ssl/ssl_sess.c

   1 /* ssl/ssl_sess.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include <openssl/lhash.h>
  61 #include <openssl/rand.h>
  62 #include "ssl_locl.h"
  63
  64 static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s);
  65 static void SSL_SESSION_list_add(SSL_CTX *ctx,SSL_SESSION *s);
  66 static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lck);
  67 static int ssl_session_num=0;
  68 static STACK *ssl_session_meth=NULL;
  69
  70 SSL_SESSION *SSL_get_session(SSL *ssl)
  71         {
  72         return(ssl->session);
  73         }
  74
  75 int SSL_SESSION_get_ex_new_index(long argl, char *argp, int (*new_func)(),
  76              int (*dup_func)(), void (*free_func)())
  77         {
  78         ssl_session_num++;
  79         return(CRYPTO_get_ex_new_index(ssl_session_num-1,
  80                 &ssl_session_meth,
  81                 argl,argp,new_func,dup_func,free_func));
  82         }
  83
  84 int SSL_SESSION_set_ex_data(SSL_SESSION *s, int idx, void *arg)
  85         {
  86         return(CRYPTO_set_ex_data(&s->ex_data,idx,arg));
  87         }
  88
  89 void *SSL_SESSION_get_ex_data(SSL_SESSION *s, int idx)
  90         {
  91         return(CRYPTO_get_ex_data(&s->ex_data,idx));
  92         }
  93
  94 SSL_SESSION *SSL_SESSION_new(void)
  95         {
  96         SSL_SESSION *ss;
  97
  98         ss=(SSL_SESSION *)Malloc(sizeof(SSL_SESSION));
  99         if (ss == NULL)
 100                 {
 101                 SSLerr(SSL_F_SSL_SESSION_NEW,ERR_R_MALLOC_FAILURE);
 102                 return(0);
 103                 }
 104         memset(ss,0,sizeof(SSL_SESSION));
 105
 106         ss->references=1;
 107         ss->timeout=60*5+4; /* 5 minute timeout by default */
 108         ss->time=time(NULL);
 109         ss->prev=NULL;
 110         ss->next=NULL;
 111         ss->compress_meth=0;
 112         CRYPTO_new_ex_data(ssl_session_meth,(char *)ss,&ss->ex_data);
 113         return(ss);
 114         }
 115
 116 int ssl_get_new_session(SSL *s, int session)
 117         {
 118         SSL_SESSION *ss=NULL;
 119
 120         if ((ss=SSL_SESSION_new()) == NULL) return(0);
 121
 122         /* If the context has a default timeout, use it */
 123         if (s->ctx->session_timeout == 0)
 124                 ss->timeout=SSL_get_default_timeout(s);
 125         else
 126                 ss->timeout=s->ctx->session_timeout;
 127
 128         if (s->session != NULL)
 129                 {
 130                 SSL_SESSION_free(s->session);
 131                 s->session=NULL;
 132                 }
 133
 134         if (session)
 135                 {
 136                 if (s->version == SSL2_VERSION)
 137                         {
 138                         ss->ssl_version=SSL2_VERSION;
 139                         ss->session_id_length=SSL2_SSL_SESSION_ID_LENGTH;
 140                         }
 141                 else if (s->version == SSL3_VERSION)
 142                         {
 143                         ss->ssl_version=SSL3_VERSION;
 144                         ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
 145                         }
 146                 else if (s->version == TLS1_VERSION)
 147                         {
 148                         ss->ssl_version=TLS1_VERSION;
 149                         ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
 150                         }
 151                 else
 152                         {
 153                         SSLerr(SSL_F_SSL_GET_NEW_SESSION,SSL_R_UNSUPPORTED_SSL_VERSION);
 154                         SSL_SESSION_free(ss);
 155                         return(0);
 156                         }
 157
 158                 for (;;)
 159                         {
 160                         SSL_SESSION *r;
 161
 162                         RAND_bytes(ss->session_id,ss->session_id_length);
 163                         CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
 164                         r=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,
 165                                 (char *)ss);
 166                         CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
 167                         if (r == NULL) break;
 168                         /* else - woops a session_id match */
 169                         }
 170                 }
 171         else
 172                 {
 173                 ss->session_id_length=0;
 174                 }
 175
 176         memcpy(ss->sid_ctx,s->sid_ctx,s->sid_ctx_length);
 177         ss->sid_ctx_length=s->sid_ctx_length;
 178         s->session=ss;
 179         ss->ssl_version=s->version;
 180
 181         return(1);
 182         }
 183
 184 int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
 185         {
 186         SSL_SESSION *ret=NULL,data;
 187         int copy=1;
 188
 189         /* conn_init();*/
 190         data.ssl_version=s->version;
 191         data.session_id_length=len;
 192         if (len > SSL_MAX_SSL_SESSION_ID_LENGTH)
 193                 return(0);
 194         memcpy(data.session_id,session_id,len);
 195
 196         if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_LOOKUP))
 197                 {
 198                 CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
 199                 ret=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,(char *)&data);
 200                 CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
 201                 }
 202
 203         if (ret == NULL)
 204                 {
 205                 s->ctx->stats.sess_miss++;
 206                 ret=NULL;
 207                 if (s->ctx->get_session_cb != NULL
 208                     && (ret=s->ctx->get_session_cb(s,session_id,len,&copy))
 209                        != NULL)
 210                         {
 211                         s->ctx->stats.sess_cb_hit++;
 212
 213                         /* The following should not return 1, otherwise,
 214                          * things are very strange */
 215                         SSL_CTX_add_session(s->ctx,ret);
 216                         }
 217                 if (ret == NULL) return(0);
 218                 }
 219
 220         if((s->verify_mode&SSL_VERIFY_PEER)
 221            && (!s->sid_ctx_length || ret->sid_ctx_length != s->sid_ctx_length
 222                || memcmp(ret->sid_ctx,s->sid_ctx,ret->sid_ctx_length)))
 223             {
 224             SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
 225             return 0;
 226             }
 227
 228         /* auto free it */
 229         if (!copy)
 230             SSL_SESSION_free(ret);
 231
 232         if (ret->cipher == NULL)
 233                 {
 234                 unsigned char buf[5],*p;
 235                 unsigned long l;
 236
 237                 p=buf;
 238                 l=ret->cipher_id;
 239                 l2n(l,p);
 240                 if ((ret->ssl_version>>8) == SSL3_VERSION_MAJOR)
 241                         ret->cipher=ssl_get_cipher_by_char(s,&(buf[2]));
 242                 else
 243                         ret->cipher=ssl_get_cipher_by_char(s,&(buf[1]));
 244                 if (ret->cipher == NULL)
 245                         return(0);
 246                 }
 247
 248         /* If a thread got the session, then 'swaped', and another got
 249          * it and then due to a time-out decided to 'Free' it we could
 250          * be in trouble.  So I'll increment it now, then double decrement
 251          * later - am I speaking rubbish?. */
 252         CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
 253
 254         if ((long)(ret->time+ret->timeout) < (long)time(NULL)) /* timeout */
 255                 {
 256                 s->ctx->stats.sess_timeout++;
 257                 /* remove it from the cache */
 258                 SSL_CTX_remove_session(s->ctx,ret);
 259                 SSL_SESSION_free(ret);          /* again to actually Free it */
 260                 return(0);
 261                 }
 262
 263         s->ctx->stats.sess_hit++;
 264
 265         /* ret->time=time(NULL); */ /* rezero timeout? */
 266         /* again, just leave the session
 267          * if it is the same session, we have just incremented and
 268          * then decremented the reference count :-) */
 269         if (s->session != NULL)
 270                 SSL_SESSION_free(s->session);
 271         s->session=ret;
 272         return(1);
 273         }
 274
 275 int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *c)
 276         {
 277         int ret=0;
 278         SSL_SESSION *s;
 279
 280         /* conn_init(); */
 281         CRYPTO_add(&c->references,1,CRYPTO_LOCK_SSL_SESSION);
 282
 283         CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
 284         s=(SSL_SESSION *)lh_insert(ctx->sessions,(char *)c);
 285
 286         /* Put on the end of the queue unless it is already in the cache */
 287         if (s == NULL)
 288                 SSL_SESSION_list_add(ctx,c);
 289
 290         /* If the same session if is being 're-added', Free the old
 291          * one when the last person stops using it.
 292          * This will also work if it is alread in the cache.
 293          * The references will go up and then down :-) */
 294         if (s != NULL)
 295                 {
 296                 SSL_SESSION_free(s);
 297                 ret=0;
 298                 }
 299         else
 300                 {
 301                 ret=1;
 302
 303                 if (SSL_CTX_sess_get_cache_size(ctx) > 0)
 304                         {
 305                         while (SSL_CTX_sess_number(ctx) >
 306                                 SSL_CTX_sess_get_cache_size(ctx))
 307                                 {
 308                                 if (!remove_session_lock(ctx,
 309                                         ctx->session_cache_tail, 0))
 310                                         break;
 311                                 else
 312                                         ctx->stats.sess_cache_full++;
 313                                 }
 314                         }
 315                 }
 316         CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
 317         return(ret);
 318         }
 319
 320 int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *c)
 321 {
 322         return remove_session_lock(ctx, c, 1);
 323 }
 324
 325 int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lck)
 326         {
 327         SSL_SESSION *r;
 328         int ret=0;
 329
 330         if ((c != NULL) && (c->session_id_length != 0))
 331                 {
 332                 if(lck) CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
 333                 r=(SSL_SESSION *)lh_delete(ctx->sessions,(char *)c);
 334                 if (r != NULL)
 335                         {
 336                         ret=1;
 337                         SSL_SESSION_list_remove(ctx,c);
 338                         }
 339
 340                 if(lck) CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
 341
 342                 if (ret)
 343                         {
 344                         r->not_resumable=1;
 345                         if (ctx->remove_session_cb != NULL)
 346                                 ctx->remove_session_cb(ctx,r);
 347                         SSL_SESSION_free(r);
 348                         }
 349                 }
 350         else
 351                 ret=0;
 352         return(ret);
 353         }
 354
 355 void SSL_SESSION_free(SSL_SESSION *ss)
 356         {
 357         int i;
 358
 359         if(ss == NULL)
 360             return;
 361
 362         i=CRYPTO_add(&ss->references,-1,CRYPTO_LOCK_SSL_SESSION);
 363 #ifdef REF_PRINT
 364         REF_PRINT("SSL_SESSION",ss);
 365 #endif
 366         if (i > 0) return;
 367 #ifdef REF_CHECK
 368         if (i < 0)
 369                 {
 370                 fprintf(stderr,"SSL_SESSION_free, bad reference count\n");
 371                 abort(); /* ok */
 372                 }
 373 #endif
 374
 375         CRYPTO_free_ex_data(ssl_session_meth,(char *)ss,&ss->ex_data);
 376
 377         memset(ss->key_arg,0,SSL_MAX_KEY_ARG_LENGTH);
 378         memset(ss->master_key,0,SSL_MAX_MASTER_KEY_LENGTH);
 379         memset(ss->session_id,0,SSL_MAX_SSL_SESSION_ID_LENGTH);
 380         if (ss->cert != NULL) ssl_cert_free(ss->cert);
 381         if (ss->peer != NULL) X509_free(ss->peer);
 382         if (ss->ciphers != NULL) sk_SSL_CIPHER_free(ss->ciphers);
 383         memset(ss,0,sizeof(*ss));
 384         Free(ss);
 385         }
 386
 387 int SSL_set_session(SSL *s, SSL_SESSION *session)
 388         {
 389         int ret=0;
 390         SSL_METHOD *meth;
 391
 392         if (session != NULL)
 393                 {
 394                 meth=s->ctx->method->get_ssl_method(session->ssl_version);
 395                 if (meth == NULL)
 396                         meth=s->method->get_ssl_method(session->ssl_version);
 397                 if (meth == NULL)
 398                         {
 399                         SSLerr(SSL_F_SSL_SET_SESSION,SSL_R_UNABLE_TO_FIND_SSL_METHOD);
 400                         return(0);
 401                         }
 402
 403                 if (meth != s->method)
 404                         {
 405                         if (!SSL_set_ssl_method(s,meth))
 406                                 return(0);
 407                         if (s->ctx->session_timeout == 0)
 408                                 session->timeout=SSL_get_default_timeout(s);
 409                         else
 410                                 session->timeout=s->ctx->session_timeout;
 411                         }
 412
 413                 /* CRYPTO_w_lock(CRYPTO_LOCK_SSL);*/
 414                 CRYPTO_add(&session->references,1,CRYPTO_LOCK_SSL_SESSION);
 415                 if (s->session != NULL)
 416                         SSL_SESSION_free(s->session);
 417                 s->session=session;
 418                 /* CRYPTO_w_unlock(CRYPTO_LOCK_SSL);*/
 419                 ret=1;
 420                 }
 421         else
 422                 {
 423                 if (s->session != NULL)
 424                         {
 425                         SSL_SESSION_free(s->session);
 426                         s->session=NULL;
 427                         }
 428
 429                 meth=s->ctx->method;
 430                 if (meth != s->method)
 431                         {
 432                         if (!SSL_set_ssl_method(s,meth))
 433                                 return(0);
 434                         }
 435                 ret=1;
 436                 }
 437         return(ret);
 438         }
 439
 440 long SSL_SESSION_set_timeout(SSL_SESSION *s, long t)
 441         {
 442         if (s == NULL) return(0);
 443         s->timeout=t;
 444         return(1);
 445         }
 446
 447 long SSL_SESSION_get_timeout(SSL_SESSION *s)
 448         {
 449         if (s == NULL) return(0);
 450         return(s->timeout);
 451         }
 452
 453 long SSL_SESSION_get_time(SSL_SESSION *s)
 454         {
 455         if (s == NULL) return(0);
 456         return(s->time);
 457         }
 458
 459 long SSL_SESSION_set_time(SSL_SESSION *s, long t)
 460         {
 461         if (s == NULL) return(0);
 462         s->time=t;
 463         return(t);
 464         }
 465
 466 long SSL_CTX_set_timeout(SSL_CTX *s, long t)
 467         {
 468         long l;
 469         if (s == NULL) return(0);
 470         l=s->session_timeout;
 471         s->session_timeout=t;
 472         return(l);
 473         }
 474
 475 long SSL_CTX_get_timeout(SSL_CTX *s)
 476         {
 477         if (s == NULL) return(0);
 478         return(s->session_timeout);
 479         }
 480
 481 typedef struct timeout_param_st
 482         {
 483         SSL_CTX *ctx;
 484         long time;
 485         LHASH *cache;
 486         } TIMEOUT_PARAM;
 487
 488 static void timeout(SSL_SESSION *s, TIMEOUT_PARAM *p)
 489         {
 490         if ((p->time == 0) || (p->time > (s->time+s->timeout))) /* timeout */
 491                 {
 492                 /* The reason we don't call SSL_CTX_remove_session() is to
 493                  * save on locking overhead */
 494                 lh_delete(p->cache,(char *)s);
 495                 SSL_SESSION_list_remove(p->ctx,s);
 496                 s->not_resumable=1;
 497                 if (p->ctx->remove_session_cb != NULL)
 498                         p->ctx->remove_session_cb(p->ctx,s);
 499                 SSL_SESSION_free(s);
 500                 }
 501         }
 502
 503 void SSL_CTX_flush_sessions(SSL_CTX *s, long t)
 504         {
 505         unsigned long i;
 506         TIMEOUT_PARAM tp;
 507
 508         tp.ctx=s;
 509         tp.cache=s->sessions;
 510         if (tp.cache == NULL) return;
 511         tp.time=t;
 512         CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
 513         i=tp.cache->down_load;
 514         tp.cache->down_load=0;
 515         lh_doall_arg(tp.cache,(void (*)())timeout,(char *)&tp);
 516         tp.cache->down_load=i;
 517         CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
 518         }
 519
 520 int ssl_clear_bad_session(SSL *s)
 521         {
 522         if (    (s->session != NULL) &&
 523                 !(s->shutdown & SSL_SENT_SHUTDOWN) &&
 524                 !(SSL_in_init(s) || SSL_in_before(s)))
 525                 {
 526                 SSL_CTX_remove_session(s->ctx,s->session);
 527                 return(1);
 528                 }
 529         else
 530                 return(0);
 531         }
 532
 533 /* locked by SSL_CTX in the calling function */
 534 static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s)
 535         {
 536         if ((s->next == NULL) || (s->prev == NULL)) return;
 537
 538         if (s->next == (SSL_SESSION *)&(ctx->session_cache_tail))
 539                 { /* last element in list */
 540                 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
 541                         { /* only one element in list */
 542                         ctx->session_cache_head=NULL;
 543                         ctx->session_cache_tail=NULL;
 544                         }
 545                 else
 546                         {
 547                         ctx->session_cache_tail=s->prev;
 548                         s->prev->next=(SSL_SESSION *)&(ctx->session_cache_tail);
 549                         }
 550                 }
 551         else
 552                 {
 553                 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
 554                         { /* first element in list */
 555                         ctx->session_cache_head=s->next;
 556                         s->next->prev=(SSL_SESSION *)&(ctx->session_cache_head);
 557                         }
 558                 else
 559                         { /* middle of list */
 560                         s->next->prev=s->prev;
 561                         s->prev->next=s->next;
 562                         }
 563                 }
 564         s->prev=s->next=NULL;
 565         }
 566
 567 static void SSL_SESSION_list_add(SSL_CTX *ctx, SSL_SESSION *s)
 568         {
 569         if ((s->next != NULL) && (s->prev != NULL))
 570                 SSL_SESSION_list_remove(ctx,s);
 571
 572         if (ctx->session_cache_head == NULL)
 573                 {
 574                 ctx->session_cache_head=s;
 575                 ctx->session_cache_tail=s;
 576                 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
 577                 s->next=(SSL_SESSION *)&(ctx->session_cache_tail);
 578                 }
 579         else
 580                 {
 581                 s->next=ctx->session_cache_head;
 582                 s->next->prev=s;
 583                 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
 584                 ctx->session_cache_head=s;
 585                 }
 586         }
 587