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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"
/* 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) {
return ssl->s3->aead_write_ctx != NULL &&
ssl->s3->aead_write_ctx->version < TLS1_1_VERSION &&
(ssl->mode & SSL_MODE_CBC_RECORD_SPLITTING) != 0 &&
SSL_CIPHER_is_block_cipher(ssl->s3->aead_write_ctx->cipher);
}
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_AEAD_CTX_explicit_nonce_len(ssl->s3->aead_read_ctx);
}
size_t ssl_seal_align_prefix_len(const SSL *ssl) {
if (SSL_is_dtls(ssl)) {
return DTLS1_RT_HEADER_LENGTH +
SSL_AEAD_CTX_explicit_nonce_len(ssl->s3->aead_write_ctx);
}
size_t ret = SSL3_RT_HEADER_LENGTH +
SSL_AEAD_CTX_explicit_nonce_len(ssl->s3->aead_write_ctx);
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;
}
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_AEAD_CTX_max_overhead(ssl->s3->aead_write_ctx);
/* TLS 1.3 needs an extra byte for the encrypted record type. */
if (ssl->s3->aead_write_ctx != NULL &&
ssl->s3->aead_write_ctx->version >= TLS1_3_VERSION) {
ret += 1;
}
if (ssl_needs_record_splitting(ssl)) {
ret *= 2;
}
return ret;
}
enum ssl_open_record_t tls_open_record(SSL *ssl, uint8_t *out_type, CBS *out,
size_t *out_consumed, uint8_t *out_alert,
uint8_t *in, size_t in_len) {
*out_consumed = 0;
CBS cbs;
CBS_init(&cbs, in, in_len);
/* 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;
}
int version_ok;
if (ssl->s3->aead_read_ctx == NULL) {
/* Only check the first byte. Enforcing beyond that can prevent decoding
* version negotiation failure alerts. */
version_ok = (version >> 8) == SSL3_VERSION_MAJOR;
} else if (ssl3_protocol_version(ssl) < TLS1_3_VERSION) {
/* Earlier versions of TLS switch the record version. */
version_ok = version == ssl->version;
} else {
/* Starting TLS 1.3, the version field is frozen at {3, 1}. */
version_ok = version == TLS1_VERSION;
}
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,
SSL3_RT_HEADER_LENGTH);
*out_consumed = in_len - CBS_len(&cbs);
/* Skip early data received when expecting a second ClientHello if we rejected
* 0RTT. */
if (ssl->s3->skip_early_data &&
ssl->s3->aead_read_ctx == NULL &&
type == SSL3_RT_APPLICATION_DATA) {
goto skipped_data;
}
/* Decrypt the body in-place. */
if (!SSL_AEAD_CTX_open(ssl->s3->aead_read_ctx, out, type, version,
ssl->s3->read_sequence, (uint8_t *)CBS_data(&body),
CBS_len(&body))) {
if (ssl->s3->skip_early_data &&
ssl->s3->aead_read_ctx != NULL) {
ERR_clear_error();
goto skipped_data;
}
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 = 0;
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. */
if (ssl->s3->aead_read_ctx != NULL &&
ssl->s3->aead_read_ctx->version >= TLS1_3_VERSION) {
/* 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 (!CBS_get_last_u8(out, &type)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
*out_alert = SSL_AD_DECRYPT_ERROR;
return ssl_open_record_error;
}
} while (type == 0);
}
/* Check the plaintext length. */
if (CBS_len(out) > SSL3_RT_MAX_PLAIN_LENGTH) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_LENGTH_TOO_LONG);
*out_alert = SSL_AD_RECORD_OVERFLOW;
return ssl_open_record_error;
}
/* Limit the number of consecutive empty records. */
if (CBS_len(out) == 0) {
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 end_of_early_data alerts as-is for the caller to process. */
if (CBS_len(out) == 2 &&
CBS_data(out)[0] == SSL3_AL_WARNING &&
CBS_data(out)[1] == TLS1_AD_END_OF_EARLY_DATA) {
*out_type = type;
return ssl_open_record_success;
}
return ssl_process_alert(ssl, out_alert, CBS_data(out), CBS_len(out));
}
ssl->s3->warning_alert_count = 0;
*out_type = type;
return ssl_open_record_success;
skipped_data:
ssl->s3->early_data_skipped += *out_consumed;
if (ssl->s3->early_data_skipped < *out_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;
}
static int do_seal_record(SSL *ssl, uint8_t *out, size_t *out_len,
size_t max_out, uint8_t type, const uint8_t *in,
size_t in_len) {
assert(!buffers_alias(in, in_len, out, max_out));
/* TLS 1.3 hides the actual record type inside the encrypted data. */
if (ssl->s3->aead_write_ctx != NULL &&
ssl->s3->aead_write_ctx->version >= TLS1_3_VERSION) {
if (in_len > in_len + SSL3_RT_HEADER_LENGTH + 1 ||
max_out < in_len + SSL3_RT_HEADER_LENGTH + 1) {
OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL);
return 0;
}
OPENSSL_memcpy(out + SSL3_RT_HEADER_LENGTH, in, in_len);
out[SSL3_RT_HEADER_LENGTH + in_len] = type;
in = out + SSL3_RT_HEADER_LENGTH;
type = SSL3_RT_APPLICATION_DATA;
in_len++;
}
if (max_out < SSL3_RT_HEADER_LENGTH) {
OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL);
return 0;
}
/* The TLS record-layer version number is meaningless and, starting in
* TLS 1.3, is frozen at TLS 1.0. But for historical reasons, SSL 3.0
* ClientHellos should use SSL 3.0 and pre-TLS-1.3 expects the version
* to change after version negotiation. */
uint16_t wire_version = TLS1_VERSION;
if (ssl->version == SSL3_VERSION ||
(ssl->s3->have_version && ssl3_protocol_version(ssl) < TLS1_3_VERSION)) {
wire_version = ssl->version;
}
/* Write the non-length portions of the header. */
out[0] = type;
out[1] = wire_version >> 8;
out[2] = wire_version & 0xff;
out += 3;
max_out -= 3;
/* Write the ciphertext, leaving two bytes for the length. */
size_t ciphertext_len;
if (!SSL_AEAD_CTX_seal(ssl->s3->aead_write_ctx, out + 2, &ciphertext_len,
max_out - 2, type, wire_version,
ssl->s3->write_sequence, in, in_len) ||
!ssl_record_sequence_update(ssl->s3->write_sequence, 8)) {
return 0;
}
/* Fill in the length. */
if (ciphertext_len >= 1 << 15) {
OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
return 0;
}
out[0] = ciphertext_len >> 8;
out[1] = ciphertext_len & 0xff;
*out_len = SSL3_RT_HEADER_LENGTH + ciphertext_len;
ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_HEADER, out,
SSL3_RT_HEADER_LENGTH);
return 1;
}
int tls_seal_record(SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out,
uint8_t type, const uint8_t *in, size_t in_len) {
if (buffers_alias(in, in_len, out, max_out)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_OUTPUT_ALIASES_INPUT);
return 0;
}
size_t frag_len = 0;
if (type == SSL3_RT_APPLICATION_DATA && in_len > 1 &&
ssl_needs_record_splitting(ssl)) {
if (!do_seal_record(ssl, out, &frag_len, max_out, type, in, 1)) {
return 0;
}
in++;
in_len--;
out += frag_len;
max_out -= frag_len;
#if !defined(BORINGSSL_UNSAFE_FUZZER_MODE)
assert(SSL3_RT_HEADER_LENGTH + ssl_cipher_get_record_split_len(
ssl->s3->aead_write_ctx->cipher) ==
frag_len);
#endif
}
if (!do_seal_record(ssl, out, out_len, max_out, type, in, in_len)) {
return 0;
}
*out_len += frag_len;
return 1;
}
enum ssl_open_record_t ssl_process_alert(SSL *ssl, uint8_t *out_alert,
const uint8_t *in, size_t in_len) {
/* Alerts records may not contain fragmented or multiple alerts. */
if (in_len != 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, in_len);
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->recv_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 &&
ssl3_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) {
ssl->s3->recv_shutdown = ssl_shutdown_fatal_alert;
char tmp[16];
OPENSSL_PUT_ERROR(SSL, SSL_AD_REASON_OFFSET + alert_descr);
BIO_snprintf(tmp, sizeof(tmp), "%d", alert_descr);
ERR_add_error_data(2, "SSL alert number ", tmp);
return ssl_open_record_fatal_alert;
}
*out_alert = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_ALERT_TYPE);
return ssl_open_record_error;
}