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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;
- }
-
- Span<const uint8_t> header = in.subspan(0, SSL3_RT_HEADER_LENGTH);
- ssl_do_msg_callback(ssl, 0 /* read */, SSL3_RT_HEADER, header);
-
- *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, header,
- 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) {
- SSLAEADContext *aead = ssl->s3->aead_write_ctx.get();
- uint8_t *extra_in = NULL;
- size_t extra_in_len = 0;
- if (!aead->is_null_cipher() &&
- aead->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, ciphertext_len;
- if (!aead->SuffixLen(&suffix_len, in_len, extra_in_len) ||
- !aead->CiphertextLen(&ciphertext_len, in_len, extra_in_len)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE);
- return 0;
- }
-
- 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 = aead->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;
- Span<const uint8_t> header = MakeSpan(out_prefix, SSL3_RT_HEADER_LENGTH);
-
- if (!aead->SealScatter(out_prefix + SSL3_RT_HEADER_LENGTH, out, out_suffix,
- out_prefix[0], record_version, ssl->s3->write_sequence,
- header, 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, header);
- 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;
- }
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