1 /* 2 * SSL session cache implementation 3 * 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved 5 * SPDX-License-Identifier: GPL-2.0 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License along 18 * with this program; if not, write to the Free Software Foundation, Inc., 19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * This file is part of mbed TLS (https://tls.mbed.org) 22 */ 23 /* 24 * These session callbacks use a simple chained list 25 * to store and retrieve the session information. 26 */ 27 28 #if !defined(MBEDTLS_CONFIG_FILE) 29 #include "mbedtls/config.h" 30 #else 31 #include MBEDTLS_CONFIG_FILE 32 #endif 33 34 #if defined(MBEDTLS_SSL_CACHE_C) 35 36 #if defined(MBEDTLS_PLATFORM_C) 37 #include "mbedtls/platform.h" 38 #else 39 #include <stdlib.h> 40 #define mbedtls_calloc calloc 41 #define mbedtls_free free 42 #endif 43 44 #include "mbedtls/ssl_cache.h" 45 46 #include <string.h> 47 48 void mbedtls_ssl_cache_init( mbedtls_ssl_cache_context *cache ) 49 { 50 memset( cache, 0, sizeof( mbedtls_ssl_cache_context ) ); 51 52 cache->timeout = MBEDTLS_SSL_CACHE_DEFAULT_TIMEOUT; 53 cache->max_entries = MBEDTLS_SSL_CACHE_DEFAULT_MAX_ENTRIES; 54 55 #if defined(MBEDTLS_THREADING_C) 56 mbedtls_mutex_init( &cache->mutex ); 57 #endif 58 } 59 60 int mbedtls_ssl_cache_get( void *data, mbedtls_ssl_session *session ) 61 { 62 int ret = 1; 63 #if defined(MBEDTLS_HAVE_TIME) 64 mbedtls_time_t t = mbedtls_time( NULL ); 65 #endif 66 mbedtls_ssl_cache_context *cache = (mbedtls_ssl_cache_context *) data; 67 mbedtls_ssl_cache_entry *cur, *entry; 68 69 #if defined(MBEDTLS_THREADING_C) 70 if( mbedtls_mutex_lock( &cache->mutex ) != 0 ) 71 return( 1 ); 72 #endif 73 74 cur = cache->chain; 75 entry = NULL; 76 77 while( cur != NULL ) 78 { 79 entry = cur; 80 cur = cur->next; 81 82 #if defined(MBEDTLS_HAVE_TIME) 83 if( cache->timeout != 0 && 84 (int) ( t - entry->timestamp ) > cache->timeout ) 85 continue; 86 #endif 87 88 if( session->ciphersuite != entry->session.ciphersuite || 89 session->compression != entry->session.compression || 90 session->id_len != entry->session.id_len ) 91 continue; 92 93 if( memcmp( session->id, entry->session.id, 94 entry->session.id_len ) != 0 ) 95 continue; 96 97 memcpy( session->master, entry->session.master, 48 ); 98 99 session->verify_result = entry->session.verify_result; 100 101 #if defined(MBEDTLS_X509_CRT_PARSE_C) 102 /* 103 * Restore peer certificate (without rest of the original chain) 104 */ 105 if( entry->peer_cert.p != NULL ) 106 { 107 if( ( session->peer_cert = mbedtls_calloc( 1, 108 sizeof(mbedtls_x509_crt) ) ) == NULL ) 109 { 110 ret = 1; 111 goto exit; 112 } 113 114 mbedtls_x509_crt_init( session->peer_cert ); 115 if( mbedtls_x509_crt_parse( session->peer_cert, entry->peer_cert.p, 116 entry->peer_cert.len ) != 0 ) 117 { 118 mbedtls_free( session->peer_cert ); 119 session->peer_cert = NULL; 120 ret = 1; 121 goto exit; 122 } 123 } 124 #endif /* MBEDTLS_X509_CRT_PARSE_C */ 125 126 ret = 0; 127 goto exit; 128 } 129 130 exit: 131 #if defined(MBEDTLS_THREADING_C) 132 if( mbedtls_mutex_unlock( &cache->mutex ) != 0 ) 133 ret = 1; 134 #endif 135 136 return( ret ); 137 } 138 139 int mbedtls_ssl_cache_set( void *data, const mbedtls_ssl_session *session ) 140 { 141 int ret = 1; 142 #if defined(MBEDTLS_HAVE_TIME) 143 mbedtls_time_t t = mbedtls_time( NULL ), oldest = 0; 144 mbedtls_ssl_cache_entry *old = NULL; 145 #endif 146 mbedtls_ssl_cache_context *cache = (mbedtls_ssl_cache_context *) data; 147 mbedtls_ssl_cache_entry *cur, *prv; 148 int count = 0; 149 150 #if defined(MBEDTLS_THREADING_C) 151 if( ( ret = mbedtls_mutex_lock( &cache->mutex ) ) != 0 ) 152 return( ret ); 153 #endif 154 155 cur = cache->chain; 156 prv = NULL; 157 158 while( cur != NULL ) 159 { 160 count++; 161 162 #if defined(MBEDTLS_HAVE_TIME) 163 if( cache->timeout != 0 && 164 (int) ( t - cur->timestamp ) > cache->timeout ) 165 { 166 cur->timestamp = t; 167 break; /* expired, reuse this slot, update timestamp */ 168 } 169 #endif 170 171 if( memcmp( session->id, cur->session.id, cur->session.id_len ) == 0 ) 172 break; /* client reconnected, keep timestamp for session id */ 173 174 #if defined(MBEDTLS_HAVE_TIME) 175 if( oldest == 0 || cur->timestamp < oldest ) 176 { 177 oldest = cur->timestamp; 178 old = cur; 179 } 180 #endif 181 182 prv = cur; 183 cur = cur->next; 184 } 185 186 if( cur == NULL ) 187 { 188 #if defined(MBEDTLS_HAVE_TIME) 189 /* 190 * Reuse oldest entry if max_entries reached 191 */ 192 if( count >= cache->max_entries ) 193 { 194 if( old == NULL ) 195 { 196 ret = 1; 197 goto exit; 198 } 199 200 cur = old; 201 } 202 #else /* MBEDTLS_HAVE_TIME */ 203 /* 204 * Reuse first entry in chain if max_entries reached, 205 * but move to last place 206 */ 207 if( count >= cache->max_entries ) 208 { 209 if( cache->chain == NULL ) 210 { 211 ret = 1; 212 goto exit; 213 } 214 215 cur = cache->chain; 216 cache->chain = cur->next; 217 cur->next = NULL; 218 prv->next = cur; 219 } 220 #endif /* MBEDTLS_HAVE_TIME */ 221 else 222 { 223 /* 224 * max_entries not reached, create new entry 225 */ 226 cur = mbedtls_calloc( 1, sizeof(mbedtls_ssl_cache_entry) ); 227 if( cur == NULL ) 228 { 229 ret = 1; 230 goto exit; 231 } 232 233 if( prv == NULL ) 234 cache->chain = cur; 235 else 236 prv->next = cur; 237 } 238 239 #if defined(MBEDTLS_HAVE_TIME) 240 cur->timestamp = t; 241 #endif 242 } 243 244 memcpy( &cur->session, session, sizeof( mbedtls_ssl_session ) ); 245 246 #if defined(MBEDTLS_X509_CRT_PARSE_C) 247 /* 248 * If we're reusing an entry, free its certificate first 249 */ 250 if( cur->peer_cert.p != NULL ) 251 { 252 mbedtls_free( cur->peer_cert.p ); 253 memset( &cur->peer_cert, 0, sizeof(mbedtls_x509_buf) ); 254 } 255 256 /* 257 * Store peer certificate 258 */ 259 if( session->peer_cert != NULL ) 260 { 261 cur->peer_cert.p = mbedtls_calloc( 1, session->peer_cert->raw.len ); 262 if( cur->peer_cert.p == NULL ) 263 { 264 ret = 1; 265 goto exit; 266 } 267 268 memcpy( cur->peer_cert.p, session->peer_cert->raw.p, 269 session->peer_cert->raw.len ); 270 cur->peer_cert.len = session->peer_cert->raw.len; 271 272 cur->session.peer_cert = NULL; 273 } 274 #endif /* MBEDTLS_X509_CRT_PARSE_C */ 275 276 ret = 0; 277 278 exit: 279 #if defined(MBEDTLS_THREADING_C) 280 if( mbedtls_mutex_unlock( &cache->mutex ) != 0 ) 281 ret = 1; 282 #endif 283 284 return( ret ); 285 } 286 287 #if defined(MBEDTLS_HAVE_TIME) 288 void mbedtls_ssl_cache_set_timeout( mbedtls_ssl_cache_context *cache, int timeout ) 289 { 290 if( timeout < 0 ) timeout = 0; 291 292 cache->timeout = timeout; 293 } 294 #endif /* MBEDTLS_HAVE_TIME */ 295 296 void mbedtls_ssl_cache_set_max_entries( mbedtls_ssl_cache_context *cache, int max ) 297 { 298 if( max < 0 ) max = 0; 299 300 cache->max_entries = max; 301 } 302 303 void mbedtls_ssl_cache_free( mbedtls_ssl_cache_context *cache ) 304 { 305 mbedtls_ssl_cache_entry *cur, *prv; 306 307 cur = cache->chain; 308 309 while( cur != NULL ) 310 { 311 prv = cur; 312 cur = cur->next; 313 314 mbedtls_ssl_session_free( &prv->session ); 315 316 #if defined(MBEDTLS_X509_CRT_PARSE_C) 317 mbedtls_free( prv->peer_cert.p ); 318 #endif /* MBEDTLS_X509_CRT_PARSE_C */ 319 320 mbedtls_free( prv ); 321 } 322 323 #if defined(MBEDTLS_THREADING_C) 324 mbedtls_mutex_free( &cache->mutex ); 325 #endif 326 cache->chain = NULL; 327 } 328 329 #endif /* MBEDTLS_SSL_CACHE_C */ 330