diff options
Diffstat (limited to 'src/ssl/t1_enc.c')
| -rw-r--r-- | src/ssl/t1_enc.c | 1042 |
1 files changed, 1042 insertions, 0 deletions
diff --git a/src/ssl/t1_enc.c b/src/ssl/t1_enc.c new file mode 100644 index 0000000..014bc88 --- /dev/null +++ b/src/ssl/t1_enc.c @@ -0,0 +1,1042 @@ +/* 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) 1998-2007 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). + * + */ +/* ==================================================================== + * Copyright 2005 Nokia. All rights reserved. + * + * The portions of the attached software ("Contribution") is developed by + * Nokia Corporation and is licensed pursuant to the OpenSSL open source + * license. + * + * The Contribution, originally written by Mika Kousa and Pasi Eronen of + * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites + * support (see RFC 4279) to OpenSSL. + * + * No patent licenses or other rights except those expressly stated in + * the OpenSSL open source license shall be deemed granted or received + * expressly, by implication, estoppel, or otherwise. + * + * No assurances are provided by Nokia that the Contribution does not + * infringe the patent or other intellectual property rights of any third + * party or that the license provides you with all the necessary rights + * to make use of the Contribution. + * + * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN + * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA + * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY + * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR + * OTHERWISE. */ + +#include <stdio.h> +#include <assert.h> + +#include <openssl/err.h> +#include <openssl/evp.h> +#include <openssl/hmac.h> +#include <openssl/md5.h> +#include <openssl/mem.h> +#include <openssl/obj.h> +#include <openssl/rand.h> + +#include "ssl_locl.h" + + +/* tls1_P_hash computes the TLS P_<hash> function as described in RFC 5246, + * section 5. It writes |out_len| bytes to |out|, using |md| as the hash and + * |secret| as the secret. |seed1| through |seed3| are concatenated to form the + * seed parameter. It returns one on success and zero on failure. */ +static int tls1_P_hash(uint8_t *out, size_t out_len, const EVP_MD *md, + const uint8_t *secret, size_t secret_len, + const uint8_t *seed1, size_t seed1_len, + const uint8_t *seed2, size_t seed2_len, + const uint8_t *seed3, size_t seed3_len) { + size_t chunk; + HMAC_CTX ctx, ctx_tmp, ctx_init; + uint8_t A1[EVP_MAX_MD_SIZE]; + unsigned A1_len; + int ret = 0; + + chunk = EVP_MD_size(md); + + HMAC_CTX_init(&ctx); + HMAC_CTX_init(&ctx_tmp); + HMAC_CTX_init(&ctx_init); + if (!HMAC_Init_ex(&ctx_init, secret, secret_len, md, NULL) || + !HMAC_CTX_copy_ex(&ctx, &ctx_init) || + (seed1_len && !HMAC_Update(&ctx, seed1, seed1_len)) || + (seed2_len && !HMAC_Update(&ctx, seed2, seed2_len)) || + (seed3_len && !HMAC_Update(&ctx, seed3, seed3_len)) || + !HMAC_Final(&ctx, A1, &A1_len)) { + goto err; + } + + for (;;) { + /* Reinit mac contexts. */ + if (!HMAC_CTX_copy_ex(&ctx, &ctx_init) || + !HMAC_Update(&ctx, A1, A1_len) || + (out_len > chunk && !HMAC_CTX_copy_ex(&ctx_tmp, &ctx)) || + (seed1_len && !HMAC_Update(&ctx, seed1, seed1_len)) || + (seed2_len && !HMAC_Update(&ctx, seed2, seed2_len)) || + (seed3_len && !HMAC_Update(&ctx, seed3, seed3_len))) { + goto err; + } + + if (out_len > chunk) { + unsigned len; + if (!HMAC_Final(&ctx, out, &len)) { + goto err; + } + assert(len == chunk); + out += len; + out_len -= len; + /* Calculate the next A1 value. */ + if (!HMAC_Final(&ctx_tmp, A1, &A1_len)) { + goto err; + } + } else { + /* Last chunk. */ + if (!HMAC_Final(&ctx, A1, &A1_len)) { + goto err; + } + memcpy(out, A1, out_len); + break; + } + } + + ret = 1; + +err: + HMAC_CTX_cleanup(&ctx); + HMAC_CTX_cleanup(&ctx_tmp); + HMAC_CTX_cleanup(&ctx_init); + OPENSSL_cleanse(A1, sizeof(A1)); + return ret; +} + +int tls1_prf(SSL *s, uint8_t *out, size_t out_len, const uint8_t *secret, + size_t secret_len, const char *label, size_t label_len, + const uint8_t *seed1, size_t seed1_len, + const uint8_t *seed2, size_t seed2_len) { + size_t idx, len, count, i; + const uint8_t *S1; + long m; + const EVP_MD *md; + int ret = 0; + uint8_t *tmp; + + if (out_len == 0) { + return 1; + } + + /* Allocate a temporary buffer. */ + tmp = OPENSSL_malloc(out_len); + if (tmp == NULL) { + OPENSSL_PUT_ERROR(SSL, tls1_prf, ERR_R_MALLOC_FAILURE); + return 0; + } + + /* Count number of digests and partition |secret| evenly. */ + count = 0; + for (idx = 0; ssl_get_handshake_digest(idx, &m, &md); idx++) { + if ((m << TLS1_PRF_DGST_SHIFT) & ssl_get_algorithm2(s)) { + count++; + } + } + /* TODO(davidben): The only case where count isn't 1 is the old MD5/SHA-1 + * combination. The logic around multiple handshake digests can probably be + * simplified. */ + assert(count == 1 || count == 2); + len = secret_len / count; + if (count == 1) { + secret_len = 0; + } + S1 = secret; + memset(out, 0, out_len); + for (idx = 0; ssl_get_handshake_digest(idx, &m, &md); idx++) { + if ((m << TLS1_PRF_DGST_SHIFT) & ssl_get_algorithm2(s)) { + /* If |count| is 2 and |secret_len| is odd, |secret| is partitioned into + * two halves with an overlapping byte. */ + if (!tls1_P_hash(tmp, out_len, md, S1, len + (secret_len & 1), + (const uint8_t *)label, label_len, seed1, seed1_len, + seed2, seed2_len)) { + goto err; + } + S1 += len; + for (i = 0; i < out_len; i++) { + out[i] ^= tmp[i]; + } + } + } + ret = 1; + +err: + OPENSSL_cleanse(tmp, out_len); + OPENSSL_free(tmp); + return ret; +} + +static int tls1_generate_key_block(SSL *s, uint8_t *out, size_t out_len) { + return s->enc_method->prf(s, out, out_len, s->session->master_key, + s->session->master_key_length, + TLS_MD_KEY_EXPANSION_CONST, + TLS_MD_KEY_EXPANSION_CONST_SIZE, + s->s3->server_random, SSL3_RANDOM_SIZE, + s->s3->client_random, + SSL3_RANDOM_SIZE); +} + +/* tls1_aead_ctx_init allocates |*aead_ctx|, if needed and returns 1. It + * returns 0 on malloc error. */ +static int tls1_aead_ctx_init(SSL_AEAD_CTX **aead_ctx) { + if (*aead_ctx != NULL) { + EVP_AEAD_CTX_cleanup(&(*aead_ctx)->ctx); + } else { + *aead_ctx = (SSL_AEAD_CTX *)OPENSSL_malloc(sizeof(SSL_AEAD_CTX)); + if (*aead_ctx == NULL) { + OPENSSL_PUT_ERROR(SSL, tls1_aead_ctx_init, ERR_R_MALLOC_FAILURE); + return 0; + } + } + + return 1; +} + +static int tls1_change_cipher_state_aead(SSL *s, char is_read, + const uint8_t *key, unsigned key_len, + const uint8_t *iv, unsigned iv_len, + const uint8_t *mac_secret, + unsigned mac_secret_len) { + const EVP_AEAD *aead = s->s3->tmp.new_aead; + SSL_AEAD_CTX *aead_ctx; + /* merged_key is used to merge the MAC, cipher, and IV keys for an AEAD which + * simulates pre-AEAD cipher suites. */ + uint8_t merged_key[EVP_AEAD_MAX_KEY_LENGTH]; + + if (mac_secret_len > 0) { + /* This is a "stateful" AEAD (for compatibility with pre-AEAD cipher + * suites). */ + if (mac_secret_len + key_len + iv_len > sizeof(merged_key)) { + OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead, + ERR_R_INTERNAL_ERROR); + return 0; + } + memcpy(merged_key, mac_secret, mac_secret_len); + memcpy(merged_key + mac_secret_len, key, key_len); + memcpy(merged_key + mac_secret_len + key_len, iv, iv_len); + key = merged_key; + key_len += mac_secret_len; + key_len += iv_len; + } + + if (is_read) { + if (!tls1_aead_ctx_init(&s->aead_read_ctx)) { + return 0; + } + aead_ctx = s->aead_read_ctx; + } else { + /* When updating the cipher state for DTLS, we do not wish to overwrite the + * old ones because DTLS stores pointers to them in order to implement + * retransmission. See dtls1_hm_fragment_free. + * + * TODO(davidben): Simplify aead_write_ctx ownership, probably by just + * forbidding DTLS renego. */ + if (SSL_IS_DTLS(s)) { + s->aead_write_ctx = NULL; + } + if (!tls1_aead_ctx_init(&s->aead_write_ctx)) { + return 0; + } + aead_ctx = s->aead_write_ctx; + } + + if (!EVP_AEAD_CTX_init(&aead_ctx->ctx, aead, key, key_len, + EVP_AEAD_DEFAULT_TAG_LENGTH, NULL /* engine */)) { + OPENSSL_free(aead_ctx); + if (is_read) { + s->aead_read_ctx = NULL; + } else { + s->aead_write_ctx = NULL; + } + + return 0; + } + + if (mac_secret_len == 0) { + /* For a real AEAD, the IV is the fixed part of the nonce. */ + if (iv_len > sizeof(aead_ctx->fixed_nonce)) { + OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead, ERR_R_INTERNAL_ERROR); + return 0; + } + + memcpy(aead_ctx->fixed_nonce, iv, iv_len); + aead_ctx->fixed_nonce_len = iv_len; + aead_ctx->variable_nonce_included_in_record = + (s->s3->tmp.new_cipher->algorithm2 & + SSL_CIPHER_ALGORITHM2_VARIABLE_NONCE_INCLUDED_IN_RECORD) != 0; + aead_ctx->random_variable_nonce = 0; + aead_ctx->omit_length_in_ad = 0; + } else { + aead_ctx->fixed_nonce_len = 0; + aead_ctx->variable_nonce_included_in_record = 1; + aead_ctx->random_variable_nonce = 1; + aead_ctx->omit_length_in_ad = 1; + } + aead_ctx->variable_nonce_len = s->s3->tmp.new_variable_iv_len; + aead_ctx->omit_version_in_ad = (s->version == SSL3_VERSION); + + if (aead_ctx->variable_nonce_len + aead_ctx->fixed_nonce_len != + EVP_AEAD_nonce_length(aead)) { + OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead, ERR_R_INTERNAL_ERROR); + return 0; + } + aead_ctx->tag_len = EVP_AEAD_max_overhead(aead); + + return 1; +} + +int tls1_change_cipher_state(SSL *s, int which) { + /* is_read is true if we have just read a ChangeCipherSpec message - i.e. we + * need to update the read cipherspec. Otherwise we have just written one. */ + const char is_read = (which & SSL3_CC_READ) != 0; + /* use_client_keys is true if we wish to use the keys for the "client write" + * direction. This is the case if we're a client sending a ChangeCipherSpec, + * or a server reading a client's ChangeCipherSpec. */ + const char use_client_keys = which == SSL3_CHANGE_CIPHER_CLIENT_WRITE || + which == SSL3_CHANGE_CIPHER_SERVER_READ; + const uint8_t *client_write_mac_secret, *server_write_mac_secret, *mac_secret; + const uint8_t *client_write_key, *server_write_key, *key; + const uint8_t *client_write_iv, *server_write_iv, *iv; + const EVP_AEAD *aead = s->s3->tmp.new_aead; + size_t key_len, iv_len, mac_secret_len; + const uint8_t *key_data; + + /* Reset sequence number to zero. */ + if (!SSL_IS_DTLS(s)) { + memset(is_read ? s->s3->read_sequence : s->s3->write_sequence, 0, 8); + } + + mac_secret_len = s->s3->tmp.new_mac_secret_len; + iv_len = s->s3->tmp.new_fixed_iv_len; + + if (aead == NULL) { + OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state, ERR_R_INTERNAL_ERROR); + return 0; + } + + key_len = EVP_AEAD_key_length(aead); + if (mac_secret_len > 0) { + /* For "stateful" AEADs (i.e. compatibility with pre-AEAD cipher + * suites) the key length reported by |EVP_AEAD_key_length| will + * include the MAC and IV key bytes. */ + if (key_len < mac_secret_len + iv_len) { + OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state, ERR_R_INTERNAL_ERROR); + return 0; + } + key_len -= mac_secret_len + iv_len; + } + + key_data = s->s3->tmp.key_block; + client_write_mac_secret = key_data; + key_data += mac_secret_len; + server_write_mac_secret = key_data; + key_data += mac_secret_len; + client_write_key = key_data; + key_data += key_len; + server_write_key = key_data; + key_data += key_len; + client_write_iv = key_data; + key_data += iv_len; + server_write_iv = key_data; + key_data += iv_len; + + if (use_client_keys) { + mac_secret = client_write_mac_secret; + key = client_write_key; + iv = client_write_iv; + } else { + mac_secret = server_write_mac_secret; + key = server_write_key; + iv = server_write_iv; + } + + if (key_data - s->s3->tmp.key_block != s->s3->tmp.key_block_length) { + OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state, ERR_R_INTERNAL_ERROR); + return 0; + } + + return tls1_change_cipher_state_aead(s, is_read, key, key_len, iv, iv_len, + mac_secret, mac_secret_len); +} + +int tls1_setup_key_block(SSL *s) { + uint8_t *p; + const EVP_AEAD *aead = NULL; + int ret = 0; + size_t mac_secret_len, fixed_iv_len, variable_iv_len, key_len; + size_t key_block_len; + + if (s->s3->tmp.key_block_length != 0) { + return 1; + } + + if (s->session->cipher == NULL) { + goto cipher_unavailable_err; + } + + if (!ssl_cipher_get_evp_aead(&aead, &mac_secret_len, &fixed_iv_len, + s->session->cipher, + ssl3_version_from_wire(s, s->version))) { + goto cipher_unavailable_err; + } + key_len = EVP_AEAD_key_length(aead); + variable_iv_len = EVP_AEAD_nonce_length(aead); + if (mac_secret_len > 0) { + /* For "stateful" AEADs (i.e. compatibility with pre-AEAD cipher suites) the + * key length reported by |EVP_AEAD_key_length| will include the MAC key + * bytes and initial implicit IV. */ + if (key_len < mac_secret_len + fixed_iv_len) { + OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_INTERNAL_ERROR); + return 0; + } + key_len -= mac_secret_len + fixed_iv_len; + } else { + /* The nonce is split into a fixed portion and a variable portion. */ + if (variable_iv_len < fixed_iv_len) { + OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_INTERNAL_ERROR); + return 0; + } + variable_iv_len -= fixed_iv_len; + } + + assert(mac_secret_len < 256); + assert(fixed_iv_len < 256); + assert(variable_iv_len < 256); + + s->s3->tmp.new_aead = aead; + s->s3->tmp.new_mac_secret_len = (uint8_t)mac_secret_len; + s->s3->tmp.new_fixed_iv_len = (uint8_t)fixed_iv_len; + s->s3->tmp.new_variable_iv_len = (uint8_t)variable_iv_len; + + key_block_len = key_len + mac_secret_len + fixed_iv_len; + key_block_len *= 2; + + ssl3_cleanup_key_block(s); + + p = (uint8_t *)OPENSSL_malloc(key_block_len); + if (p == NULL) { + OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_MALLOC_FAILURE); + goto err; + } + + s->s3->tmp.key_block_length = key_block_len; + s->s3->tmp.key_block = p; + + if (!tls1_generate_key_block(s, p, key_block_len)) { + goto err; + } + + if (!SSL_USE_EXPLICIT_IV(s) && + (s->mode & SSL_MODE_CBC_RECORD_SPLITTING) != 0) { + /* enable vulnerability countermeasure for CBC ciphers with known-IV + * problem (http://www.openssl.org/~bodo/tls-cbc.txt). */ + s->s3->need_record_splitting = 1; + + if (s->session->cipher != NULL && + s->session->cipher->algorithm_enc == SSL_RC4) { + s->s3->need_record_splitting = 0; + } + } + + ret = 1; + +err: + return ret; + +cipher_unavailable_err: + OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, + SSL_R_CIPHER_OR_HASH_UNAVAILABLE); + return 0; +} + +/* tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, + * respectively. It returns one on success and zero on failure. */ +int tls1_enc(SSL *s, int send) { + SSL3_RECORD *rec; + const SSL_AEAD_CTX *aead; + + if (send) { + rec = &s->s3->wrec; + aead = s->aead_write_ctx; + } else { + rec = &s->s3->rrec; + aead = s->aead_read_ctx; + } + + if (s->session == NULL || aead == NULL) { + /* Handle the initial NULL cipher. */ + memmove(rec->data, rec->input, rec->length); + rec->input = rec->data; + return 1; + } + + uint8_t ad[13], *seq, *in, *out, nonce[EVP_AEAD_MAX_NONCE_LENGTH]; + unsigned nonce_used; + size_t n, ad_len; + + seq = send ? s->s3->write_sequence : s->s3->read_sequence; + + if (SSL_IS_DTLS(s)) { + uint8_t dtlsseq[9], *p = dtlsseq; + + s2n(send ? s->d1->w_epoch : s->d1->r_epoch, p); + memcpy(p, &seq[2], 6); + memcpy(ad, dtlsseq, 8); + } else { + int i; + memcpy(ad, seq, 8); + for (i = 7; i >= 0; i--) { + ++seq[i]; + if (seq[i] != 0) { + break; + } + } + } + + ad[8] = rec->type; + ad_len = 9; + if (!aead->omit_version_in_ad) { + ad[ad_len++] = (uint8_t)(s->version >> 8); + ad[ad_len++] = (uint8_t)(s->version); + } + + if (aead->fixed_nonce_len + aead->variable_nonce_len > sizeof(nonce)) { + OPENSSL_PUT_ERROR(SSL, tls1_enc, ERR_R_INTERNAL_ERROR); + return 0; + } + + memcpy(nonce, aead->fixed_nonce, aead->fixed_nonce_len); + nonce_used = aead->fixed_nonce_len; + + if (send) { + size_t len = rec->length; + size_t eivlen = 0; + in = rec->input; + out = rec->data; + + uint8_t *variable_nonce = nonce + nonce_used; + if (aead->random_variable_nonce) { + assert(aead->variable_nonce_included_in_record); + if (!RAND_bytes(nonce + nonce_used, aead->variable_nonce_len)) { + return 0; + } + } else { + /* When sending we use the sequence number as the variable part of the + * nonce. */ + if (aead->variable_nonce_len != 8) { + OPENSSL_PUT_ERROR(SSL, tls1_enc, ERR_R_INTERNAL_ERROR); + return 0; + } + memcpy(nonce + nonce_used, ad, aead->variable_nonce_len); + } + nonce_used += aead->variable_nonce_len; + + /* in do_ssl3_write, rec->input is moved forward by variable_nonce_len in + * order to leave space for the variable nonce. Thus we can copy the + * sequence number bytes into place without overwriting any of the + * plaintext. */ + if (aead->variable_nonce_included_in_record) { + memcpy(out, variable_nonce, aead->variable_nonce_len); + len -= aead->variable_nonce_len; + eivlen = aead->variable_nonce_len; + } + + if (!aead->omit_length_in_ad) { + ad[ad_len++] = len >> 8; + ad[ad_len++] = len & 0xff; + } + + if (!EVP_AEAD_CTX_seal(&aead->ctx, out + eivlen, &n, len + aead->tag_len, + nonce, nonce_used, in + eivlen, len, ad, ad_len)) { + return 0; + } + + if (aead->variable_nonce_included_in_record) { + n += aead->variable_nonce_len; + } + } else { + /* receive */ + size_t len = rec->length; + + if (rec->data != rec->input) { + OPENSSL_PUT_ERROR(SSL, tls1_enc, ERR_R_INTERNAL_ERROR); + return 0; + } + out = in = rec->input; + + if (len < aead->variable_nonce_len) { + return 0; + } + memcpy(nonce + nonce_used, + aead->variable_nonce_included_in_record ? in : ad, + aead->variable_nonce_len); + nonce_used += aead->variable_nonce_len; + + if (aead->variable_nonce_included_in_record) { + in += aead->variable_nonce_len; + len -= aead->variable_nonce_len; + out += aead->variable_nonce_len; + } + + if (!aead->omit_length_in_ad) { + if (len < aead->tag_len) { + return 0; + } + size_t plaintext_len = len - aead->tag_len; + + ad[ad_len++] = plaintext_len >> 8; + ad[ad_len++] = plaintext_len & 0xff; + } + + if (!EVP_AEAD_CTX_open(&aead->ctx, out, &n, rec->length, nonce, nonce_used, in, + len, ad, ad_len)) { + return 0; + } + + rec->data = rec->input = out; + } + + rec->length = n; + return 1; +} + +int tls1_cert_verify_mac(SSL *s, int md_nid, uint8_t *out) { + unsigned int ret; + EVP_MD_CTX ctx, *d = NULL; + int i; + + if (s->s3->handshake_buffer && + !ssl3_digest_cached_records(s, free_handshake_buffer)) { + return 0; + } + + for (i = 0; i < SSL_MAX_DIGEST; i++) { + if (s->s3->handshake_dgst[i] && + EVP_MD_CTX_type(s->s3->handshake_dgst[i]) == md_nid) { + d = s->s3->handshake_dgst[i]; + break; + } + } + + if (!d) { + OPENSSL_PUT_ERROR(SSL, tls1_cert_verify_mac, SSL_R_NO_REQUIRED_DIGEST); + return 0; + } + + EVP_MD_CTX_init(&ctx); + EVP_MD_CTX_copy_ex(&ctx, d); + EVP_DigestFinal_ex(&ctx, out, &ret); + EVP_MD_CTX_cleanup(&ctx); + + return ret; +} + +/* tls1_handshake_digest calculates the current handshake hash and writes it to + * |out|, which has space for |out_len| bytes. It returns the number of bytes + * written or -1 in the event of an error. This function works on a copy of the + * underlying digests so can be called multiple times and prior to the final + * update etc. */ +int tls1_handshake_digest(SSL *s, uint8_t *out, size_t out_len) { + const EVP_MD *md; + EVP_MD_CTX ctx; + int err = 0, len = 0; + size_t i; + long mask; + + EVP_MD_CTX_init(&ctx); + + for (i = 0; ssl_get_handshake_digest(i, &mask, &md); i++) { + size_t hash_size; + unsigned int digest_len; + EVP_MD_CTX *hdgst = s->s3->handshake_dgst[i]; + + if ((mask & ssl_get_algorithm2(s)) == 0) { + continue; + } + + hash_size = EVP_MD_size(md); + if (!hdgst || + hash_size > out_len || + !EVP_MD_CTX_copy_ex(&ctx, hdgst) || + !EVP_DigestFinal_ex(&ctx, out, &digest_len) || + digest_len != hash_size /* internal error */) { + err = 1; + break; + } + + out += digest_len; + out_len -= digest_len; + len += digest_len; + } + + EVP_MD_CTX_cleanup(&ctx); + + if (err != 0) { + return -1; + } + return len; +} + +int tls1_final_finish_mac(SSL *s, const char *str, int slen, uint8_t *out) { + uint8_t buf[2 * EVP_MAX_MD_SIZE]; + int err = 0; + int digests_len; + + if (s->s3->handshake_buffer && + !ssl3_digest_cached_records(s, free_handshake_buffer)) { + return 0; + } + + digests_len = tls1_handshake_digest(s, buf, sizeof(buf)); + if (digests_len < 0) { + err = 1; + digests_len = 0; + } + + if (!s->enc_method->prf(s, out, 12, s->session->master_key, + s->session->master_key_length, str, slen, buf, + digests_len, NULL, 0)) { + err = 1; + } + + if (err) { + return 0; + } else { + return 12; + } +} + +int tls1_generate_master_secret(SSL *s, uint8_t *out, const uint8_t *premaster, + size_t premaster_len) { + if (s->s3->tmp.extended_master_secret) { + uint8_t digests[2 * EVP_MAX_MD_SIZE]; + int digests_len; + + /* The master secret is based on the handshake hash just after sending the + * ClientKeyExchange. However, we might have a client certificate to send, + * in which case we might need different hashes for the verification and + * thus still need the handshake buffer around. Keeping both a handshake + * buffer *and* running hashes isn't yet supported so, when it comes to + * calculating the Finished hash, we'll have to hash the handshake buffer + * again. */ + if (s->s3->handshake_buffer && + !ssl3_digest_cached_records(s, dont_free_handshake_buffer)) { + return 0; + } + + digests_len = tls1_handshake_digest(s, digests, sizeof(digests)); + if (digests_len == -1) { + return 0; + } + + if (!s->enc_method->prf(s, out, SSL3_MASTER_SECRET_SIZE, premaster, + premaster_len, TLS_MD_EXTENDED_MASTER_SECRET_CONST, + TLS_MD_EXTENDED_MASTER_SECRET_CONST_SIZE, digests, + digests_len, NULL, 0)) { + return 0; + } + } else { + if (!s->enc_method->prf(s, out, SSL3_MASTER_SECRET_SIZE, premaster, + premaster_len, TLS_MD_MASTER_SECRET_CONST, + TLS_MD_MASTER_SECRET_CONST_SIZE, + s->s3->client_random, SSL3_RANDOM_SIZE, + s->s3->server_random, SSL3_RANDOM_SIZE)) { + return 0; + } + } + + return SSL3_MASTER_SECRET_SIZE; +} + +int tls1_export_keying_material(SSL *s, uint8_t *out, size_t olen, + const char *label, size_t llen, + const uint8_t *context, size_t contextlen, + int use_context) { + uint8_t *val = NULL; + size_t vallen, currentvalpos; + int ret; + + /* construct PRF arguments we construct the PRF argument ourself rather than + * passing separate values into the TLS PRF to ensure that the concatenation + * of values does not create a prohibited label. */ + vallen = llen + SSL3_RANDOM_SIZE * 2; + if (use_context) { + vallen += 2 + contextlen; + } + + val = OPENSSL_malloc(vallen); + if (val == NULL) { + goto err2; + } + + currentvalpos = 0; + memcpy(val + currentvalpos, (uint8_t *)label, llen); + currentvalpos += llen; + memcpy(val + currentvalpos, s->s3->client_random, SSL3_RANDOM_SIZE); + currentvalpos += SSL3_RANDOM_SIZE; + memcpy(val + currentvalpos, s->s3->server_random, SSL3_RANDOM_SIZE); + currentvalpos += SSL3_RANDOM_SIZE; + + if (use_context) { + val[currentvalpos] = (contextlen >> 8) & 0xff; + currentvalpos++; + val[currentvalpos] = contextlen & 0xff; + currentvalpos++; + if (contextlen > 0 || context != NULL) { + memcpy(val + currentvalpos, context, contextlen); + } + } + + /* disallow prohibited labels note that SSL3_RANDOM_SIZE > max(prohibited + * label len) = 15, so size of val > max(prohibited label len) = 15 and the + * comparisons won't have buffer overflow. */ + if (memcmp(val, TLS_MD_CLIENT_FINISH_CONST, + TLS_MD_CLIENT_FINISH_CONST_SIZE) == 0 || + memcmp(val, TLS_MD_SERVER_FINISH_CONST, + TLS_MD_SERVER_FINISH_CONST_SIZE) == 0 || + memcmp(val, TLS_MD_MASTER_SECRET_CONST, + TLS_MD_MASTER_SECRET_CONST_SIZE) == 0 || + memcmp(val, TLS_MD_KEY_EXPANSION_CONST, + TLS_MD_KEY_EXPANSION_CONST_SIZE) == 0) { + goto err1; + } + + /* SSL_export_keying_material is not implemented for SSLv3, so passing + * everything through the label parameter works. */ + assert(s->version != SSL3_VERSION); + ret = s->enc_method->prf(s, out, olen, s->session->master_key, + s->session->master_key_length, (const char *)val, + vallen, NULL, 0, NULL, 0); + goto out; + +err1: + OPENSSL_PUT_ERROR(SSL, tls1_export_keying_material, + SSL_R_TLS_ILLEGAL_EXPORTER_LABEL); + ret = 0; + goto out; + +err2: + OPENSSL_PUT_ERROR(SSL, tls1_export_keying_material, ERR_R_MALLOC_FAILURE); + ret = 0; + +out: + if (val != NULL) { + OPENSSL_free(val); + } + + return ret; +} + +int tls1_alert_code(int code) { + switch (code) { + case SSL_AD_CLOSE_NOTIFY: + return SSL3_AD_CLOSE_NOTIFY; + + case SSL_AD_UNEXPECTED_MESSAGE: + return SSL3_AD_UNEXPECTED_MESSAGE; + + case SSL_AD_BAD_RECORD_MAC: + return SSL3_AD_BAD_RECORD_MAC; + + case SSL_AD_DECRYPTION_FAILED: + return TLS1_AD_DECRYPTION_FAILED; + + case SSL_AD_RECORD_OVERFLOW: + return TLS1_AD_RECORD_OVERFLOW; + + case SSL_AD_DECOMPRESSION_FAILURE: + return SSL3_AD_DECOMPRESSION_FAILURE; + + case SSL_AD_HANDSHAKE_FAILURE: + return SSL3_AD_HANDSHAKE_FAILURE; + + case SSL_AD_NO_CERTIFICATE: + return -1; + + case SSL_AD_BAD_CERTIFICATE: + return SSL3_AD_BAD_CERTIFICATE; + + case SSL_AD_UNSUPPORTED_CERTIFICATE: + return SSL3_AD_UNSUPPORTED_CERTIFICATE; + + case SSL_AD_CERTIFICATE_REVOKED: + return SSL3_AD_CERTIFICATE_REVOKED; + + case SSL_AD_CERTIFICATE_EXPIRED: + return SSL3_AD_CERTIFICATE_EXPIRED; + + case SSL_AD_CERTIFICATE_UNKNOWN: + return SSL3_AD_CERTIFICATE_UNKNOWN; + + case SSL_AD_ILLEGAL_PARAMETER: + return SSL3_AD_ILLEGAL_PARAMETER; + + case SSL_AD_UNKNOWN_CA: + return TLS1_AD_UNKNOWN_CA; + + case SSL_AD_ACCESS_DENIED: + return TLS1_AD_ACCESS_DENIED; + + case SSL_AD_DECODE_ERROR: + return TLS1_AD_DECODE_ERROR; + + case SSL_AD_DECRYPT_ERROR: + return TLS1_AD_DECRYPT_ERROR; + case SSL_AD_EXPORT_RESTRICTION: + return TLS1_AD_EXPORT_RESTRICTION; + + case SSL_AD_PROTOCOL_VERSION: + return TLS1_AD_PROTOCOL_VERSION; + + case SSL_AD_INSUFFICIENT_SECURITY: + return TLS1_AD_INSUFFICIENT_SECURITY; + + case SSL_AD_INTERNAL_ERROR: + return TLS1_AD_INTERNAL_ERROR; + + case SSL_AD_USER_CANCELLED: + return TLS1_AD_USER_CANCELLED; + + case SSL_AD_NO_RENEGOTIATION: + return TLS1_AD_NO_RENEGOTIATION; + + case SSL_AD_UNSUPPORTED_EXTENSION: + return TLS1_AD_UNSUPPORTED_EXTENSION; + + case SSL_AD_CERTIFICATE_UNOBTAINABLE: + return TLS1_AD_CERTIFICATE_UNOBTAINABLE; + + case SSL_AD_UNRECOGNIZED_NAME: + return TLS1_AD_UNRECOGNIZED_NAME; + + case SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE: + return TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE; + + case SSL_AD_BAD_CERTIFICATE_HASH_VALUE: + return TLS1_AD_BAD_CERTIFICATE_HASH_VALUE; + + case SSL_AD_UNKNOWN_PSK_IDENTITY: + return TLS1_AD_UNKNOWN_PSK_IDENTITY; + + case SSL_AD_INAPPROPRIATE_FALLBACK: + return SSL3_AD_INAPPROPRIATE_FALLBACK; + + default: + return -1; + } +} |