/* 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 #include #include #include #include #include #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) { #if !defined(BORINGSSL_UNSAFE_FUZZER_MODE) 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); #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_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_prefix, uint8_t *out, uint8_t *out_suffix, size_t *out_suffix_len, const size_t max_out_suffix_len, uint8_t type, const uint8_t *in, const size_t 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, max_out_suffix_len)); /* TLS 1.3 hides the actual record type inside the encrypted data. */ uint8_t *extra_in = NULL; size_t extra_in_len = 0; if (ssl->s3->aead_write_ctx != NULL && ssl->s3->aead_write_ctx->version >= TLS1_3_VERSION) { extra_in = &type; extra_in_len = 1; out_prefix[0] = SSL3_RT_APPLICATION_DATA; } else { out_prefix[0] = type; } /* 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->s3->hs != NULL && ssl->s3->hs->max_version == SSL3_VERSION) { wire_version = SSL3_VERSION; } if (ssl->s3->have_version && ssl3_protocol_version(ssl) < TLS1_3_VERSION) { wire_version = ssl->version; } out_prefix[1] = wire_version >> 8; out_prefix[2] = wire_version & 0xff; /* Write the ciphertext, leaving two bytes for the length. */ if (!SSL_AEAD_CTX_seal_scatter( ssl->s3->aead_write_ctx, out_prefix + SSL3_RT_HEADER_LENGTH, out, out_suffix, out_suffix_len, max_out_suffix_len, type, wire_version, ssl->s3->write_sequence, in, in_len, extra_in, extra_in_len) || !ssl_record_sequence_update(ssl->s3->write_sequence, 8)) { return 0; } /* Fill in the length. */ const size_t ciphertext_len = SSL_AEAD_CTX_explicit_nonce_len(ssl->s3->aead_write_ctx) + in_len + *out_suffix_len; if (ciphertext_len >= 1 << 15) { OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW); return 0; } out_prefix[3] = ciphertext_len >> 8; out_prefix[4] = ciphertext_len & 0xff; ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_HEADER, 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_AEAD_CTX_explicit_nonce_len(ssl->s3->aead_write_ctx); } return ret; } /* 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 up to 1 + |SSL_AEAD_CTX_max_overhead| bytes to * |out_suffix|. |*out_suffix_len| is set to the actual number of bytes written * 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, size_t *out_suffix_len, size_t max_out_suffix_len, 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_AEAD_CTX_explicit_nonce_len(ssl->s3->aead_write_ctx) == 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; /* TODO(martinkr): Make AEAD code not complain if max_suffix_len is lower * than |EVP_AEAD_max_overhead| but still sufficiently large. */ size_t split_max_suffix_len = SSL_AEAD_CTX_max_suffix_len(ssl->s3->aead_write_ctx, 0); size_t split_suffix_len = 0; if (!do_seal_record(ssl, out_prefix, split_body, split_suffix, &split_suffix_len, split_max_suffix_len, type, in, 1)) { return 0; } size_t split_record_len = prefix_len + 1 + split_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, out_suffix_len, max_out_suffix_len, 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, out_suffix_len, max_out_suffix_len, 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); if (in_len + prefix_len < in_len) { OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE); return 0; } if (max_out_len < in_len + prefix_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; size_t max_suffix_len = max_out_len - prefix_len - in_len; size_t suffix_len = 0; if (!tls_seal_scatter_record(ssl, prefix, body, suffix, &suffix_len, max_suffix_len, type, in, in_len)) { return 0; } if (prefix_len + in_len + suffix_len < prefix_len + in_len) { OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE); 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, 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; }