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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* ====================================================================
* Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com). */
#include <openssl/ssl.h>
#include <assert.h>
#include <string.h>
#include <openssl/bytestring.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include "internal.h"
#include "../crypto/internal.h"
namespace bssl {
// kMaxEmptyRecords is the number of consecutive, empty records that will be
// processed. Without this limit an attacker could send empty records at a
// faster rate than we can process and cause record processing to loop
// forever.
static const uint8_t kMaxEmptyRecords = 32;
// kMaxEarlyDataSkipped is the maximum number of rejected early data bytes that
// will be skipped. Without this limit an attacker could send records at a
// faster rate than we can process and cause trial decryption to loop forever.
// This value should be slightly above kMaxEarlyDataAccepted, which is measured
// in plaintext.
static const size_t kMaxEarlyDataSkipped = 16384;
// kMaxWarningAlerts is the number of consecutive warning alerts that will be
// processed.
static const uint8_t kMaxWarningAlerts = 4;
// ssl_needs_record_splitting returns one if |ssl|'s current outgoing cipher
// state needs record-splitting and zero otherwise.
static int ssl_needs_record_splitting(const SSL *ssl) {
#if !defined(BORINGSSL_UNSAFE_FUZZER_MODE)
return !ssl->s3->aead_write_ctx->is_null_cipher() &&
ssl->s3->aead_write_ctx->ProtocolVersion() < TLS1_1_VERSION &&
(ssl->mode & SSL_MODE_CBC_RECORD_SPLITTING) != 0 &&
SSL_CIPHER_is_block_cipher(ssl->s3->aead_write_ctx->cipher());
#else
return 0;
#endif
}
int ssl_record_sequence_update(uint8_t *seq, size_t seq_len) {
for (size_t i = seq_len - 1; i < seq_len; i--) {
++seq[i];
if (seq[i] != 0) {
return 1;
}
}
OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
return 0;
}
size_t ssl_record_prefix_len(const SSL *ssl) {
size_t header_len;
if (SSL_is_dtls(ssl)) {
header_len = DTLS1_RT_HEADER_LENGTH;
} else {
header_len = SSL3_RT_HEADER_LENGTH;
}
return header_len + ssl->s3->aead_read_ctx->ExplicitNonceLen();
}
size_t ssl_seal_align_prefix_len(const SSL *ssl) {
if (SSL_is_dtls(ssl)) {
return DTLS1_RT_HEADER_LENGTH + ssl->s3->aead_write_ctx->ExplicitNonceLen();
}
size_t ret =
SSL3_RT_HEADER_LENGTH + ssl->s3->aead_write_ctx->ExplicitNonceLen();
if (ssl_needs_record_splitting(ssl)) {
ret += SSL3_RT_HEADER_LENGTH;
ret += ssl_cipher_get_record_split_len(ssl->s3->aead_write_ctx->cipher());
}
return ret;
}
static ssl_open_record_t skip_early_data(SSL *ssl, uint8_t *out_alert,
size_t consumed) {
ssl->s3->early_data_skipped += consumed;
if (ssl->s3->early_data_skipped < consumed) {
ssl->s3->early_data_skipped = kMaxEarlyDataSkipped + 1;
}
if (ssl->s3->early_data_skipped > kMaxEarlyDataSkipped) {
OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MUCH_SKIPPED_EARLY_DATA);
*out_alert = SSL_AD_UNEXPECTED_MESSAGE;
return ssl_open_record_error;
}
return ssl_open_record_discard;
}
ssl_open_record_t tls_open_record(SSL *ssl, uint8_t *out_type,
Span<uint8_t> *out, size_t *out_consumed,
uint8_t *out_alert, Span<uint8_t> in) {
*out_consumed = 0;
if (ssl->s3->read_shutdown == ssl_shutdown_close_notify) {
return ssl_open_record_close_notify;
}
// If there is an unprocessed handshake message or we are already buffering
// too much, stop before decrypting another handshake record.
if (!tls_can_accept_handshake_data(ssl, out_alert)) {
return ssl_open_record_error;
}
CBS cbs = CBS(in);
// Decode the record header.
uint8_t type;
uint16_t version, ciphertext_len;
if (!CBS_get_u8(&cbs, &type) ||
!CBS_get_u16(&cbs, &version) ||
!CBS_get_u16(&cbs, &ciphertext_len)) {
*out_consumed = SSL3_RT_HEADER_LENGTH;
return ssl_open_record_partial;
}
bool version_ok;
if (ssl->s3->aead_read_ctx->is_null_cipher()) {
// Only check the first byte. Enforcing beyond that can prevent decoding
// version negotiation failure alerts.
version_ok = (version >> 8) == SSL3_VERSION_MAJOR;
} else {
version_ok = version == ssl->s3->aead_read_ctx->RecordVersion();
}
if (!version_ok) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_VERSION_NUMBER);
*out_alert = SSL_AD_PROTOCOL_VERSION;
return ssl_open_record_error;
}
// Check the ciphertext length.
if (ciphertext_len > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
OPENSSL_PUT_ERROR(SSL, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
*out_alert = SSL_AD_RECORD_OVERFLOW;
return ssl_open_record_error;
}
// Extract the body.
CBS body;
if (!CBS_get_bytes(&cbs, &body, ciphertext_len)) {
*out_consumed = SSL3_RT_HEADER_LENGTH + (size_t)ciphertext_len;
return ssl_open_record_partial;
}
ssl_do_msg_callback(ssl, 0 /* read */, SSL3_RT_HEADER,
in.subspan(0, SSL3_RT_HEADER_LENGTH));
*out_consumed = in.size() - CBS_len(&cbs);
if (ssl->s3->have_version &&
ssl_protocol_version(ssl) >= TLS1_3_VERSION &&
SSL_in_init(ssl) &&
type == SSL3_RT_CHANGE_CIPHER_SPEC &&
ciphertext_len == 1 &&
CBS_data(&body)[0] == 1) {
ssl->s3->empty_record_count++;
if (ssl->s3->empty_record_count > kMaxEmptyRecords) {
OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MANY_EMPTY_FRAGMENTS);
*out_alert = SSL_AD_UNEXPECTED_MESSAGE;
return ssl_open_record_error;
}
return ssl_open_record_discard;
}
// Skip early data received when expecting a second ClientHello if we rejected
// 0RTT.
if (ssl->s3->skip_early_data &&
ssl->s3->aead_read_ctx->is_null_cipher() &&
type == SSL3_RT_APPLICATION_DATA) {
return skip_early_data(ssl, out_alert, *out_consumed);
}
// Decrypt the body in-place.
if (!ssl->s3->aead_read_ctx->Open(
out, type, version, ssl->s3->read_sequence,
MakeSpan(const_cast<uint8_t *>(CBS_data(&body)), CBS_len(&body)))) {
if (ssl->s3->skip_early_data && !ssl->s3->aead_read_ctx->is_null_cipher()) {
ERR_clear_error();
return skip_early_data(ssl, out_alert, *out_consumed);
}
OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
*out_alert = SSL_AD_BAD_RECORD_MAC;
return ssl_open_record_error;
}
ssl->s3->skip_early_data = false;
if (!ssl_record_sequence_update(ssl->s3->read_sequence, 8)) {
*out_alert = SSL_AD_INTERNAL_ERROR;
return ssl_open_record_error;
}
// TLS 1.3 hides the record type inside the encrypted data.
bool has_padding =
!ssl->s3->aead_read_ctx->is_null_cipher() &&
ssl->s3->aead_read_ctx->ProtocolVersion() >= TLS1_3_VERSION;
// If there is padding, the plaintext limit includes the padding, but includes
// extra room for the inner content type.
size_t plaintext_limit =
has_padding ? SSL3_RT_MAX_PLAIN_LENGTH + 1 : SSL3_RT_MAX_PLAIN_LENGTH;
if (out->size() > plaintext_limit) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_LENGTH_TOO_LONG);
*out_alert = SSL_AD_RECORD_OVERFLOW;
return ssl_open_record_error;
}
if (has_padding) {
// The outer record type is always application_data.
if (type != SSL3_RT_APPLICATION_DATA) {
OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_OUTER_RECORD_TYPE);
*out_alert = SSL_AD_DECODE_ERROR;
return ssl_open_record_error;
}
do {
if (out->empty()) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
*out_alert = SSL_AD_DECRYPT_ERROR;
return ssl_open_record_error;
}
type = out->back();
*out = out->subspan(0, out->size() - 1);
} while (type == 0);
}
// Limit the number of consecutive empty records.
if (out->empty()) {
ssl->s3->empty_record_count++;
if (ssl->s3->empty_record_count > kMaxEmptyRecords) {
OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MANY_EMPTY_FRAGMENTS);
*out_alert = SSL_AD_UNEXPECTED_MESSAGE;
return ssl_open_record_error;
}
// Apart from the limit, empty records are returned up to the caller. This
// allows the caller to reject records of the wrong type.
} else {
ssl->s3->empty_record_count = 0;
}
if (type == SSL3_RT_ALERT) {
return ssl_process_alert(ssl, out_alert, *out);
}
// Handshake messages may not interleave with any other record type.
if (type != SSL3_RT_HANDSHAKE &&
tls_has_unprocessed_handshake_data(ssl)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
*out_alert = SSL_AD_UNEXPECTED_MESSAGE;
return ssl_open_record_error;
}
ssl->s3->warning_alert_count = 0;
*out_type = type;
return ssl_open_record_success;
}
static int do_seal_record(SSL *ssl, uint8_t *out_prefix, uint8_t *out,
uint8_t *out_suffix, uint8_t type, const uint8_t *in,
const size_t in_len) {
uint8_t *extra_in = NULL;
size_t extra_in_len = 0;
if (!ssl->s3->aead_write_ctx->is_null_cipher() &&
ssl->s3->aead_write_ctx->ProtocolVersion() >= TLS1_3_VERSION) {
// TLS 1.3 hides the actual record type inside the encrypted data.
extra_in = &type;
extra_in_len = 1;
}
size_t suffix_len;
if (!ssl->s3->aead_write_ctx->SuffixLen(&suffix_len, in_len, extra_in_len)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE);
return 0;
}
size_t ciphertext_len =
ssl->s3->aead_write_ctx->ExplicitNonceLen() + suffix_len;
if (ciphertext_len + in_len < ciphertext_len) {
OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE);
return 0;
}
ciphertext_len += in_len;
assert(in == out || !buffers_alias(in, in_len, out, in_len));
assert(!buffers_alias(in, in_len, out_prefix, ssl_record_prefix_len(ssl)));
assert(!buffers_alias(in, in_len, out_suffix, suffix_len));
if (extra_in_len) {
out_prefix[0] = SSL3_RT_APPLICATION_DATA;
} else {
out_prefix[0] = type;
}
uint16_t record_version = ssl->s3->aead_write_ctx->RecordVersion();
out_prefix[1] = record_version >> 8;
out_prefix[2] = record_version & 0xff;
out_prefix[3] = ciphertext_len >> 8;
out_prefix[4] = ciphertext_len & 0xff;
if (!ssl->s3->aead_write_ctx->SealScatter(
out_prefix + SSL3_RT_HEADER_LENGTH, out, out_suffix, out_prefix[0],
record_version, ssl->s3->write_sequence, in, in_len, extra_in,
extra_in_len) ||
!ssl_record_sequence_update(ssl->s3->write_sequence, 8)) {
return 0;
}
ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_HEADER,
MakeSpan(out_prefix, SSL3_RT_HEADER_LENGTH));
return 1;
}
static size_t tls_seal_scatter_prefix_len(const SSL *ssl, uint8_t type,
size_t in_len) {
size_t ret = SSL3_RT_HEADER_LENGTH;
if (type == SSL3_RT_APPLICATION_DATA && in_len > 1 &&
ssl_needs_record_splitting(ssl)) {
// In the case of record splitting, the 1-byte record (of the 1/n-1 split)
// will be placed in the prefix, as will four of the five bytes of the
// record header for the main record. The final byte will replace the first
// byte of the plaintext that was used in the small record.
ret += ssl_cipher_get_record_split_len(ssl->s3->aead_write_ctx->cipher());
ret += SSL3_RT_HEADER_LENGTH - 1;
} else {
ret += ssl->s3->aead_write_ctx->ExplicitNonceLen();
}
return ret;
}
static bool tls_seal_scatter_suffix_len(const SSL *ssl, size_t *out_suffix_len,
uint8_t type, size_t in_len) {
size_t extra_in_len = 0;
if (!ssl->s3->aead_write_ctx->is_null_cipher() &&
ssl->s3->aead_write_ctx->ProtocolVersion() >= TLS1_3_VERSION) {
// TLS 1.3 adds an extra byte for encrypted record type.
extra_in_len = 1;
}
if (type == SSL3_RT_APPLICATION_DATA && // clang-format off
in_len > 1 &&
ssl_needs_record_splitting(ssl)) {
// With record splitting enabled, the first byte gets sealed into a separate
// record which is written into the prefix.
in_len -= 1;
}
return ssl->s3->aead_write_ctx->SuffixLen(out_suffix_len, in_len, extra_in_len);
}
// tls_seal_scatter_record seals a new record of type |type| and body |in| and
// splits it between |out_prefix|, |out|, and |out_suffix|. Exactly
// |tls_seal_scatter_prefix_len| bytes are written to |out_prefix|, |in_len|
// bytes to |out|, and |tls_seal_scatter_suffix_len| bytes to |out_suffix|. It
// returns one on success and zero on error. If enabled,
// |tls_seal_scatter_record| implements TLS 1.0 CBC 1/n-1 record splitting and
// may write two records concatenated.
static int tls_seal_scatter_record(SSL *ssl, uint8_t *out_prefix, uint8_t *out,
uint8_t *out_suffix, uint8_t type,
const uint8_t *in, size_t in_len) {
if (type == SSL3_RT_APPLICATION_DATA && in_len > 1 &&
ssl_needs_record_splitting(ssl)) {
assert(ssl->s3->aead_write_ctx->ExplicitNonceLen() == 0);
const size_t prefix_len = SSL3_RT_HEADER_LENGTH;
// Write the 1-byte fragment into |out_prefix|.
uint8_t *split_body = out_prefix + prefix_len;
uint8_t *split_suffix = split_body + 1;
if (!do_seal_record(ssl, out_prefix, split_body, split_suffix, type, in,
1)) {
return 0;
}
size_t split_record_suffix_len;
if (!ssl->s3->aead_write_ctx->SuffixLen(&split_record_suffix_len, 1, 0)) {
assert(false);
return 0;
}
const size_t split_record_len = prefix_len + 1 + split_record_suffix_len;
assert(SSL3_RT_HEADER_LENGTH + ssl_cipher_get_record_split_len(
ssl->s3->aead_write_ctx->cipher()) ==
split_record_len);
// Write the n-1-byte fragment. The header gets split between |out_prefix|
// (header[:-1]) and |out| (header[-1:]).
uint8_t tmp_prefix[SSL3_RT_HEADER_LENGTH];
if (!do_seal_record(ssl, tmp_prefix, out + 1, out_suffix, type, in + 1,
in_len - 1)) {
return 0;
}
assert(tls_seal_scatter_prefix_len(ssl, type, in_len) ==
split_record_len + SSL3_RT_HEADER_LENGTH - 1);
OPENSSL_memcpy(out_prefix + split_record_len, tmp_prefix,
SSL3_RT_HEADER_LENGTH - 1);
OPENSSL_memcpy(out, tmp_prefix + SSL3_RT_HEADER_LENGTH - 1, 1);
return 1;
}
return do_seal_record(ssl, out_prefix, out, out_suffix, type, in, in_len);
}
int tls_seal_record(SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out_len,
uint8_t type, const uint8_t *in, size_t in_len) {
if (buffers_alias(in, in_len, out, max_out_len)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_OUTPUT_ALIASES_INPUT);
return 0;
}
const size_t prefix_len = tls_seal_scatter_prefix_len(ssl, type, in_len);
size_t suffix_len;
if (!tls_seal_scatter_suffix_len(ssl, &suffix_len, type, in_len)) {
return false;
}
if (in_len + prefix_len < in_len ||
prefix_len + in_len + suffix_len < prefix_len + in_len) {
OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE);
return 0;
}
if (max_out_len < in_len + prefix_len + suffix_len) {
OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL);
return 0;
}
uint8_t *prefix = out;
uint8_t *body = out + prefix_len;
uint8_t *suffix = body + in_len;
if (!tls_seal_scatter_record(ssl, prefix, body, suffix, type, in, in_len)) {
return 0;
}
*out_len = prefix_len + in_len + suffix_len;
return 1;
}
enum ssl_open_record_t ssl_process_alert(SSL *ssl, uint8_t *out_alert,
Span<const uint8_t> in) {
// Alerts records may not contain fragmented or multiple alerts.
if (in.size() != 2) {
*out_alert = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT);
return ssl_open_record_error;
}
ssl_do_msg_callback(ssl, 0 /* read */, SSL3_RT_ALERT, in);
const uint8_t alert_level = in[0];
const uint8_t alert_descr = in[1];
uint16_t alert = (alert_level << 8) | alert_descr;
ssl_do_info_callback(ssl, SSL_CB_READ_ALERT, alert);
if (alert_level == SSL3_AL_WARNING) {
if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
ssl->s3->read_shutdown = ssl_shutdown_close_notify;
return ssl_open_record_close_notify;
}
// Warning alerts do not exist in TLS 1.3.
if (ssl->s3->have_version &&
ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
*out_alert = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT);
return ssl_open_record_error;
}
ssl->s3->warning_alert_count++;
if (ssl->s3->warning_alert_count > kMaxWarningAlerts) {
*out_alert = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_TOO_MANY_WARNING_ALERTS);
return ssl_open_record_error;
}
return ssl_open_record_discard;
}
if (alert_level == SSL3_AL_FATAL) {
OPENSSL_PUT_ERROR(SSL, SSL_AD_REASON_OFFSET + alert_descr);
ERR_add_error_dataf("SSL alert number %d", alert_descr);
*out_alert = 0; // No alert to send back to the peer.
return ssl_open_record_error;
}
*out_alert = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_ALERT_TYPE);
return ssl_open_record_error;
}
OpenRecordResult OpenRecord(SSL *ssl, Span<uint8_t> *out,
size_t *out_record_len, uint8_t *out_alert,
const Span<uint8_t> in) {
// This API is a work in progress and currently only works for TLS 1.2 servers
// and below.
if (SSL_in_init(ssl) ||
SSL_is_dtls(ssl) ||
ssl_protocol_version(ssl) > TLS1_2_VERSION) {
assert(false);
*out_alert = SSL_AD_INTERNAL_ERROR;
return OpenRecordResult::kError;
}
Span<uint8_t> plaintext;
uint8_t type = 0;
const ssl_open_record_t result = tls_open_record(
ssl, &type, &plaintext, out_record_len, out_alert, in);
switch (result) {
case ssl_open_record_success:
if (type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_ALERT) {
*out_alert = SSL_AD_UNEXPECTED_MESSAGE;
return OpenRecordResult::kError;
}
*out = plaintext;
return OpenRecordResult::kOK;
case ssl_open_record_discard:
return OpenRecordResult::kDiscard;
case ssl_open_record_partial:
return OpenRecordResult::kIncompleteRecord;
case ssl_open_record_close_notify:
return OpenRecordResult::kAlertCloseNotify;
case ssl_open_record_error:
return OpenRecordResult::kError;
}
assert(false);
return OpenRecordResult::kError;
}
size_t SealRecordPrefixLen(const SSL *ssl, const size_t record_len) {
return tls_seal_scatter_prefix_len(ssl, SSL3_RT_APPLICATION_DATA, record_len);
}
size_t SealRecordSuffixLen(const SSL *ssl, const size_t plaintext_len) {
assert(plaintext_len <= SSL3_RT_MAX_PLAIN_LENGTH);
size_t suffix_len;
if (!tls_seal_scatter_suffix_len(ssl, &suffix_len, SSL3_RT_APPLICATION_DATA,
plaintext_len)) {
assert(false);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return 0;
}
assert(suffix_len <= SSL3_RT_MAX_ENCRYPTED_OVERHEAD);
return suffix_len;
}
bool SealRecord(SSL *ssl, const Span<uint8_t> out_prefix,
const Span<uint8_t> out, Span<uint8_t> out_suffix,
const Span<const uint8_t> in) {
// This API is a work in progress and currently only works for TLS 1.2 servers
// and below.
if (SSL_in_init(ssl) ||
SSL_is_dtls(ssl) ||
ssl_protocol_version(ssl) > TLS1_2_VERSION) {
assert(false);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return false;
}
if (out_prefix.size() != SealRecordPrefixLen(ssl, in.size()) ||
out.size() != in.size() ||
out_suffix.size() != SealRecordSuffixLen(ssl, in.size())) {
OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL);
return false;
}
return tls_seal_scatter_record(ssl, out_prefix.data(), out.data(),
out_suffix.data(), SSL3_RT_APPLICATION_DATA,
in.data(), in.size());
}
} // namespace bssl
using namespace bssl;
size_t SSL_max_seal_overhead(const SSL *ssl) {
if (SSL_is_dtls(ssl)) {
return dtls_max_seal_overhead(ssl, dtls1_use_current_epoch);
}
size_t ret = SSL3_RT_HEADER_LENGTH;
ret += ssl->s3->aead_write_ctx->MaxOverhead();
// TLS 1.3 needs an extra byte for the encrypted record type.
if (!ssl->s3->aead_write_ctx->is_null_cipher() &&
ssl->s3->aead_write_ctx->ProtocolVersion() >= TLS1_3_VERSION) {
ret += 1;
}
if (ssl_needs_record_splitting(ssl)) {
ret *= 2;
}
return ret;
}