| /* 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; |
| } |