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pigweed/third_party/github/h2o/picotls/90dc689a5f04b4aa40e888fbd3646cbbf8c005a2/./lib/picotls.c
blob: 81132bb7a4fe577d74557abb6b029e7cc1556aea [file]
/*
* 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.
*/
#include <assert.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef _WINDOWS
#include "wincompat.h"
#else
#include <sys/time.h>
#endif
#include "picotls.h"
#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_HELLO_RANDOM_SIZE 32
#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_HANDSHAKE_TYPE_CLIENT_HELLO 1
#define PTLS_HANDSHAKE_TYPE_SERVER_HELLO 2
#define PTLS_HANDSHAKE_TYPE_NEW_SESSION_TICKET 4
#define PTLS_HANDSHAKE_TYPE_END_OF_EARLY_DATA 5
#define PTLS_HANDSHAKE_TYPE_ENCRYPTED_EXTENSIONS 8
#define PTLS_HANDSHAKE_TYPE_CERTIFICATE 11
#define PTLS_HANDSHAKE_TYPE_CERTIFICATE_REQUEST 13
#define PTLS_HANDSHAKE_TYPE_CERTIFICATE_VERIFY 15
#define PTLS_HANDSHAKE_TYPE_FINISHED 20
#define PTLS_HANDSHAKE_TYPE_KEY_UPDATE 24
#define PTLS_HANDSHAKE_TYPE_MESSAGE_HASH 254
#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_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_PROTOCOL_VERSION_DRAFT26 0x7f1a
#define PTLS_PROTOCOL_VERSION_DRAFT27 0x7f1b
#define PTLS_PROTOCOL_VERSION_DRAFT28 0x7f1c
#define PTLS_SERVER_NAME_TYPE_HOSTNAME 0
#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 */
#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
/**
* list of supported versions in the preferred order
*/
static const uint16_t supported_versions[] = {PTLS_PROTOCOL_VERSION_DRAFT28, PTLS_PROTOCOL_VERSION_DRAFT27,
PTLS_PROTOCOL_VERSION_DRAFT26};
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;
};
struct st_ptls_message_emitter_t {
ptls_buffer_t *buf;
struct st_ptls_traffic_protection_t *enc;
size_t record_header_length;
int (*begin_message)(struct st_ptls_message_emitter_t *self);
int (*commit_message)(struct st_ptls_message_emitter_t *self);
};
struct st_ptls_record_message_emitter_t {
struct st_ptls_message_emitter_t super;
size_t rec_start;
};
struct st_ptls_early_data_t {
uint8_t next_secret[PTLS_MAX_DIGEST_SIZE];
};
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_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_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
*/
struct st_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
*/
uint8_t client_random[PTLS_HELLO_RANDOM_SIZE];
/* flags */
unsigned is_server : 1;
unsigned is_psk_handshake : 1;
unsigned skip_early_data : 1; /* if early-data is not recognized by the server */
unsigned send_change_cipher_spec : 1;
/**
* exporter master secret (either 0rtt or 1rtt)
*/
struct {
uint8_t *early;
uint8_t *one_rtt;
} exporter_master_secret;
/**
* misc.
*/
union {
struct {
uint8_t legacy_session_id[16];
ptls_key_exchange_context_t *key_share_ctx;
unsigned offered_psk : 1;
struct st_ptls_certificate_request_t certificate_request;
} client;
struct {
uint8_t pending_traffic_secret[PTLS_MAX_DIGEST_SIZE];
} server;
};
/**
* certificate verify
* will be used by the client and the server (if require_client_authentication is set).
*/
struct {
int (*cb)(void *verify_ctx, ptls_iovec_t data, ptls_iovec_t signature);
void *verify_ctx;
} certificate_verify;
/**
* the value contains the traffic secret to be commisioned after END_OF_EARLY_DATA
* END_OF_EARLY_DATA
*/
struct st_ptls_early_data_t *early_data;
/**
* 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
struct st_ptls_client_hello_t {
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 {
ptls_iovec_t all;
ptls_iovec_t tbs;
ptls_iovec_t ch1_hash;
ptls_iovec_t signature;
unsigned sent_key_share : 1;
} cookie;
struct {
const uint8_t *hash_end;
struct {
struct st_ptls_client_hello_psk_t list[4];
size_t count;
} identities;
unsigned ke_modes;
int early_data_indication;
} psk;
ptls_raw_extension_t unknown_extensions[MAX_UNKNOWN_EXTENSIONS + 1];
unsigned status_request : 1;
};
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;
} 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;
} 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 {
uint8_t bits[8]; /* only ids below 64 is tracked */
};
static uint8_t zeroes_of_max_digest_size[PTLS_MAX_DIGEST_SIZE] = {0};
static int is_supported_version(uint16_t v)
{
size_t i;
for (i = 0; i != sizeof(supported_versions) / sizeof(supported_versions[0]); ++i)
if (supported_versions[i] == v)
return 1;
return 0;
}
static inline int extension_bitmap_is_set(struct st_ptls_extension_bitmap_t *bitmap, uint16_t id)
{
if (id < sizeof(bitmap->bits) * 8)
return (bitmap->bits[id / 8] & (1 << (id % 8))) != 0;
return 0;
}
static inline void extension_bitmap_set(struct st_ptls_extension_bitmap_t *bitmap, uint16_t id)
{
if (id < sizeof(bitmap->bits) * 8)
bitmap->bits[id / 8] |= 1 << (id % 8);
}
static inline void init_extension_bitmap(struct st_ptls_extension_bitmap_t *bitmap, uint8_t hstype)
{
*bitmap = (struct st_ptls_extension_bitmap_t){{0}};
#define EXT(extid, proc) \
do { \
int _found = 0; \
do { \
proc \
} while (0); \
if (!_found) \
extension_bitmap_set(bitmap, PTLS_EXTENSION_TYPE_##extid); \
} while (0)
#define ALLOW(allowed_hstype) _found = _found || hstype == PTLS_HANDSHAKE_TYPE_##allowed_hstype
/* Implements the table found in section 4.2 of draft-19; "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."
*/
EXT(SERVER_NAME, {
ALLOW(CLIENT_HELLO);
ALLOW(ENCRYPTED_EXTENSIONS);
});
EXT(STATUS_REQUEST, {
ALLOW(CLIENT_HELLO);
ALLOW(CERTIFICATE);
});
EXT(SUPPORTED_GROUPS, {
ALLOW(CLIENT_HELLO);
ALLOW(ENCRYPTED_EXTENSIONS);
});
EXT(SIGNATURE_ALGORITHMS, {
ALLOW(CLIENT_HELLO);
ALLOW(CERTIFICATE_REQUEST);
});
EXT(ALPN, {
ALLOW(CLIENT_HELLO);
ALLOW(ENCRYPTED_EXTENSIONS);
});
EXT(KEY_SHARE, {
ALLOW(CLIENT_HELLO);
ALLOW(SERVER_HELLO);
});
EXT(PRE_SHARED_KEY, {
ALLOW(CLIENT_HELLO);
ALLOW(SERVER_HELLO);
});
EXT(PSK_KEY_EXCHANGE_MODES, { ALLOW(CLIENT_HELLO); });
EXT(EARLY_DATA, {
ALLOW(CLIENT_HELLO);
ALLOW(ENCRYPTED_EXTENSIONS);
ALLOW(NEW_SESSION_TICKET);
});
EXT(COOKIE, {
ALLOW(CLIENT_HELLO);
ALLOW(SERVER_HELLO);
});
EXT(SUPPORTED_VERSIONS, {
ALLOW(CLIENT_HELLO);
ALLOW(SERVER_HELLO);
});
#undef ALLOW
#undef EXT
}
static uint16_t ntoh16(const uint8_t *src)
{
return (uint16_t)src[0] << 8 | src[1];
}
static uint32_t ntoh24(const uint8_t *src)
{
return (uint32_t)src[0] << 16 | (uint32_t)src[1] << 8 | src[2];
}
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];
}
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];
}
void ptls_buffer__release_memory(ptls_buffer_t *buf)
{
ptls_clear_memory(buf->base, buf->off);
if (buf->is_allocated)
free(buf->base);
}
int ptls_buffer_reserve(ptls_buffer_t *buf, size_t delta)
{
if (buf->base == NULL)
return PTLS_ERROR_NO_MEMORY;
if (PTLS_MEMORY_DEBUG || buf->capacity < buf->off + delta) {
uint8_t *newp;
size_t new_capacity = buf->capacity;
if (new_capacity < 1024)
new_capacity = 1024;
while (new_capacity < buf->off + delta) {
new_capacity *= 2;
}
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;
}
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_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;
}
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)
{
uint8_t aad[5];
size_t off = 0;
build_aad(aad, inlen + 1 + ctx->aead->algo->tag_size);
ptls_aead_encrypt_init(ctx->aead, ctx->seq++, aad, sizeof(aad));
off += ptls_aead_encrypt_update(ctx->aead, ((uint8_t *)output) + off, input, inlen);
off += ptls_aead_encrypt_update(ctx->aead, ((uint8_t *)output) + off, &content_type, 1);
off += ptls_aead_encrypt_final(ctx->aead, ((uint8_t *)output) + off);
return off;
}
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;
}
#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;
buffer_push_record(buf, PTLS_CONTENT_TYPE_APPDATA, {
if ((ret = ptls_buffer_reserve(buf, chunk_size + enc->aead->algo->tag_size + 1)) != 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 */
if (bodylen <= PTLS_MAX_PLAINTEXT_RECORD_SIZE) {
size_t overhead = 1 + enc->aead->algo->tag_size;
if ((ret = ptls_buffer_reserve(buf, overhead)) != 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(struct st_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(struct st_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] = sz >> 8;
self->super.buf->base[self->rec_start + 4] = sz;
ret = 0;
}
return ret;
}
#define buffer_push_handshake_body(buf, key_sched, type, block) \
do { \
size_t mess_start = (buf)->off; \
ptls_buffer_push((buf), (type)); \
ptls_buffer_push_block((buf), 3, { \
do { \
block \
} while (0); \
}); \
if ((key_sched) != NULL) \
key_schedule_update_hash((key_sched), (buf)->base + (mess_start), (buf)->off - (mess_start)); \
} while (0)
#define push_message(emitter, key_sched, type, block) \
do { \
if ((ret = (emitter)->begin_message(emitter)) != 0) \
goto Exit; \
buffer_push_handshake_body((emitter)->buf, (key_sched), (type), block); \
if ((ret = (emitter)->commit_message(emitter)) != 0) \
goto Exit; \
} while (0)
#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; \
init_extension_bitmap(&bitmap, (hstype)); \
ptls_decode_open_block((src), end, 2, { \
while ((src) != end) { \
if ((ret = ptls_decode16((exttype), &(src), end)) != 0) \
goto Exit; \
if (extension_bitmap_is_set(&bitmap, *(exttype)) != 0) { \
ret = PTLS_ALERT_ILLEGAL_PARAMETER; \
goto Exit; \
} \
extension_bitmap_set(&bitmap, *(exttype)); \
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_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_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;
}
static void key_schedule_free(struct st_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);
free(sched);
}
static struct st_ptls_key_schedule_t *key_schedule_new(ptls_cipher_suite_t *preferred, ptls_cipher_suite_t **offered)
{
#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)
struct st_ptls_key_schedule_t *sched;
{ /* allocate */
size_t num_hashes = 0;
FOREACH_HASH({ ++num_hashes; });
if ((sched = malloc(offsetof(struct st_ptls_key_schedule_t, hashes) + sizeof(sched->hashes[0]) * num_hashes)) == NULL)
return NULL;
*sched = (struct st_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;
++sched->num_hashes;
});
return sched;
Fail:
key_schedule_free(sched);
return NULL;
#undef FOREACH_HASH
}
static int key_schedule_extract(struct st_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_one(struct st_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 (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_update_hash(struct st_ptls_key_schedule_t *sched, const uint8_t *msg, size_t msglen)
{
size_t i;
PTLS_DEBUGF("%s:%zu\n", __FUNCTION__, msglen);
for (i = 0; i != sched->num_hashes; ++i)
sched->hashes[i].ctx->update(sched->hashes[i].ctx, msg, msglen);
}
static void key_schedule_update_ch1hash_prefix(struct st_ptls_key_schedule_t *sched)
{
uint8_t prefix[4] = {PTLS_HANDSHAKE_TYPE_MESSAGE_HASH, 0, 0, (uint8_t)sched->hashes[0].algo->digest_size};
key_schedule_update_hash(sched, prefix, sizeof(prefix));
}
static void key_schedule_extract_ch1hash(struct st_ptls_key_schedule_t *sched, uint8_t *hash)
{
sched->hashes[0].ctx->final(sched->hashes[0].ctx, hash, PTLS_HASH_FINAL_MODE_RESET);
}
static void key_schedule_transform_post_ch1hash(struct st_ptls_key_schedule_t *sched)
{
uint8_t ch1hash[PTLS_MAX_DIGEST_SIZE];
key_schedule_extract_ch1hash(sched, ch1hash);
key_schedule_update_ch1hash_prefix(sched);
key_schedule_update_hash(sched, ch1hash, sched->hashes[0].algo->digest_size);
}
static int derive_secret_with_hash(struct st_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(struct st_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(struct st_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;
if (tls->ctx->log_secret != NULL) {
const char *log_label = is_early ? "EARLY_EXPORTER_SECRET" : "EXPORTER_SECRET";
tls->ctx->log_secret->cb(tls->ctx->log_secret, tls, log_label,
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(struct st_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(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, {
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_context_t *ctx, 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(&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 = 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 = 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 = ctx->get_time->cb(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,
const char *base_label)
{
return ptls_hkdf_expand_label(algo, key, key_size, ptls_iovec_init(secret, algo->digest_size), is_iv ? "iv" : "key",
ptls_iovec_init(NULL, 0), base_label);
}
static int setup_traffic_protection(ptls_t *tls, int is_enc, const char *secret_label, size_t epoch)
{
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;
/* special path for applications having their own record layer */
if (tls->ctx->update_traffic_key != NULL)
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, NULL)) == NULL)
return PTLS_ERROR_NO_MEMORY; /* TODO obtain error from ptls_aead_new */
ctx->seq = 0;
if (tls->ctx->log_secret != NULL)
tls->ctx->log_secret->cb(tls->ctx->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));
PTLS_DEBUGF("[%s] %02x%02x,%02x%02x\n", log_labels[is_server][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 retire_early_data_secret(ptls_t *tls, int is_enc)
{
assert(tls->early_data != NULL);
memcpy((is_enc ? &tls->traffic_protection.enc : &tls->traffic_protection.dec)->secret, tls->early_data->next_secret,
PTLS_MAX_DIGEST_SIZE);
ptls_clear_memory(tls->early_data, sizeof(*tls->early_data));
free(tls->early_data);
tls->early_data = NULL;
return setup_traffic_protection(tls, is_enc, NULL, 2);
}
#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,
struct st_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, struct st_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, struct st_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 (memcmp(message.base + PTLS_HANDSHAKE_HEADER_SIZE, verify_data, tls->key_schedule->hashes[0].algo->digest_size) != 0) {
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, struct st_ptls_message_emitter_t *emitter)
{
int ret;
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, struct st_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);
{ /* calculate verify-data that will be sent by the client */
size_t orig_off = emitter->buf->off;
if (tls->early_data != NULL) {
assert(tls->state == PTLS_STATE_SERVER_EXPECT_END_OF_EARLY_DATA);
buffer_push_handshake_body(emitter->buf, tls->key_schedule, PTLS_HANDSHAKE_TYPE_END_OF_EARLY_DATA, {});
emitter->buf->off = orig_off;
}
buffer_push_handshake_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->early_data != NULL ? tls->early_data->next_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 */
ptls_buffer_init(&session_id, session_id_smallbuf, sizeof(session_id_smallbuf));
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 */
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_buffer_t *sendbuf)
{
int ret = 0;
if (!tls->send_change_cipher_spec)
goto Exit;
buffer_push_record(sendbuf, PTLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC, { ptls_buffer_push(sendbuf, 1); });
tls->send_change_cipher_spec = 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_buffer_t *sendbuf)
{
int ret;
ptls_buffer_push_block(sendbuf, 2, {
ptls_buffer_push16(sendbuf, PTLS_SIGNATURE_RSA_PSS_RSAE_SHA256);
ptls_buffer_push16(sendbuf, PTLS_SIGNATURE_ECDSA_SECP256R1_SHA256);
ptls_buffer_push16(sendbuf, PTLS_SIGNATURE_RSA_PKCS1_SHA256);
ptls_buffer_push16(sendbuf, PTLS_SIGNATURE_RSA_PKCS1_SHA1);
});
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 < sizeof(sa->list) / sizeof(sa->list[0]))
sa->list[sa->count++] = id;
} while (*src != end);
});
ret = 0;
Exit:
return ret;
}
static int send_client_hello(ptls_t *tls, struct st_ptls_message_emitter_t *emitter, ptls_handshake_properties_t *properties,
ptls_iovec_t *cookie)
{
ptls_iovec_t resumption_secret = {NULL}, resumption_ticket;
uint32_t obfuscated_ticket_age = 0;
size_t msghash_off;
uint8_t binder_key[PTLS_MAX_DIGEST_SIZE];
int ret, is_second_flight = tls->key_schedule != NULL;
if (properties != NULL) {
/* 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->ctx, &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;
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) {
*properties->client.max_early_data_size = max_early_data_size;
if ((tls->early_data = malloc(sizeof(*tls->early_data))) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
}
} else {
resumption_secret = ptls_iovec_init(NULL, 0);
}
}
if (properties->client.max_early_data_size != NULL && tls->early_data == NULL)
*properties->client.max_early_data_size = 0;
}
/* 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];
if (!is_second_flight) {
tls->key_schedule = key_schedule_new(tls->cipher_suite, tls->ctx->cipher_suites);
if ((ret = key_schedule_extract(tls->key_schedule, resumption_secret)) != 0)
goto Exit;
}
msghash_off = emitter->buf->off + emitter->record_header_length;
push_message(emitter, NULL, PTLS_HANDSHAKE_TYPE_CLIENT_HELLO, {
ptls_buffer_t *sendbuf = emitter->buf;
/* legacy_version */
ptls_buffer_push16(sendbuf, 0x0303);
/* random_bytes */
ptls_buffer_pushv(sendbuf, tls->client_random, sizeof(tls->client_random));
/* lecagy_session_id */
ptls_buffer_push_block(
sendbuf, 1, { ptls_buffer_pushv(sendbuf, tls->client.legacy_session_id, sizeof(tls->client.legacy_session_id)); });
/* cipher_suites */
ptls_buffer_push_block(sendbuf, 2, {
ptls_cipher_suite_t **cs = tls->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 (tls->server_name != NULL) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SERVER_NAME, {
ptls_buffer_push_block(sendbuf, 2, {
ptls_buffer_push(sendbuf, PTLS_SERVER_NAME_TYPE_HOSTNAME);
ptls_buffer_push_block(sendbuf, 2,
{ ptls_buffer_pushv(sendbuf, tls->server_name, strlen(tls->server_name)); });
});
});
}
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);
});
}
});
});
}
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SUPPORTED_VERSIONS, {
ptls_buffer_push_block(sendbuf, 1, {
size_t i;
for (i = 0; i != sizeof(supported_versions) / sizeof(supported_versions[0]); ++i)
ptls_buffer_push16(sendbuf, supported_versions[i]);
});
});
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SIGNATURE_ALGORITHMS, {
if ((ret = push_signature_algorithms(sendbuf)) != 0)
goto Exit;
});
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_SUPPORTED_GROUPS, {
ptls_key_exchange_algorithm_t **algo = tls->ctx->key_exchanges;
ptls_buffer_push_block(sendbuf, 2, {
for (; *algo != NULL; ++algo)
ptls_buffer_push16(sendbuf, (*algo)->id);
});
});
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_KEY_SHARE, {
ptls_buffer_push_block(sendbuf, 2, {
if (tls->key_share != NULL) {
ptls_iovec_t pubkey;
if ((ret = tls->key_share->create(&tls->client.key_share_ctx, &pubkey)) != 0)
goto Exit;
ptls_buffer_push16(sendbuf, tls->key_share->id);
ptls_buffer_push_block(sendbuf, 2, { ptls_buffer_pushv(sendbuf, pubkey.base, pubkey.len); });
}
});
});
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 ((ret = push_additional_extensions(properties, sendbuf)) != 0)
goto Exit;
if (tls->ctx->save_ticket != NULL) {
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_PSK_KEY_EXCHANGE_MODES, {
ptls_buffer_push_block(sendbuf, 1, {
if (!tls->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 (tls->early_data != NULL && !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,
{ ptls_buffer_pushv(sendbuf, resumption_ticket.base, resumption_ticket.len); });
ptls_buffer_push32(sendbuf, obfuscated_ticket_age);
});
/* allocate space for PSK binder. the space is filled at the bottom of the function */
ptls_buffer_push_block(sendbuf, 2, {
ptls_buffer_push_block(sendbuf, 1, {
if ((ret = ptls_buffer_reserve(sendbuf, tls->key_schedule->hashes[0].algo->digest_size)) != 0)
goto Exit;
sendbuf->off += tls->key_schedule->hashes[0].algo->digest_size;
});
});
});
}
}
});
});
/* 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;
key_schedule_update_hash(tls->key_schedule, emitter->buf->base + msghash_off, psk_binder_off - msghash_off);
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;
}
key_schedule_update_hash(tls->key_schedule, emitter->buf->base + msghash_off, emitter->buf->off - msghash_off);
if (tls->early_data != NULL) {
if ((ret = setup_traffic_protection(tls, 1, "c e traffic", 1)) != 0)
goto Exit;
if ((ret = push_change_cipher_spec(tls, emitter->buf)) != 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_clear_memory(binder_key, sizeof(binder_key));
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 ptls_cipher_suite_t *find_cipher_suite(ptls_context_t *ctx, uint16_t id)
{
ptls_cipher_suite_t **cs;
for (cs = ctx->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 = find_cipher_suite(tls->ctx, csid)) == NULL) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
}
/* legacy_compression_method */
if (src == end || *src++ != 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, PTLS_HANDSHAKE_TYPE_SERVER_HELLO, &exttype, {
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:
if (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;
});
} else {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
break;
case PTLS_EXTENSION_TYPE_PRE_SHARED_KEY:
if (sh->is_retry_request) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
} else {
if ((ret = ptls_decode16(&selected_psk_identity, &src, end)) != 0)
goto Exit;
}
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, struct st_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, NULL, ptls_iovec_init(NULL, 0));
tls->client.key_share_ctx = NULL;
}
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;
}
key_schedule_transform_post_ch1hash(tls->key_schedule);
key_schedule_update_hash(tls->key_schedule, message.base, message.len);
ret = send_client_hello(tls, emitter, properties, &sh->retry_request.cookie);
Exit:
return ret;
}
static int client_handle_hello(ptls_t *tls, struct st_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 == sizeof(tls->client.legacy_session_id) &&
memcmp(sh.legacy_session_id.base, tls->client.legacy_session_id, sizeof(tls->client.legacy_session_id)) == 0)) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
if (sh.is_retry_request) {
if ((ret = key_schedule_select_one(tls->key_schedule, tls->cipher_suite, 0)) != 0)
goto Exit;
return handle_hello_retry_request(tls, emitter, &sh, message, properties);
}
if ((ret = key_schedule_select_one(tls->key_schedule, tls->cipher_suite, tls->client.offered_psk && !tls->is_psk_handshake)) !=
0)
goto Exit;
if (sh.peerkey.base != NULL) {
if ((ret = tls->client.key_share_ctx->on_exchange(&tls->client.key_share_ctx, &ecdh_secret, sh.peerkey)) != 0)
goto Exit;
}
key_schedule_update_hash(tls->key_schedule, message.base, message.len);
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)
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 handle_unknown_extension(ptls_t *tls, ptls_handshake_properties_t *properties, uint16_t type, const uint8_t *src,
const uint8_t *const end, ptls_raw_extension_t *slots)
{
if (properties != NULL && properties->collect_extension != NULL && properties->collect_extension(tls, properties, type)) {
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;
ptls_raw_extension_t unknown_extensions[MAX_UNKNOWN_EXTENSIONS + 1];
int ret, skip_early_data = 1;
unknown_extensions[0].type = UINT16_MAX;
decode_extensions(src, end, PTLS_HANDSHAKE_TYPE_ENCRYPTED_EXTENSIONS, &type, {
switch (type) {
case PTLS_EXTENSION_TYPE_SERVER_NAME:
if (src != end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
if (tls->server_name == NULL) {
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 ((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->early_data == NULL) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
skip_early_data = 0;
break;
default:
handle_unknown_extension(tls, properties, type, src, end, unknown_extensions);
break;
}
src = end;
});
if (tls->early_data != NULL) {
tls->skip_early_data = skip_early_data;
if (properties != NULL && !skip_early_data)
properties->client.early_data_accepted_by_peer = 1;
if ((ret = derive_secret(tls->key_schedule, tls->early_data->next_secret, "c hs traffic")) != 0)
goto Exit;
} else {
if ((ret = setup_traffic_protection(tls, 1, "c hs traffic", 2)) != 0)
goto Exit;
}
if ((ret = report_unknown_extensions(tls, properties, unknown_extensions)) != 0)
goto Exit;
key_schedule_update_hash(tls->key_schedule, message.base, message.len);
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:
return ret;
}
static int decode_certificate_request(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, {
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;
}
static int send_certificate_and_certificate_verify(ptls_t *tls, struct st_ptls_message_emitter_t *emitter,
struct st_ptls_signature_algorithms_t *signature_algorithms,
ptls_iovec_t context, const char *context_string, uint8_t push_status_request)
{
int ret;
if (signature_algorithms->count == 0) {
ret = PTLS_ALERT_MISSING_EXTENSION;
goto Exit;
}
/* send Certificate */
push_message(emitter, tls->key_schedule, PTLS_HANDSHAKE_TYPE_CERTIFICATE, {
ptls_buffer_t *sendbuf = emitter->buf;
ptls_buffer_push_block(sendbuf, 1, { ptls_buffer_pushv(sendbuf, context.base, context.len); });
ptls_buffer_push_block(sendbuf, 3, {
size_t i;
for (i = 0; i != tls->ctx->certificates.count; ++i) {
ptls_buffer_push_block(sendbuf, 3, {
ptls_buffer_pushv(sendbuf, tls->ctx->certificates.list[i].base, tls->ctx->certificates.list[i].len);
});
ptls_buffer_push_block(sendbuf, 2, {
/* emit OCSP stapling only when requested and when the callback successfully returns one */
if (push_status_request && i == 0 && tls->ctx->staple_ocsp != NULL) {
size_t reset_off_to = sendbuf->off;
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_STATUS_REQUEST, {
ptls_buffer_push(sendbuf, 1); /* status_type == ocsp */
ptls_buffer_push_block(sendbuf, 3, {
if ((ret = tls->ctx->staple_ocsp->cb(tls->ctx->staple_ocsp, tls, sendbuf, i)) == 0) {
reset_off_to = 0;
}
});
});
if (reset_off_to != 0) {
sendbuf->off = reset_off_to;
}
}
});
}
});
});
/* build and send CertificateVerify */
if (tls->ctx->sign_certificate != NULL) {
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, &algo, sendbuf,
ptls_iovec_init(data, datalen), signature_algorithms->list,
signature_algorithms->count)) != 0) {
goto Exit;
}
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;
if ((ret = decode_certificate_request(&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;
key_schedule_update_hash(tls->key_schedule, message.base, message.len);
return PTLS_ERROR_IN_PROGRESS;
}
static int handle_certificate(ptls_t *tls, ptls_iovec_t message, int *got_certs)
{
const uint8_t *src = message.base + PTLS_HANDSHAKE_HEADER_SIZE, *const end = message.base + message.len;
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 < sizeof(certs) / sizeof(certs[0]))
certs[num_certs++] = ptls_iovec_init(src, end - src);
src = end;
});
uint16_t type;
decode_open_extensions(src, end, PTLS_HANDSHAKE_TYPE_CERTIFICATE, &type, { src = end; });
}
});
if (num_certs != 0 && tls->ctx->verify_certificate != NULL) {
if ((ret = tls->ctx->verify_certificate->cb(tls->ctx->verify_certificate, tls, &tls->certificate_verify.cb,
&tls->certificate_verify.verify_ctx, certs, num_certs)) != 0)
goto Exit;
}
key_schedule_update_hash(tls->key_schedule, message.base, message.len);
*got_certs = num_certs != 0;
Exit:
return ret;
}
static int client_handle_certificate(ptls_t *tls, ptls_iovec_t message)
{
int got_certs, ret;
if ((ret = handle_certificate(tls, message, &got_certs)) != 0)
return ret;
if (!got_certs)
return PTLS_ALERT_ILLEGAL_PARAMETER;
tls->state = PTLS_STATE_CLIENT_EXPECT_CERTIFICATE_VERIFY;
return PTLS_ERROR_IN_PROGRESS;
}
static int server_handle_certificate(ptls_t *tls, ptls_iovec_t message)
{
int got_certs, ret;
if ((ret = handle_certificate(tls, message, &got_certs)) != 0)
return ret;
if (!got_certs)
return PTLS_ALERT_CERTIFICATE_REQUIRED;
tls->state = PTLS_STATE_SERVER_EXPECT_CERTIFICATE_VERIFY;
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;
});
/* validate */
switch (algo) {
case PTLS_SIGNATURE_RSA_PSS_RSAE_SHA256:
case PTLS_SIGNATURE_ECDSA_SECP256R1_SHA256:
/* ok */
break;
default:
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
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, 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;
}
key_schedule_update_hash(tls->key_schedule, message.base, message.len);
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, struct st_ptls_message_emitter_t *emitter, ptls_iovec_t message)
{
uint8_t send_secret[PTLS_MAX_DIGEST_SIZE];
int ret;
if ((ret = verify_finished(tls, message)) != 0)
goto Exit;
key_schedule_update_hash(tls->key_schedule, message.base, message.len);
/* 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)
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->early_data != NULL) {
assert(tls->traffic_protection.enc.aead != NULL || tls->ctx->update_traffic_key != NULL);
if (!tls->skip_early_data) {
push_message(emitter, tls->key_schedule, PTLS_HANDSHAKE_TYPE_END_OF_EARLY_DATA, {});
}
if ((ret = retire_early_data_secret(tls, 1)) != 0)
goto Exit;
}
if (tls->client.certificate_request.context.base != NULL) {
/* If this is a resumed session, the server must not send the certificate request in the handshake */
if (tls->is_psk_handshake) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
ret = send_certificate_and_certificate_verify(tls, emitter, &tls->client.certificate_request.signature_algorithms,
tls->client.certificate_request.context,
PTLS_CLIENT_CERTIFICATE_VERIFY_CONTEXT_STRING, 0);
free(tls->client.certificate_request.context.base);
tls->client.certificate_request.context = ptls_iovec_init(NULL, 0);
if (ret != 0)
goto Exit;
}
if ((ret = push_change_cipher_spec(tls, emitter->buf)) != 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)
goto Exit;
tls->state = PTLS_STATE_CLIENT_POST_HANDSHAKE;
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(&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;
uint8_t ticket_buf_small[512];
ptls_buffer_init(&ticket_buf, ticket_buf_small, sizeof(ticket_buf_small));
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_block(src, end, 2, {
if (src == end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
do {
uint8_t type = *src++;
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_cipher_suite(ptls_cipher_suite_t **selected, ptls_cipher_suite_t **candidates, const uint8_t *src,
const uint8_t *const end)
{
int ret;
ptls_decode_block(src, end, 2, {
while (src != end) {
uint16_t id;
if ((ret = ptls_decode16(&id, &src, end)) != 0)
goto Exit;
ptls_cipher_suite_t **c = candidates;
for (; *c != NULL; ++c) {
if ((*c)->id == id) {
*selected = *c;
return 0;
}
}
}
});
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
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 ret;
ptls_decode_block(src, end, 2, {
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 ((*c)->id == group) {
*selected = *c;
*peer_key = key;
return 0;
}
}
}
});
*selected = NULL;
ret = 0;
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_t *tls, struct st_ptls_client_hello_t *ch, const uint8_t *src, const uint8_t *const end,
ptls_handshake_properties_t *properties)
{
uint16_t exttype = 0;
int ret;
{ /* check protocol version */
uint16_t protver;
if ((ret = ptls_decode16(&protver, &src, end)) != 0)
goto Exit;
if (protver != 0x0303) {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
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, {
ch->cipher_suites = ptls_iovec_init(src - 2, end - src + 2);
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;
});
/* decode extensions */
decode_extensions(src, end, PTLS_HANDSHAKE_TYPE_CLIENT_HELLO, &exttype, {
switch (exttype) {
case PTLS_EXTENSION_TYPE_SERVER_NAME:
if ((ret = client_hello_decode_server_name(&ch->server_name, src, end)) != 0)
goto Exit;
break;
case PTLS_EXTENSION_TYPE_ALPN:
ptls_decode_block(src, end, 2, {
do {
ptls_decode_open_block(src, end, 1, {
if (ch->alpn.count < sizeof(ch->alpn.list) / sizeof(ch->alpn.list[0]))
ch->alpn.list[ch->alpn.count++] = ptls_iovec_init(src, end - src);
src = end;
});
} 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 = sizeof(supported_versions) / sizeof(supported_versions[0]);
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 != sizeof(supported_versions) / sizeof(supported_versions[0]))
ch->selected_version = supported_versions[selected_index];
});
break;
case PTLS_EXTENSION_TYPE_COOKIE:
if (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;
});
if (src == end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
switch (*src++) {
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 < sizeof(ch->psk.identities.list) / sizeof(ch->psk.identities.list[0]))
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;
}
});
} break;
case PTLS_EXTENSION_TYPE_PSK_KEY_EXCHANGE_MODES:
ptls_decode_block(src, end, 1, {
if (src == end) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
for (; src != end; ++src) {
if (*src < sizeof(ch->psk.ke_modes) * 8)
ch->psk.ke_modes |= 1u << *src;
}
});
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;
default:
handle_unknown_extension(tls, properties, exttype, src, end, ch->unknown_extensions);
break;
}
src = end;
});
/* check if client hello make sense */
if (is_supported_version(ch->selected_version)) {
if (!(ch->compression_methods.count == 1 && ch->compression_methods.ids[0] == 0)) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
/* pre-shared key */
if (ch->psk.hash_end != NULL) {
/* PSK must be the last extension */
if (exttype != PTLS_EXTENSION_TYPE_PRE_SHARED_KEY) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
} else {
if (ch->psk.early_data_indication) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
goto Exit;
}
}
} else {
ret = PTLS_ALERT_PROTOCOL_VERSION;
goto Exit;
}
ret = 0;
Exit:
return ret;
}
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 decbuf_small[256], binder_key[PTLS_MAX_DIGEST_SIZE], verify_data[PTLS_MAX_DIGEST_SIZE];
int ret;
ptls_buffer_init(&decbuf, decbuf_small, sizeof(decbuf_small));
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 */
decbuf.off = 0;
if ((tls->ctx->encrypt_ticket->cb(tls->ctx->encrypt_ticket, tls, 0, &decbuf, identity->identity)) != 0)
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) {
int64_t delta = (now - issue_at) - (identity->obfuscated_ticket_age - age_add);
if (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;
key_schedule_update_hash(tls->key_schedule, ch_trunc.base, ch_trunc.len);
if ((ret = calc_verify_data(verify_data, tls->key_schedule, binder_key)) != 0)
goto Exit;
if (memcmp(ch->psk.identities.list[*psk_index].binder.base, verify_data, tls->key_schedule->hashes[0].algo->digest_size) != 0) {
ret = PTLS_ALERT_DECRYPT_ERROR;
goto Exit;
}
ret = 0;
Exit:
ptls_buffer_dispose(&decbuf);
ptls_clear_memory(binder_key, sizeof(binder_key));
ptls_clear_memory(verify_data, sizeof(verify_data));
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 server_handle_hello(ptls_t *tls, struct st_ptls_message_emitter_t *emitter, ptls_iovec_t message,
ptls_handshake_properties_t *properties)
{
#define EMIT_SERVER_HELLO(sched, fill_rand, extensions) \
push_message(emitter, (sched), PTLS_HANDSHAKE_TYPE_SERVER_HELLO, { \
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); \
}); \
});
#define EMIT_HELLO_RETRY_REQUEST(sched, negotiated_group, additional_extensions) \
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); \
})
struct st_ptls_client_hello_t ch = {NULL, {NULL}, {NULL}, 0, {NULL}, {NULL}, {NULL},
{{0}}, {NULL}, {{{NULL}}}, {{NULL}}, {NULL}, {{UINT16_MAX}}};
struct {
ptls_key_exchange_algorithm_t *algorithm;
ptls_iovec_t peer_key;
} key_share = {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};
uint8_t finished_key[PTLS_MAX_DIGEST_SIZE];
int accept_early_data = 0, is_second_flight = tls->state == PTLS_STATE_SERVER_EXPECT_SECOND_CLIENT_HELLO, ret;
/* decode ClientHello */
if ((ret = decode_client_hello(tls, &ch, message.base + PTLS_HANDSHAKE_HEADER_SIZE, message.base + message.len, properties)) !=
0)
goto Exit;
if (tls->ctx->require_dhe_on_psk)
ch.psk.ke_modes &= ~(1u << PTLS_PSK_KE_MODE_PSK);
/* handle client_random and SNI */
if (!is_second_flight) {
memcpy(tls->client_random, ch.random_bytes, sizeof(tls->client_random));
if (ch.server_name.base != NULL) {
if ((tls->server_name = malloc(ch.server_name.len + 1)) == NULL) {
ret = PTLS_ERROR_NO_MEMORY;
goto Exit;
}
memcpy(tls->server_name, ch.server_name.base, ch.server_name.len);
tls->server_name[ch.server_name.len] = '\0';
}
if (tls->ctx->on_client_hello != NULL &&
(ret = tls->ctx->on_client_hello->cb(tls->ctx->on_client_hello, tls, ch.server_name, ch.alpn.list, ch.alpn.count,
ch.signature_algorithms.list, ch.signature_algorithms.count)) != 0)
goto Exit;
} else {
if (ch.psk.early_data_indication) {
ret = PTLS_ALERT_DECODE_ERROR;
goto Exit;
}
if (memcmp(tls->client_random, ch.random_bytes, sizeof(tls->client_random)) != 0 ||
(tls->server_name != NULL) != (ch.server_name.base != NULL) ||
(tls->server_name != NULL &&
!(strncmp(tls->server_name, (char *)ch.server_name.base, ch.server_name.len) == 0 &&
tls->server_name[ch.server_name.len] == '\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_suite(&cs, tls->ctx->cipher_suites, ch.cipher_suites.base,
ch.cipher_suites.base + ch.cipher_suites.len)) != 0)
goto Exit;
if (!is_second_flight) {
tls->cipher_suite = cs;
tls->key_schedule = key_schedule_new(cs, NULL);
} else {
if (tls->cipher_suite != cs) {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
goto Exit;
}
}
}
/* select key_share */
if (ch.key_shares.base != NULL &&
(ret = select_key_share(&key_share.algorithm, &key_share.peer_key, tls->ctx->key_exchanges, ch.key_shares.base,
ch.key_shares.base + ch.key_shares.len)) != 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 && memcmp(ch.cookie.signature.base, sig, sigsize) == 0)) {
ret = PTLS_ALERT_HANDSHAKE_FAILURE;
goto Exit;
}
/* integrity check passed; update states */
key_schedule_update_ch1hash_prefix(tls->key_schedule);
key_schedule_update_hash(tls->key_schedule, ch.cookie.ch1_hash.base, ch.cookie.ch1_hash.len);
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;
key_schedule_update_hash(tls->key_schedule, message.base, message.len);
assert(tls->key_schedule->generation == 0);
if (properties != NULL && properties->server.retry_uses_cookie) {
/* emit HRR with cookie (note: we MUST omit KeyShare if the client has specified the correct one; see 46554f0) */
EMIT_HELLO_RETRY_REQUEST(NULL, key_share.algorithm != NULL ? NULL : negotiated_group, {
ptls_buffer_t *sendbuf = emitter->buf;
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 ((ret = push_change_cipher_spec(tls, emitter->buf)) != 0)
goto Exit;
ret = PTLS_ERROR_STATELESS_RETRY;
} else {
/* invoking stateful retry; roll the key schedule and emit HRR */
key_schedule_transform_post_ch1hash(tls->key_schedule);
key_schedule_extract(tls->key_schedule, ptls_iovec_init(NULL, 0));
EMIT_HELLO_RETRY_REQUEST(tls->key_schedule, key_share.algorithm != NULL ? NULL : negotiated_group, {});
if ((ret = push_change_cipher_spec(tls, emitter->buf)) != 0)
goto Exit;
tls->state = PTLS_STATE_SERVER_EXPECT_SECOND_CLIENT_HELLO;
if (ch.psk.early_data_indication)
tls->skip_early_data = 1;
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) {
key_schedule_update_hash(tls->key_schedule, message.base, message.len);
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 {
key_schedule_update_hash(tls->key_schedule, ch.psk.hash_end, message.base + message.len - ch.psk.hash_end);
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;
}
}
if (accept_early_data && tls->ctx->max_early_data_size != 0 && psk_index == 0) {
if ((tls->early_data = malloc(sizeof(*tls->early_data))) == 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)
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(&pubkey, &ecdh_secret, key_share.peer_key)) != 0)
goto Exit;
tls->key_share = key_share.algorithm;
}
/* send ServerHello */
EMIT_SERVER_HELLO(tls->key_schedule,
{ tls->ctx->random_bytes(emitter->buf->base + emitter->buf->off, PTLS_HELLO_RANDOM_SIZE); },
{
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 ((ret = push_change_cipher_spec(tls, emitter->buf)) != 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)
goto Exit;
if (tls->early_data != NULL) {
if ((ret = derive_secret(tls->key_schedule, tls->early_data->next_secret, "c hs traffic")) != 0)
goto Exit;
} else {
if ((ret = setup_traffic_protection(tls, 0, "c hs traffic", 2)) != 0)
goto Exit;
if (ch.psk.early_data_indication)
tls->skip_early_data = 1;
}
/* send EncryptedExtensions */
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->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->early_data != NULL)
buffer_push_extension(sendbuf, PTLS_EXTENSION_TYPE_EARLY_DATA, {});
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) {
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(sendbuf)) != 0)
goto Exit;
});
});
});
if (ret != 0) {
goto Exit;
}
}
ret = send_certificate_and_certificate_verify(tls, emitter, &ch.signature_algorithms, ptls_iovec_init(NULL, 0),
PTLS_SERVER_CERTIFICATE_VERIFY_CONTEXT_STRING, ch.status_request);
if (ret != 0) {
goto Exit;
}
}
send_finished(tls, emitter);
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)
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->early_data != NULL) {
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 (ch.psk.ke_modes != 0 && 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:
free(pubkey.base);
free(ecdh_secret.base);
ptls_clear_memory(finished_key, sizeof(finished_key));
return ret;
#undef EMIT_SERVER_HELLO
#undef EMIT_HELLO_RETRY_REQUEST
}
static int server_handle_end_of_early_data(ptls_t *tls, ptls_iovec_t message)
{
int ret;
if ((ret = retire_early_data_secret(tls, 0)) != 0)
goto Exit;
key_schedule_update_hash(tls->key_schedule, message.base, message.len);
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)
return ret;
key_schedule_update_hash(tls->key_schedule, message.base, message.len);
tls->state = PTLS_STATE_SERVER_POST_HANDSHAKE;
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;
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);
}
ptls_t *ptls_new(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;
if (!is_server) {
tls->state = PTLS_STATE_CLIENT_HANDSHAKE_START;
tls->ctx->random_bytes(tls->client_random, sizeof(tls->client_random));
tls->ctx->random_bytes(tls->client.legacy_session_id, sizeof(tls->client.legacy_session_id));
} else {
tls->state = PTLS_STATE_SERVER_EXPECT_CLIENT_HELLO;
}
return tls;
}
void ptls_free(ptls_t *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);
if (tls->is_server) {
/* nothing to do */
} else {
if (tls->client.key_share_ctx != NULL)
tls->client.key_share_ctx->on_exchange(&tls->client.key_share_ctx, 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, ptls_iovec_init(NULL, 0), ptls_iovec_init(NULL, 0));
}
if (tls->early_data != NULL) {
ptls_clear_memory(tls->early_data, sizeof(*tls->early_data));
free(tls->early_data);
}
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_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;
}
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) {
if (server_name_len == 0)
server_name_len = strlen(server_name);
if ((duped = malloc(server_name_len + 1)) == NULL)
return PTLS_ERROR_NO_MEMORY;
memcpy(duped, server_name, server_name_len);
duped[server_name_len] = '\0';
}
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) {
if (protocol_len == 0)
protocol_len = strlen(protocol);
if ((duped = malloc(protocol_len + 1)) == NULL)
return PTLS_ERROR_NO_MEMORY;
memcpy(duped, protocol, protocol_len);
duped[protocol_len] = '\0';
}
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;
}
void **ptls_get_data_ptr(ptls_t *tls)
{
return &tls->data_ptr;
}
static int handle_handshake_message(ptls_t *tls, struct st_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:
switch (type) {
case PTLS_HANDSHAKE_TYPE_CERTIFICATE_REQUEST:
ret = client_handle_certificate_request(tls, message, properties);
break;
case PTLS_HANDSHAKE_TYPE_CERTIFICATE:
ret = client_handle_certificate(tls, message);
break;
default:
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
break;
}
break;
case PTLS_STATE_CLIENT_EXPECT_CERTIFICATE:
if (type == PTLS_HANDSHAKE_TYPE_CERTIFICATE) {
ret = client_handle_certificate(tls, message);
} else {
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
}
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_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:
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_CLIENT_POST_HANDSHAKE:
switch (type) {
case PTLS_HANDSHAKE_TYPE_NEW_SESSION_TICKET:
ret = client_handle_new_session_ticket(tls, message);
break;
default:
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
break;
}
break;
case PTLS_STATE_SERVER_POST_HANDSHAKE:
ret = PTLS_ALERT_UNEXPECTED_MESSAGE;
break;
default:
assert(!"unexpected state");
break;
}
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 level = src[0], desc = src[1];
/* ignore certain warnings */
if (level == PTLS_ALERT_LEVEL_WARNING) {
switch (desc) {
case PTLS_ALERT_USER_CANCELED:
return 0;
default:
break;
}
}
/* all other alerts are considered fatal, regardless of the transmitted level (section 6) */
return PTLS_ALERT_TO_PEER_ERROR(desc);
}
static int handle_handshake_record(ptls_t *tls,
int (*cb)(ptls_t *tls, struct st_ptls_message_emitter_t *emitter, ptls_iovec_t message,
int is_end_of_record, ptls_handshake_properties_t *properties),
struct st_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 ((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_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) {
if (tls->recvbuf.mess.base == NULL) {
ptls_buffer_init(&tls->recvbuf.mess, "", 0);
if ((ret = ptls_buffer_reserve(&tls->recvbuf.mess, src_end - src)) != 0)
return ret;
memcpy(tls->recvbuf.mess.base, src, src_end - src);
} else {
memmove(tls->recvbuf.mess.base, src, src_end - src);
}
tls->recvbuf.mess.off = src_end - src;
ret = PTLS_ERROR_IN_PROGRESS;
} else {
ptls_buffer_dispose(&tls->recvbuf.mess);
}
return ret;
}
static int handle_input(ptls_t *tls, struct st_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) {
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, &rec.length, rec.fragment,
rec.length)) != 0) {
if (tls->skip_early_data) {
ret = PTLS_ERROR_IN_PROGRESS;
goto NextRecord;
}
return ret;
}
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->skip_early_data) {
ret = PTLS_ERROR_IN_PROGRESS;
goto NextRecord;
}
if (tls->recvbuf.mess.base != NULL || rec.type == PTLS_CONTENT_TYPE_HANDSHAKE) {
/* handshake record */
ret = handle_handshake_record(tls, handle_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;
}
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 = {
{_sendbuf, &tls->traffic_protection.enc, 5, begin_record_message, commit_record_message}};
size_t sendbuf_orig_off = emitter.super.buf->off;
int ret;
assert(tls->state < PTLS_STATE_POST_HANDSHAKE_MIN);
/* 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);
}
default:
break;
}
const uint8_t *src = input, *const src_end = src + *inlen;
ptls_buffer_t decryptbuf;
uint8_t decryptbuf_small[256];
ptls_buffer_init(&decryptbuf, decryptbuf_small, sizeof(decryptbuf_small));
/* 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:
break;
default:
/* flush partially written response */
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;
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;
}
int ptls_send(ptls_t *tls, ptls_buffer_t *sendbuf, const void *input, size_t inlen)
{
assert(tls->traffic_protection.enc.aead != NULL);
return buffer_push_encrypted_records(sendbuf, PTLS_CONTENT_TYPE_APPDATA, input, inlen, &tls->traffic_protection.enc);
}
size_t ptls_get_record_overhead(ptls_t *tls)
{
return 6 + tls->traffic_protection.enc.aead->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;
ptls_hash_context_t *hctx;
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 ((hctx = algo->create()) == NULL)
return PTLS_ERROR_NO_MEMORY;
hctx->update(hctx, context_value.base, context_value.len);
hctx->final(hctx, context_value_hash, PTLS_HASH_FINAL_MODE_FREE);
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;
}
}
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;
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 *base_label)
{
ptls_buffer_t hkdf_label;
uint8_t hkdf_label_buf[512];
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 (base_label == NULL)
base_label = "tls13 ";
ptls_buffer_pushv(&hkdf_label, base_label, strlen(base_label));
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;
}
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 *ptls_aead_new(ptls_aead_algorithm_t *aead, ptls_hash_algorithm_t *hash, int is_enc, const void *secret,
const char *base_label)
{
ptls_aead_context_t *ctx;
uint8_t key[PTLS_MAX_SECRET_SIZE];
int ret;
if ((ctx = (ptls_aead_context_t *)malloc(aead->context_size)) == NULL)
return NULL;
*ctx = (ptls_aead_context_t){aead};
if ((ret = get_traffic_key(hash, key, aead->key_size, 0, secret, base_label)) != 0)
goto Exit;
if ((ret = get_traffic_key(hash, ctx->static_iv, aead->iv_size, 1, secret, base_label)) != 0)
goto Exit;
ret = aead->setup_crypto(ctx, is_enc, key);
Exit:
ptls_clear_memory(key, aead->key_size);
if (ret != 0) {
ptls_clear_memory(ctx->static_iv, aead->iv_size);
free(ctx);
ctx = NULL;
}
return ctx;
}
void ptls_aead_free(ptls_aead_context_t *ctx)
{
ctx->dispose_crypto(ctx);
ptls_clear_memory(ctx->static_iv, ctx->algo->iv_size);
free(ctx);
}
size_t ptls_aead_encrypt(ptls_aead_context_t *ctx, void *output, const void *input, size_t inlen, uint64_t seq, const void *aad,
size_t aadlen)
{
size_t off = 0;
ptls_aead_encrypt_init(ctx, seq, aad, aadlen);
off += ptls_aead_encrypt_update(ctx, ((uint8_t *)output) + off, input, inlen);
off += ptls_aead_encrypt_final(ctx, ((uint8_t *)output) + off);
return off;
}
void ptls_aead__build_iv(ptls_aead_context_t *ctx, uint8_t *iv, uint64_t seq)
{
size_t iv_size = ctx->algo->iv_size, i;
const uint8_t *s = ctx->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 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};
int ptls_is_server(ptls_t *tls)
{
return tls->is_server;
}
struct st_ptls_raw_message_emitter_t {
struct st_ptls_message_emitter_t super;
size_t *epoch_offsets;
};
static int begin_raw_message(struct st_ptls_message_emitter_t *_self)
{
return 0;
}
static int commit_raw_message(struct st_ptls_message_emitter_t *_self)
{
struct st_ptls_raw_message_emitter_t *self = (void *)_self;
size_t i;
for (i = self->super.enc->epoch + 1; i < 5; ++i)
self->epoch_offsets[i] = self->super.buf->off;
return 0;
}
static int validate_epoch(enum en_ptls_state_t state, size_t epoch)
{
switch (epoch) {
case 0: /* plaintext */
switch (state) {
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 1;
default:
break;
}
break;
case 1: /* 0-rtt */
switch (state) {
case PTLS_STATE_SERVER_EXPECT_END_OF_EARLY_DATA:
return 1;
default:
break;
}
break;
case 2: /* handshake */
switch (state) {
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_EXPECT_CERTIFICATE:
case PTLS_STATE_SERVER_EXPECT_CERTIFICATE_VERIFY:
case PTLS_STATE_SERVER_EXPECT_FINISHED:
return 1;
default:
break;
}
break;
case 3: /* 1-rtt */
switch (state) {
case PTLS_STATE_CLIENT_POST_HANDSHAKE:
case PTLS_STATE_SERVER_POST_HANDSHAKE:
return 1;
default:
break;
}
break;
default:
break;
}
return 0;
}
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)
{
struct st_ptls_raw_message_emitter_t emitter = {
{sendbuf, &tls->traffic_protection.enc, 0, begin_raw_message, commit_raw_message}, 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 (!validate_epoch(tls->state, in_epoch))
return PTLS_ALERT_UNEXPECTED_MESSAGE;
return handle_handshake_record(tls, handle_handshake_message, &emitter.super, &rec, properties);
}