/* 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 "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; /* 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_USE_EXPLICIT_IV(ssl) && ssl->s3->aead_write_ctx != NULL && (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) { size_t i; for (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) { if (SSL_IS_DTLS(ssl)) { return DTLS1_RT_HEADER_LENGTH + SSL_AEAD_CTX_explicit_nonce_len(ssl->s3->aead_read_ctx); } else { return SSL3_RT_HEADER_LENGTH + SSL_AEAD_CTX_explicit_nonce_len(ssl->s3->aead_read_ctx); } } size_t ssl_seal_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); } else { 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 DTLS1_RT_HEADER_LENGTH + SSL_AEAD_CTX_max_overhead(ssl->s3->aead_write_ctx); } else { size_t ret = SSL3_RT_HEADER_LENGTH + SSL_AEAD_CTX_max_overhead(ssl->s3->aead_write_ctx); if (ssl_needs_record_splitting(ssl)) { ret *= 2; } return ret; } } enum ssl_open_record_t tls_open_record( SSL *ssl, uint8_t *out_type, uint8_t *out, size_t *out_len, size_t *out_consumed, uint8_t *out_alert, size_t max_out, const uint8_t *in, size_t in_len) { 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; } /* Check the version. */ if ((ssl->s3->have_version && version != ssl->version) || (version >> 8) != SSL3_VERSION_MAJOR) { 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; } if (ssl->msg_callback != NULL) { ssl->msg_callback(0 /* read */, 0, SSL3_RT_HEADER, in, SSL3_RT_HEADER_LENGTH, ssl, ssl->msg_callback_arg); } /* Decrypt the body. */ size_t plaintext_len; if (!SSL_AEAD_CTX_open(ssl->s3->aead_read_ctx, out, &plaintext_len, max_out, type, version, ssl->s3->read_sequence, CBS_data(&body), CBS_len(&body))) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); *out_alert = SSL_AD_BAD_RECORD_MAC; return ssl_open_record_error; } if (!ssl_record_sequence_update(ssl->s3->read_sequence, 8)) { *out_alert = SSL_AD_INTERNAL_ERROR; return ssl_open_record_error; } /* Check the plaintext length. */ if (plaintext_len > 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 (plaintext_len == 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; } *out_type = type; *out_len = plaintext_len; *out_consumed = in_len - CBS_len(&cbs); return ssl_open_record_success; } 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) { if (max_out < SSL3_RT_HEADER_LENGTH) { OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL); return 0; } /* Check the record header does not alias any part of the input. * |SSL_AEAD_CTX_seal| will internally enforce other aliasing requirements. */ if (in < out + SSL3_RT_HEADER_LENGTH && out < in + in_len) { OPENSSL_PUT_ERROR(SSL, SSL_R_OUTPUT_ALIASES_INPUT); return 0; } out[0] = type; /* Some servers hang if initial ClientHello is larger than 256 bytes and * record version number > TLS 1.0. */ uint16_t wire_version = ssl->version; if (!ssl->s3->have_version && ssl->version > SSL3_VERSION) { wire_version = TLS1_VERSION; } out[1] = wire_version >> 8; out[2] = wire_version & 0xff; size_t ciphertext_len; if (!SSL_AEAD_CTX_seal(ssl->s3->aead_write_ctx, out + SSL3_RT_HEADER_LENGTH, &ciphertext_len, max_out - SSL3_RT_HEADER_LENGTH, type, wire_version, ssl->s3->write_sequence, in, in_len) || !ssl_record_sequence_update(ssl->s3->write_sequence, 8)) { return 0; } if (ciphertext_len >= 1 << 16) { OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW); return 0; } out[3] = ciphertext_len >> 8; out[4] = ciphertext_len & 0xff; *out_len = SSL3_RT_HEADER_LENGTH + ciphertext_len; if (ssl->msg_callback) { ssl->msg_callback(1 /* write */, 0, SSL3_RT_HEADER, out, SSL3_RT_HEADER_LENGTH, ssl, ssl->msg_callback_arg); } 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) { size_t frag_len = 0; if (type == SSL3_RT_APPLICATION_DATA && in_len > 1 && ssl_needs_record_splitting(ssl)) { /* |do_seal_record| will notice if it clobbers |in[0]|, but not if it * aliases the rest of |in|. */ if (in + 1 <= out && out < in + in_len) { OPENSSL_PUT_ERROR(SSL, SSL_R_OUTPUT_ALIASES_INPUT); return 0; } /* Ensure |do_seal_record| does not write beyond |in[0]|. */ size_t frag_max_out = max_out; if (out <= in + 1 && in + 1 < out + frag_max_out) { frag_max_out = (size_t)(in + 1 - out); } if (!do_seal_record(ssl, out, &frag_len, frag_max_out, type, in, 1)) { return 0; } in++; in_len--; out += frag_len; max_out -= frag_len; assert(SSL3_RT_HEADER_LENGTH + ssl_cipher_get_record_split_len( ssl->s3->aead_write_ctx->cipher) == frag_len); } if (!do_seal_record(ssl, out, out_len, max_out, type, in, in_len)) { return 0; } *out_len += frag_len; return 1; } void ssl_set_read_state(SSL *ssl, SSL_AEAD_CTX *aead_ctx) { if (SSL_IS_DTLS(ssl)) { ssl->d1->r_epoch++; memset(&ssl->d1->bitmap, 0, sizeof(ssl->d1->bitmap)); } memset(ssl->s3->read_sequence, 0, sizeof(ssl->s3->read_sequence)); SSL_AEAD_CTX_free(ssl->s3->aead_read_ctx); ssl->s3->aead_read_ctx = aead_ctx; } void ssl_set_write_state(SSL *ssl, SSL_AEAD_CTX *aead_ctx) { if (SSL_IS_DTLS(ssl)) { ssl->d1->w_epoch++; memcpy(ssl->d1->last_write_sequence, ssl->s3->write_sequence, sizeof(ssl->s3->write_sequence)); } memset(ssl->s3->write_sequence, 0, sizeof(ssl->s3->write_sequence)); SSL_AEAD_CTX_free(ssl->s3->aead_write_ctx); ssl->s3->aead_write_ctx = aead_ctx; }