, digest, PTLS_HASH_FINAL_MODE_SNAPSHOT);
PTLS_DEBUGF("%s: %02x%02x,%02x%02x\n", __FUNCTION__, ((uint8_t *)secret)[0], ((uint8_t *)secret)[1], digest[0], digest[1]);
hmac->update(hmac, digest, sched->hashes[0].algo->digest_size);
ptls_clear_memory(digest, sizeof(digest));
hmac->final(hmac, output, PTLS_HASH_FINAL_MODE_FREE);
return 0;
}
static int verify_finished(ptls_t *tls, ptls_iovec_t message)
{
uint8_t verify_data[PTLS_MAX_DIGEST_SIZE];
int ret;
if (PTLS_HANDSHAKE_HEADER_SIZE + tls->key_schedule->hashes[0].algo->digest_size != message.len) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
if ((ret = calc_verify_data(verify_data, tls->key_schedule, tls->traffic_protection.dec.secret)) != 0)
goto Exit;
if (!ptls_mem_equal(message.base + PTLS_HANDSHAKE_HEADER_SIZE, verify_data, tls->key_schedule->hashes[0].algo->digest_size)) {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
goto Exit;
}
Exit:
ptls_clear_memory(verify_data, sizeof(verify_data));
return ret;
}
static int send_finished(ptls_t *tls, ptls_message_emitter_t *emitter)
{
int ret;
ptls_push_message(emitter, tls->key_schedule, PTLS_HANDSHAKE_TYPE_FINISHED, {
if ((ret = ptls_buffer_reserve(emitter->buf, tls->key_schedule->hashes[0].algo->digest_size)) != 0)
goto Exit;
if ((ret = calc_verify_data(emitter->buf->base + emitter->buf->off, tls->key_schedule,
tls->traffic_protection.enc.secret)) != 0)
goto Exit;
emitter->buf->off += tls->key_schedule->hashes[0].algo->digest_size;
});
Exit:
return ret;
}
static int send_session_ticket(ptls_t *tls, ptls_message_emitter_t *emitter)
{
ptls_hash_context_t *msghash_backup = tls->key_schedule->hashes[0].ctx->clone_(tls->key_schedule->hashes[0].ctx);
ptls_buffer_t session_id;
char session_id_smallbuf[128];
uint32_t ticket_age_add;
int ret = 0;
assert(tls->ctx->ticket_lifetime != 0);
assert(tls->ctx->encrypt_ticket != NULL);
ptls_buffer_init(&session_id, session_id_smallbuf, sizeof(session_id_smallbuf));
{ /* calculate verify-data that will be sent by the client */
size_t orig_off = emitter->buf->off;
if (tls->pending_handshake_secret != NULL && !tls->ctx->omit_end_of_early_data) {
assert(tls->state == PTLS_STATE_SERVER_EXPECT_END_OF_EARLY_DATA);
ptls_buffer_push_message_body(emitter->buf, tls->key_schedule, PTLS_HANDSHAKE_TYPE_END_OF_EARLY_DATA, {});
emitter->buf->off = orig_off;
}
ptls_buffer_push_message_body(emitter->buf, tls->key_schedule, PTLS_HANDSHAKE_TYPE_FINISHED, {
if ((ret = ptls_buffer_reserve(emitter->buf, tls->key_schedule->hashes[0].algo->digest_size)) != 0)
goto Exit;
if ((ret = calc_verify_data(emitter->buf->base + emitter->buf->off, tls->key_schedule,
tls->pending_handshake_secret != NULL ? tls->pending_handshake_secret
: tls->traffic_protection.dec.secret)) != 0)
goto Exit;
emitter->buf->off += tls->key_schedule->hashes[0].algo->digest_size;
});
emitter->buf->off = orig_off;
}
tls->ctx->random_bytes(&ticket_age_add, sizeof(ticket_age_add));
/* build the raw nsk */
ret = encode_session_identifier(tls->ctx, &session_id, ticket_age_add, ptls_iovec_init(NULL, 0), tls->key_schedule,
tls->server_name, tls->key_share->id, tls->cipher_suite->id, tls->negotiated_protocol);
if (ret != 0)
goto Exit;
/* encrypt and send */
ptls_push_message(emitter, tls->key_schedule, PTLS_HANDSHAKE_TYPE_NEW_SESSION_TICKET, {
ptls_buffer_push32(emitter->buf, tls->ctx->ticket_lifetime);
ptls_buffer_push32(emitter->buf, ticket_age_add);
ptls_buffer_push_block(emitter->buf, 1, {});
ptls_buffer_push_block(emitter->buf, 2, {
if ((ret = tls->ctx->encrypt_ticket->cb(tls->ctx->encrypt_ticket, tls, 1, emitter->buf,
ptls_iovec_init(session_id.base, session_id.off))) != 0)
goto Exit;
});
ptls_buffer_push_block(emitter->buf, 2, {
if (tls->ctx->max_early_data_size != 0)
buffer_push_extension(emitter->buf, PTLS_EXTENSION_TYPE_EARLY_DATA,
{ ptls_buffer_push32(emitter->buf, tls->ctx->max_early_data_size); });
});
});
Exit:
ptls_buffer_dispose(&session_id);
/* restore handshake state */
tls->key_schedule->hashes[0].ctx->final(tls->key_schedule->hashes[0].ctx, NULL, PTLS_HASH_FINAL_MODE_FREE);
tls->key_schedule->hashes[0].ctx = msghash_backup;
return ret;
}
static int push_change_cipher_spec(ptls_t *tls, ptls_message_emitter_t *emitter)
{
int ret;
/* check if we are requested to (or still need to) */
if (!tls->send_change_cipher_spec) {
ret = 0;
goto Exit;
}
/* CCS is a record, can only be sent when using a record-based protocol. */
if (emitter->begin_message != begin_record_message) {
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
goto Exit;
}
/* emit CCS */
buffer_push_record(emitter->buf, PTLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC, { ptls_buffer_push(emitter->buf, 1); });
tls->send_change_cipher_spec = 0;
ret = 0;
Exit:
return ret;
}
static int push_additional_extensions(ptls_handshake_properties_t *properties, ptls_buffer_t *sendbuf)
{
int ret;
if (properties != NULL && properties->additional_extensions != NULL) {
ptls_raw_extension_t *ext;
for (ext = properties->additional_extensions; ext->type != UINT16_MAX; ++ext) {
buffer_push_extension(sendbuf, ext->type, { ptls_buffer_pushv(sendbuf, ext->data.base, ext->data.len); });
}
}
ret = 0;
Exit:
return ret;
}
static int push_signature_algorithms(ptls_verify_certificate_t *vc, ptls_buffer_t *sendbuf)
{
/* The list sent when verify callback is not registered */
static const uint16_t default_algos[] = {PTLS_SIGNATURE_RSA_PSS_RSAE_SHA256, PTLS_SIGNATURE_ECDSA_SECP256R1_SHA256,
PTLS_SIGNATURE_RSA_PKCS1_SHA256, PTLS_SIGNATURE_RSA_PKCS1_SHA1, UINT16_MAX};
int ret;
ptls_buffer_push_block(sendbuf, 2, {
for (const uint16_t *p = vc != NULL ? vc->algos : default_algos; *p != UINT16_MAX; ++p)
ptls_buffer_push16(sendbuf, *p);
});
ret = 0;
Exit:
return ret;
}
static int decode_signature_algorithms(struct st_ptls_signature_algorithms_t *sa, const uint8_t **src, const uint8_t *end)
{
int ret;
ptls_decode_block(*src, end, 2, {
do {
uint16_t id;
if ((ret = ptls_decode16(&id, src, end)) != 0)
goto Exit;
if (sa->count < PTLS_ELEMENTSOF(sa->list))
sa->list[sa->count++] = id;
} while (*src != end);
});
ret = 0;
Exit:
return ret;
}
static int select_cipher(ptls_cipher_suite_t **selected, ptls_cipher_suite_t **candidates, const uint8_t *src,
const uint8_t *const end, int server_preference, int server_chacha_priority)
{
size_t found_index = SIZE_MAX;
int ret;
while (src != end) {
uint16_t id;
if ((ret = ptls_decode16(&id, &src, end)) != 0)
goto Exit;
for (size_t i = 0; candidates[i] != NULL; ++i) {
if (candidates[i]->id == id) {
if (server_preference && !(server_chacha_priority && id == PTLS_CIPHER_SUITE_CHACHA20_POLY1305_SHA256)) {
/* preserve smallest matching index, and proceed to the next input */
if (i < found_index) {
found_index = i;
break;
}
} else {
/* return the pointer matching to the first input that can be used */
*selected = candidates[i];
goto Exit;
}
}
}
/* first position of the server list matched (server_preference) */
if (found_index == 0)
break;
/* server preference is overridden only if the first entry of client-provided list is chachapoly */
server_chacha_priority = 0;
}
if (found_index != SIZE_MAX) {
*selected = candidates[found_index];
ret = 0;
} else {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
}
Exit:
return ret;
}
static int push_key_share_entry(ptls_buffer_t *buf, uint16_t group, ptls_iovec_t pubkey)
{
int ret;
ptls_buffer_push16(buf, group);
ptls_buffer_push_block(buf, 2, { ptls_buffer_pushv(buf, pubkey.base, pubkey.len); });
ret = 0;
Exit:
return ret;
}
static int decode_key_share_entry(uint16_t *group, ptls_iovec_t *key_exchange, const uint8_t **src, const uint8_t *const end)
{
int ret;
if ((ret = ptls_decode16(group, src, end)) != 0)
goto Exit;
ptls_decode_open_block(*src, end, 2, {
*key_exchange = ptls_iovec_init(*src, end - *src);
*src = end;
});
Exit:
return ret;
}
static int select_key_share(ptls_key_exchange_algorithm_t **selected, ptls_iovec_t *peer_key,
ptls_key_exchange_algorithm_t **candidates, const uint8_t **src, const uint8_t *const end,
int expect_one)
{
int ret;
*selected = NULL;
if (expect_one && *src == end) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
while (*src != end) {
uint16_t group;
ptls_iovec_t key;
if ((ret = decode_key_share_entry(&group, &key, src, end)) != 0)
goto Exit;
ptls_key_exchange_algorithm_t **c = candidates;
for (; *c != NULL; ++c) {
if (*selected == NULL && (*c)->id == group) {
*selected = *c;
*peer_key = key;
}
}
if (expect_one) {
ret = *selected != NULL ? 0 : PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
}
ret = 0;
Exit:
return ret;
}
static int emit_server_name_extension(ptls_buffer_t *buf, const char *server_name)
{
int ret;
ptls_buffer_push_block(buf, 2, {
ptls_buffer_push(buf, PTLS_SERVER_NAME_TYPE_HOSTNAME);
ptls_buffer_push_block(buf, 2, { ptls_buffer_pushv(buf, server_name, strlen(server_name)); });
});
ret = 0;
Exit:
return ret;
}
/**
* Within the outer ECH extension, returns the number of bytes that preceeds the AEAD-encrypted payload.
*/
static inline size_t outer_ech_header_size(size_t enc_size)
{
return 10 + enc_size;
}
/**
* Flag to indicate which of ClientHelloInner, EncodedClientHelloInner, ClientHelloOuter is to be generated. When ECH is inactive,
* only ClientHelloInner is used.
*/
enum encode_ch_mode { ENCODE_CH_MODE_INNER, ENCODE_CH_MODE_ENCODED_INNER, ENCODE_CH_MODE_OUTER };
static int encode_client_hello(ptls_context_t *ctx, ptls_buffer_t *sendbuf, enum encode_ch_mode mode, int is_second_flight,
ptls_handshake_properties_t *properties, const void *client_random,
ptls_key_exchange_context_t *key_share_ctx, const char *sni_name, ptls_iovec_t legacy_session_id,
struct st_ptls_ech_t *ech, size_t *ech_size_offset, ptls_iovec_t ech_replay,
ptls_iovec_t resumption_secret, ptls_iovec_t resumption_ticket, uint32_t obfuscated_ticket_age,
size_t psk_binder_size, ptls_iovec_t *cookie, int using_early_data)
{
int ret;
assert(mode == ENCODE_CH_MODE_INNER || ech != NULL);
ptls_buffer_push_message_body(sendbuf, NULL, PTLS_HANDSHAKE_TYPE_CLIENT_HELLO, {
/* legacy_version */
ptls_buffer_push16(sendbuf, 0x0303);
/* random_bytes */
ptls_buffer_pushv(sendbuf, client_random, PTLS_HELLO_RANDOM_SIZE);
/* lecagy_session_id */
ptls_buffer_push_block(sendbuf, 1, {
if (mode != ENCODE_CH_MODE_ENCODED_INNER)
ptls_buffer_pushv(sendbuf, legacy_session_id.base, legacy_session_id.len);
});
/* cipher_suites */
ptls_buffer_push_block(sendbuf, 2, {
ptls_cipher_suite_t **cs = ctx->cipher_suites;
for (; *cs != NULL; ++cs)
ptls_buffer_push16(sendbuf, (*cs)->id);
});
/* legacy_compression_methods */
ptls_buffer_push_block(sendbuf, 1, { ptls_buffer_push(sendbuf, 0); });
/* extensions */
ptls_buffer_push_block(sendbuf, 2, {
if (mode == ENCODE_CH_MODE_OUTER) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_ENCRYPTED_CLIENT_HELLO, {
size_t ext_payload_from = sendbuf->off;
ptls_buffer_push(sendbuf, PTLS_ECH_CLIENT_HELLO_TYPE_OUTER);
ptls_buffer_push16(sendbuf, ech->cipher->id.kdf);
ptls_buffer_push16(sendbuf, ech->cipher->id.aead);
ptls_buffer_push(sendbuf, ech->config_id);
ptls_buffer_push_block(sendbuf, 2, {
if (!is_second_flight)
ptls_buffer_pushv(sendbuf, ech->client.enc.base, ech->client.enc.len);
});
ptls_buffer_push_block(sendbuf, 2, {
assert(sendbuf->off - ext_payload_from ==
outer_ech_header_size(is_second_flight ? 0 : ech->client.enc.len));
if ((ret = ptls_buffer_reserve(sendbuf, *ech_size_offset)) != 0)
goto Exit;
memset(sendbuf->base + sendbuf->off, 0, *ech_size_offset);
sendbuf->off += *ech_size_offset;
*ech_size_offset = sendbuf->off - *ech_size_offset;
});
});
} else if (ech->aead != NULL) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_ENCRYPTED_CLIENT_HELLO,
{ ptls_buffer_push(sendbuf, PTLS_ECH_CLIENT_HELLO_TYPE_INNER); });
} else if (ech_replay.base != NULL) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_ENCRYPTED_CLIENT_HELLO,
{ ptls_buffer_pushv(sendbuf, ech_replay.base, ech_replay.len); });
}
if (mode == ENCODE_CH_MODE_ENCODED_INNER) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_ECH_OUTER_EXTENSIONS, {
ptls_buffer_push_block(sendbuf, 1, { ptls_buffer_push16(sendbuf, PTLS_EXTENSION_TYPE_KEY_SHARE); });
});
} else {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_KEY_SHARE, {
ptls_buffer_push_block(sendbuf, 2, {
if (key_share_ctx != NULL &&
(ret = push_key_share_entry(sendbuf, key_share_ctx->algo->id, key_share_ctx->pubkey)) != 0)
goto Exit;
});
});
}
if (sni_name != NULL) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SERVER_NAME, {
if ((ret = emit_server_name_extension(sendbuf, sni_name)) != 0)
goto Exit;
});
}
if (properties != NULL && properties->client.negotiated_protocols.count != 0) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_ALPN, {
ptls_buffer_push_block(sendbuf, 2, {
size_t i;
for (i = 0; i != properties->client.negotiated_protocols.count; ++i) {
ptls_buffer_push_block(sendbuf, 1, {
ptls_iovec_t p = properties->client.negotiated_protocols.list[i];
ptls_buffer_pushv(sendbuf, p.base, p.len);
});
}
});
});
}
if (ctx->decompress_certificate != NULL) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_COMPRESS_CERTIFICATE, {
ptls_buffer_push_block(sendbuf, 1, {
const uint16_t *algo = ctx->decompress_certificate->supported_algorithms;
assert(*algo != UINT16_MAX);
for (; *algo != UINT16_MAX; ++algo)
ptls_buffer_push16(sendbuf, *algo);
});
});
}
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SUPPORTED_VERSIONS, {
ptls_buffer_push_block(sendbuf, 1, {
size_t i;
for (i = 0; i != PTLS_ELEMENTSOF(supported_versions); ++i)
ptls_buffer_push16(sendbuf, supported_versions[i]);
});
});
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SIGNATURE_ALGORITHMS, {
if ((ret = push_signature_algorithms(ctx->verify_certificate, sendbuf)) != 0)
goto Exit;
});
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SUPPORTED_GROUPS, {
ptls_key_exchange_algorithm_t **algo = ctx->key_exchanges;
ptls_buffer_push_block(sendbuf, 2, {
for (; *algo != NULL; ++algo)
ptls_buffer_push16(sendbuf, (*algo)->id);
});
});
if (cookie != NULL && cookie->base != NULL) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_COOKIE, {
ptls_buffer_push_block(sendbuf, 2, { ptls_buffer_pushv(sendbuf, cookie->base, cookie->len); });
});
}
if (ctx->use_raw_public_keys) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SERVER_CERTIFICATE_TYPE, {
ptls_buffer_push_block(sendbuf, 1, { ptls_buffer_push(sendbuf, PTLS_CERTIFICATE_TYPE_RAW_PUBLIC_KEY); });
});
}
if ((ret = push_additional_extensions(properties, sendbuf)) != 0)
goto Exit;
if (ctx->save_ticket != NULL || resumption_secret.base != NULL) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_PSK_KEY_EXCHANGE_MODES, {
ptls_buffer_push_block(sendbuf, 1, {
if (!ctx->require_dhe_on_psk)
ptls_buffer_push(sendbuf, PTLS_PSK_KE_MODE_PSK);
ptls_buffer_push(sendbuf, PTLS_PSK_KE_MODE_PSK_DHE);
});
});
}
if (resumption_secret.base != NULL) {
if (using_early_data && !is_second_flight)
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_EARLY_DATA, {});
/* pre-shared key "MUST be the last extension in the ClientHello" (draft-17 section 4.2.6) */
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_PRE_SHARED_KEY, {
ptls_buffer_push_block(sendbuf, 2, {
ptls_buffer_push_block(sendbuf, 2, {
if (mode == ENCODE_CH_MODE_OUTER) {
if ((ret = ptls_buffer_reserve(sendbuf, resumption_ticket.len)) != 0)
goto Exit;
ctx->random_bytes(sendbuf->base + sendbuf->off, resumption_ticket.len);
sendbuf->off += resumption_ticket.len;
} else {
ptls_buffer_pushv(sendbuf, resumption_ticket.base, resumption_ticket.len);
}
});
uint32_t age;
if (mode == ENCODE_CH_MODE_OUTER) {
ctx->random_bytes(&age, sizeof(age));
} else {
age = obfuscated_ticket_age;
}
ptls_buffer_push32(sendbuf, age);
});
/* allocate space for PSK binder. The space is filled initially filled by a random value (meeting the
* requirement of ClientHelloOuter), and later gets filled with the correct binder value if necessary. */
ptls_buffer_push_block(sendbuf, 2, {
ptls_buffer_push_block(sendbuf, 1, {
if ((ret = ptls_buffer_reserve(sendbuf, psk_binder_size)) != 0)
goto Exit;
ctx->random_bytes(sendbuf->base + sendbuf->off, psk_binder_size);
sendbuf->off += psk_binder_size;
});
});
});
}
});
});
Exit:
return ret;
}
static int send_client_hello(ptls_t *tls, ptls_message_emitter_t *emitter, ptls_handshake_properties_t *properties,
ptls_iovec_t *cookie)
{
ptls_iovec_t resumption_secret = {NULL}, resumption_ticket = {NULL};
uint32_t obfuscated_ticket_age = 0;
const char *sni_name = NULL;
size_t mess_start, msghash_off;
uint8_t binder_key[PTLS_MAX_DIGEST_SIZE];
ptls_buffer_t encoded_ch_inner;
int ret, is_second_flight = tls->key_schedule != NULL;
ptls_buffer_init(&encoded_ch_inner, "", 0);
if (tls->server_name != NULL && !ptls_server_name_is_ipaddr(tls->server_name))
sni_name = tls->server_name;
if (properties != NULL) {
/* try to use ECH (ignore broken ECHConfigList; it is delivered insecurely) */
if (!is_second_flight && sni_name != NULL && tls->ctx->ech.client.ciphers != NULL) {
if (properties->client.ech.configs.len != 0) {
struct st_decoded_ech_config_t decoded;
client_decode_ech_config_list(tls->ctx, &decoded, properties->client.ech.configs);
if (decoded.kem != NULL && decoded.cipher != NULL) {
if ((ret = client_setup_ech(&tls->ech, &decoded, tls->ctx->random_bytes)) != 0)
goto Exit;
}
} else {
/* zero-length config indicates ECH greasing */
client_setup_ech_grease(&tls->ech, tls->ctx->random_bytes, tls->ctx->ech.client.kems, tls->ctx->ech.client.ciphers,
sni_name);
}
}
/* setup resumption-related data. If successful, resumption_secret becomes a non-zero value. */
if (properties->client.session_ticket.base != NULL) {
ptls_key_exchange_algorithm_t *key_share = NULL;
ptls_cipher_suite_t *cipher_suite = NULL;
uint32_t max_early_data_size;
if (decode_stored_session_ticket(tls, &key_share, &cipher_suite, &resumption_secret, &obfuscated_ticket_age,
&resumption_ticket, &max_early_data_size, properties->client.session_ticket.base,
properties->client.session_ticket.base + properties->client.session_ticket.len) == 0) {
tls->client.offered_psk = 1;
/* key-share selected by HRR should not be overridden */
if (tls->key_share == NULL)
tls->key_share = key_share;
tls->cipher_suite = cipher_suite;
if (!is_second_flight && max_early_data_size != 0 && properties->client.max_early_data_size != NULL) {
tls->client.using_early_data = 1;
*properties->client.max_early_data_size = max_early_data_size;
}
} else {
resumption_secret = ptls_iovec_init(NULL, 0);
}
}
if (tls->client.using_early_data) {
properties->client.early_data_acceptance = PTLS_EARLY_DATA_ACCEPTANCE_UNKNOWN;
} else {
if (properties->client.max_early_data_size != NULL)
*properties->client.max_early_data_size = 0;
properties->client.early_data_acceptance = PTLS_EARLY_DATA_REJECTED;
}
}
/* use the default key share if still not undetermined */
if (tls->key_share == NULL && !(properties != NULL && properties->client.negotiate_before_key_exchange))
tls->key_share = tls->ctx->key_exchanges[0];
/* instantiate key share context */
assert(tls->client.key_share_ctx == NULL);
if (tls->key_share != NULL) {
if ((ret = tls->key_share->create(tls->key_share, &tls->client.key_share_ctx)) != 0)
goto Exit;
}
/* initialize key schedule */
if (!is_second_flight) {
if ((tls->key_schedule = key_schedule_new(tls->cipher_suite, tls->ctx->cipher_suites, tls->ech.aead != NULL)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
if ((ret = key_schedule_extract(tls->key_schedule, resumption_secret)) != 0)
goto Exit;
}
/* start generating CH */
if ((ret = emitter->begin_message(emitter)) != 0)
goto Exit;
mess_start = msghash_off = emitter->buf->off;
/* generate true (inner) CH */
if ((ret = encode_client_hello(tls->ctx, emitter->buf, ENCODE_CH_MODE_INNER, is_second_flight, properties,
tls->ech.aead != NULL ? tls->ech.inner_client_random : tls->client_random,
tls->client.key_share_ctx, sni_name, tls->client.legacy_session_id, &tls->ech, NULL,
tls->ech.client.first_ech, resumption_secret, resumption_ticket, obfuscated_ticket_age,
tls->key_schedule->hashes[0].algo->digest_size, cookie, tls->client.using_early_data)) != 0)
goto Exit;
/* update the message hash, filling in the PSK binder HMAC if necessary */
if (resumption_secret.base != NULL) {
size_t psk_binder_off = emitter->buf->off - (3 + tls->key_schedule->hashes[0].algo->digest_size);
if ((ret = derive_secret_with_empty_digest(tls->key_schedule, binder_key, "res binder")) != 0)
goto Exit;
ptls__key_schedule_update_hash(tls->key_schedule, emitter->buf->base + msghash_off, psk_binder_off - msghash_off, 0);
msghash_off = psk_binder_off;
if ((ret = calc_verify_data(emitter->buf->base + psk_binder_off + 3, tls->key_schedule, binder_key)) != 0)
goto Exit;
}
ptls__key_schedule_update_hash(tls->key_schedule, emitter->buf->base + msghash_off, emitter->buf->off - msghash_off, 0);
/* ECH */
if (tls->ech.aead != NULL) {
/* build EncodedCHInner */
if ((ret = encode_client_hello(tls->ctx, &encoded_ch_inner, ENCODE_CH_MODE_ENCODED_INNER, is_second_flight, properties,
tls->ech.inner_client_random, tls->client.key_share_ctx, sni_name,
tls->client.legacy_session_id, &tls->ech, NULL, ptls_iovec_init(NULL, 0), resumption_secret,
resumption_ticket, obfuscated_ticket_age, tls->key_schedule->hashes[0].algo->digest_size,
cookie, tls->client.using_early_data)) != 0)
goto Exit;
if (resumption_secret.base != NULL)
memcpy(encoded_ch_inner.base + encoded_ch_inner.off - tls->key_schedule->hashes[0].algo->digest_size,
emitter->buf->base + emitter->buf->off - tls->key_schedule->hashes[0].algo->digest_size,
tls->key_schedule->hashes[0].algo->digest_size);
{ /* pad EncodedCHInner (following draft-ietf-tls-esni-15 6.1.3) */
size_t padding_len;
if (sni_name != NULL) {
padding_len = strlen(sni_name);
if (padding_len < tls->ech.client.max_name_length)
padding_len = tls->ech.client.max_name_length;
} else {
padding_len = tls->ech.client.max_name_length + 9;
}
size_t final_len = encoded_ch_inner.off - PTLS_HANDSHAKE_HEADER_SIZE + padding_len;
final_len = (final_len + 31) / 32 * 32;
padding_len = final_len - (encoded_ch_inner.off - PTLS_HANDSHAKE_HEADER_SIZE);
if (padding_len != 0) {
if ((ret = ptls_buffer_reserve(&encoded_ch_inner, padding_len)) != 0)
goto Exit;
memset(encoded_ch_inner.base + encoded_ch_inner.off, 0, padding_len);
encoded_ch_inner.off += padding_len;
}
}
/* flush CHInner, build CHOuterAAD */
emitter->buf->off = mess_start;
size_t ech_payload_size = encoded_ch_inner.off - PTLS_HANDSHAKE_HEADER_SIZE + tls->ech.aead->algo->tag_size,
ech_size_offset = ech_payload_size;
if ((ret = encode_client_hello(tls->ctx, emitter->buf, ENCODE_CH_MODE_OUTER, is_second_flight, properties,
tls->client_random, tls->client.key_share_ctx, tls->ech.client.public_name,
tls->client.legacy_session_id, &tls->ech, &ech_size_offset, ptls_iovec_init(NULL, 0),
resumption_secret, resumption_ticket, obfuscated_ticket_age,
tls->key_schedule->hashes[0].algo->digest_size, cookie, tls->client.using_early_data)) != 0)
goto Exit;
/* overwrite ECH payload */
ptls_aead_encrypt(tls->ech.aead, emitter->buf->base + ech_size_offset, encoded_ch_inner.base + PTLS_HANDSHAKE_HEADER_SIZE,
encoded_ch_inner.off - PTLS_HANDSHAKE_HEADER_SIZE, is_second_flight,
emitter->buf->base + mess_start + PTLS_HANDSHAKE_HEADER_SIZE,
emitter->buf->off - (mess_start + PTLS_HANDSHAKE_HEADER_SIZE));
/* keep the copy of the 1st ECH extension so that we can send it again in 2nd CH in response to rejection with HRR */
if (!is_second_flight) {
size_t len = outer_ech_header_size(tls->ech.client.enc.len) + ech_payload_size;
if ((tls->ech.client.first_ech.base = malloc(len)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
memcpy(tls->ech.client.first_ech.base,
emitter->buf->base + ech_size_offset - outer_ech_header_size(tls->ech.client.enc.len), len);
tls->ech.client.first_ech.len = len;
if (properties->client.ech.configs.len != 0) {
tls->ech.offered = 1;
} else {
tls->ech.offered_grease = 1;
}
}
/* update hash */
ptls__key_schedule_update_hash(tls->key_schedule, emitter->buf->base + mess_start, emitter->buf->off - mess_start, 1);
}
/* commit CH to the record layer */
if ((ret = emitter->commit_message(emitter)) != 0)
goto Exit;
if (tls->client.using_early_data) {
assert(!is_second_flight);
if ((ret = setup_traffic_protection(tls, 1, "c e traffic", 1, 0)) != 0)
goto Exit;
if ((ret = push_change_cipher_spec(tls, emitter)) != 0)
goto Exit;
}
if (resumption_secret.base != NULL && !is_second_flight) {
if ((ret = derive_exporter_secret(tls, 1)) != 0)
goto Exit;
}
tls->state = cookie == NULL ? PTLS_STATE_CLIENT_EXPECT_SERVER_HELLO : PTLS_STATE_CLIENT_EXPECT_SECOND_SERVER_HELLO;
ret = PTLS_ERROR_IN_PROGRESS;
Exit:
ptls_buffer_dispose(&encoded_ch_inner);
ptls_clear_memory(binder_key, sizeof(binder_key));
return ret;
}
ptls_cipher_suite_t *ptls_find_cipher_suite(ptls_cipher_suite_t **cipher_suites, uint16_t id)
{
ptls_cipher_suite_t **cs;
if (cipher_suites == NULL)
return NULL;
for (cs = cipher_suites; *cs != NULL && (*cs)->id != id; ++cs)
;
return *cs;
}
static int decode_server_hello(ptls_t *tls, struct st_ptls_server_hello_t *sh, const uint8_t *src, const uint8_t *const end)
{
int ret;
*sh = (struct st_ptls_server_hello_t){{0}};
/* ignore legacy-version */
if (end - src < 2) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
src += 2;
/* random */
if (end - src < PTLS_HELLO_RANDOM_SIZE) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
sh->is_retry_request = memcmp(src, hello_retry_random, PTLS_HELLO_RANDOM_SIZE) == 0;
src += PTLS_HELLO_RANDOM_SIZE;
/* legacy_session_id */
ptls_decode_open_block(src, end, 1, {
if (end - src > 32) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
sh->legacy_session_id = ptls_iovec_init(src, end - src);
src = end;
});
{ /* select cipher_suite */
uint16_t csid;
if ((ret = ptls_decode16(&csid, &src, end)) != 0)
goto Exit;
if ((tls->cipher_suite = ptls_find_cipher_suite(tls->ctx->cipher_suites, csid)) == NULL) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
}
{ /* legacy_compression_method */
uint8_t method;
if ((ret = ptls_decode8(&method, &src, end)) != 0)
goto Exit;
if (method != 0) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
}
if (sh->is_retry_request)
sh->retry_request.selected_group = UINT16_MAX;
uint16_t exttype, found_version = UINT16_MAX, selected_psk_identity = UINT16_MAX;
decode_extensions(src, end, sh->is_retry_request ? PTLS_HANDSHAKE_TYPE_PSEUDO_HRR : PTLS_HANDSHAKE_TYPE_SERVER_HELLO, &exttype,
{
if (tls->ctx->on_extension != NULL &&
(ret = tls->ctx->on_extension->cb(tls->ctx->on_extension, tls, PTLS_HANDSHAKE_TYPE_SERVER_HELLO,
exttype, ptls_iovec_init(src, end - src)) != 0))
goto Exit;
switch (exttype) {
case PTLS_EXTENSION_TYPE_SUPPORTED_VERSIONS:
if ((ret = ptls_decode16(&found_version, &src, end)) != 0)
goto Exit;
break;
case PTLS_EXTENSION_TYPE_KEY_SHARE:
if (sh->is_retry_request) {
if ((ret = ptls_decode16(&sh->retry_request.selected_group, &src, end)) != 0)
goto Exit;
} else {
uint16_t group;
if ((ret = decode_key_share_entry(&group, &sh->peerkey, &src, end)) != 0)
goto Exit;
if (src != end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
if (tls->key_share == NULL || tls->key_share->id != group) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
}
break;
case PTLS_EXTENSION_TYPE_COOKIE:
assert(sh->is_retry_request);
ptls_decode_block(src, end, 2, {
if (src == end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
sh->retry_request.cookie = ptls_iovec_init(src, end - src);
src = end;
});
break;
case PTLS_EXTENSION_TYPE_PRE_SHARED_KEY:
assert(!sh->is_retry_request);
if ((ret = ptls_decode16(&selected_psk_identity, &src, end)) != 0)
goto Exit;
break;
case PTLS_EXTENSION_TYPE_ENCRYPTED_CLIENT_HELLO:
assert(sh->is_retry_request);
if (!(tls->ech.offered || tls->ech.offered_grease)) {
ret = PTLS_ALERT_UNSUPPORTED_EXTENSION;
goto Exit;
}
if (end - src != PTLS_ECH_CONFIRM_LENGTH) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
sh->retry_request.ech = src;
src = end;
break;
default:
src = end;
break;
}
});
if (!is_supported_version(found_version)) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
if (!sh->is_retry_request) {
if (selected_psk_identity != UINT16_MAX) {
if (!tls->client.offered_psk) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
if (selected_psk_identity != 0) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
tls->is_psk_handshake = 1;
}
if (sh->peerkey.base == NULL && !tls->is_psk_handshake) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
}
ret = 0;
Exit:
return ret;
}
static int handle_hello_retry_request(ptls_t *tls, ptls_message_emitter_t *emitter, struct st_ptls_server_hello_t *sh,
ptls_iovec_t message, ptls_handshake_properties_t *properties)
{
int ret;
if (tls->client.key_share_ctx != NULL) {
tls->client.key_share_ctx->on_exchange(&tls->client.key_share_ctx, 1, NULL, ptls_iovec_init(NULL, 0));
tls->client.key_share_ctx = NULL;
}
if (tls->client.using_early_data) {
/* release traffic encryption key so that 2nd CH goes out in cleartext, but keep the epoch at 1 since we've already
* called derive-secret */
if (tls->ctx->update_traffic_key == NULL) {
assert(tls->traffic_protection.enc.aead != NULL);
ptls_aead_free(tls->traffic_protection.enc.aead);
tls->traffic_protection.enc.aead = NULL;
}
tls->client.using_early_data = 0;
}
if (sh->retry_request.selected_group != UINT16_MAX) {
/* we offer the first key_exchanges[0] as KEY_SHARE unless client.negotiate_before_key_exchange is set */
ptls_key_exchange_algorithm_t **cand;
for (cand = tls->ctx->key_exchanges; *cand != NULL; ++cand)
if ((*cand)->id == sh->retry_request.selected_group)
break;
if (*cand == NULL) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
tls->key_share = *cand;
} else if (tls->key_share != NULL) {
/* retain the key-share using in first CH, if server does not specify one */
} else {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
ret = send_client_hello(tls, emitter, properties, &sh->retry_request.cookie);
Exit:
return ret;
}
static int client_ech_select_hello(ptls_t *tls, ptls_iovec_t message, size_t confirm_hash_off, const char *label)
{
uint8_t confirm_hash_delivered[PTLS_ECH_CONFIRM_LENGTH], confirm_hash_expected[PTLS_ECH_CONFIRM_LENGTH];
int ret = 0;
/* Determine if ECH has been accepted by checking the confirmation hash. `confirm_hash_off` set to zero indicates that HRR was
* received wo. ECH extension, which is an indication that ECH was rejected. */
if (confirm_hash_off != 0) {
memcpy(confirm_hash_delivered, message.base + confirm_hash_off, sizeof(confirm_hash_delivered));
memset(message.base + confirm_hash_off, 0, sizeof(confirm_hash_delivered));
if ((ret = ech_calc_confirmation(tls->key_schedule, confirm_hash_expected, tls->ech.inner_client_random, label, message)) !=
0)
goto Exit;
tls->ech.accepted = ptls_mem_equal(confirm_hash_delivered, confirm_hash_expected, sizeof(confirm_hash_delivered));
memcpy(message.base + confirm_hash_off, confirm_hash_delivered, sizeof(confirm_hash_delivered));
if (tls->ech.accepted)
goto Exit;
}
/* dispose ECH AEAD state to indicate rejection, adopting outer CH for the rest of the handshake */
ptls_aead_free(tls->ech.aead);
tls->ech.aead = NULL;
key_schedule_select_outer(tls->key_schedule);
Exit:
PTLS_PROBE(ECH_SELECTION, tls, !!tls->ech.accepted);
PTLS_LOG_CONN(ech_selection, tls, { PTLS_LOG_ELEMENT_BOOL(is_ech, tls->ech.accepted); });
ptls_clear_memory(confirm_hash_expected, sizeof(confirm_hash_expected));
return ret;
}
static int client_handle_hello(ptls_t *tls, ptls_message_emitter_t *emitter, ptls_iovec_t message,
ptls_handshake_properties_t *properties)
{
struct st_ptls_server_hello_t sh;
ptls_iovec_t ecdh_secret = {NULL};
int ret;
if ((ret = decode_server_hello(tls, &sh, message.base + PTLS_HANDSHAKE_HEADER_SIZE, message.base + message.len)) != 0)
goto Exit;
if (!(sh.legacy_session_id.len == tls->client.legacy_session_id.len &&
ptls_mem_equal(sh.legacy_session_id.base, tls->client.legacy_session_id.base, tls->client.legacy_session_id.len))) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
if (sh.is_retry_request) {
if ((ret = key_schedule_select_cipher(tls->key_schedule, tls->cipher_suite, 0)) != 0)
goto Exit;
key_schedule_transform_post_ch1hash(tls->key_schedule);
if (tls->ech.aead != NULL) {
size_t confirm_hash_off = 0;
if (tls->ech.offered) {
if (sh.retry_request.ech != NULL)
confirm_hash_off = sh.retry_request.ech - message.base;
} else {
assert(tls->ech.offered_grease);
}
if ((ret = client_ech_select_hello(tls, message, confirm_hash_off, ECH_CONFIRMATION_HRR)) != 0)
goto Exit;
}
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
return handle_hello_retry_request(tls, emitter, &sh, message, properties);
}
if ((ret = key_schedule_select_cipher(tls->key_schedule, tls->cipher_suite,
tls->client.offered_psk && !tls->is_psk_handshake)) != 0)
goto Exit;
/* check if ECH is accepted */
if (tls->ech.aead != NULL) {
size_t confirm_hash_off = 0;
if (tls->ech.offered) {
confirm_hash_off =
PTLS_HANDSHAKE_HEADER_SIZE + 2 /* legacy_version */ + PTLS_HELLO_RANDOM_SIZE - PTLS_ECH_CONFIRM_LENGTH;
} else {
assert(tls->ech.offered_grease);
}
if ((ret = client_ech_select_hello(tls, message, confirm_hash_off, ECH_CONFIRMATION_SERVER_HELLO)) != 0)
goto Exit;
}
/* clear sensitive and space-consuming ECH state, now that are done with handling sending and decoding Hellos */
clear_ech(&tls->ech, 0);
if (tls->key_schedule->hashes[0].ctx_outer != NULL) {
tls->key_schedule->hashes[0].ctx_outer->final(tls->key_schedule->hashes[0].ctx_outer, NULL, PTLS_HASH_FINAL_MODE_FREE);
tls->key_schedule->hashes[0].ctx_outer = NULL;
}
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
if (sh.peerkey.base != NULL) {
if ((ret = tls->client.key_share_ctx->on_exchange(&tls->client.key_share_ctx, 1, &ecdh_secret, sh.peerkey)) != 0)
goto Exit;
}
if ((ret = key_schedule_extract(tls->key_schedule, ecdh_secret)) != 0)
goto Exit;
if ((ret = setup_traffic_protection(tls, 0, "s hs traffic", 2, 0)) != 0)
goto Exit;
if (tls->client.using_early_data) {
if ((tls->pending_handshake_secret = malloc(PTLS_MAX_DIGEST_SIZE)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
if ((ret = derive_secret(tls->key_schedule, tls->pending_handshake_secret, "c hs traffic")) != 0)
goto Exit;
if (tls->ctx->update_traffic_key != NULL &&
(ret = tls->ctx->update_traffic_key->cb(tls->ctx->update_traffic_key, tls, 1, 2, tls->pending_handshake_secret)) != 0)
goto Exit;
} else {
if ((ret = setup_traffic_protection(tls, 1, "c hs traffic", 2, 0)) != 0)
goto Exit;
}
tls->state = PTLS_STATE_CLIENT_EXPECT_ENCRYPTED_EXTENSIONS;
ret = PTLS_ERROR_IN_PROGRESS;
Exit:
if (ecdh_secret.base != NULL) {
ptls_clear_memory(ecdh_secret.base, ecdh_secret.len);
free(ecdh_secret.base);
}
return ret;
}
static int should_collect_unknown_extension(ptls_t *tls, ptls_handshake_properties_t *properties, uint16_t type)
{
return properties != NULL && properties->collect_extension != NULL && properties->collect_extension(tls, properties, type);
}
static int collect_unknown_extension(ptls_t *tls, uint16_t type, const uint8_t *src, const uint8_t *const end,
ptls_raw_extension_t *slots)
{
size_t i;
for (i = 0; slots[i].type != UINT16_MAX; ++i) {
assert(i < MAX_UNKNOWN_EXTENSIONS);
if (slots[i].type == type)
return PTLS_ALERT_ILLEGAL_PARAMETER;
}
if (i < MAX_UNKNOWN_EXTENSIONS) {
slots[i].type = type;
slots[i].data = ptls_iovec_init(src, end - src);
slots[i + 1].type = UINT16_MAX;
}
return 0;
}
static int report_unknown_extensions(ptls_t *tls, ptls_handshake_properties_t *properties, ptls_raw_extension_t *slots)
{
if (properties != NULL && properties->collect_extension != NULL) {
assert(properties->collected_extensions != NULL);
return properties->collected_extensions(tls, properties, slots);
} else {
return 0;
}
}
static int client_handle_encrypted_extensions(ptls_t *tls, ptls_iovec_t message, ptls_handshake_properties_t *properties)
{
const uint8_t *src = message.base + PTLS_HANDSHAKE_HEADER_SIZE, *const end = message.base + message.len;
uint16_t type;
static const ptls_raw_extension_t no_unknown_extensions = {UINT16_MAX};
ptls_raw_extension_t *unknown_extensions = (ptls_raw_extension_t *)&no_unknown_extensions;
int ret, skip_early_data = 1;
uint8_t server_offered_cert_type = PTLS_CERTIFICATE_TYPE_X509;
decode_extensions(src, end, PTLS_HANDSHAKE_TYPE_ENCRYPTED_EXTENSIONS, &type, {
if (tls->ctx->on_extension != NULL &&
(ret = tls->ctx->on_extension->cb(tls->ctx->on_extension, tls, PTLS_HANDSHAKE_TYPE_ENCRYPTED_EXTENSIONS, type,
ptls_iovec_init(src, end - src)) != 0))
goto Exit;
switch (type) {
case PTLS_EXTENSION_TYPE_SERVER_NAME:
if (src != end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
if (!(tls->server_name != NULL && !ptls_server_name_is_ipaddr(tls->server_name))) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
break;
case PTLS_EXTENSION_TYPE_ALPN:
ptls_decode_block(src, end, 2, {
ptls_decode_open_block(src, end, 1, {
if (src == end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
if ((ret = ptls_set_negotiated_protocol(tls, (const char *)src, end - src)) != 0)
goto Exit;
src = end;
});
if (src != end) {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
goto Exit;
}
});
break;
case PTLS_EXTENSION_TYPE_EARLY_DATA:
if (!tls->client.using_early_data) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
skip_early_data = 0;
break;
case PTLS_EXTENSION_TYPE_SERVER_CERTIFICATE_TYPE:
if (end - src != 1) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
server_offered_cert_type = *src;
src = end;
break;
case PTLS_EXTENSION_TYPE_ENCRYPTED_CLIENT_HELLO: {
/* accept retry_configs only if we offered ECH but rejected */
if (!((tls->ech.offered || tls->ech.offered_grease) && !ptls_is_ech_handshake(tls, NULL, NULL, NULL))) {
ret = PTLS_ALERT_UNSUPPORTED_EXTENSION;
goto Exit;
}
/* parse retry_config, and if it is applicable, provide that to the application */
struct st_decoded_ech_config_t decoded;
if ((ret = client_decode_ech_config_list(tls->ctx, &decoded, ptls_iovec_init(src, end - src))) != 0)
goto Exit;
if (decoded.kem != NULL && decoded.cipher != NULL && properties != NULL &&
properties->client.ech.retry_configs != NULL) {
if ((properties->client.ech.retry_configs->base = malloc(end - src)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
memcpy(properties->client.ech.retry_configs->base, src, end - src);
properties->client.ech.retry_configs->len = end - src;
}
src = end;
} break;
default:
if (should_collect_unknown_extension(tls, properties, type)) {
if (unknown_extensions == &no_unknown_extensions) {
if ((unknown_extensions = malloc(sizeof(*unknown_extensions) * (MAX_UNKNOWN_EXTENSIONS + 1))) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
unknown_extensions[0].type = UINT16_MAX;
}
if ((ret = collect_unknown_extension(tls, type, src, end, unknown_extensions)) != 0)
goto Exit;
}
break;
}
src = end;
});
if (server_offered_cert_type !=
(tls->ctx->use_raw_public_keys ? PTLS_CERTIFICATE_TYPE_RAW_PUBLIC_KEY : PTLS_CERTIFICATE_TYPE_X509)) {
ret = PTLS_ALERT_UNSUPPORTED_CERTIFICATE;
goto Exit;
}
if (tls->client.using_early_data) {
if (skip_early_data)
tls->client.using_early_data = 0;
if (properties != NULL)
properties->client.early_data_acceptance = skip_early_data ? PTLS_EARLY_DATA_REJECTED : PTLS_EARLY_DATA_ACCEPTED;
}
if ((ret = report_unknown_extensions(tls, properties, unknown_extensions)) != 0)
goto Exit;
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
tls->state =
tls->is_psk_handshake ? PTLS_STATE_CLIENT_EXPECT_FINISHED : PTLS_STATE_CLIENT_EXPECT_CERTIFICATE_REQUEST_OR_CERTIFICATE;
ret = PTLS_ERROR_IN_PROGRESS;
Exit:
if (unknown_extensions != &no_unknown_extensions)
free(unknown_extensions);
return ret;
}
static int decode_certificate_request(ptls_t *tls, struct st_ptls_certificate_request_t *cr, const uint8_t *src,
const uint8_t *const end)
{
int ret;
uint16_t exttype = 0;
/* certificate request context */
ptls_decode_open_block(src, end, 1, {
size_t len = end - src;
if (len > 255) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
if ((cr->context.base = malloc(len != 0 ? len : 1)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
cr->context.len = len;
memcpy(cr->context.base, src, len);
src = end;
});
/* decode extensions */
decode_extensions(src, end, PTLS_HANDSHAKE_TYPE_CERTIFICATE_REQUEST, &exttype, {
if (tls->ctx->on_extension != NULL &&
(ret = tls->ctx->on_extension->cb(tls->ctx->on_extension, tls, PTLS_HANDSHAKE_TYPE_CERTIFICATE_REQUEST, exttype,
ptls_iovec_init(src, end - src)) != 0))
goto Exit;
switch (exttype) {
case PTLS_EXTENSION_TYPE_SIGNATURE_ALGORITHMS:
if ((ret = decode_signature_algorithms(&cr->signature_algorithms, &src, end)) != 0)
goto Exit;
break;
}
src = end;
});
if (cr->signature_algorithms.count == 0) {
ret = PTLS_ALERT_MISSING_EXTENSION;
goto Exit;
}
ret = 0;
Exit:
return ret;
}
int ptls_build_certificate_message(ptls_buffer_t *buf, ptls_iovec_t context, ptls_iovec_t *certificates, size_t num_certificates,
ptls_iovec_t ocsp_status)
{
int ret;
ptls_buffer_push_block(buf, 1, { ptls_buffer_pushv(buf, context.base, context.len); });
ptls_buffer_push_block(buf, 3, {
size_t i;
for (i = 0; i != num_certificates; ++i) {
ptls_buffer_push_block(buf, 3, { ptls_buffer_pushv(buf, certificates[i].base, certificates[i].len); });
ptls_buffer_push_block(buf, 2, {
if (i == 0 && ocsp_status.len != 0) {
buffer_push_extension(buf, PTLS_EXTENSION_TYPE_STATUS_REQUEST, {
ptls_buffer_push(buf, 1); /* status_type == ocsp */
ptls_buffer_push_block(buf, 3, { ptls_buffer_pushv(buf, ocsp_status.base, ocsp_status.len); });
});
}
});
}
});
ret = 0;
Exit:
return ret;
}
static int default_emit_certificate_cb(ptls_emit_certificate_t *_self, ptls_t *tls, ptls_message_emitter_t *emitter,
ptls_key_schedule_t *key_sched, ptls_iovec_t context, int push_status_request,
const uint16_t *compress_algos, size_t num_compress_algos)
{
int ret;
ptls_push_message(emitter, key_sched, PTLS_HANDSHAKE_TYPE_CERTIFICATE, {
if ((ret = ptls_build_certificate_message(emitter->buf, context, tls->ctx->certificates.list, tls->ctx->certificates.count,
ptls_iovec_init(NULL, 0))) != 0)
goto Exit;
});
ret = 0;
Exit:
return ret;
}
static int send_certificate(ptls_t *tls, ptls_message_emitter_t *emitter,
struct st_ptls_signature_algorithms_t *signature_algorithms, ptls_iovec_t context,
int push_status_request, const uint16_t *compress_algos, size_t num_compress_algos)
{
int ret;
if (signature_algorithms->count == 0) {
ret = PTLS_ALERT_MISSING_EXTENSION;
goto Exit;
}
{ /* send Certificate (or the equivalent) */
static ptls_emit_certificate_t default_emit_certificate = {default_emit_certificate_cb};
ptls_emit_certificate_t *emit_certificate =
tls->ctx->emit_certificate != NULL ? tls->ctx->emit_certificate : &default_emit_certificate;
Redo:
if ((ret = emit_certificate->cb(emit_certificate, tls, emitter, tls->key_schedule, context, push_status_request,
compress_algos, num_compress_algos)) != 0) {
if (ret == PTLS_ERROR_DELEGATE) {
assert(emit_certificate != &default_emit_certificate);
emit_certificate = &default_emit_certificate;
goto Redo;
}
goto Exit;
}
}
Exit:
return ret;
}
static int send_certificate_verify(ptls_t *tls, ptls_message_emitter_t *emitter,
struct st_ptls_signature_algorithms_t *signature_algorithms, const char *context_string)
{
size_t start_off = emitter->buf->off;
int ret;
if (tls->ctx->sign_certificate == NULL)
return 0;
/* build and send CertificateVerify */
ptls_push_message(emitter, tls->key_schedule, PTLS_HANDSHAKE_TYPE_CERTIFICATE_VERIFY, {
ptls_buffer_t *sendbuf = emitter->buf;
size_t algo_off = sendbuf->off;
ptls_buffer_push16(sendbuf, 0); /* filled in later */
ptls_buffer_push_block(sendbuf, 2, {
uint16_t algo;
uint8_t data[PTLS_MAX_CERTIFICATE_VERIFY_SIGNDATA_SIZE];
size_t datalen = build_certificate_verify_signdata(data, tls->key_schedule, context_string);
if ((ret = tls->ctx->sign_certificate->cb(
tls->ctx->sign_certificate, tls, tls->is_server ? &tls->server.async_job : NULL, &algo, sendbuf,
ptls_iovec_init(data, datalen), signature_algorithms != NULL ? signature_algorithms->list : NULL,
signature_algorithms != NULL ? signature_algorithms->count : 0)) != 0) {
if (ret == PTLS_ERROR_ASYNC_OPERATION) {
assert(tls->is_server || !"async operation only supported on the server-side");
assert(tls->server.async_job != NULL);
/* Reset the output to the end of the previous handshake message. CertificateVerify will be rebuilt when the
* async operation completes. */
emitter->buf->off = start_off;
} else {
assert(tls->server.async_job == NULL);
}
goto Exit;
}
assert(tls->server.async_job == NULL);
sendbuf->base[algo_off] = (uint8_t)(algo >> 8);
sendbuf->base[algo_off + 1] = (uint8_t)algo;
});
});
Exit:
return ret;
}
static int client_handle_certificate_request(ptls_t *tls, ptls_iovec_t message, ptls_handshake_properties_t *properties)
{
const uint8_t *src = message.base + PTLS_HANDSHAKE_HEADER_SIZE, *const end = message.base + message.len;
int ret = 0;
assert(!tls->is_psk_handshake && "state machine asserts that this message is never delivered when PSK is used");
if ((ret = decode_certificate_request(tls, &tls->client.certificate_request, src, end)) != 0)
return ret;
/* This field SHALL be zero length unless used for the post-handshake authentication exchanges (section 4.3.2) */
if (tls->client.certificate_request.context.len != 0)
return PTLS_ALERT_ILLEGAL_PARAMETER;
tls->state = PTLS_STATE_CLIENT_EXPECT_CERTIFICATE;
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
return PTLS_ERROR_IN_PROGRESS;
}
static int handle_certificate(ptls_t *tls, const uint8_t *src, const uint8_t *end, int *got_certs)
{
ptls_iovec_t certs[16];
size_t num_certs = 0;
int ret = 0;
/* certificate request context */
ptls_decode_open_block(src, end, 1, {
if (src != end) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
});
/* certificate_list */
ptls_decode_block(src, end, 3, {
while (src != end) {
ptls_decode_open_block(src, end, 3, {
if (num_certs < PTLS_ELEMENTSOF(certs))
certs[num_certs++] = ptls_iovec_init(src, end - src);
src = end;
});
uint16_t type;
decode_open_extensions(src, end, PTLS_HANDSHAKE_TYPE_CERTIFICATE, &type, {
if (tls->ctx->on_extension != NULL &&
(ret = tls->ctx->on_extension->cb(tls->ctx->on_extension, tls, PTLS_HANDSHAKE_TYPE_CERTIFICATE, type,
ptls_iovec_init(src, end - src)) != 0))
goto Exit;
src = end;
});
}
});
if (tls->ctx->verify_certificate != NULL) {
const char *server_name = NULL;
if (!ptls_is_server(tls)) {
if (tls->ech.offered && !ptls_is_ech_handshake(tls, NULL, NULL, NULL)) {
server_name = tls->ech.client.public_name;
} else {
server_name = tls->server_name;
}
}
if ((ret = tls->ctx->verify_certificate->cb(tls->ctx->verify_certificate, tls, server_name, &tls->certificate_verify.cb,
&tls->certificate_verify.verify_ctx, certs, num_certs)) != 0)
goto Exit;
}
*got_certs = num_certs != 0;
Exit:
return ret;
}
static int client_do_handle_certificate(ptls_t *tls, const uint8_t *src, const uint8_t *end)
{
int got_certs, ret;
if ((ret = handle_certificate(tls, src, end, &got_certs)) != 0)
return ret;
if (!got_certs)
return PTLS_ALERT_ILLEGAL_PARAMETER;
return 0;
}
static int client_handle_certificate(ptls_t *tls, ptls_iovec_t message)
{
int ret;
if ((ret = client_do_handle_certificate(tls, message.base + PTLS_HANDSHAKE_HEADER_SIZE, message.base + message.len)) != 0)
return ret;
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
tls->state = PTLS_STATE_CLIENT_EXPECT_CERTIFICATE_VERIFY;
return PTLS_ERROR_IN_PROGRESS;
}
static int client_handle_compressed_certificate(ptls_t *tls, ptls_iovec_t message)
{
const uint8_t *src = message.base + PTLS_HANDSHAKE_HEADER_SIZE, *const end = message.base + message.len;
uint16_t algo;
uint32_t uncompressed_size;
uint8_t *uncompressed = NULL;
int ret;
if (tls->ctx->decompress_certificate == NULL) {
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
goto Exit;
}
/* decode */
if ((ret = ptls_decode16(&algo, &src, end)) != 0)
goto Exit;
if ((ret = ptls_decode24(&uncompressed_size, &src, end)) != 0)
goto Exit;
if (uncompressed_size > 65536) { /* TODO find a sensible number */
ret = PTLS_ALERT_BAD_CERTIFICATE;
goto Exit;
}
if ((uncompressed = malloc(uncompressed_size)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
ptls_decode_block(src, end, 3, {
if ((ret = tls->ctx->decompress_certificate->cb(tls->ctx->decompress_certificate, tls, algo,
ptls_iovec_init(uncompressed, uncompressed_size),
ptls_iovec_init(src, end - src))) != 0)
goto Exit;
src = end;
});
/* handle */
if ((ret = client_do_handle_certificate(tls, uncompressed, uncompressed + uncompressed_size)) != 0)
goto Exit;
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
tls->state = PTLS_STATE_CLIENT_EXPECT_CERTIFICATE_VERIFY;
ret = PTLS_ERROR_IN_PROGRESS;
Exit:
free(uncompressed);
return ret;
}
static int server_handle_certificate(ptls_t *tls, ptls_iovec_t message)
{
int got_certs, ret;
if ((ret = handle_certificate(tls, message.base + PTLS_HANDSHAKE_HEADER_SIZE, message.base + message.len, &got_certs)) != 0)
return ret;
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
if (got_certs) {
tls->state = PTLS_STATE_SERVER_EXPECT_CERTIFICATE_VERIFY;
} else {
/* Client did not provide certificate, and the verifier says we can fail open. Therefore, the next message is Finished. */
tls->state = PTLS_STATE_SERVER_EXPECT_FINISHED;
}
return PTLS_ERROR_IN_PROGRESS;
}
static int handle_certificate_verify(ptls_t *tls, ptls_iovec_t message, const char *context_string)
{
const uint8_t *src = message.base + PTLS_HANDSHAKE_HEADER_SIZE, *const end = message.base + message.len;
uint16_t algo;
ptls_iovec_t signature;
uint8_t signdata[PTLS_MAX_CERTIFICATE_VERIFY_SIGNDATA_SIZE];
size_t signdata_size;
int ret;
/* decode */
if ((ret = ptls_decode16(&algo, &src, end)) != 0)
goto Exit;
ptls_decode_block(src, end, 2, {
signature = ptls_iovec_init(src, end - src);
src = end;
});
signdata_size = build_certificate_verify_signdata(signdata, tls->key_schedule, context_string);
if (tls->certificate_verify.cb != NULL) {
ret = tls->certificate_verify.cb(tls->certificate_verify.verify_ctx, algo, ptls_iovec_init(signdata, signdata_size),
signature);
} else {
ret = 0;
}
ptls_clear_memory(signdata, signdata_size);
tls->certificate_verify.cb = NULL;
if (ret != 0) {
goto Exit;
}
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
Exit:
return ret;
}
static int client_handle_certificate_verify(ptls_t *tls, ptls_iovec_t message)
{
int ret = handle_certificate_verify(tls, message, PTLS_SERVER_CERTIFICATE_VERIFY_CONTEXT_STRING);
if (ret == 0) {
tls->state = PTLS_STATE_CLIENT_EXPECT_FINISHED;
ret = PTLS_ERROR_IN_PROGRESS;
}
return ret;
}
static int server_handle_certificate_verify(ptls_t *tls, ptls_iovec_t message)
{
int ret = handle_certificate_verify(tls, message, PTLS_CLIENT_CERTIFICATE_VERIFY_CONTEXT_STRING);
if (ret == 0) {
tls->state = PTLS_STATE_SERVER_EXPECT_FINISHED;
ret = PTLS_ERROR_IN_PROGRESS;
}
return ret;
}
static int client_handle_finished(ptls_t *tls, ptls_message_emitter_t *emitter, ptls_iovec_t message)
{
uint8_t send_secret[PTLS_MAX_DIGEST_SIZE];
int alert_ech_required = tls->ech.offered && !ptls_is_ech_handshake(tls, NULL, NULL, NULL), ret;
if ((ret = verify_finished(tls, message)) != 0)
goto Exit;
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
/* update traffic keys by using messages upto ServerFinished, but commission them after sending ClientFinished */
if ((ret = key_schedule_extract(tls->key_schedule, ptls_iovec_init(NULL, 0))) != 0)
goto Exit;
if ((ret = setup_traffic_protection(tls, 0, "s ap traffic", 3, 0)) != 0)
goto Exit;
if ((ret = derive_secret(tls->key_schedule, send_secret, "c ap traffic")) != 0)
goto Exit;
if ((ret = derive_exporter_secret(tls, 0)) != 0)
goto Exit;
/* if sending early data, emit EOED and commision the client handshake traffic secret */
if (tls->pending_handshake_secret != NULL) {
assert(tls->traffic_protection.enc.aead != NULL || tls->ctx->update_traffic_key != NULL);
if (tls->client.using_early_data && !tls->ctx->omit_end_of_early_data)
ptls_push_message(emitter, tls->key_schedule, PTLS_HANDSHAKE_TYPE_END_OF_EARLY_DATA, {});
tls->client.using_early_data = 0;
if ((ret = commission_handshake_secret(tls)) != 0)
goto Exit;
}
if ((ret = push_change_cipher_spec(tls, emitter)) != 0)
goto Exit;
if (!alert_ech_required && tls->client.certificate_request.context.base != NULL) {
if ((ret = send_certificate(tls, emitter, &tls->client.certificate_request.signature_algorithms,
tls->client.certificate_request.context, 0, NULL, 0)) == 0)
ret = send_certificate_verify(tls, emitter, &tls->client.certificate_request.signature_algorithms,
PTLS_CLIENT_CERTIFICATE_VERIFY_CONTEXT_STRING);
free(tls->client.certificate_request.context.base);
tls->client.certificate_request.context = ptls_iovec_init(NULL, 0);
if (ret != 0)
goto Exit;
}
ret = send_finished(tls, emitter);
memcpy(tls->traffic_protection.enc.secret, send_secret, sizeof(send_secret));
if ((ret = setup_traffic_protection(tls, 1, NULL, 3, 0)) != 0)
goto Exit;
tls->state = PTLS_STATE_CLIENT_POST_HANDSHAKE;
/* if ECH was rejected, close the connection with ECH_REQUIRED alert after verifying messages up to Finished */
if (alert_ech_required)
ret = PTLS_ALERT_ECH_REQUIRED;
Exit:
ptls_clear_memory(send_secret, sizeof(send_secret));
return ret;
}
static int client_handle_new_session_ticket(ptls_t *tls, ptls_iovec_t message)
{
const uint8_t *src = message.base + PTLS_HANDSHAKE_HEADER_SIZE, *const end = message.base + message.len;
ptls_iovec_t ticket_nonce;
int ret;
{ /* verify the format */
uint32_t ticket_lifetime, ticket_age_add, max_early_data_size;
ptls_iovec_t ticket;
if ((ret = decode_new_session_ticket(tls, &ticket_lifetime, &ticket_age_add, &ticket_nonce, &ticket, &max_early_data_size,
src, end)) != 0)
return ret;
}
/* do nothing if use of session ticket is disabled */
if (tls->ctx->save_ticket == NULL)
return 0;
/* save the extension, along with the key of myself */
ptls_buffer_t ticket_buf;
ptls_buffer_init(&ticket_buf, "", 0);
ptls_buffer_push64(&ticket_buf, tls->ctx->get_time->cb(tls->ctx->get_time));
ptls_buffer_push16(&ticket_buf, tls->key_share->id);
ptls_buffer_push16(&ticket_buf, tls->cipher_suite->id);
ptls_buffer_push_block(&ticket_buf, 3, { ptls_buffer_pushv(&ticket_buf, src, end - src); });
ptls_buffer_push_block(&ticket_buf, 2, {
if ((ret = ptls_buffer_reserve(&ticket_buf, tls->key_schedule->hashes[0].algo->digest_size)) != 0)
goto Exit;
if ((ret = derive_resumption_secret(tls->key_schedule, ticket_buf.base + ticket_buf.off, ticket_nonce)) != 0)
goto Exit;
ticket_buf.off += tls->key_schedule->hashes[0].algo->digest_size;
});
if ((ret = tls->ctx->save_ticket->cb(tls->ctx->save_ticket, tls, ptls_iovec_init(ticket_buf.base, ticket_buf.off))) != 0)
goto Exit;
ret = 0;
Exit:
ptls_buffer_dispose(&ticket_buf);
return ret;
}
static int client_hello_decode_server_name(ptls_iovec_t *name, const uint8_t **src, const uint8_t *const end)
{
int ret = 0;
ptls_decode_open_block(*src, end, 2, {
do {
uint8_t type;
if ((ret = ptls_decode8(&type, src, end)) != 0)
goto Exit;
ptls_decode_open_block(*src, end, 2, {
switch (type) {
case PTLS_SERVER_NAME_TYPE_HOSTNAME:
if (memchr(*src, '\0', end - *src) != 0) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
*name = ptls_iovec_init(*src, end - *src);
break;
default:
break;
}
*src = end;
});
} while (*src != end);
});
Exit:
return ret;
}
static int select_negotiated_group(ptls_key_exchange_algorithm_t **selected, ptls_key_exchange_algorithm_t **candidates,
const uint8_t *src, const uint8_t *const end)
{
int ret;
ptls_decode_block(src, end, 2, {
while (src != end) {
uint16_t group;
if ((ret = ptls_decode16(&group, &src, end)) != 0)
goto Exit;
ptls_key_exchange_algorithm_t **c = candidates;
for (; *c != NULL; ++c) {
if ((*c)->id == group) {
*selected = *c;
return 0;
}
}
}
});
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
Exit:
return ret;
}
static int decode_client_hello(ptls_context_t *ctx, struct st_ptls_client_hello_t *ch, const uint8_t *src, const uint8_t *const end,
ptls_handshake_properties_t *properties, ptls_t *tls_cbarg)
{
const uint8_t *start = src;
uint16_t exttype = 0;
int ret;
/* decode protocol version (do not bare to decode something older than TLS 1.0) */
if ((ret = ptls_decode16(&ch->legacy_version, &src, end)) != 0)
goto Exit;
if (ch->legacy_version < 0x0301) {
ret = PTLS_ALERT_PROTOCOL_VERSION;
goto Exit;
}
/* skip random */
if (end - src < PTLS_HELLO_RANDOM_SIZE) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
ch->random_bytes = src;
src += PTLS_HELLO_RANDOM_SIZE;
/* skip legacy_session_id */
ptls_decode_open_block(src, end, 1, {
if (end - src > 32) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
ch->legacy_session_id = ptls_iovec_init(src, end - src);
src = end;
});
/* decode and select from ciphersuites */
ptls_decode_open_block(src, end, 2, {
if ((end - src) % 2 != 0) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
ch->cipher_suites = ptls_iovec_init(src, end - src);
src = end;
});
/* decode legacy_compression_methods */
ptls_decode_open_block(src, end, 1, {
if (src == end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
ch->compression_methods.ids = src;
ch->compression_methods.count = end - src;
src = end;
});
/* In TLS versions 1.2 and earlier CH might not have an extensions block (or they might, see what OpenSSL 1.0.0 sends); so bail
* out if that is the case after parsing the main variables. Zero is returned as it is a valid ClientHello. However
* `ptls_t::selected_version` remains zero indicating that no compatible version were found. */
if (src == end) {
ret = 0;
goto Exit;
}
/* decode extensions */
ch->first_extension_at = src - start + 2;
decode_extensions(src, end, PTLS_HANDSHAKE_TYPE_CLIENT_HELLO, &exttype, {
ch->psk.is_last_extension = 0;
if (ctx->on_extension != NULL && tls_cbarg != NULL &&
(ret = ctx->on_extension->cb(ctx->on_extension, tls_cbarg, PTLS_HANDSHAKE_TYPE_CLIENT_HELLO, exttype,
ptls_iovec_init(src, end - src)) != 0))
goto Exit;
switch (exttype) {
case PTLS_EXTENSION_TYPE_SERVER_NAME:
if ((ret = client_hello_decode_server_name(&ch->server_name, &src, end)) != 0)
goto Exit;
if (src != end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
break;
case PTLS_EXTENSION_TYPE_ALPN:
ptls_decode_block(src, end, 2, {
do {
ptls_decode_open_block(src, end, 1, {
/* rfc7301 3.1: empty strings MUST NOT be included */
if (src == end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
if (ch->alpn.count < PTLS_ELEMENTSOF(ch->alpn.list))
ch->alpn.list[ch->alpn.count++] = ptls_iovec_init(src, end - src);
src = end;
});
} while (src != end);
});
break;
case PTLS_EXTENSION_TYPE_SERVER_CERTIFICATE_TYPE:
ptls_decode_block(src, end, 1, {
size_t list_size = end - src;
/* RFC7250 4.1: No empty list, no list with single x509 element */
if (list_size == 0 || (list_size == 1 && *src == PTLS_CERTIFICATE_TYPE_X509)) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
do {
if (ch->server_certificate_types.count < PTLS_ELEMENTSOF(ch->server_certificate_types.list))
ch->server_certificate_types.list[ch->server_certificate_types.count++] = *src;
src++;
} while (src != end);
});
break;
case PTLS_EXTENSION_TYPE_COMPRESS_CERTIFICATE:
ptls_decode_block(src, end, 1, {
do {
uint16_t id;
if ((ret = ptls_decode16(&id, &src, end)) != 0)
goto Exit;
if (ch->cert_compression_algos.count < PTLS_ELEMENTSOF(ch->cert_compression_algos.list))
ch->cert_compression_algos.list[ch->cert_compression_algos.count++] = id;
} while (src != end);
});
break;
case PTLS_EXTENSION_TYPE_SUPPORTED_GROUPS:
ch->negotiated_groups = ptls_iovec_init(src, end - src);
break;
case PTLS_EXTENSION_TYPE_SIGNATURE_ALGORITHMS:
if ((ret = decode_signature_algorithms(&ch->signature_algorithms, &src, end)) != 0)
goto Exit;
break;
case PTLS_EXTENSION_TYPE_KEY_SHARE:
ch->key_shares = ptls_iovec_init(src, end - src);
break;
case PTLS_EXTENSION_TYPE_SUPPORTED_VERSIONS:
ptls_decode_block(src, end, 1, {
size_t selected_index = PTLS_ELEMENTSOF(supported_versions);
do {
size_t i;
uint16_t v;
if ((ret = ptls_decode16(&v, &src, end)) != 0)
goto Exit;
for (i = 0; i != selected_index; ++i) {
if (supported_versions[i] == v) {
selected_index = i;
break;
}
}
} while (src != end);
if (selected_index != PTLS_ELEMENTSOF(supported_versions))
ch->selected_version = supported_versions[selected_index];
});
break;
case PTLS_EXTENSION_TYPE_COOKIE:
if (properties == NULL || properties->server.cookie.key == NULL) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
ch->cookie.all = ptls_iovec_init(src, end - src);
ptls_decode_block(src, end, 2, {
ch->cookie.tbs.base = (void *)src;
ptls_decode_open_block(src, end, 2, {
ptls_decode_open_block(src, end, 1, {
ch->cookie.ch1_hash = ptls_iovec_init(src, end - src);
src = end;
});
uint8_t sent_key_share;
if ((ret = ptls_decode8(&sent_key_share, &src, end)) != 0)
goto Exit;
switch (sent_key_share) {
case 0:
assert(!ch->cookie.sent_key_share);
break;
case 1:
ch->cookie.sent_key_share = 1;
break;
default:
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
});
ch->cookie.tbs.len = src - ch->cookie.tbs.base;
ptls_decode_block(src, end, 1, {
ch->cookie.signature = ptls_iovec_init(src, end - src);
src = end;
});
});
break;
case PTLS_EXTENSION_TYPE_PRE_SHARED_KEY: {
size_t num_identities = 0;
ptls_decode_open_block(src, end, 2, {
do {
struct st_ptls_client_hello_psk_t psk = {{NULL}};
ptls_decode_open_block(src, end, 2, {
psk.identity = ptls_iovec_init(src, end - src);
src = end;
});
if ((ret = ptls_decode32(&psk.obfuscated_ticket_age, &src, end)) != 0)
goto Exit;
if (ch->psk.identities.count < PTLS_ELEMENTSOF(ch->psk.identities.list))
ch->psk.identities.list[ch->psk.identities.count++] = psk;
++num_identities;
} while (src != end);
});
ch->psk.hash_end = src;
ptls_decode_block(src, end, 2, {
size_t num_binders = 0;
do {
ptls_decode_open_block(src, end, 1, {
if (num_binders < ch->psk.identities.count)
ch->psk.identities.list[num_binders].binder = ptls_iovec_init(src, end - src);
src = end;
});
++num_binders;
} while (src != end);
if (num_identities != num_binders) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
});
ch->psk.is_last_extension = 1;
} break;
case PTLS_EXTENSION_TYPE_PSK_KEY_EXCHANGE_MODES:
ptls_decode_block(src, end, 1, {
do {
uint8_t mode;
if ((ret = ptls_decode8(&mode, &src, end)) != 0)
goto Exit;
if (mode < sizeof(ch->psk.ke_modes) * 8)
ch->psk.ke_modes |= 1u << mode;
} while (src != end);
});
break;
case PTLS_EXTENSION_TYPE_EARLY_DATA:
ch->psk.early_data_indication = 1;
break;
case PTLS_EXTENSION_TYPE_STATUS_REQUEST:
ch->status_request = 1;
break;
case PTLS_EXTENSION_TYPE_ENCRYPTED_CLIENT_HELLO:
if ((ret = ptls_decode8(&ch->ech.type, &src, end)) != 0)
goto Exit;
switch (ch->ech.type) {
case PTLS_ECH_CLIENT_HELLO_TYPE_OUTER:
if ((ret = ptls_decode16(&ch->ech.cipher_suite.kdf, &src, end)) != 0 ||
(ret = ptls_decode16(&ch->ech.cipher_suite.aead, &src, end)) != 0)
goto Exit;
if ((ret = ptls_decode8(&ch->ech.config_id, &src, end)) != 0)
goto Exit;
ptls_decode_open_block(src, end, 2, {
ch->ech.enc = ptls_iovec_init(src, end - src);
src = end;
});
ptls_decode_open_block(src, end, 2, {
if (src == end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
ch->ech.payload = ptls_iovec_init(src, end - src);
src = end;
});
break;
case PTLS_ECH_CLIENT_HELLO_TYPE_INNER:
if (src != end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
ch->ech.payload = ptls_iovec_init("", 0); /* non-zero base indicates that the extension was received */
break;
default:
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
src = end;
break;
default:
if (tls_cbarg != NULL && should_collect_unknown_extension(tls_cbarg, properties, exttype)) {
if ((ret = collect_unknown_extension(tls_cbarg, exttype, src, end, ch->unknown_extensions)) != 0)
goto Exit;
}
break;
}
src = end;
});
ret = 0;
Exit:
return ret;
}
static int rebuild_ch_inner_extensions(ptls_buffer_t *buf, const uint8_t **src, const uint8_t *const end, const uint8_t *outer_ext,
const uint8_t *outer_ext_end)
{
int ret;
ptls_buffer_push_block(buf, 2, {
ptls_decode_open_block(*src, end, 2, {
while (*src != end) {
uint16_t exttype;
if ((ret = ptls_decode16(&exttype, src, end)) != 0)
goto Exit;
ptls_decode_open_block(*src, end, 2, {
if (exttype == PTLS_EXTENSION_TYPE_ECH_OUTER_EXTENSIONS) {
ptls_decode_open_block(*src, end, 1, {
do {
uint16_t reftype;
uint16_t outertype;
uint16_t outersize;
if ((ret = ptls_decode16(&reftype, src, end)) != 0)
goto Exit;
if (reftype == PTLS_EXTENSION_TYPE_ENCRYPTED_CLIENT_HELLO) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
while (1) {
if (ptls_decode16(&outertype, &outer_ext, outer_ext_end) != 0 ||
ptls_decode16(&outersize, &outer_ext, outer_ext_end) != 0) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
assert(outer_ext_end - outer_ext >= outersize);
if (outertype == reftype)
break;
outer_ext += outersize;
}
buffer_push_extension(buf, reftype, {
ptls_buffer_pushv(buf, outer_ext, outersize);
outer_ext += outersize;
});
} while (*src != end);
});
} else {
buffer_push_extension(buf, exttype, {
ptls_buffer_pushv(buf, *src, end - *src);
*src = end;
});
}
});
}
});
});
Exit:
return ret;
}
static int rebuild_ch_inner(ptls_buffer_t *buf, const uint8_t *src, const uint8_t *const end,
struct st_ptls_client_hello_t *outer_ch, const uint8_t *outer_ext, const uint8_t *outer_ext_end)
{
#define COPY_BLOCK(capacity) \
do { \
ptls_decode_open_block(src, end, (capacity), { \
ptls_buffer_push_block(buf, (capacity), { ptls_buffer_pushv(buf, src, end - src); }); \
src = end; \
}); \
} while (0)
int ret;
ptls_buffer_push_message_body(buf, NULL, PTLS_HANDSHAKE_TYPE_CLIENT_HELLO, {
{ /* legacy_version */
uint16_t legacy_version;
if ((ret = ptls_decode16(&legacy_version, &src, end)) != 0)
goto Exit;
ptls_buffer_push16(buf, legacy_version);
}
/* hello random */
if (end - src < PTLS_HELLO_RANDOM_SIZE) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
ptls_buffer_pushv(buf, src, PTLS_HELLO_RANDOM_SIZE);
src += PTLS_HELLO_RANDOM_SIZE;
ptls_decode_open_block(src, end, 1, {
if (src != end) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
});
ptls_buffer_push_block(buf, 1,
{ ptls_buffer_pushv(buf, outer_ch->legacy_session_id.base, outer_ch->legacy_session_id.len); });
/* cipher-suites and legacy-compression-methods */
COPY_BLOCK(2);
COPY_BLOCK(1);
/* extensions */
if ((ret = rebuild_ch_inner_extensions(buf, &src, end, outer_ext, outer_ext_end)) != 0)
goto Exit;
});
/* padding must be all zero */
for (; src != end; ++src) {
if (*src != '\0') {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
}
Exit:
return ret;
#undef COPY_BLOCK
}
/* Wrapper function for invoking the on_client_hello callback, taking an exhaustive list of parameters as arguments. The intention
* is to not miss setting them as we add new parameters to the struct. */
static inline int call_on_client_hello_cb(ptls_t *tls, ptls_iovec_t server_name, ptls_iovec_t raw_message,
ptls_iovec_t cipher_suites, ptls_iovec_t *alpns, size_t num_alpns,
const uint16_t *sig_algos, size_t num_sig_algos, const uint16_t *cert_comp_algos,
size_t num_cert_comp_algos, const uint8_t *server_cert_types,
size_t num_server_cert_types, int incompatible_version)
{
if (tls->ctx->on_client_hello == NULL)
return 0;
ptls_on_client_hello_parameters_t params = {server_name,
raw_message,
cipher_suites,
{alpns, num_alpns},
{sig_algos, num_sig_algos},
{cert_comp_algos, num_cert_comp_algos},
{server_cert_types, num_server_cert_types},
incompatible_version};
return tls->ctx->on_client_hello->cb(tls->ctx->on_client_hello, tls, &params);
}
static int check_client_hello_constraints(ptls_context_t *ctx, struct st_ptls_client_hello_t *ch, const void *prev_random,
int ech_is_inner_ch, ptls_iovec_t raw_message, ptls_t *tls_cbarg)
{
int is_second_flight = prev_random != 0;
/* The following check is necessary so that we would be able to track the connection in SSLKEYLOGFILE, even though it might not
* be for the safety of the protocol. */
if (is_second_flight && !ptls_mem_equal(ch->random_bytes, prev_random, PTLS_HELLO_RANDOM_SIZE))
return PTLS_ALERT_HANDSHAKE_FAILURE;
/* bail out if CH cannot be handled as TLS 1.3 */
if (!is_supported_version(ch->selected_version)) {
/* ECH: server MUST abort with an "illegal_parameter" alert if the client offers TLS 1.2 or below (draft-15 7.1) */
if (ech_is_inner_ch)
return PTLS_ALERT_ILLEGAL_PARAMETER;
/* fail with PROTOCOL_VERSION alert, after providing the applications the raw CH and SNI to help them fallback */
if (!is_second_flight) {
int ret;
if ((ret = call_on_client_hello_cb(tls_cbarg, ch->server_name, raw_message, ch->cipher_suites, ch->alpn.list,
ch->alpn.count, NULL, 0, NULL, 0, NULL, 0, 1)) != 0)
return ret;
}
return PTLS_ALERT_PROTOCOL_VERSION;
}
/* Check TLS 1.3-specific constraints. Hereafter, we might exit without calling on_client_hello. That's fine because this CH is
* ought to be rejected. */
if (ch->legacy_version <= 0x0300) {
/* RFC 8446 Appendix D.5: any endpoint receiving a Hello message with legacy_version set to 0x0300 MUST abort the handshake
* with a "protocol_version" alert. */
return PTLS_ALERT_PROTOCOL_VERSION;
}
if (!(ch->compression_methods.count == 1 && ch->compression_methods.ids[0] == 0))
return PTLS_ALERT_ILLEGAL_PARAMETER;
/* pre-shared key */
if (ch->psk.hash_end != NULL) {
/* PSK must be the last extension */
if (!ch->psk.is_last_extension)
return PTLS_ALERT_ILLEGAL_PARAMETER;
} else {
if (ch->psk.early_data_indication)
return PTLS_ALERT_ILLEGAL_PARAMETER;
}
if (ech_is_inner_ch && ch->ech.payload.base == NULL)
return PTLS_ALERT_ILLEGAL_PARAMETER;
if (ch->ech.payload.base != NULL &&
ch->ech.type != (ech_is_inner_ch ? PTLS_ECH_CLIENT_HELLO_TYPE_INNER : PTLS_ECH_CLIENT_HELLO_TYPE_OUTER))
return PTLS_ALERT_ILLEGAL_PARAMETER;
return 0;
}
static int vec_is_string(ptls_iovec_t x, const char *y)
{
return strncmp((const char *)x.base, y, x.len) == 0 && y[x.len] == '\0';
}
static int try_psk_handshake(ptls_t *tls, size_t *psk_index, int *accept_early_data, struct st_ptls_client_hello_t *ch,
ptls_iovec_t ch_trunc)
{
ptls_buffer_t decbuf;
ptls_iovec_t ticket_psk, ticket_server_name, ticket_negotiated_protocol;
uint64_t issue_at, now = tls->ctx->get_time->cb(tls->ctx->get_time);
uint32_t age_add;
uint16_t ticket_key_exchange_id, ticket_csid;
uint8_t binder_key[PTLS_MAX_DIGEST_SIZE];
int ret;
ptls_buffer_init(&decbuf, "", 0);
for (*psk_index = 0; *psk_index < ch->psk.identities.count; ++*psk_index) {
struct st_ptls_client_hello_psk_t *identity = ch->psk.identities.list + *psk_index;
/* decrypt and decode */
int can_accept_early_data = 1;
decbuf.off = 0;
switch (tls->ctx->encrypt_ticket->cb(tls->ctx->encrypt_ticket, tls, 0, &decbuf, identity->identity)) {
case 0: /* decrypted */
break;
case PTLS_ERROR_REJECT_EARLY_DATA: /* decrypted, but early data is rejected */
can_accept_early_data = 0;
break;
default: /* decryption failure */
continue;
}
if (decode_session_identifier(&issue_at, &ticket_psk, &age_add, &ticket_server_name, &ticket_key_exchange_id, &ticket_csid,
&ticket_negotiated_protocol, decbuf.base, decbuf.base + decbuf.off) != 0)
continue;
/* check age */
if (now < issue_at)
continue;
if (now - issue_at > (uint64_t)tls->ctx->ticket_lifetime * 1000)
continue;
*accept_early_data = 0;
if (ch->psk.early_data_indication && can_accept_early_data) {
/* accept early-data if abs(diff) between the reported age and the actual age is within += 10 seconds */
int64_t delta = (now - issue_at) - (identity->obfuscated_ticket_age - age_add);
if (delta < 0)
delta = -delta;
if (tls->ctx->max_early_data_size != 0 && delta <= PTLS_EARLY_DATA_MAX_DELAY)
*accept_early_data = 1;
}
/* check server-name */
if (ticket_server_name.len != 0) {
if (tls->server_name == NULL)
continue;
if (!vec_is_string(ticket_server_name, tls->server_name))
continue;
} else {
if (tls->server_name != NULL)
continue;
}
{ /* check key-exchange */
ptls_key_exchange_algorithm_t **a;
for (a = tls->ctx->key_exchanges; *a != NULL && (*a)->id != ticket_key_exchange_id; ++a)
;
if (*a == NULL)
continue;
tls->key_share = *a;
}
/* check cipher-suite */
if (ticket_csid != tls->cipher_suite->id)
continue;
/* check negotiated-protocol */
if (ticket_negotiated_protocol.len != 0) {
if (tls->negotiated_protocol == NULL)
continue;
if (!vec_is_string(ticket_negotiated_protocol, tls->negotiated_protocol))
continue;
}
/* check the length of the decrypted psk and the PSK binder */
if (ticket_psk.len != tls->key_schedule->hashes[0].algo->digest_size)
continue;
if (ch->psk.identities.list[*psk_index].binder.len != tls->key_schedule->hashes[0].algo->digest_size)
continue;
/* found */
goto Found;
}
/* not found */
*psk_index = SIZE_MAX;
*accept_early_data = 0;
tls->key_share = NULL;
ret = 0;
goto Exit;
Found:
if ((ret = key_schedule_extract(tls->key_schedule, ticket_psk)) != 0)
goto Exit;
if ((ret = derive_secret(tls->key_schedule, binder_key, "res binder")) != 0)
goto Exit;
ptls__key_schedule_update_hash(tls->key_schedule, ch_trunc.base, ch_trunc.len, 0);
if ((ret = calc_verify_data(binder_key /* to conserve space, reuse binder_key for storing verify_data */, tls->key_schedule,
binder_key)) != 0)
goto Exit;
if (!ptls_mem_equal(ch->psk.identities.list[*psk_index].binder.base, binder_key,
tls->key_schedule->hashes[0].algo->digest_size)) {
ret = PTLS_ALERT_DECRYPT_ERROR;
goto Exit;
}
ret = 0;
Exit:
ptls_buffer_dispose(&decbuf);
ptls_clear_memory(binder_key, sizeof(binder_key));
return ret;
}
static int calc_cookie_signature(ptls_t *tls, ptls_handshake_properties_t *properties,
ptls_key_exchange_algorithm_t *negotiated_group, ptls_iovec_t tbs, uint8_t *sig)
{
ptls_hash_algorithm_t *algo = tls->ctx->cipher_suites[0]->hash;
ptls_hash_context_t *hctx;
if ((hctx = ptls_hmac_create(algo, properties->server.cookie.key, algo->digest_size)) == NULL)
return PTLS_ERROR_NO_MEMORY;
#define UPDATE_BLOCK(p, _len) \
do { \
size_t len = (_len); \
assert(len < UINT8_MAX); \
uint8_t len8 = (uint8_t)len; \
hctx->update(hctx, &len8, 1); \
hctx->update(hctx, (p), len); \
} while (0)
#define UPDATE16(_v) \
do { \
uint16_t v = (_v); \
uint8_t b[2] = {v >> 8, v & 0xff}; \
hctx->update(hctx, b, 2); \
} while (0)
UPDATE_BLOCK(tls->client_random, sizeof(tls->client_random));
UPDATE_BLOCK(tls->server_name, tls->server_name != NULL ? strlen(tls->server_name) : 0);
UPDATE16(tls->cipher_suite->id);
UPDATE16(negotiated_group->id);
UPDATE_BLOCK(properties->server.cookie.additional_data.base, properties->server.cookie.additional_data.len);
UPDATE_BLOCK(tbs.base, tbs.len);
#undef UPDATE_BLOCK
#undef UPDATE16
hctx->final(hctx, sig, PTLS_HASH_FINAL_MODE_FREE);
return 0;
}
static int certificate_type_exists(uint8_t *list, size_t count, uint8_t desired_type)
{
/* empty type list means that we default to x509 */
if (desired_type == PTLS_CERTIFICATE_TYPE_X509 && count == 0)
return 1;
for (size_t i = 0; i < count; i++) {
if (list[i] == desired_type)
return 1;
}
return 0;
}
static int server_handle_hello(ptls_t *tls, ptls_message_emitter_t *emitter, ptls_iovec_t message,
ptls_handshake_properties_t *properties)
{
#define EMIT_SERVER_HELLO(sched, fill_rand, extensions, post_action) \
do { \
size_t sh_start_off; \
ptls_push_message(emitter, NULL, PTLS_HANDSHAKE_TYPE_SERVER_HELLO, { \
sh_start_off = emitter->buf->off - PTLS_HANDSHAKE_HEADER_SIZE; \
ptls_buffer_push16(emitter->buf, 0x0303 /* legacy version */); \
if ((ret = ptls_buffer_reserve(emitter->buf, PTLS_HELLO_RANDOM_SIZE)) != 0) \
goto Exit; \
do { \
fill_rand \
} while (0); \
emitter->buf->off += PTLS_HELLO_RANDOM_SIZE; \
ptls_buffer_push_block(emitter->buf, 1, \
{ ptls_buffer_pushv(emitter->buf, ch->legacy_session_id.base, ch->legacy_session_id.len); }); \
ptls_buffer_push16(emitter->buf, tls->cipher_suite->id); \
ptls_buffer_push(emitter->buf, 0); \
ptls_buffer_push_block(emitter->buf, 2, { \
buffer_push_extension(emitter->buf, PTLS_EXTENSION_TYPE_SUPPORTED_VERSIONS, \
{ ptls_buffer_push16(emitter->buf, ch->selected_version); }); \
do { \
extensions \
} while (0); \
}); \
}); \
do { \
post_action \
} while (0); \
ptls__key_schedule_update_hash((sched), emitter->buf->base + sh_start_off, emitter->buf->off - sh_start_off, 0); \
} while (0)
#define EMIT_HELLO_RETRY_REQUEST(sched, negotiated_group, additional_extensions, post_action) \
EMIT_SERVER_HELLO((sched), { memcpy(emitter->buf->base + emitter->buf->off, hello_retry_random, PTLS_HELLO_RANDOM_SIZE); }, \
{ \
ptls_key_exchange_algorithm_t *_negotiated_group = (negotiated_group); \
if (_negotiated_group != NULL) { \
buffer_push_extension(emitter->buf, PTLS_EXTENSION_TYPE_KEY_SHARE, \
{ ptls_buffer_push16(emitter->buf, _negotiated_group->id); }); \
} \
do { \
additional_extensions \
} while (0); \
}, \
post_action)
struct st_ptls_client_hello_t *ch;
struct {
ptls_key_exchange_algorithm_t *algorithm;
ptls_iovec_t peer_key;
} key_share = {NULL};
struct {
uint8_t *encoded_ch_inner;
uint8_t *ch_outer_aad;
ptls_buffer_t ch_inner;
} ech = {NULL};
enum { HANDSHAKE_MODE_FULL, HANDSHAKE_MODE_PSK, HANDSHAKE_MODE_PSK_DHE } mode;
size_t psk_index = SIZE_MAX;
ptls_iovec_t pubkey = {0}, ecdh_secret = {0};
int accept_early_data = 0, is_second_flight = tls->state == PTLS_STATE_SERVER_EXPECT_SECOND_CLIENT_HELLO, ret;
ptls_buffer_init(&ech.ch_inner, "", 0);
if ((ch = malloc(sizeof(*ch))) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
*ch = (struct st_ptls_client_hello_t){.unknown_extensions = {{UINT16_MAX}}};
/* decode ClientHello */
if ((ret = decode_client_hello(tls->ctx, ch, message.base + PTLS_HANDSHAKE_HEADER_SIZE, message.base + message.len, properties,
tls)) != 0)
goto Exit;
if ((ret = check_client_hello_constraints(tls->ctx, ch, is_second_flight ? tls->client_random : NULL, 0, message, tls)) != 0)
goto Exit;
if (!is_second_flight) {
memcpy(tls->client_random, ch->random_bytes, PTLS_HELLO_RANDOM_SIZE);
log_client_random(tls);
} else {
/* consistency check for ECH extension in response to HRR */
if (tls->ech.aead != NULL) {
if (ch->ech.payload.base == NULL) {
ret = PTLS_ALERT_MISSING_EXTENSION;
goto Exit;
}
if (!(ch->ech.config_id == tls->ech.config_id && ch->ech.cipher_suite.kdf == tls->ech.cipher->id.kdf &&
ch->ech.cipher_suite.aead == tls->ech.cipher->id.aead && ch->ech.enc.len == 0)) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
}
}
/* ECH */
if (ch->ech.payload.base != NULL) {
if (ch->ech.type != PTLS_ECH_CLIENT_HELLO_TYPE_OUTER) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
if (!is_second_flight)
tls->ech.offered = 1;
/* obtain AEAD context for opening inner CH */
if (!is_second_flight && ch->ech.payload.base != NULL && tls->ctx->ech.server.create_opener != NULL) {
if ((tls->ech.aead = tls->ctx->ech.server.create_opener->cb(
tls->ctx->ech.server.create_opener, &tls->ech.kem, &tls->ech.cipher, tls, ch->ech.config_id,
ch->ech.cipher_suite, ch->ech.enc, ptls_iovec_init(ech_info_prefix, sizeof(ech_info_prefix)))) != NULL)
tls->ech.config_id = ch->ech.config_id;
}
if (!is_second_flight) {
PTLS_PROBE(ECH_SELECTION, tls, tls->ech.aead != NULL);
PTLS_LOG_CONN(ech_selection, tls, { PTLS_LOG_ELEMENT_BOOL(is_ech, tls->ech.aead != NULL); });
}
if (tls->ech.aead != NULL) {
/* now that AEAD context is available, create AAD and decrypt inner CH */
if ((ech.encoded_ch_inner = malloc(ch->ech.payload.len - tls->ech.aead->algo->tag_size)) == NULL ||
(ech.ch_outer_aad = malloc(message.len - PTLS_HANDSHAKE_HEADER_SIZE)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
memcpy(ech.ch_outer_aad, message.base + PTLS_HANDSHAKE_HEADER_SIZE, message.len - PTLS_HANDSHAKE_HEADER_SIZE);
memset(ech.ch_outer_aad + (ch->ech.payload.base - (message.base + PTLS_HANDSHAKE_HEADER_SIZE)), 0, ch->ech.payload.len);
if (ptls_aead_decrypt(tls->ech.aead, ech.encoded_ch_inner, ch->ech.payload.base, ch->ech.payload.len, is_second_flight,
ech.ch_outer_aad, message.len - PTLS_HANDSHAKE_HEADER_SIZE) != SIZE_MAX) {
tls->ech.accepted = 1;
/* successfully decrypted EncodedCHInner, build CHInner */
if ((ret = rebuild_ch_inner(&ech.ch_inner, ech.encoded_ch_inner,
ech.encoded_ch_inner + ch->ech.payload.len - tls->ech.aead->algo->tag_size, ch,
message.base + PTLS_HANDSHAKE_HEADER_SIZE + ch->first_extension_at,
message.base + message.len)) != 0)
goto Exit;
/* treat inner ch as the message being received, re-decode it */
message = ptls_iovec_init(ech.ch_inner.base, ech.ch_inner.off);
*ch = (struct st_ptls_client_hello_t){.unknown_extensions = {{UINT16_MAX}}};
if ((ret = decode_client_hello(tls->ctx, ch, ech.ch_inner.base + PTLS_HANDSHAKE_HEADER_SIZE,
ech.ch_inner.base + ech.ch_inner.off, properties, tls)) != 0)
goto Exit;
if ((ret = check_client_hello_constraints(tls->ctx, ch, is_second_flight ? tls->ech.inner_client_random : NULL, 1,
message, tls)) != 0)
goto Exit;
if (!is_second_flight)
memcpy(tls->ech.inner_client_random, ch->random_bytes, PTLS_HELLO_RANDOM_SIZE);
} else if (is_second_flight) {
/* decryption failure of inner CH in 2nd CH is fatal */
ret = PTLS_ALERT_DECRYPT_ERROR;
goto Exit;
} else {
/* decryption failure of 1st CH indicates key mismatch; dispose of AEAD context to indicate adoption of outerCH */
ptls_aead_free(tls->ech.aead);
tls->ech.aead = NULL;
}
}
} else if (tls->ech.offered) {
assert(is_second_flight);
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
if (tls->ctx->require_dhe_on_psk)
ch->psk.ke_modes &= ~(1u << PTLS_PSK_KE_MODE_PSK);
/* handle client_random, legacy_session_id, SNI, ESNI */
if (!is_second_flight) {
if (ch->legacy_session_id.len != 0)
tls->send_change_cipher_spec = 1;
ptls_iovec_t server_name = {NULL};
if (ch->server_name.base != NULL)
server_name = ch->server_name;
if ((ret = call_on_client_hello_cb(tls, server_name, message, ch->cipher_suites, ch->alpn.list, ch->alpn.count,
ch->signature_algorithms.list, ch->signature_algorithms.count,
ch->cert_compression_algos.list, ch->cert_compression_algos.count,
ch->server_certificate_types.list, ch->server_certificate_types.count, 0)) != 0)
goto Exit;
if (!certificate_type_exists(ch->server_certificate_types.list, ch->server_certificate_types.count,
tls->ctx->use_raw_public_keys ? PTLS_CERTIFICATE_TYPE_RAW_PUBLIC_KEY
: PTLS_CERTIFICATE_TYPE_X509)) {
ret = PTLS_ALERT_UNSUPPORTED_CERTIFICATE;
goto Exit;
}
} else {
if (ch->psk.early_data_indication) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
/* We compare SNI only when the value is saved by the on_client_hello callback. This should be OK because we are
* ignoring the value unless the callback saves the server-name. */
if (tls->server_name != NULL) {
size_t l = strlen(tls->server_name);
if (!(ch->server_name.len == l && memcmp(ch->server_name.base, tls->server_name, l) == 0)) {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
goto Exit;
}
}
}
{ /* select (or check) cipher-suite, create key_schedule */
ptls_cipher_suite_t *cs;
if ((ret = select_cipher(&cs, tls->ctx->cipher_suites, ch->cipher_suites.base,
ch->cipher_suites.base + ch->cipher_suites.len, tls->ctx->server_cipher_preference, tls->ctx->server_cipher_chacha_priority)) != 0)
goto Exit;
if (!is_second_flight) {
tls->cipher_suite = cs;
if ((tls->key_schedule = key_schedule_new(cs, NULL, 0)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
} else {
if (tls->cipher_suite != cs) {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
goto Exit;
}
}
}
/* select key_share */
if (key_share.algorithm == NULL && ch->key_shares.base != NULL) {
const uint8_t *src = ch->key_shares.base, *const end = src + ch->key_shares.len;
ptls_decode_block(src, end, 2, {
if ((ret = select_key_share(&key_share.algorithm, &key_share.peer_key, tls->ctx->key_exchanges, &src, end, 0)) != 0)
goto Exit;
});
}
if (!is_second_flight) {
if (ch->cookie.all.len != 0 && key_share.algorithm != NULL) {
{ /* use cookie to check the integrity of the handshake, and update the context */
uint8_t sig[PTLS_MAX_DIGEST_SIZE];
size_t sigsize = tls->ctx->cipher_suites[0]->hash->digest_size;
if ((ret = calc_cookie_signature(tls, properties, key_share.algorithm, ch->cookie.tbs, sig)) != 0)
goto Exit;
if (!(ch->cookie.signature.len == sigsize && ptls_mem_equal(ch->cookie.signature.base, sig, sigsize))) {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
goto Exit;
}
}
/* integrity check passed; update states */
key_schedule_update_ch1hash_prefix(tls->key_schedule);
ptls__key_schedule_update_hash(tls->key_schedule, ch->cookie.ch1_hash.base, ch->cookie.ch1_hash.len, 0);
key_schedule_extract(tls->key_schedule, ptls_iovec_init(NULL, 0));
/* ... reusing sendbuf to rebuild HRR for hash calculation */
size_t hrr_start = emitter->buf->off;
EMIT_HELLO_RETRY_REQUEST(tls->key_schedule, ch->cookie.sent_key_share ? key_share.algorithm : NULL,
{
buffer_push_extension(emitter->buf, PTLS_EXTENSION_TYPE_COOKIE, {
ptls_buffer_pushv(emitter->buf, ch->cookie.all.base, ch->cookie.all.len);
});
},
{});
emitter->buf->off = hrr_start;
is_second_flight = 1;
} else if (key_share.algorithm == NULL || (properties != NULL && properties->server.enforce_retry)) {
/* send HelloRetryRequest */
if (ch->negotiated_groups.base == NULL) {
ret = PTLS_ALERT_MISSING_EXTENSION;
goto Exit;
}
ptls_key_exchange_algorithm_t *negotiated_group;
if ((ret = select_negotiated_group(&negotiated_group, tls->ctx->key_exchanges, ch->negotiated_groups.base,
ch->negotiated_groups.base + ch->negotiated_groups.len)) != 0)
goto Exit;
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
assert(tls->key_schedule->generation == 0);
/* Either send a stateless retry (w. cookies) or a stateful one. When sending the latter, run the state machine. At the
* moment, stateless retry is disabled when ECH is used (do we need to support it?). */
int retry_uses_cookie =
properties != NULL && properties->server.retry_uses_cookie && !ptls_is_ech_handshake(tls, NULL, NULL, NULL);
if (!retry_uses_cookie) {
key_schedule_transform_post_ch1hash(tls->key_schedule);
key_schedule_extract(tls->key_schedule, ptls_iovec_init(NULL, 0));
}
size_t ech_confirm_off = 0;
EMIT_HELLO_RETRY_REQUEST(
tls->key_schedule, key_share.algorithm != NULL ? NULL : negotiated_group,
{
ptls_buffer_t *sendbuf = emitter->buf;
if (ptls_is_ech_handshake(tls, NULL, NULL, NULL)) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_ENCRYPTED_CLIENT_HELLO, {
if ((ret = ptls_buffer_reserve(sendbuf, PTLS_ECH_CONFIRM_LENGTH)) != 0)
goto Exit;
memset(sendbuf->base + sendbuf->off, 0, PTLS_ECH_CONFIRM_LENGTH);
ech_confirm_off = sendbuf->off;
sendbuf->off += PTLS_ECH_CONFIRM_LENGTH;
});
}
if (retry_uses_cookie) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_COOKIE, {
ptls_buffer_push_block(sendbuf, 2, {
/* push to-be-signed data */
size_t tbs_start = sendbuf->off;
ptls_buffer_push_block(sendbuf, 2, {
/* first block of the cookie data is the hash(ch1) */
ptls_buffer_push_block(sendbuf, 1, {
size_t sz = tls->cipher_suite->hash->digest_size;
if ((ret = ptls_buffer_reserve(sendbuf, sz)) != 0)
goto Exit;
key_schedule_extract_ch1hash(tls->key_schedule, sendbuf->base + sendbuf->off);
sendbuf->off += sz;
});
/* second is if we have sent key_share extension */
ptls_buffer_push(sendbuf, key_share.algorithm == NULL);
/* we can add more data here */
});
size_t tbs_len = sendbuf->off - tbs_start;
/* push the signature */
ptls_buffer_push_block(sendbuf, 1, {
size_t sz = tls->ctx->cipher_suites[0]->hash->digest_size;
if ((ret = ptls_buffer_reserve(sendbuf, sz)) != 0)
goto Exit;
if ((ret = calc_cookie_signature(tls, properties, negotiated_group,
ptls_iovec_init(sendbuf->base + tbs_start, tbs_len),
sendbuf->base + sendbuf->off)) != 0)
goto Exit;
sendbuf->off += sz;
});
});
});
}
},
{
if (ech_confirm_off != 0 &&
(ret = ech_calc_confirmation(
tls->key_schedule, emitter->buf->base + ech_confirm_off, tls->ech.inner_client_random,
ECH_CONFIRMATION_HRR,
ptls_iovec_init(emitter->buf->base + sh_start_off, emitter->buf->off - sh_start_off))) != 0)
goto Exit;
});
if (retry_uses_cookie) {
if ((ret = push_change_cipher_spec(tls, emitter)) != 0)
goto Exit;
ret = PTLS_ERROR_STATELESS_RETRY;
} else {
tls->state = PTLS_STATE_SERVER_EXPECT_SECOND_CLIENT_HELLO;
if (ch->psk.early_data_indication)
tls->server.early_data_skipped_bytes = 0;
ret = PTLS_ERROR_IN_PROGRESS;
}
goto Exit;
}
}
/* handle unknown extensions */
if ((ret = report_unknown_extensions(tls, properties, ch->unknown_extensions)) != 0)
goto Exit;
/* try psk handshake */
if (!is_second_flight && ch->psk.hash_end != 0 &&
(ch->psk.ke_modes & ((1u << PTLS_PSK_KE_MODE_PSK) | (1u << PTLS_PSK_KE_MODE_PSK_DHE))) != 0 &&
tls->ctx->encrypt_ticket != NULL && !tls->ctx->require_client_authentication) {
if ((ret = try_psk_handshake(tls, &psk_index, &accept_early_data, ch,
ptls_iovec_init(message.base, ch->psk.hash_end - message.base))) != 0) {
goto Exit;
}
}
/* If client authentication is enabled, we always force a full handshake.
* TODO: Check for `post_handshake_auth` extension and if that is present, do not force full handshake!
* Remove also the check `!require_client_authentication` above.
*
* adjust key_schedule, determine handshake mode
*/
if (psk_index == SIZE_MAX || tls->ctx->require_client_authentication) {
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
if (!is_second_flight) {
assert(tls->key_schedule->generation == 0);
key_schedule_extract(tls->key_schedule, ptls_iovec_init(NULL, 0));
}
mode = HANDSHAKE_MODE_FULL;
if (properties != NULL)
properties->server.selected_psk_binder.len = 0;
} else {
ptls__key_schedule_update_hash(tls->key_schedule, ch->psk.hash_end, message.base + message.len - ch->psk.hash_end, 0);
if ((ch->psk.ke_modes & (1u << PTLS_PSK_KE_MODE_PSK)) != 0) {
mode = HANDSHAKE_MODE_PSK;
} else {
assert((ch->psk.ke_modes & (1u << PTLS_PSK_KE_MODE_PSK_DHE)) != 0);
mode = HANDSHAKE_MODE_PSK_DHE;
}
tls->is_psk_handshake = 1;
if (properties != NULL) {
ptls_iovec_t *selected = &ch->psk.identities.list[psk_index].binder;
memcpy(properties->server.selected_psk_binder.base, selected->base, selected->len);
properties->server.selected_psk_binder.len = selected->len;
}
}
tls->server.can_send_session_ticket = ch->psk.ke_modes != 0;
if (accept_early_data && tls->ctx->max_early_data_size != 0 && psk_index == 0) {
if ((tls->pending_handshake_secret = malloc(PTLS_MAX_DIGEST_SIZE)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
if ((ret = derive_exporter_secret(tls, 1)) != 0)
goto Exit;
if ((ret = setup_traffic_protection(tls, 0, "c e traffic", 1, 0)) != 0)
goto Exit;
}
/* run key-exchange, to obtain pubkey and secret */
if (mode != HANDSHAKE_MODE_PSK) {
if (key_share.algorithm == NULL) {
ret = ch->key_shares.base != NULL ? PTLS_ALERT_HANDSHAKE_FAILURE : PTLS_ALERT_MISSING_EXTENSION;
goto Exit;
}
if ((ret = key_share.algorithm->exchange(key_share.algorithm, &pubkey, &ecdh_secret, key_share.peer_key)) != 0)
goto Exit;
tls->key_share = key_share.algorithm;
}
{ /* send ServerHello */
size_t ech_confirm_off = 0;
EMIT_SERVER_HELLO(
tls->key_schedule,
{
tls->ctx->random_bytes(emitter->buf->base + emitter->buf->off, PTLS_HELLO_RANDOM_SIZE);
/* when accepting CHInner, last 8 byte of SH.random is zero for the handshake transcript */
if (ptls_is_ech_handshake(tls, NULL, NULL, NULL)) {
ech_confirm_off = emitter->buf->off + PTLS_HELLO_RANDOM_SIZE - PTLS_ECH_CONFIRM_LENGTH;
memset(emitter->buf->base + ech_confirm_off, 0, PTLS_ECH_CONFIRM_LENGTH);
}
},
{
ptls_buffer_t *sendbuf = emitter->buf;
if (mode != HANDSHAKE_MODE_PSK) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_KEY_SHARE, {
ptls_buffer_push16(sendbuf, key_share.algorithm->id);
ptls_buffer_push_block(sendbuf, 2, { ptls_buffer_pushv(sendbuf, pubkey.base, pubkey.len); });
});
}
if (mode != HANDSHAKE_MODE_FULL) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_PRE_SHARED_KEY,
{ ptls_buffer_push16(sendbuf, (uint16_t)psk_index); });
}
},
{
if (ech_confirm_off != 0 &&
(ret = ech_calc_confirmation(
tls->key_schedule, emitter->buf->base + ech_confirm_off, tls->ech.inner_client_random,
ECH_CONFIRMATION_SERVER_HELLO,
ptls_iovec_init(emitter->buf->base + sh_start_off, emitter->buf->off - sh_start_off))) != 0)
goto Exit;
});
}
/* processing of ECH is complete; dispose state */
clear_ech(&tls->ech, 1);
if ((ret = push_change_cipher_spec(tls, emitter)) != 0)
goto Exit;
/* create protection contexts for the handshake */
assert(tls->key_schedule->generation == 1);
key_schedule_extract(tls->key_schedule, ecdh_secret);
if ((ret = setup_traffic_protection(tls, 1, "s hs traffic", 2, 0)) != 0)
goto Exit;
if (tls->pending_handshake_secret != NULL) {
if ((ret = derive_secret(tls->key_schedule, tls->pending_handshake_secret, "c hs traffic")) != 0)
goto Exit;
if (tls->ctx->update_traffic_key != NULL &&
(ret = tls->ctx->update_traffic_key->cb(tls->ctx->update_traffic_key, tls, 0, 2, tls->pending_handshake_secret)) != 0)
goto Exit;
} else {
if ((ret = setup_traffic_protection(tls, 0, "c hs traffic", 2, 0)) != 0)
goto Exit;
if (ch->psk.early_data_indication)
tls->server.early_data_skipped_bytes = 0;
}
/* send EncryptedExtensions */
ptls_push_message(emitter, tls->key_schedule, PTLS_HANDSHAKE_TYPE_ENCRYPTED_EXTENSIONS, {
ptls_buffer_t *sendbuf = emitter->buf;
ptls_buffer_push_block(sendbuf, 2, {
if (tls->server_name != NULL) {
/* In this event, the server SHALL include an extension of type "server_name" in the (extended) server hello.
* The "extension_data" field of this extension SHALL be empty. (RFC 6066 section 3) */
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SERVER_NAME, {});
}
if (tls->ctx->use_raw_public_keys) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SERVER_CERTIFICATE_TYPE,
{ ptls_buffer_push(sendbuf, PTLS_CERTIFICATE_TYPE_RAW_PUBLIC_KEY); });
}
if (tls->negotiated_protocol != NULL) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_ALPN, {
ptls_buffer_push_block(sendbuf, 2, {
ptls_buffer_push_block(sendbuf, 1, {
ptls_buffer_pushv(sendbuf, tls->negotiated_protocol, strlen(tls->negotiated_protocol));
});
});
});
}
if (tls->pending_handshake_secret != NULL)
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_EARLY_DATA, {});
/* send ECH retry_configs, if ECH was offered by rejected, even though we (the server) could have accepted ECH */
if (tls->ech.offered && !ptls_is_ech_handshake(tls, NULL, NULL, NULL) && tls->ctx->ech.server.create_opener != NULL &&
tls->ctx->ech.server.retry_configs.len != 0)
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_ENCRYPTED_CLIENT_HELLO, {
ptls_buffer_pushv(sendbuf, tls->ctx->ech.server.retry_configs.base, tls->ctx->ech.server.retry_configs.len);
});
if ((ret = push_additional_extensions(properties, sendbuf)) != 0)
goto Exit;
});
});
if (mode == HANDSHAKE_MODE_FULL) {
/* send certificate request if client authentication is activated */
if (tls->ctx->require_client_authentication) {
ptls_push_message(emitter, tls->key_schedule, PTLS_HANDSHAKE_TYPE_CERTIFICATE_REQUEST, {
/* certificate_request_context, this field SHALL be zero length, unless the certificate
* request is used for post-handshake authentication.
*/
ptls_buffer_t *sendbuf = emitter->buf;
ptls_buffer_push(sendbuf, 0);
/* extensions */
ptls_buffer_push_block(sendbuf, 2, {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SIGNATURE_ALGORITHMS, {
if ((ret = push_signature_algorithms(tls->ctx->verify_certificate, sendbuf)) != 0)
goto Exit;
});
});
});
if (ret != 0) {
goto Exit;
}
}
/* send certificate */
if ((ret = send_certificate(tls, emitter, &ch->signature_algorithms, ptls_iovec_init(NULL, 0), ch->status_request,
ch->cert_compression_algos.list, ch->cert_compression_algos.count)) != 0)
goto Exit;
/* send certificateverify, finished, and complete the handshake */
if ((ret = server_finish_handshake(tls, emitter, 1, &ch->signature_algorithms)) != 0)
goto Exit;
} else {
/* send finished, and complete the handshake */
if ((ret = server_finish_handshake(tls, emitter, 0, NULL)) != 0)
goto Exit;
}
Exit:
free(pubkey.base);
if (ecdh_secret.base != NULL) {
ptls_clear_memory(ecdh_secret.base, ecdh_secret.len);
free(ecdh_secret.base);
}
free(ech.encoded_ch_inner);
free(ech.ch_outer_aad);
ptls_buffer_dispose(&ech.ch_inner);
free(ch);
return ret;
#undef EMIT_SERVER_HELLO
#undef EMIT_HELLO_RETRY_REQUEST
}
static int server_finish_handshake(ptls_t *tls, ptls_message_emitter_t *emitter, int send_cert_verify,
struct st_ptls_signature_algorithms_t *signature_algorithms)
{
int ret;
if (send_cert_verify) {
if ((ret = send_certificate_verify(tls, emitter, signature_algorithms, PTLS_SERVER_CERTIFICATE_VERIFY_CONTEXT_STRING)) !=
0) {
if (ret == PTLS_ERROR_ASYNC_OPERATION) {
tls->state = PTLS_STATE_SERVER_GENERATING_CERTIFICATE_VERIFY;
}
goto Exit;
}
}
if ((ret = send_finished(tls, emitter)) != 0)
goto Exit;
assert(tls->key_schedule->generation == 2);
if ((ret = key_schedule_extract(tls->key_schedule, ptls_iovec_init(NULL, 0))) != 0)
goto Exit;
if ((ret = setup_traffic_protection(tls, 1, "s ap traffic", 3, 0)) != 0)
goto Exit;
if ((ret = derive_secret(tls->key_schedule, tls->server.pending_traffic_secret, "c ap traffic")) != 0)
goto Exit;
if ((ret = derive_exporter_secret(tls, 0)) != 0)
goto Exit;
if (tls->pending_handshake_secret != NULL) {
if (tls->ctx->omit_end_of_early_data) {
if ((ret = commission_handshake_secret(tls)) != 0)
goto Exit;
tls->state = PTLS_STATE_SERVER_EXPECT_FINISHED;
} else {
tls->state = PTLS_STATE_SERVER_EXPECT_END_OF_EARLY_DATA;
}
} else if (tls->ctx->require_client_authentication) {
tls->state = PTLS_STATE_SERVER_EXPECT_CERTIFICATE;
} else {
tls->state = PTLS_STATE_SERVER_EXPECT_FINISHED;
}
/* send session ticket if necessary */
if (tls->server.can_send_session_ticket && tls->ctx->ticket_lifetime != 0) {
if ((ret = send_session_ticket(tls, emitter)) != 0)
goto Exit;
}
if (tls->ctx->require_client_authentication) {
ret = PTLS_ERROR_IN_PROGRESS;
} else {
ret = 0;
}
Exit:
return ret;
}
static int server_handle_end_of_early_data(ptls_t *tls, ptls_iovec_t message)
{
int ret;
if ((ret = commission_handshake_secret(tls)) != 0)
goto Exit;
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
tls->state = PTLS_STATE_SERVER_EXPECT_FINISHED;
ret = PTLS_ERROR_IN_PROGRESS;
Exit:
return ret;
}
static int server_handle_finished(ptls_t *tls, ptls_iovec_t message)
{
int ret;
if ((ret = verify_finished(tls, message)) != 0)
return ret;
memcpy(tls->traffic_protection.dec.secret, tls->server.pending_traffic_secret, sizeof(tls->server.pending_traffic_secret));
ptls_clear_memory(tls->server.pending_traffic_secret, sizeof(tls->server.pending_traffic_secret));
if ((ret = setup_traffic_protection(tls, 0, NULL, 3, 0)) != 0)
return ret;
ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
tls->state = PTLS_STATE_SERVER_POST_HANDSHAKE;
return 0;
}
static int update_traffic_key(ptls_t *tls, int is_enc)
{
struct st_ptls_traffic_protection_t *tp = is_enc ? &tls->traffic_protection.enc : &tls->traffic_protection.dec;
uint8_t secret[PTLS_MAX_DIGEST_SIZE];
int ret;
ptls_hash_algorithm_t *hash = tls->key_schedule->hashes[0].algo;
if ((ret = ptls_hkdf_expand_label(hash, secret, hash->digest_size, ptls_iovec_init(tp->secret, hash->digest_size),
"traffic upd", ptls_iovec_init(NULL, 0), NULL)) != 0)
goto Exit;
memcpy(tp->secret, secret, sizeof(secret));
ret = setup_traffic_protection(tls, is_enc, NULL, 3, 1);
Exit:
ptls_clear_memory(secret, sizeof(secret));
return ret;
}
static int handle_key_update(ptls_t *tls, ptls_message_emitter_t *emitter, ptls_iovec_t message)
{
const uint8_t *src = message.base + PTLS_HANDSHAKE_HEADER_SIZE, *const end = message.base + message.len;
int ret;
/* validate */
if (end - src != 1 || *src > 1)
return PTLS_ALERT_DECODE_ERROR;
/* update receive key */
if ((ret = update_traffic_key(tls, 0)) != 0)
return ret;
if (*src) {
if (tls->ctx->update_traffic_key != NULL)
return PTLS_ALERT_UNEXPECTED_MESSAGE;
tls->needs_key_update = 1;
}
return 0;
}
static int parse_record_header(struct st_ptls_record_t *rec, const uint8_t *src)
{
rec->type = src[0];
rec->version = ntoh16(src + 1);
rec->length = ntoh16(src + 3);
if (rec->length >
(size_t)(rec->type == PTLS_CONTENT_TYPE_APPDATA ? PTLS_MAX_ENCRYPTED_RECORD_SIZE : PTLS_MAX_PLAINTEXT_RECORD_SIZE))
return PTLS_ALERT_DECODE_ERROR;
return 0;
}
static int parse_record(ptls_t *tls, struct st_ptls_record_t *rec, const uint8_t *src, size_t *len)
{
int ret;
assert(*len != 0);
/* Check if the first byte is something that we can handle, otherwise do not bother parsing / buffering the entire record as it
* is obviously broken. SSL 2.0 handshakes fall into this path as well. */
if (tls->recvbuf.rec.base == NULL) {
uint8_t type = src[0];
switch (type) {
case PTLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC:
case PTLS_CONTENT_TYPE_ALERT:
case PTLS_CONTENT_TYPE_HANDSHAKE:
case PTLS_CONTENT_TYPE_APPDATA:
break;
default:
return PTLS_ALERT_DECODE_ERROR;
}
}
if (tls->recvbuf.rec.base == NULL && *len >= 5) {
/* fast path */
if ((ret = parse_record_header(rec, src)) != 0)
return ret;
if (5 + rec->length <= *len) {
rec->fragment = src + 5;
*len = rec->length + 5;
return 0;
}
}
/* slow path */
const uint8_t *const end = src + *len;
*rec = (struct st_ptls_record_t){0};
if (tls->recvbuf.rec.base == NULL) {
ptls_buffer_init(&tls->recvbuf.rec, "", 0);
if ((ret = ptls_buffer_reserve(&tls->recvbuf.rec, 5)) != 0)
return ret;
}
/* fill and parse the header */
while (tls->recvbuf.rec.off < 5) {
if (src == end)
return PTLS_ERROR_IN_PROGRESS;
tls->recvbuf.rec.base[tls->recvbuf.rec.off++] = *src++;
}
if ((ret = parse_record_header(rec, tls->recvbuf.rec.base)) != 0)
return ret;
/* fill the fragment */
size_t addlen = rec->length + 5 - tls->recvbuf.rec.off;
if (addlen != 0) {
if ((ret = ptls_buffer_reserve(&tls->recvbuf.rec, addlen)) != 0)
return ret;
if (addlen > (size_t)(end - src))
addlen = end - src;
if (addlen != 0) {
memcpy(tls->recvbuf.rec.base + tls->recvbuf.rec.off, src, addlen);
tls->recvbuf.rec.off += addlen;
src += addlen;
}
}
/* set rec->fragment if a complete record has been parsed */
if (tls->recvbuf.rec.off == rec->length + 5) {
rec->fragment = tls->recvbuf.rec.base + 5;
ret = 0;
} else {
ret = PTLS_ERROR_IN_PROGRESS;
}
*len -= end - src;
return ret;
}
static void update_open_count(ptls_context_t *ctx, ssize_t delta)
{
if (ctx->update_open_count != NULL)
ctx->update_open_count->cb(ctx->update_open_count, delta);
}
static ptls_t *new_instance(ptls_context_t *ctx, int is_server)
{
ptls_t *tls;
assert(ctx->get_time != NULL && "please set ctx->get_time to `&ptls_get_time`; see #92");
if ((tls = malloc(sizeof(*tls))) == NULL)
return NULL;
update_open_count(ctx, 1);
*tls = (ptls_t){ctx};
tls->is_server = is_server;
tls->send_change_cipher_spec = ctx->send_change_cipher_spec;
tls->skip_tracing = ptls_default_skip_tracing;
return tls;
}
ptls_t *ptls_client_new(ptls_context_t *ctx)
{
ptls_t *tls = new_instance(ctx, 0);
tls->state = PTLS_STATE_CLIENT_HANDSHAKE_START;
tls->ctx->random_bytes(tls->client_random, sizeof(tls->client_random));
log_client_random(tls);
if (tls->send_change_cipher_spec) {
tls->client.legacy_session_id =
ptls_iovec_init(tls->client.legacy_session_id_buf, sizeof(tls->client.legacy_session_id_buf));
tls->ctx->random_bytes(tls->client.legacy_session_id.base, tls->client.legacy_session_id.len);
}
PTLS_PROBE(NEW, tls, 0);
PTLS_LOG_CONN(new, tls, { PTLS_LOG_ELEMENT_BOOL(is_server, 0); });
return tls;
}
ptls_t *ptls_server_new(ptls_context_t *ctx)
{
ptls_t *tls = new_instance(ctx, 1);
tls->state = PTLS_STATE_SERVER_EXPECT_CLIENT_HELLO;
tls->server.early_data_skipped_bytes = UINT32_MAX;
PTLS_PROBE(NEW, tls, 1);
PTLS_LOG_CONN(new, tls, { PTLS_LOG_ELEMENT_BOOL(is_server, 1); });
return tls;
}
static int export_tls12_params(ptls_buffer_t *output, int is_server, int session_reused, ptls_cipher_suite_t *cipher,
const void *client_random, const char *server_name, ptls_iovec_t negotiated_protocol,
const void *enc_key, const void *enc_iv, uint64_t enc_seq, uint64_t enc_record_iv,
const void *dec_key, const void *dec_iv, uint64_t dec_seq)
{
int ret;
ptls_buffer_push_block(output, 2, {
ptls_buffer_push(output, is_server);
ptls_buffer_push(output, session_reused);
ptls_buffer_push16(output, PTLS_PROTOCOL_VERSION_TLS12);
ptls_buffer_push16(output, cipher->id);
ptls_buffer_pushv(output, client_random, PTLS_HELLO_RANDOM_SIZE);
ptls_buffer_push_block(output, 2, {
size_t len = server_name != NULL ? strlen(server_name) : 0;
ptls_buffer_pushv(output, server_name, len);
});
ptls_buffer_push_block(output, 2, { ptls_buffer_pushv(output, negotiated_protocol.base, negotiated_protocol.len); });
ptls_buffer_push_block(output, 2, {
ptls_buffer_pushv(output, enc_key, cipher->aead->key_size);
ptls_buffer_pushv(output, enc_iv, cipher->aead->tls12.fixed_iv_size);
ptls_buffer_push64(output, enc_seq);
if (cipher->aead->tls12.record_iv_size != 0)
ptls_buffer_push64(output, enc_record_iv);
ptls_buffer_pushv(output, dec_key, cipher->aead->key_size);
ptls_buffer_pushv(output, dec_iv, cipher->aead->tls12.fixed_iv_size);
ptls_buffer_push64(output, dec_seq);
});
ptls_buffer_push_block(output, 2, {}); /* for future extensions */
});
Exit:
return ret;
}
int ptls_build_tls12_export_params(ptls_context_t *ctx, ptls_buffer_t *output, int is_server, int session_reused,
ptls_cipher_suite_t *cipher, const void *master_secret, const void *hello_randoms,
uint64_t next_send_record_iv, const char *server_name, ptls_iovec_t negotiated_protocol)
{
assert(cipher->aead->tls12.fixed_iv_size + cipher->aead->tls12.record_iv_size != 0 || !"given cipher-suite supports TLS/1.2");
uint8_t key_block[(PTLS_MAX_SECRET_SIZE + PTLS_MAX_IV_SIZE) * 2];
size_t key_block_len = (cipher->aead->key_size + cipher->aead->tls12.fixed_iv_size) * 2;
int ret;
assert(key_block_len <= sizeof(key_block));
/* generate key block */
if ((ret =
ptls_tls12_phash(cipher->hash, key_block, key_block_len, ptls_iovec_init(master_secret, PTLS_TLS12_MASTER_SECRET_SIZE),
"key expansion", ptls_iovec_init(hello_randoms, PTLS_HELLO_RANDOM_SIZE * 2))) != 0)
goto Exit;
/* determine key locations */
struct {
const void *key;
const void *iv;
} client_secret, server_secret, *enc_secret = is_server ? &server_secret : &client_secret,
*dec_secret = is_server ? &client_secret : &server_secret;
client_secret.key = key_block;
server_secret.key = key_block + cipher->aead->key_size;
client_secret.iv = key_block + cipher->aead->key_size * 2;
server_secret.iv = key_block + cipher->aead->key_size * 2 + cipher->aead->tls12.fixed_iv_size;
/* Serialize prams. Sequence number of the first application record is 1, because Finished is the only message sent after
* ChangeCipherSpec. */
ret = export_tls12_params(output, is_server, session_reused, cipher, (uint8_t *)hello_randoms + PTLS_HELLO_RANDOM_SIZE,
server_name, negotiated_protocol, enc_secret->key, enc_secret->iv, 1, next_send_record_iv,
dec_secret->key, dec_secret->iv, 1);
Exit:
ptls_clear_memory(key_block, sizeof(key_block));
return ret;
}
int ptls_export(ptls_t *tls, ptls_buffer_t *output)
{
/* TODO add tls13 support */
if (!tls->traffic_protection.enc.tls12)
return PTLS_ERROR_LIBRARY;
ptls_iovec_t negotiated_protocol =
ptls_iovec_init(tls->negotiated_protocol, tls->negotiated_protocol != NULL ? strlen(tls->negotiated_protocol) : 0);
return export_tls12_params(output, tls->is_server, tls->is_psk_handshake, tls->cipher_suite, tls->client_random,
tls->server_name, negotiated_protocol, tls->traffic_protection.enc.secret,
tls->traffic_protection.enc.secret + PTLS_MAX_SECRET_SIZE, tls->traffic_protection.enc.seq,
tls->traffic_protection.enc.tls12_enc_record_iv, tls->traffic_protection.dec.secret,
tls->traffic_protection.dec.secret + PTLS_MAX_SECRET_SIZE, tls->traffic_protection.dec.seq);
}
static int build_tls12_traffic_protection(ptls_t *tls, int is_enc, const uint8_t **src, const uint8_t *const end)
{
struct st_ptls_traffic_protection_t *tp = is_enc ? &tls->traffic_protection.enc : &tls->traffic_protection.dec;
if ((size_t)(end - *src) < tls->cipher_suite->aead->key_size + tls->cipher_suite->aead->tls12.fixed_iv_size + sizeof(uint64_t))
return PTLS_ALERT_DECODE_ERROR;
/* set properties */
memcpy(tp->secret, *src, tls->cipher_suite->aead->key_size);
*src += tls->cipher_suite->aead->key_size;
memcpy(tp->secret + PTLS_MAX_SECRET_SIZE, *src, tls->cipher_suite->aead->tls12.fixed_iv_size);
*src += tls->cipher_suite->aead->tls12.fixed_iv_size;
if (ptls_decode64(&tp->seq, src, end) != 0)
return PTLS_ALERT_DECODE_ERROR;
if (is_enc && tls->cipher_suite->aead->tls12.record_iv_size != 0) {
if (ptls_decode64(&tp->tls12_enc_record_iv, src, end) != 0)
return PTLS_ALERT_DECODE_ERROR;
}
tp->tls12 = 1;
/* instantiate aead */
if ((tp->aead = ptls_aead_new_direct(tls->cipher_suite->aead, is_enc, tp->secret, tp->secret + PTLS_MAX_SECRET_SIZE)) == NULL)
return PTLS_ERROR_NO_MEMORY;
return 0;
}
int ptls_import(ptls_context_t *ctx, ptls_t **tls, ptls_iovec_t params)
{
const uint8_t *src = params.base, *const end = src + params.len;
uint16_t protocol_version, csid;
int ret;
*tls = NULL;
/* TODO handle flags like psk_handshake, ech_handshake as we add support for TLS/1.3 import */
ptls_decode_block(src, end, 2, {
/* instantiate, based on the is_server flag */
if (end - src < 2) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
if ((*tls = new_instance(ctx, *src++)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
(*tls)->is_psk_handshake = *src++;
/* determine protocol version and cipher suite */
if ((ret = ptls_decode16(&protocol_version, &src, end)) != 0)
goto Exit;
if ((ret = ptls_decode16(&csid, &src, end)) != 0)
goto Exit;
(*tls)->cipher_suite = ptls_find_cipher_suite(ctx->tls12_cipher_suites, csid);
if ((*tls)->cipher_suite == NULL) {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
goto Exit;
}
/* other version-independent stuff */
if (end - src < PTLS_HELLO_RANDOM_SIZE) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
memcpy((*tls)->client_random, src, PTLS_HELLO_RANDOM_SIZE);
src += PTLS_HELLO_RANDOM_SIZE;
ptls_decode_open_block(src, end, 2, {
if (src != end) {
if ((ret = ptls_set_server_name(*tls, (const char *)src, end - src)) != 0)
goto Exit;
src = end;
}
});
ptls_decode_open_block(src, end, 2, {
if (src != end) {
if ((ret = ptls_set_negotiated_protocol(*tls, (const char *)src, end - src)) != 0)
goto Exit;
src = end;
}
});
/* version-dependent stuff */
ptls_decode_open_block(src, end, 2, {
switch (protocol_version) {
case PTLS_PROTOCOL_VERSION_TLS12:
/* setup AEAD keys */
if ((ret = build_tls12_traffic_protection(*tls, 1, &src, end)) != 0)
goto Exit;
if ((ret = build_tls12_traffic_protection(*tls, 0, &src, end)) != 0)
goto Exit;
break;
default:
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
break;
}
});
/* extensions */
ptls_decode_open_block(src, end, 2, {
src = end; /* unused */
});
});
(*tls)->state = ptls_is_server(*tls) ? PTLS_STATE_SERVER_POST_HANDSHAKE : PTLS_STATE_CLIENT_POST_HANDSHAKE;
Exit:
if (ret != 0) {
if (*tls != NULL) {
ptls_free(*tls);
*tls = NULL;
}
}
return ret;
}
void ptls_free(ptls_t *tls)
{
PTLS_PROBE0(FREE, tls);
PTLS_LOG_CONN(free, tls, {});
ptls_buffer_dispose(&tls->recvbuf.rec);
ptls_buffer_dispose(&tls->recvbuf.mess);
free_exporter_master_secret(tls, 1);
free_exporter_master_secret(tls, 0);
if (tls->key_schedule != NULL)
key_schedule_free(tls->key_schedule);
if (tls->traffic_protection.dec.aead != NULL)
ptls_aead_free(tls->traffic_protection.dec.aead);
if (tls->traffic_protection.enc.aead != NULL)
ptls_aead_free(tls->traffic_protection.enc.aead);
free(tls->server_name);
free(tls->negotiated_protocol);
clear_ech(&tls->ech, tls->is_server);
if (tls->is_server) {
if (tls->server.async_job != NULL)
tls->server.async_job->destroy_(tls->server.async_job);
} else {
if (tls->client.key_share_ctx != NULL)
tls->client.key_share_ctx->on_exchange(&tls->client.key_share_ctx, 1, NULL, ptls_iovec_init(NULL, 0));
if (tls->client.certificate_request.context.base != NULL)
free(tls->client.certificate_request.context.base);
}
if (tls->certificate_verify.cb != NULL)
tls->certificate_verify.cb(tls->certificate_verify.verify_ctx, 0, ptls_iovec_init(NULL, 0), ptls_iovec_init(NULL, 0));
if (tls->pending_handshake_secret != NULL) {
ptls_clear_memory(tls->pending_handshake_secret, PTLS_MAX_DIGEST_SIZE);
free(tls->pending_handshake_secret);
}
update_open_count(tls->ctx, -1);
ptls_clear_memory(tls, sizeof(*tls));
free(tls);
}
ptls_context_t *ptls_get_context(ptls_t *tls)
{
return tls->ctx;
}
void ptls_set_context(ptls_t *tls, ptls_context_t *ctx)
{
update_open_count(ctx, 1);
update_open_count(tls->ctx, -1);
tls->ctx = ctx;
}
ptls_async_job_t *ptls_get_async_job(ptls_t *tls)
{
return tls->server.async_job;
}
ptls_iovec_t ptls_get_client_random(ptls_t *tls)
{
return ptls_iovec_init(tls->client_random, PTLS_HELLO_RANDOM_SIZE);
}
ptls_cipher_suite_t *ptls_get_cipher(ptls_t *tls)
{
return tls->cipher_suite;
}
uint16_t ptls_get_protocol_version(ptls_t *tls)
{
if (tls->traffic_protection.enc.tls12)
return PTLS_PROTOCOL_VERSION_TLS12;
return PTLS_PROTOCOL_VERSION_TLS13;
}
int ptls_get_traffic_keys(ptls_t *tls, int is_enc, uint8_t *key, uint8_t *iv, uint64_t *seq)
{
struct st_ptls_traffic_protection_t *ctx = is_enc ? &tls->traffic_protection.enc : &tls->traffic_protection.dec;
int ret;
if ((ret = get_traffic_keys(tls->cipher_suite->aead, tls->cipher_suite->hash, key, iv, ctx->secret, ptls_iovec_init(NULL, 0),
NULL)) != 0)
return ret;
*seq = ctx->seq;
return 0;
}
const char *ptls_get_server_name(ptls_t *tls)
{
return tls->server_name;
}
int ptls_set_server_name(ptls_t *tls, const char *server_name, size_t server_name_len)
{
char *duped = NULL;
if (server_name != NULL &&
(duped = duplicate_as_str(server_name, server_name_len != 0 ? server_name_len : strlen(server_name))) == NULL)
return PTLS_ERROR_NO_MEMORY;
free(tls->server_name);
tls->server_name = duped;
return 0;
}
const char *ptls_get_negotiated_protocol(ptls_t *tls)
{
return tls->negotiated_protocol;
}
int ptls_set_negotiated_protocol(ptls_t *tls, const char *protocol, size_t protocol_len)
{
char *duped = NULL;
if (protocol != NULL && (duped = duplicate_as_str(protocol, protocol_len != 0 ? protocol_len : strlen(protocol))) == NULL)
return PTLS_ERROR_NO_MEMORY;
free(tls->negotiated_protocol);
tls->negotiated_protocol = duped;
return 0;
}
int ptls_handshake_is_complete(ptls_t *tls)
{
return tls->state >= PTLS_STATE_POST_HANDSHAKE_MIN;
}
int ptls_is_psk_handshake(ptls_t *tls)
{
return tls->is_psk_handshake;
}
int ptls_is_ech_handshake(ptls_t *tls, uint8_t *config_id, ptls_hpke_kem_t **kem, ptls_hpke_cipher_suite_t **cipher)
{
if (tls->ech.accepted) {
if (config_id != NULL)
*config_id = tls->ech.config_id;
if (kem != NULL)
*kem = tls->ech.kem;
if (cipher != NULL)
*cipher = tls->ech.cipher;
return 1;
}
return 0;
}
void **ptls_get_data_ptr(ptls_t *tls)
{
return &tls->data_ptr;
}
int ptls_skip_tracing(ptls_t *tls)
{
return tls->skip_tracing;
}
void ptls_set_skip_tracing(ptls_t *tls, int skip_tracing)
{
tls->skip_tracing = skip_tracing;
}
static int handle_client_handshake_message(ptls_t *tls, ptls_message_emitter_t *emitter, ptls_iovec_t message, int is_end_of_record,
ptls_handshake_properties_t *properties)
{
uint8_t type = message.base[0];
int ret;
switch (tls->state) {
case PTLS_STATE_CLIENT_EXPECT_SERVER_HELLO:
case PTLS_STATE_CLIENT_EXPECT_SECOND_SERVER_HELLO:
if (type == PTLS_HANDSHAKE_TYPE_SERVER_HELLO && is_end_of_record) {
ret = client_handle_hello(tls, emitter, message, properties);
} else {
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
}
break;
case PTLS_STATE_CLIENT_EXPECT_ENCRYPTED_EXTENSIONS:
if (type == PTLS_HANDSHAKE_TYPE_ENCRYPTED_EXTENSIONS) {
ret = client_handle_encrypted_extensions(tls, message, properties);
} else {
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
}
break;
case PTLS_STATE_CLIENT_EXPECT_CERTIFICATE_REQUEST_OR_CERTIFICATE:
if (type == PTLS_HANDSHAKE_TYPE_CERTIFICATE_REQUEST) {
ret = client_handle_certificate_request(tls, message, properties);
break;
}
/* fall through */
case PTLS_STATE_CLIENT_EXPECT_CERTIFICATE:
switch (type) {
case PTLS_HANDSHAKE_TYPE_CERTIFICATE:
ret = client_handle_certificate(tls, message);
break;
case PTLS_HANDSHAKE_TYPE_COMPRESSED_CERTIFICATE:
ret = client_handle_compressed_certificate(tls, message);
break;
default:
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
break;
}
break;
case PTLS_STATE_CLIENT_EXPECT_CERTIFICATE_VERIFY:
if (type == PTLS_HANDSHAKE_TYPE_CERTIFICATE_VERIFY) {
ret = client_handle_certificate_verify(tls, message);
} else {
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
}
break;
case PTLS_STATE_CLIENT_EXPECT_FINISHED:
if (type == PTLS_HANDSHAKE_TYPE_FINISHED && is_end_of_record) {
ret = client_handle_finished(tls, emitter, message);
} else {
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
}
break;
case PTLS_STATE_CLIENT_POST_HANDSHAKE:
switch (type) {
case PTLS_HANDSHAKE_TYPE_NEW_SESSION_TICKET:
ret = client_handle_new_session_ticket(tls, message);
break;
case PTLS_HANDSHAKE_TYPE_KEY_UPDATE:
ret = handle_key_update(tls, emitter, message);
break;
default:
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
break;
}
break;
default:
assert(!"unexpected state");
ret = PTLS_ALERT_INTERNAL_ERROR;
break;
}
PTLS_PROBE(RECEIVE_MESSAGE, tls, message.base[0], message.base + PTLS_HANDSHAKE_HEADER_SIZE,
message.len - PTLS_HANDSHAKE_HEADER_SIZE, ret);
PTLS_LOG_CONN(receive_message, tls, {
PTLS_LOG_ELEMENT_UNSIGNED(message, message.base[0]);
PTLS_LOG_ELEMENT_UNSIGNED(len, message.len - PTLS_HANDSHAKE_HEADER_SIZE);
PTLS_LOG_ELEMENT_SIGNED(result, ret);
});
return ret;
}
static int handle_server_handshake_message(ptls_t *tls, ptls_message_emitter_t *emitter, ptls_iovec_t message, int is_end_of_record,
ptls_handshake_properties_t *properties)
{
uint8_t type = message.base[0];
int ret;
switch (tls->state) {
case PTLS_STATE_SERVER_EXPECT_CLIENT_HELLO:
case PTLS_STATE_SERVER_EXPECT_SECOND_CLIENT_HELLO:
if (type == PTLS_HANDSHAKE_TYPE_CLIENT_HELLO && is_end_of_record) {
ret = server_handle_hello(tls, emitter, message, properties);
} else {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
}
break;
case PTLS_STATE_SERVER_EXPECT_CERTIFICATE:
if (type == PTLS_HANDSHAKE_TYPE_CERTIFICATE) {
ret = server_handle_certificate(tls, message);
} else {
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
}
break;
case PTLS_STATE_SERVER_EXPECT_CERTIFICATE_VERIFY:
if (type == PTLS_HANDSHAKE_TYPE_CERTIFICATE_VERIFY) {
ret = server_handle_certificate_verify(tls, message);
} else {
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
}
break;
case PTLS_STATE_SERVER_EXPECT_END_OF_EARLY_DATA:
assert(!tls->ctx->omit_end_of_early_data);
if (type == PTLS_HANDSHAKE_TYPE_END_OF_EARLY_DATA) {
ret = server_handle_end_of_early_data(tls, message);
} else {
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
}
break;
case PTLS_STATE_SERVER_EXPECT_FINISHED:
if (type == PTLS_HANDSHAKE_TYPE_FINISHED && is_end_of_record) {
ret = server_handle_finished(tls, message);
} else {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
}
break;
case PTLS_STATE_SERVER_POST_HANDSHAKE:
switch (type) {
case PTLS_HANDSHAKE_TYPE_KEY_UPDATE:
ret = handle_key_update(tls, emitter, message);
break;
default:
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
break;
}
break;
default:
assert(!"unexpected state");
ret = PTLS_ALERT_INTERNAL_ERROR;
break;
}
PTLS_PROBE(RECEIVE_MESSAGE, tls, message.base[0], message.base + PTLS_HANDSHAKE_HEADER_SIZE,
message.len - PTLS_HANDSHAKE_HEADER_SIZE, ret);
PTLS_LOG_CONN(receive_message, tls, {
PTLS_LOG_ELEMENT_UNSIGNED(message, message.base[0]);
PTLS_LOG_ELEMENT_UNSIGNED(len, message.len - PTLS_HANDSHAKE_HEADER_SIZE);
PTLS_LOG_ELEMENT_SIGNED(result, ret);
});
return ret;
}
static int handle_alert(ptls_t *tls, const uint8_t *src, size_t len)
{
if (len != 2)
return PTLS_ALERT_DECODE_ERROR;
uint8_t desc = src[1];
/* all fatal alerts and USER_CANCELLED warning tears down the connection immediately, regardless of the transmitted level */
return PTLS_ALERT_TO_PEER_ERROR(desc);
}
static int message_buffer_is_overflow(ptls_context_t *ctx, size_t size)
{
if (ctx->max_buffer_size == 0)
return 0;
if (size <= ctx->max_buffer_size)
return 0;
return 1;
}
static int handle_handshake_record(ptls_t *tls,
int (*cb)(ptls_t *tls, ptls_message_emitter_t *emitter, ptls_iovec_t message,
int is_end_of_record, ptls_handshake_properties_t *properties),
ptls_message_emitter_t *emitter, struct st_ptls_record_t *rec,
ptls_handshake_properties_t *properties)
{
int ret;
/* handshake */
if (rec->type != PTLS_CONTENT_TYPE_HANDSHAKE)
return PTLS_ALERT_DECODE_ERROR;
/* flatten the unhandled messages */
const uint8_t *src, *src_end;
if (tls->recvbuf.mess.base == NULL) {
src = rec->fragment;
src_end = src + rec->length;
} else {
if (message_buffer_is_overflow(tls->ctx, tls->recvbuf.mess.off + rec->length))
return PTLS_ALERT_HANDSHAKE_FAILURE;
if ((ret = ptls_buffer_reserve(&tls->recvbuf.mess, rec->length)) != 0)
return ret;
memcpy(tls->recvbuf.mess.base + tls->recvbuf.mess.off, rec->fragment, rec->length);
tls->recvbuf.mess.off += rec->length;
src = tls->recvbuf.mess.base;
src_end = src + tls->recvbuf.mess.off;
}
/* handle the messages */
ret = PTLS_ERROR_IN_PROGRESS;
while (src_end - src >= 4) {
size_t mess_len = 4 + ntoh24(src + 1);
if (src_end - src < (int)mess_len)
break;
ret = cb(tls, emitter, ptls_iovec_init(src, mess_len), src_end - src == mess_len, properties);
switch (ret) {
case 0:
case PTLS_ERROR_ASYNC_OPERATION:
case PTLS_ERROR_IN_PROGRESS:
break;
default:
ptls_buffer_dispose(&tls->recvbuf.mess);
return ret;
}
src += mess_len;
}
/* keep last partial message in buffer */
if (src != src_end) {
size_t new_size = src_end - src;
if (message_buffer_is_overflow(tls->ctx, new_size))
return PTLS_ALERT_HANDSHAKE_FAILURE;
if (tls->recvbuf.mess.base == NULL) {
ptls_buffer_init(&tls->recvbuf.mess, "", 0);
if ((ret = ptls_buffer_reserve(&tls->recvbuf.mess, new_size)) != 0)
return ret;
memcpy(tls->recvbuf.mess.base, src, new_size);
} else {
memmove(tls->recvbuf.mess.base, src, new_size);
}
tls->recvbuf.mess.off = new_size;
ret = PTLS_ERROR_IN_PROGRESS;
} else {
ptls_buffer_dispose(&tls->recvbuf.mess);
}
return ret;
}
static int handle_input(ptls_t *tls, ptls_message_emitter_t *emitter, ptls_buffer_t *decryptbuf, const void *input, size_t *inlen,
ptls_handshake_properties_t *properties)
{
struct st_ptls_record_t rec;
int ret;
/* extract the record */
if ((ret = parse_record(tls, &rec, input, inlen)) != 0)
return ret;
assert(rec.fragment != NULL);
/* decrypt the record */
if (rec.type == PTLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC) {
if (tls->state < PTLS_STATE_POST_HANDSHAKE_MIN) {
if (!(rec.length == 1 && rec.fragment[0] == 0x01))
return PTLS_ALERT_ILLEGAL_PARAMETER;
} else {
return PTLS_ALERT_HANDSHAKE_FAILURE;
}
ret = PTLS_ERROR_IN_PROGRESS;
goto NextRecord;
}
if (tls->traffic_protection.dec.aead != NULL && rec.type != PTLS_CONTENT_TYPE_ALERT) {
size_t decrypted_length;
if (rec.type != PTLS_CONTENT_TYPE_APPDATA)
return PTLS_ALERT_HANDSHAKE_FAILURE;
if ((ret = ptls_buffer_reserve(decryptbuf, 5 + rec.length)) != 0)
return ret;
if ((ret = aead_decrypt(&tls->traffic_protection.dec, decryptbuf->base + decryptbuf->off, &decrypted_length, rec.fragment,
rec.length)) != 0) {
if (tls->is_server && tls->server.early_data_skipped_bytes != UINT32_MAX)
goto ServerSkipEarlyData;
return ret;
}
rec.length = decrypted_length;
rec.fragment = decryptbuf->base + decryptbuf->off;
/* skip padding */
for (; rec.length != 0; --rec.length)
if (rec.fragment[rec.length - 1] != 0)
break;
if (rec.length == 0)
return PTLS_ALERT_UNEXPECTED_MESSAGE;
rec.type = rec.fragment[--rec.length];
} else if (rec.type == PTLS_CONTENT_TYPE_APPDATA && tls->is_server && tls->server.early_data_skipped_bytes != UINT32_MAX) {
goto ServerSkipEarlyData;
}
if (tls->recvbuf.mess.base != NULL || rec.type == PTLS_CONTENT_TYPE_HANDSHAKE) {
/* handshake record */
ret = handle_handshake_record(tls, tls->is_server ? handle_server_handshake_message : handle_client_handshake_message,
emitter, &rec, properties);
} else {
/* handling of an alert or an application record */
switch (rec.type) {
case PTLS_CONTENT_TYPE_APPDATA:
if (tls->state >= PTLS_STATE_POST_HANDSHAKE_MIN) {
decryptbuf->off += rec.length;
ret = 0;
} else if (tls->state == PTLS_STATE_SERVER_EXPECT_END_OF_EARLY_DATA) {
if (tls->traffic_protection.dec.aead != NULL)
decryptbuf->off += rec.length;
ret = 0;
} else {
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
}
break;
case PTLS_CONTENT_TYPE_ALERT:
ret = handle_alert(tls, rec.fragment, rec.length);
break;
default:
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
break;
}
}
NextRecord:
ptls_buffer_dispose(&tls->recvbuf.rec);
return ret;
ServerSkipEarlyData:
tls->server.early_data_skipped_bytes += (uint32_t)rec.length;
if (tls->server.early_data_skipped_bytes > PTLS_MAX_EARLY_DATA_SKIP_SIZE)
return PTLS_ALERT_HANDSHAKE_FAILURE;
ret = PTLS_ERROR_IN_PROGRESS;
goto NextRecord;
}
static int handle_input_tls12(ptls_t *tls, ptls_buffer_t *decryptbuf, const void *input, size_t *inlen)
{
struct st_ptls_record_t rec;
int ret;
/* extract the record, or bail out */
if ((ret = parse_record(tls, &rec, input, inlen)) != 0)
return ret;
assert(rec.fragment != NULL);
const uint8_t *src = rec.fragment, *end = src + rec.length;
uint64_t nonce;
uint8_t aad[PTLS_TLS12_AAD_SIZE];
/* determine the nonce */
if (tls->traffic_protection.dec.aead->algo->tls12.record_iv_size != 0) {
assert(tls->traffic_protection.dec.aead->algo->tls12.record_iv_size == 8);
if ((ret = ptls_decode64(&nonce, &src, end)) != 0)
goto Exit;
} else {
nonce = tls->traffic_protection.dec.seq;
}
/* determine cleartext length */
size_t textlen = end - src;
if (textlen < tls->traffic_protection.dec.aead->algo->tag_size) {
ret = PTLS_ALERT_BAD_RECORD_MAC;
goto Exit;
}
textlen -= tls->traffic_protection.dec.aead->algo->tag_size;
/* build aad */
build_tls12_aad(aad, rec.type, tls->traffic_protection.dec.seq, (uint16_t)textlen);
/* decrypt input to decryptbuf */
if ((ret = ptls_buffer_reserve(decryptbuf, textlen)) != 0)
goto Exit;
if (ptls_aead_decrypt(tls->traffic_protection.dec.aead, decryptbuf->base + decryptbuf->off, src, end - src, nonce, aad,
sizeof(aad)) != textlen) {
ret = PTLS_ALERT_BAD_RECORD_MAC;
goto Exit;
}
++tls->traffic_protection.dec.seq;
/* record-type specific action */
switch (rec.type) {
case PTLS_CONTENT_TYPE_APPDATA:
/* if application data, retain the bytes being decrypted */
decryptbuf->off += textlen;
break;
case PTLS_CONTENT_TYPE_ALERT:
/* submit alert without adjusting decryptbuf, so that the decrypted data would be dropped after handling the alert */
ret = handle_alert(tls, decryptbuf->base + decryptbuf->off, textlen);
break;
default:
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
break;
}
Exit:
ptls_buffer_dispose(&tls->recvbuf.rec);
ptls_clear_memory(aad, sizeof(aad));
return 0;
}
static void init_record_message_emitter(ptls_t *tls, struct st_ptls_record_message_emitter_t *emitter, ptls_buffer_t *sendbuf)
{
*emitter = (struct st_ptls_record_message_emitter_t){
{sendbuf, &tls->traffic_protection.enc, 5, begin_record_message, commit_record_message}};
}
int ptls_handshake(ptls_t *tls, ptls_buffer_t *_sendbuf, const void *input, size_t *inlen, ptls_handshake_properties_t *properties)
{
struct st_ptls_record_message_emitter_t emitter;
int ret;
assert(tls->state < PTLS_STATE_POST_HANDSHAKE_MIN);
init_record_message_emitter(tls, &emitter, _sendbuf);
size_t sendbuf_orig_off = emitter.super.buf->off;
/* special handlings */
switch (tls->state) {
case PTLS_STATE_CLIENT_HANDSHAKE_START: {
assert(input == NULL || *inlen == 0);
assert(tls->ctx->key_exchanges[0] != NULL);
return send_client_hello(tls, &emitter.super, properties, NULL);
}
case PTLS_STATE_SERVER_GENERATING_CERTIFICATE_VERIFY:
return server_finish_handshake(tls, &emitter.super, 1, NULL);
default:
break;
}
const uint8_t *src = input, *const src_end = src + *inlen;
ptls_buffer_t decryptbuf;
ptls_buffer_init(&decryptbuf, "", 0);
/* perform handhake until completion or until all the input has been swallowed */
ret = PTLS_ERROR_IN_PROGRESS;
while (ret == PTLS_ERROR_IN_PROGRESS && src != src_end) {
size_t consumed = src_end - src;
ret = handle_input(tls, &emitter.super, &decryptbuf, src, &consumed, properties);
src += consumed;
assert(decryptbuf.off == 0);
}
ptls_buffer_dispose(&decryptbuf);
switch (ret) {
case 0:
case PTLS_ERROR_IN_PROGRESS:
case PTLS_ERROR_STATELESS_RETRY:
case PTLS_ERROR_ASYNC_OPERATION:
break;
default:
/* Flush handshake messages that have been written partially. ECH_REQUIRED sticks out because it is a message sent
* post-handshake compared to other alerts that are generating *during* the handshake. */
if (ret != PTLS_ALERT_ECH_REQUIRED) {
ptls_clear_memory(emitter.super.buf->base + sendbuf_orig_off, emitter.super.buf->off - sendbuf_orig_off);
emitter.super.buf->off = sendbuf_orig_off;
}
/* send alert immediately */
if (PTLS_ERROR_GET_CLASS(ret) != PTLS_ERROR_CLASS_PEER_ALERT)
if (ptls_send_alert(tls, emitter.super.buf, PTLS_ALERT_LEVEL_FATAL,
PTLS_ERROR_GET_CLASS(ret) == PTLS_ERROR_CLASS_SELF_ALERT ? ret : PTLS_ALERT_INTERNAL_ERROR) != 0)
emitter.super.buf->off = sendbuf_orig_off;
break;
}
*inlen -= src_end - src;
return ret;
}
int ptls_receive(ptls_t *tls, ptls_buffer_t *decryptbuf, const void *_input, size_t *inlen)
{
const uint8_t *input = (const uint8_t *)_input, *const end = input + *inlen;
size_t decryptbuf_orig_size = decryptbuf->off;
int ret = 0;
assert(tls->state >= PTLS_STATE_SERVER_EXPECT_END_OF_EARLY_DATA);
/* loop until we decrypt some application data (or an error) */
while (ret == 0 && input != end && decryptbuf_orig_size == decryptbuf->off) {
size_t consumed = end - input;
if (tls->traffic_protection.dec.tls12) {
ret = handle_input_tls12(tls, decryptbuf, input, &consumed);
} else {
ret = handle_input(tls, NULL, decryptbuf, input, &consumed, NULL);
}
input += consumed;
switch (ret) {
case 0:
break;
case PTLS_ERROR_IN_PROGRESS:
ret = 0;
break;
case PTLS_ERROR_CLASS_PEER_ALERT + PTLS_ALERT_CLOSE_NOTIFY:
/* TODO send close alert */
break;
default:
if (PTLS_ERROR_GET_CLASS(ret) == PTLS_ERROR_CLASS_SELF_ALERT) {
/* TODO send alert */
}
break;
}
}
*inlen -= end - input;
return ret;
}
static int update_send_key(ptls_t *tls, ptls_buffer_t *_sendbuf, int request_update)
{
struct st_ptls_record_message_emitter_t emitter;
int ret;
init_record_message_emitter(tls, &emitter, _sendbuf);
size_t sendbuf_orig_off = emitter.super.buf->off;
ptls_push_message(&emitter.super, NULL, PTLS_HANDSHAKE_TYPE_KEY_UPDATE,
{ ptls_buffer_push(emitter.super.buf, !!request_update); });
if ((ret = update_traffic_key(tls, 1)) != 0)
goto Exit;
ret = 0;
Exit:
if (ret != 0)
emitter.super.buf->off = sendbuf_orig_off;
return ret;
}
int ptls_send(ptls_t *tls, ptls_buffer_t *sendbuf, const void *input, size_t inlen)
{
assert(tls->traffic_protection.enc.aead != NULL);
/* "For AES-GCM, up to 2^24.5 full-size records (about 24 million) may be encrypted on a given connection while keeping a
* safety margin of approximately 2^-57 for Authenticated Encryption (AE) security." (RFC 8446 section 5.5).
*
* Key updates do not happen with tls 1.2, check `key_schedule` to see if we are using tls/1.3
*/
if (tls->traffic_protection.enc.seq >= 16777216 && tls->key_schedule != NULL)
tls->needs_key_update = 1;
if (tls->needs_key_update) {
int ret;
if ((ret = update_send_key(tls, sendbuf, tls->key_update_send_request)) != 0)
return ret;
tls->needs_key_update = 0;
tls->key_update_send_request = 0;
}
return buffer_push_encrypted_records(sendbuf, PTLS_CONTENT_TYPE_APPDATA, input, inlen, &tls->traffic_protection.enc);
}
int ptls_update_key(ptls_t *tls, int request_update)
{
assert(tls->ctx->update_traffic_key == NULL);
tls->needs_key_update = 1;
tls->key_update_send_request = request_update;
return 0;
}
size_t ptls_get_record_overhead(ptls_t *tls)
{
ptls_aead_algorithm_t *algo = tls->traffic_protection.enc.aead->algo;
if (tls->traffic_protection.enc.tls12) {
return 5 + algo->tls12.record_iv_size + algo->tag_size;
} else {
return 6 + algo->tag_size;
}
}
int ptls_send_alert(ptls_t *tls, ptls_buffer_t *sendbuf, uint8_t level, uint8_t description)
{
size_t rec_start = sendbuf->off;
int ret = 0;
buffer_push_record(sendbuf, PTLS_CONTENT_TYPE_ALERT, { ptls_buffer_push(sendbuf, level, description); });
/* encrypt the alert if we have the encryption keys, unless when it is the early data key */
if (tls->traffic_protection.enc.aead != NULL && !(tls->state <= PTLS_STATE_CLIENT_EXPECT_FINISHED)) {
if ((ret = buffer_encrypt_record(sendbuf, rec_start, &tls->traffic_protection.enc)) != 0)
goto Exit;
}
Exit:
return ret;
}
int ptls_export_secret(ptls_t *tls, void *output, size_t outlen, const char *label, ptls_iovec_t context_value, int is_early)
{
ptls_hash_algorithm_t *algo = tls->key_schedule->hashes[0].algo;
uint8_t *master_secret = is_early ? tls->exporter_master_secret.early : tls->exporter_master_secret.one_rtt,
derived_secret[PTLS_MAX_DIGEST_SIZE], context_value_hash[PTLS_MAX_DIGEST_SIZE];
int ret;
if (master_secret == NULL) {
if (is_early) {
switch (tls->state) {
case PTLS_STATE_CLIENT_HANDSHAKE_START:
case PTLS_STATE_SERVER_EXPECT_CLIENT_HELLO:
ret = PTLS_ERROR_IN_PROGRESS;
break;
default:
ret = PTLS_ERROR_NOT_AVAILABLE;
break;
}
} else {
ret = PTLS_ERROR_IN_PROGRESS;
}
return ret;
}
if ((ret = ptls_calc_hash(algo, context_value_hash, context_value.base, context_value.len)) != 0)
return ret;
if ((ret = ptls_hkdf_expand_label(algo, derived_secret, algo->digest_size, ptls_iovec_init(master_secret, algo->digest_size),
label, ptls_iovec_init(algo->empty_digest, algo->digest_size), NULL)) != 0)
goto Exit;
ret = ptls_hkdf_expand_label(algo, output, outlen, ptls_iovec_init(derived_secret, algo->digest_size), "exporter",
ptls_iovec_init(context_value_hash, algo->digest_size), NULL);
Exit:
ptls_clear_memory(derived_secret, sizeof(derived_secret));
ptls_clear_memory(context_value_hash, sizeof(context_value_hash));
return ret;
}
struct st_picotls_hmac_context_t {
ptls_hash_context_t super;
ptls_hash_algorithm_t *algo;
ptls_hash_context_t *hash;
uint8_t key[1];
};
static void hmac_update(ptls_hash_context_t *_ctx, const void *src, size_t len)
{
struct st_picotls_hmac_context_t *ctx = (struct st_picotls_hmac_context_t *)_ctx;
ctx->hash->update(ctx->hash, src, len);
}
static void hmac_apply_key(struct st_picotls_hmac_context_t *ctx, uint8_t pad)
{
size_t i;
for (i = 0; i != ctx->algo->block_size; ++i)
ctx->key[i] ^= pad;
ctx->hash->update(ctx->hash, ctx->key, ctx->algo->block_size);
for (i = 0; i != ctx->algo->block_size; ++i)
ctx->key[i] ^= pad;
}
static void hmac_final(ptls_hash_context_t *_ctx, void *md, ptls_hash_final_mode_t mode)
{
struct st_picotls_hmac_context_t *ctx = (struct st_picotls_hmac_context_t *)_ctx;
assert(mode != PTLS_HASH_FINAL_MODE_SNAPSHOT || !"not supported");
if (md != NULL) {
ctx->hash->final(ctx->hash, md, PTLS_HASH_FINAL_MODE_RESET);
hmac_apply_key(ctx, 0x5c);
ctx->hash->update(ctx->hash, md, ctx->algo->digest_size);
}
ctx->hash->final(ctx->hash, md, mode);
switch (mode) {
case PTLS_HASH_FINAL_MODE_FREE:
ptls_clear_memory(ctx->key, ctx->algo->block_size);
free(ctx);
break;
case PTLS_HASH_FINAL_MODE_RESET:
hmac_apply_key(ctx, 0x36);
break;
default:
assert(!"FIXME");
break;
}
}
int ptls_calc_hash(ptls_hash_algorithm_t *algo, void *output, const void *src, size_t len)
{
ptls_hash_context_t *ctx;
if ((ctx = algo->create()) == NULL)
return PTLS_ERROR_NO_MEMORY;
ctx->update(ctx, src, len);
ctx->final(ctx, output, PTLS_HASH_FINAL_MODE_FREE);
return 0;
}
ptls_hash_context_t *ptls_hmac_create(ptls_hash_algorithm_t *algo, const void *key, size_t key_size)
{
struct st_picotls_hmac_context_t *ctx;
assert(key_size <= algo->block_size);
if ((ctx = malloc(offsetof(struct st_picotls_hmac_context_t, key) + algo->block_size)) == NULL)
return NULL;
*ctx = (struct st_picotls_hmac_context_t){{hmac_update, hmac_final}, algo};
if ((ctx->hash = algo->create()) == NULL) {
free(ctx);
return NULL;
}
memset(ctx->key, 0, algo->block_size);
memcpy(ctx->key, key, key_size);
hmac_apply_key(ctx, 0x36);
return &ctx->super;
}
int ptls_hkdf_extract(ptls_hash_algorithm_t *algo, void *output, ptls_iovec_t salt, ptls_iovec_t ikm)
{
ptls_hash_context_t *hash;
if (salt.len == 0)
salt = ptls_iovec_init(zeroes_of_max_digest_size, algo->digest_size);
if ((hash = ptls_hmac_create(algo, salt.base, salt.len)) == NULL)
return PTLS_ERROR_NO_MEMORY;
hash->update(hash, ikm.base, ikm.len);
hash->final(hash, output, PTLS_HASH_FINAL_MODE_FREE);
return 0;
}
int ptls_hkdf_expand(ptls_hash_algorithm_t *algo, void *output, size_t outlen, ptls_iovec_t prk, ptls_iovec_t info)
{
ptls_hash_context_t *hmac = NULL;
size_t i;
uint8_t digest[PTLS_MAX_DIGEST_SIZE];
for (i = 0; (i * algo->digest_size) < outlen; ++i) {
if (hmac == NULL) {
if ((hmac = ptls_hmac_create(algo, prk.base, prk.len)) == NULL)
return PTLS_ERROR_NO_MEMORY;
} else {
hmac->update(hmac, digest, algo->digest_size);
}
hmac->update(hmac, info.base, info.len);
uint8_t gen = (uint8_t)(i + 1);
hmac->update(hmac, &gen, 1);
hmac->final(hmac, digest, 1);
size_t off_start = i * algo->digest_size, off_end = off_start + algo->digest_size;
if (off_end > outlen)
off_end = outlen;
memcpy((uint8_t *)output + off_start, digest, off_end - off_start);
}
if (hmac != NULL)
hmac->final(hmac, NULL, PTLS_HASH_FINAL_MODE_FREE);
ptls_clear_memory(digest, algo->digest_size);
return 0;
}
int ptls_hkdf_expand_label(ptls_hash_algorithm_t *algo, void *output, size_t outlen, ptls_iovec_t secret, const char *label,
ptls_iovec_t hash_value, const char *label_prefix)
{
ptls_buffer_t hkdf_label;
uint8_t hkdf_label_buf[80];
int ret;
ptls_buffer_init(&hkdf_label, hkdf_label_buf, sizeof(hkdf_label_buf));
ptls_buffer_push16(&hkdf_label, (uint16_t)outlen);
ptls_buffer_push_block(&hkdf_label, 1, {
if (label_prefix == NULL)
label_prefix = PTLS_HKDF_EXPAND_LABEL_PREFIX;
ptls_buffer_pushv(&hkdf_label, label_prefix, strlen(label_prefix));
ptls_buffer_pushv(&hkdf_label, label, strlen(label));
});
ptls_buffer_push_block(&hkdf_label, 1, { ptls_buffer_pushv(&hkdf_label, hash_value.base, hash_value.len); });
ret = ptls_hkdf_expand(algo, output, outlen, secret, ptls_iovec_init(hkdf_label.base, hkdf_label.off));
Exit:
ptls_buffer_dispose(&hkdf_label);
return ret;
}
int ptls_tls12_phash(ptls_hash_algorithm_t *algo, void *output, size_t outlen, ptls_iovec_t secret, const char *label,
ptls_iovec_t seed)
{
ptls_hash_context_t *hmac;
uint8_t An[PTLS_MAX_DIGEST_SIZE];
size_t output_off = 0;
if ((hmac = ptls_hmac_create(algo, secret.base, secret.len)) == NULL)
return PTLS_ERROR_NO_MEMORY;
/* A(1) = HMAC_hash(secret, label + seed) */
if (label != NULL)
hmac->update(hmac, label, strlen(label));
hmac->update(hmac, seed.base, seed.len);
hmac->final(hmac, An, PTLS_HASH_FINAL_MODE_RESET);
while (1) {
/* output += HMAC_hash(secret, A(i) + label + seed) */
hmac->update(hmac, An, algo->digest_size);
if (label != NULL)
hmac->update(hmac, label, strlen(label));
hmac->update(hmac, seed.base, seed.len);
if (outlen - output_off <= algo->digest_size) {
/* digest of last chunk is at first written to An then the necessary bytes are copied to output */
hmac->final(hmac, An, PTLS_HASH_FINAL_MODE_FREE);
memcpy((uint8_t *)output + output_off, An, outlen - output_off);
break;
}
hmac->final(hmac, (uint8_t *)output + output_off, PTLS_HASH_FINAL_MODE_RESET);
output_off += algo->digest_size;
/* A(i) = HMAC_hash(secret, A(i-1)) */
hmac->update(hmac, An, algo->digest_size);
hmac->final(hmac, An, PTLS_HASH_FINAL_MODE_RESET);
}
ptls_clear_memory(An, algo->digest_size);
return 0;
}
ptls_cipher_context_t *ptls_cipher_new(ptls_cipher_algorithm_t *algo, int is_enc, const void *key)
{
ptls_cipher_context_t *ctx;
if ((ctx = (ptls_cipher_context_t *)malloc(algo->context_size)) == NULL)
return NULL;
*ctx = (ptls_cipher_context_t){algo};
if (algo->setup_crypto(ctx, is_enc, key) != 0) {
free(ctx);
ctx = NULL;
}
return ctx;
}
void ptls_cipher_free(ptls_cipher_context_t *ctx)
{
ctx->do_dispose(ctx);
free(ctx);
}
ptls_aead_context_t *new_aead(ptls_aead_algorithm_t *aead, ptls_hash_algorithm_t *hash, int is_enc, const void *secret,
ptls_iovec_t hash_value, const char *label_prefix)
{
ptls_aead_context_t *ctx = NULL;
struct {
uint8_t key[PTLS_MAX_SECRET_SIZE];
uint8_t iv[PTLS_MAX_IV_SIZE];
} key_iv;
int ret;
if ((ret = get_traffic_keys(aead, hash, key_iv.key, key_iv.iv, secret, hash_value, label_prefix)) != 0)
goto Exit;
ctx = ptls_aead_new_direct(aead, is_enc, key_iv.key, key_iv.iv);
Exit:
ptls_clear_memory(&key_iv, sizeof(key_iv));
return ctx;
}
ptls_aead_context_t *ptls_aead_new(ptls_aead_algorithm_t *aead, ptls_hash_algorithm_t *hash, int is_enc, const void *secret,
const char *label_prefix)
{
return new_aead(aead, hash, is_enc, secret, ptls_iovec_init(NULL, 0), label_prefix);
}
ptls_aead_context_t *ptls_aead_new_direct(ptls_aead_algorithm_t *aead, int is_enc, const void *key, const void *iv)
{
ptls_aead_context_t *ctx;
if ((ctx = (ptls_aead_context_t *)malloc(aead->context_size)) == NULL)
return NULL;
*ctx = (ptls_aead_context_t){aead};
if (aead->setup_crypto(ctx, is_enc, key, iv) != 0) {
free(ctx);
return NULL;
}
return ctx;
}
void ptls_aead_free(ptls_aead_context_t *ctx)
{
ctx->dispose_crypto(ctx);
free(ctx);
}
void ptls_aead_xor_iv(ptls_aead_context_t *ctx, const void *_bytes, size_t len)
{
const uint8_t *bytes = _bytes;
uint8_t iv[PTLS_MAX_IV_SIZE];
ptls_aead_get_iv(ctx, iv);
for (size_t i = 0; i < len; ++i)
iv[i] ^= bytes[i];
ptls_aead_set_iv(ctx, iv);
}
void ptls_aead__build_iv(ptls_aead_algorithm_t *algo, uint8_t *iv, const uint8_t *static_iv, uint64_t seq)
{
size_t iv_size = algo->iv_size, i;
const uint8_t *s = static_iv;
uint8_t *d = iv;
/* build iv */
for (i = iv_size - 8; i != 0; --i)
*d++ = *s++;
i = 64;
do {
i -= 8;
*d++ = *s++ ^ (uint8_t)(seq >> i);
} while (i != 0);
}
static void clear_memory(void *p, size_t len)
{
if (len != 0)
memset(p, 0, len);
}
void (*volatile ptls_clear_memory)(void *p, size_t len) = clear_memory;
static int mem_equal(const void *_x, const void *_y, size_t len)
{
const volatile uint8_t *x = _x, *y = _y;
uint8_t t = 0;
for (; len != 0; --len)
t |= *x++ ^ *y++;
return t == 0;
}
int (*volatile ptls_mem_equal)(const void *x, const void *y, size_t len) = mem_equal;
static uint64_t get_time(ptls_get_time_t *self)
{
struct timeval tv;
gettimeofday(&tv, NULL);
return (uint64_t)tv.tv_sec * 1000 + tv.tv_usec / 1000;
}
ptls_get_time_t ptls_get_time = {get_time};
#if PICOTLS_USE_DTRACE
PTLS_THREADLOCAL unsigned ptls_default_skip_tracing = 0;
#endif
int ptls_is_server(ptls_t *tls)
{
return tls->is_server;
}
struct st_ptls_raw_message_emitter_t {
ptls_message_emitter_t super;
size_t start_off;
size_t *epoch_offsets;
};
static int begin_raw_message(ptls_message_emitter_t *_self)
{
struct st_ptls_raw_message_emitter_t *self = (void *)_self;
self->start_off = self->super.buf->off;
return 0;
}
static int commit_raw_message(ptls_message_emitter_t *_self)
{
struct st_ptls_raw_message_emitter_t *self = (void *)_self;
size_t epoch;
/* epoch is the key epoch, with the only exception being 2nd CH generated after 0-RTT key */
epoch = self->super.enc->epoch;
if (epoch == 1 && self->super.buf->base[self->start_off] == PTLS_HANDSHAKE_TYPE_CLIENT_HELLO)
epoch = 0;
for (++epoch; epoch < 5; ++epoch) {
assert(self->epoch_offsets[epoch] == self->start_off);
self->epoch_offsets[epoch] = self->super.buf->off;
}
self->start_off = SIZE_MAX;
return 0;
}
size_t ptls_get_read_epoch(ptls_t *tls)
{
switch (tls->state) {
case PTLS_STATE_CLIENT_HANDSHAKE_START:
case PTLS_STATE_CLIENT_EXPECT_SERVER_HELLO:
case PTLS_STATE_CLIENT_EXPECT_SECOND_SERVER_HELLO:
case PTLS_STATE_SERVER_EXPECT_CLIENT_HELLO:
case PTLS_STATE_SERVER_EXPECT_SECOND_CLIENT_HELLO:
return 0; /* plaintext */
case PTLS_STATE_SERVER_EXPECT_END_OF_EARLY_DATA:
assert(!tls->ctx->omit_end_of_early_data);
return 1; /* 0-rtt */
case PTLS_STATE_CLIENT_EXPECT_ENCRYPTED_EXTENSIONS:
case PTLS_STATE_CLIENT_EXPECT_CERTIFICATE_REQUEST_OR_CERTIFICATE:
case PTLS_STATE_CLIENT_EXPECT_CERTIFICATE:
case PTLS_STATE_CLIENT_EXPECT_CERTIFICATE_VERIFY:
case PTLS_STATE_CLIENT_EXPECT_FINISHED:
case PTLS_STATE_SERVER_GENERATING_CERTIFICATE_VERIFY:
case PTLS_STATE_SERVER_EXPECT_CERTIFICATE:
case PTLS_STATE_SERVER_EXPECT_CERTIFICATE_VERIFY:
case PTLS_STATE_SERVER_EXPECT_FINISHED:
return 2; /* handshake */
case PTLS_STATE_CLIENT_POST_HANDSHAKE:
case PTLS_STATE_SERVER_POST_HANDSHAKE:
return 3; /* 1-rtt */
default:
assert(!"invalid state");
return SIZE_MAX;
}
}
int ptls_handle_message(ptls_t *tls, ptls_buffer_t *sendbuf, size_t epoch_offsets[5], size_t in_epoch, const void *input,
size_t inlen, ptls_handshake_properties_t *properties)
{
return tls->is_server ? ptls_server_handle_message(tls, sendbuf, epoch_offsets, in_epoch, input, inlen, properties)
: ptls_client_handle_message(tls, sendbuf, epoch_offsets, in_epoch, input, inlen, properties);
}
int ptls_client_handle_message(ptls_t *tls, ptls_buffer_t *sendbuf, size_t epoch_offsets[5], size_t in_epoch, const void *input,
size_t inlen, ptls_handshake_properties_t *properties)
{
assert(!tls->is_server);
struct st_ptls_raw_message_emitter_t emitter = {
{sendbuf, &tls->traffic_protection.enc, 0, begin_raw_message, commit_raw_message}, SIZE_MAX, epoch_offsets};
struct st_ptls_record_t rec = {PTLS_CONTENT_TYPE_HANDSHAKE, 0, inlen, input};
if (input == NULL)
return send_client_hello(tls, &emitter.super, properties, NULL);
if (ptls_get_read_epoch(tls) != in_epoch)
return PTLS_ALERT_UNEXPECTED_MESSAGE;
return handle_handshake_record(tls, handle_client_handshake_message, &emitter.super, &rec, properties);
}
int ptls_server_handle_message(ptls_t *tls, ptls_buffer_t *sendbuf, size_t epoch_offsets[5], size_t in_epoch, const void *input,
size_t inlen, ptls_handshake_properties_t *properties)
{
assert(tls->is_server);
struct st_ptls_raw_message_emitter_t emitter = {
{sendbuf, &tls->traffic_protection.enc, 0, begin_raw_message, commit_raw_message}, SIZE_MAX, epoch_offsets};
struct st_ptls_record_t rec = {PTLS_CONTENT_TYPE_HANDSHAKE, 0, inlen, input};
if (tls->state == PTLS_STATE_SERVER_GENERATING_CERTIFICATE_VERIFY) {
assert(input == NULL || inlen == 0);
return server_finish_handshake(tls, &emitter.super, 1, NULL);
}
assert(input != NULL);
if (ptls_get_read_epoch(tls) != in_epoch)
return PTLS_ALERT_UNEXPECTED_MESSAGE;
return handle_handshake_record(tls, handle_server_handshake_message, &emitter.super, &rec, properties);
}
/**
* checks if given name looks like an IP address
*/
int ptls_server_name_is_ipaddr(const char *name)
{
#ifdef AF_INET
struct sockaddr_in sin;
if (inet_pton(AF_INET, name, &sin) == 1)
return 1;
#endif
#ifdef AF_INET6
struct sockaddr_in6 sin6;
if (inet_pton(AF_INET6, name, &sin6) == 1)
return 1;
#endif
return 0;
}
int ptls_ech_encode_config(ptls_buffer_t *buf, uint8_t config_id, ptls_hpke_kem_t *kem, ptls_iovec_t public_key,
ptls_hpke_cipher_suite_t **ciphers, uint8_t max_name_length, const char *public_name)
{
int ret;
ptls_buffer_push16(buf, PTLS_ECH_CONFIG_VERSION);
ptls_buffer_push_block(buf, 2, {
ptls_buffer_push(buf, config_id);
ptls_buffer_push16(buf, kem->id);
ptls_buffer_push_block(buf, 2, { ptls_buffer_pushv(buf, public_key.base, public_key.len); });
ptls_buffer_push_block(buf, 2, {
for (size_t i = 0; ciphers[i] != NULL; ++i) {
ptls_buffer_push16(buf, ciphers[i]->id.kdf);
ptls_buffer_push16(buf, ciphers[i]->id.aead);
}
});
ptls_buffer_push(buf, max_name_length);
ptls_buffer_push_block(buf, 1, { ptls_buffer_pushv(buf, public_name, strlen(public_name)); });
ptls_buffer_push_block(buf, 2, {/* extensions */});
});
Exit:
return ret;
}
static char *byte_to_hex(char *dst, uint8_t v)
{
*dst++ = "0123456789abcdef"[v >> 4];
*dst++ = "0123456789abcdef"[v & 0xf];
return dst;
}
char *ptls_hexdump(char *dst, const void *_src, size_t len)
{
char *buf = dst;
const uint8_t *src = _src;
for (size_t i = 0; i != len; ++i)
dst = byte_to_hex(dst, src[i]);
*dst = '\0';
return buf;
}
char *ptls_jsonescape(char *buf, const char *unsafe_str, size_t len)
{
char *dst = buf;
const uint8_t *src = (const uint8_t *)unsafe_str, *end = src + len;
for (; src != end; ++src) {
switch (*src) {
#define MAP(ch, escaped) \
case ch: \
memcpy(dst, (escaped), sizeof(escaped) - 1); \
dst += sizeof(escaped) - 1; \
break
MAP('"', "\\\"");
MAP('\\', "\\\\");
MAP('/', "\\/");
MAP('\b', "\\b");
MAP('\f', "\\f");
MAP('\n', "\\n");
MAP('\r', "\\r");
MAP('\t', "\\t");
#undef MAP
default:
if (*src < 0x20 || *src == 0x7f) {
*dst++ = '\\';
*dst++ = 'u';
*dst++ = '0';
*dst++ = '0';
dst = byte_to_hex(dst, *src);
} else {
*dst++ = *src;
}
break;
}
}
*dst = '\0';
return dst;
}
int ptls_log__do_pushv(ptls_buffer_t *buf, const void *p, size_t l)
{
if (ptls_buffer_reserve(buf, l) != 0)
return 0;
memcpy(buf->base + buf->off, p, l);
buf->off += l;
return 1;
}
int ptls_log__do_push_unsafestr(ptls_buffer_t *buf, const char *s, size_t l)
{
if (ptls_buffer_reserve(buf, l * (sizeof("\\uXXXX") - 1) + 1) != 0)
return 0;
buf->off = (uint8_t *)ptls_jsonescape((char *)(buf->base + buf->off), s, l) - buf->base;
return 1;
}
int ptls_log__do_push_hexdump(ptls_buffer_t *buf, const void *s, size_t l)
{
if (ptls_buffer_reserve(buf, l * 2 + 1) != 0)
return 0;
ptls_hexdump((char *)(buf->base + buf->off), s, l);
buf->off += l * 2;
return 1;
}
int ptls_log__do_push_signed32(ptls_buffer_t *buf, int32_t v)
{
/* TODO optimize */
char s[sizeof("-2147483648")];
int len = snprintf(s, sizeof(s), "%" PRId32, v);
return ptls_log__do_pushv(buf, s, (size_t)len);
}
int ptls_log__do_push_signed64(ptls_buffer_t *buf, int64_t v)
{
/* TODO optimize */
char s[sizeof("-9223372036854775808")];
int len = snprintf(s, sizeof(s), "%" PRId64, v);
return ptls_log__do_pushv(buf, s, (size_t)len);
}
int ptls_log__do_push_unsigned32(ptls_buffer_t *buf, uint32_t v)
{
/* TODO optimize */
char s[sizeof("4294967295")];
int len = snprintf(s, sizeof(s), "%" PRIu32, v);
return ptls_log__do_pushv(buf, s, (size_t)len);
}
int ptls_log__do_push_unsigned64(ptls_buffer_t *buf, uint64_t v)
{
/* TODO optimize */
char s[sizeof("18446744073709551615")];
int len = snprintf(s, sizeof(s), "%" PRIu64, v);
return ptls_log__do_pushv(buf, s, (size_t)len);
}
#if PTLS_HAVE_LOG
volatile ptls_log_t ptls_log = {};
static struct {
int *fds;
size_t num_fds;
size_t num_lost;
pthread_mutex_t mutex;
} logctx = {.mutex = PTHREAD_MUTEX_INITIALIZER};
size_t ptls_log_num_lost(void)
{
return logctx.num_lost;
}
int ptls_log_add_fd(int fd)
{
int ret;
pthread_mutex_lock(&logctx.mutex);
int *newfds;
if ((newfds = realloc(logctx.fds, sizeof(logctx.fds[0]) * (logctx.num_fds + 1))) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
logctx.fds = newfds;
logctx.fds[logctx.num_fds++] = fd;
ptls_log.is_active = 1;
ret = 0; /* success */
Exit:
pthread_mutex_unlock(&logctx.mutex);
return ret;
}
#endif
void ptls_log__do_write(const ptls_buffer_t *buf)
{
#if PTLS_HAVE_LOG
pthread_mutex_lock(&logctx.mutex);
for (size_t fd_index = 0; fd_index < logctx.num_fds;) {
ssize_t ret;
while ((ret = write(logctx.fds[fd_index], buf->base, buf->off)) == -1 && errno == EINTR)
;
if (ret == buf->off) {
/* success */
++fd_index;
} else if (ret > 0 || (ret == -1 && (errno == EAGAIN || errno == EWOULDBLOCK))) {
/* partial write or buffer full */
++logctx.num_lost;
++fd_index;
} else {
/* write error; close and remove that fd from array */
close(logctx.fds[fd_index]);
logctx.fds[fd_index] = logctx.fds[logctx.num_fds - 1];
--logctx.num_fds;
if (logctx.num_fds == 0)
ptls_log.is_active = 0;
}
}
pthread_mutex_unlock(&logctx.mutex);
#endif
}