1 /* $OpenBSD: ssl_transcript.c,v 1.5 2021/05/16 14:10:43 jsing Exp $ */ 2 /* 3 * Copyright (c) 2017 Joel Sing <jsing@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include <openssl/ssl.h> 19 20 #include "ssl_locl.h" 21 22 int 23 tls1_transcript_hash_init(SSL *s) 24 { 25 const unsigned char *data; 26 const EVP_MD *md; 27 size_t len; 28 29 tls1_transcript_hash_free(s); 30 31 if (!ssl_get_handshake_evp_md(s, &md)) { 32 SSLerrorx(ERR_R_INTERNAL_ERROR); 33 goto err; 34 } 35 36 if ((S3I(s)->handshake_hash = EVP_MD_CTX_new()) == NULL) { 37 SSLerror(s, ERR_R_MALLOC_FAILURE); 38 goto err; 39 } 40 if (!EVP_DigestInit_ex(S3I(s)->handshake_hash, md, NULL)) { 41 SSLerror(s, ERR_R_EVP_LIB); 42 goto err; 43 } 44 45 if (!tls1_transcript_data(s, &data, &len)) { 46 SSLerror(s, SSL_R_BAD_HANDSHAKE_LENGTH); 47 goto err; 48 } 49 if (!tls1_transcript_hash_update(s, data, len)) { 50 SSLerror(s, ERR_R_EVP_LIB); 51 goto err; 52 } 53 54 return 1; 55 56 err: 57 tls1_transcript_hash_free(s); 58 59 return 0; 60 } 61 62 int 63 tls1_transcript_hash_update(SSL *s, const unsigned char *buf, size_t len) 64 { 65 if (S3I(s)->handshake_hash == NULL) 66 return 1; 67 68 return EVP_DigestUpdate(S3I(s)->handshake_hash, buf, len); 69 } 70 71 int 72 tls1_transcript_hash_value(SSL *s, const unsigned char *out, size_t len, 73 size_t *outlen) 74 { 75 EVP_MD_CTX *mdctx = NULL; 76 unsigned int mdlen; 77 int ret = 0; 78 79 if (S3I(s)->handshake_hash == NULL) 80 goto err; 81 82 if (EVP_MD_CTX_size(S3I(s)->handshake_hash) > len) 83 goto err; 84 85 if ((mdctx = EVP_MD_CTX_new()) == NULL) { 86 SSLerror(s, ERR_R_MALLOC_FAILURE); 87 goto err; 88 } 89 if (!EVP_MD_CTX_copy_ex(mdctx, S3I(s)->handshake_hash)) { 90 SSLerror(s, ERR_R_EVP_LIB); 91 goto err; 92 } 93 if (!EVP_DigestFinal_ex(mdctx, (unsigned char *)out, &mdlen)) { 94 SSLerror(s, ERR_R_EVP_LIB); 95 goto err; 96 } 97 if (outlen != NULL) 98 *outlen = mdlen; 99 100 ret = 1; 101 102 err: 103 EVP_MD_CTX_free(mdctx); 104 105 return (ret); 106 } 107 108 void 109 tls1_transcript_hash_free(SSL *s) 110 { 111 EVP_MD_CTX_free(S3I(s)->handshake_hash); 112 S3I(s)->handshake_hash = NULL; 113 } 114 115 int 116 tls1_transcript_init(SSL *s) 117 { 118 if (S3I(s)->handshake_transcript != NULL) 119 return 0; 120 121 if ((S3I(s)->handshake_transcript = BUF_MEM_new()) == NULL) 122 return 0; 123 124 tls1_transcript_reset(s); 125 126 return 1; 127 } 128 129 void 130 tls1_transcript_free(SSL *s) 131 { 132 BUF_MEM_free(S3I(s)->handshake_transcript); 133 S3I(s)->handshake_transcript = NULL; 134 } 135 136 void 137 tls1_transcript_reset(SSL *s) 138 { 139 /* 140 * We should check the return value of BUF_MEM_grow_clean(), however 141 * due to yet another bad API design, when called with a length of zero 142 * it is impossible to tell if it succeeded (returning a length of zero) 143 * or if it failed (and returned zero)... our implementation never 144 * fails with a length of zero, so we trust all is okay... 145 */ 146 (void)BUF_MEM_grow_clean(S3I(s)->handshake_transcript, 0); 147 148 tls1_transcript_unfreeze(s); 149 } 150 151 int 152 tls1_transcript_append(SSL *s, const unsigned char *buf, size_t len) 153 { 154 size_t olen, nlen; 155 156 if (S3I(s)->handshake_transcript == NULL) 157 return 1; 158 159 if (s->s3->flags & TLS1_FLAGS_FREEZE_TRANSCRIPT) 160 return 1; 161 162 olen = S3I(s)->handshake_transcript->length; 163 nlen = olen + len; 164 165 if (nlen < olen) 166 return 0; 167 168 if (BUF_MEM_grow(S3I(s)->handshake_transcript, nlen) == 0) 169 return 0; 170 171 memcpy(S3I(s)->handshake_transcript->data + olen, buf, len); 172 173 return 1; 174 } 175 176 int 177 tls1_transcript_data(SSL *s, const unsigned char **data, size_t *len) 178 { 179 if (S3I(s)->handshake_transcript == NULL) 180 return 0; 181 182 *data = S3I(s)->handshake_transcript->data; 183 *len = S3I(s)->handshake_transcript->length; 184 185 return 1; 186 } 187 188 void 189 tls1_transcript_freeze(SSL *s) 190 { 191 s->s3->flags |= TLS1_FLAGS_FREEZE_TRANSCRIPT; 192 } 193 194 void 195 tls1_transcript_unfreeze(SSL *s) 196 { 197 s->s3->flags &= ~TLS1_FLAGS_FREEZE_TRANSCRIPT; 198 } 199 200 int 201 tls1_transcript_record(SSL *s, const unsigned char *buf, size_t len) 202 { 203 if (!tls1_transcript_hash_update(s, buf, len)) 204 return 0; 205 206 if (!tls1_transcript_append(s, buf, len)) 207 return 0; 208 209 return 1; 210 } 211