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         /* This gets used by clients and servers. */
 119
 120         SSL_SESSION *ss=NULL;
 121
 122         if ((ss=SSL_SESSION_new()) == NULL) return(0);
 123
 124         /* If the context has a default timeout, use it */
 125         if (s->ctx->session_timeout == 0)
 126                 ss->timeout=SSL_get_default_timeout(s);
 127         else
 128                 ss->timeout=s->ctx->session_timeout;
 129
 130         if (s->session != NULL)
 131                 {
 132                 SSL_SESSION_free(s->session);
 133                 s->session=NULL;
 134                 }
 135
 136         if (session)
 137                 {
 138                 if (s->version == SSL2_VERSION)
 139                         {
 140                         ss->ssl_version=SSL2_VERSION;
 141                         ss->session_id_length=SSL2_SSL_SESSION_ID_LENGTH;
 142                         }
 143                 else if (s->version == SSL3_VERSION)
 144                         {
 145                         ss->ssl_version=SSL3_VERSION;
 146                         ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
 147                         }
 148                 else if (s->version == TLS1_VERSION)
 149                         {
 150                         ss->ssl_version=TLS1_VERSION;
 151                         ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
 152                         }
 153                 else
 154                         {
 155                         SSLerr(SSL_F_SSL_GET_NEW_SESSION,SSL_R_UNSUPPORTED_SSL_VERSION);
 156                         SSL_SESSION_free(ss);
 157                         return(0);
 158                         }
 159
 160                 for (;;)
 161                         {
 162                         SSL_SESSION *r;
 163
 164                         RAND_bytes(ss->session_id,ss->session_id_length);
 165                         CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
 166                         r=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,
 167                                 (char *)ss);
 168                         CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
 169                         if (r == NULL) break;
 170                         /* else - woops a session_id match */
 171                         }
 172                 }
 173         else
 174                 {
 175                 ss->session_id_length=0;
 176                 }
 177
 178         memcpy(ss->sid_ctx,s->sid_ctx,s->sid_ctx_length);
 179         ss->sid_ctx_length=s->sid_ctx_length;
 180         s->session=ss;
 181         ss->ssl_version=s->version;
 182
 183         return(1);
 184         }
 185
 186 int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
 187         {
 188         /* This is used only by servers. */
 189
 190         SSL_SESSION *ret=NULL,data;
 191
 192         /* conn_init();*/
 193         data.ssl_version=s->version;
 194         data.session_id_length=len;
 195         if (len > SSL_MAX_SSL_SESSION_ID_LENGTH)
 196                 return(0);
 197         memcpy(data.session_id,session_id,len);
 198
 199         if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_LOOKUP))
 200                 {
 201                 CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
 202                 ret=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,(char *)&data);
 203                 CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
 204                 }
 205
 206         if (ret == NULL)
 207                 {
 208                 int copy=1;
 209
 210                 s->ctx->stats.sess_miss++;
 211                 ret=NULL;
 212                 if (s->ctx->get_session_cb != NULL
 213                     && (ret=s->ctx->get_session_cb(s,session_id,len,&copy))
 214                        != NULL)
 215                         {
 216                         s->ctx->stats.sess_cb_hit++;
 217
 218                         /* The following should not return 1, otherwise,
 219                          * things are very strange */
 220                         SSL_CTX_add_session(s->ctx,ret);
 221                         /* auto free it (decrement reference count now) */
 222                         if (!copy)
 223                                 SSL_SESSION_free(ret);
 224                         }
 225                 if (ret == NULL) return(0);
 226                 }
 227
 228         if((s->verify_mode&SSL_VERIFY_PEER)
 229            && (!s->sid_ctx_length || ret->sid_ctx_length != s->sid_ctx_length
 230                || memcmp(ret->sid_ctx,s->sid_ctx,ret->sid_ctx_length)))
 231             {
 232                 if (s->sid_ctx_length)
 233                         SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
 234                 else
 235                         /* application should have used SSL[_CTX]_set_session_id_context */
 236                         SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED);
 237             return 0;
 238             }
 239
 240         if (ret->cipher == NULL)
 241                 {
 242                 unsigned char buf[5],*p;
 243                 unsigned long l;
 244
 245                 p=buf;
 246                 l=ret->cipher_id;
 247                 l2n(l,p);
 248                 if ((ret->ssl_version>>8) == SSL3_VERSION_MAJOR)
 249                         ret->cipher=ssl_get_cipher_by_char(s,&(buf[2]));
 250                 else
 251                         ret->cipher=ssl_get_cipher_by_char(s,&(buf[1]));
 252                 if (ret->cipher == NULL)
 253                         return(0);
 254                 }
 255
 256         /* If a thread got the session, then 'swaped', and another got
 257          * it and then due to a time-out decided to 'Free' it we could
 258          * be in trouble.  So I'll increment it now, then double decrement
 259          * later - am I speaking rubbish?. */
 260         CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
 261
 262         if ((long)(ret->time+ret->timeout) < (long)time(NULL)) /* timeout */
 263                 {
 264                 s->ctx->stats.sess_timeout++;
 265                 /* remove it from the cache */
 266                 SSL_CTX_remove_session(s->ctx,ret);
 267                 SSL_SESSION_free(ret);          /* again to actually Free it */
 268                 return(0);
 269                 }
 270
 271         s->ctx->stats.sess_hit++;
 272
 273         /* ret->time=time(NULL); */ /* rezero timeout? */
 274         /* again, just leave the session
 275          * if it is the same session, we have just incremented and
 276          * then decremented the reference count :-) */
 277         if (s->session != NULL)
 278                 SSL_SESSION_free(s->session);
 279         s->session=ret;
 280         return(1);
 281         }
 282
 283 int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *c)
 284         {
 285         int ret=0;
 286         SSL_SESSION *s;
 287
 288         /* conn_init(); */
 289         CRYPTO_add(&c->references,1,CRYPTO_LOCK_SSL_SESSION);
 290
 291         CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
 292         s=(SSL_SESSION *)lh_insert(ctx->sessions,(char *)c);
 293
 294         /* Put on the end of the queue unless it is already in the cache */
 295         if (s == NULL)
 296                 SSL_SESSION_list_add(ctx,c);
 297
 298         /* If the same session if is being 're-added', Free the old
 299          * one when the last person stops using it.
 300          * This will also work if it is alread in the cache.
 301          * The references will go up and then down :-) */
 302         if (s != NULL)
 303                 {
 304                 SSL_SESSION_free(s);
 305                 ret=0;
 306                 }
 307         else
 308                 {
 309                 ret=1;
 310
 311                 if (SSL_CTX_sess_get_cache_size(ctx) > 0)
 312                         {
 313                         while (SSL_CTX_sess_number(ctx) >
 314                                 SSL_CTX_sess_get_cache_size(ctx))
 315                                 {
 316                                 if (!remove_session_lock(ctx,
 317                                         ctx->session_cache_tail, 0))
 318                                         break;
 319                                 else
 320                                         ctx->stats.sess_cache_full++;
 321                                 }
 322                         }
 323                 }
 324         CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
 325         return(ret);
 326         }
 327
 328 int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *c)
 329 {
 330         return remove_session_lock(ctx, c, 1);
 331 }
 332
 333 static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lck)
 334         {
 335         SSL_SESSION *r;
 336         int ret=0;
 337
 338         if ((c != NULL) && (c->session_id_length != 0))
 339                 {
 340                 if(lck) CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
 341                 r=(SSL_SESSION *)lh_delete(ctx->sessions,(char *)c);
 342                 if (r != NULL)
 343                         {
 344                         ret=1;
 345                         SSL_SESSION_list_remove(ctx,c);
 346                         }
 347
 348                 if(lck) CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
 349
 350                 if (ret)
 351                         {
 352                         r->not_resumable=1;
 353                         if (ctx->remove_session_cb != NULL)
 354                                 ctx->remove_session_cb(ctx,r);
 355                         SSL_SESSION_free(r);
 356                         }
 357                 }
 358         else
 359                 ret=0;
 360         return(ret);
 361         }
 362
 363 void SSL_SESSION_free(SSL_SESSION *ss)
 364         {
 365         int i;
 366
 367         if(ss == NULL)
 368             return;
 369
 370         i=CRYPTO_add(&ss->references,-1,CRYPTO_LOCK_SSL_SESSION);
 371 #ifdef REF_PRINT
 372         REF_PRINT("SSL_SESSION",ss);
 373 #endif
 374         if (i > 0) return;
 375 #ifdef REF_CHECK
 376         if (i < 0)
 377                 {
 378                 fprintf(stderr,"SSL_SESSION_free, bad reference count\n");
 379                 abort(); /* ok */
 380                 }
 381 #endif
 382
 383         CRYPTO_free_ex_data(ssl_session_meth,(char *)ss,&ss->ex_data);
 384
 385         memset(ss->key_arg,0,SSL_MAX_KEY_ARG_LENGTH);
 386         memset(ss->master_key,0,SSL_MAX_MASTER_KEY_LENGTH);
 387         memset(ss->session_id,0,SSL_MAX_SSL_SESSION_ID_LENGTH);
 388         if (ss->sess_cert != NULL) ssl_sess_cert_free(ss->sess_cert);
 389         if (ss->peer != NULL) X509_free(ss->peer);
 390         if (ss->ciphers != NULL) sk_SSL_CIPHER_free(ss->ciphers);
 391         memset(ss,0,sizeof(*ss));
 392         Free(ss);
 393         }
 394
 395 int SSL_set_session(SSL *s, SSL_SESSION *session)
 396         {
 397         int ret=0;
 398         SSL_METHOD *meth;
 399
 400         if (session != NULL)
 401                 {
 402                 meth=s->ctx->method->get_ssl_method(session->ssl_version);
 403                 if (meth == NULL)
 404                         meth=s->method->get_ssl_method(session->ssl_version);
 405                 if (meth == NULL)
 406                         {
 407                         SSLerr(SSL_F_SSL_SET_SESSION,SSL_R_UNABLE_TO_FIND_SSL_METHOD);
 408                         return(0);
 409                         }
 410
 411                 if (meth != s->method)
 412                         {
 413                         if (!SSL_set_ssl_method(s,meth))
 414                                 return(0);
 415                         if (s->ctx->session_timeout == 0)
 416                                 session->timeout=SSL_get_default_timeout(s);
 417                         else
 418                                 session->timeout=s->ctx->session_timeout;
 419                         }
 420
 421                 /* CRYPTO_w_lock(CRYPTO_LOCK_SSL);*/
 422                 CRYPTO_add(&session->references,1,CRYPTO_LOCK_SSL_SESSION);
 423                 if (s->session != NULL)
 424                         SSL_SESSION_free(s->session);
 425                 s->session=session;
 426                 /* CRYPTO_w_unlock(CRYPTO_LOCK_SSL);*/
 427                 ret=1;
 428                 }
 429         else
 430                 {
 431                 if (s->session != NULL)
 432                         {
 433                         SSL_SESSION_free(s->session);
 434                         s->session=NULL;
 435                         }
 436
 437                 meth=s->ctx->method;
 438                 if (meth != s->method)
 439                         {
 440                         if (!SSL_set_ssl_method(s,meth))
 441                                 return(0);
 442                         }
 443                 ret=1;
 444                 }
 445         return(ret);
 446         }
 447
 448 long SSL_SESSION_set_timeout(SSL_SESSION *s, long t)
 449         {
 450         if (s == NULL) return(0);
 451         s->timeout=t;
 452         return(1);
 453         }
 454
 455 long SSL_SESSION_get_timeout(SSL_SESSION *s)
 456         {
 457         if (s == NULL) return(0);
 458         return(s->timeout);
 459         }
 460
 461 long SSL_SESSION_get_time(SSL_SESSION *s)
 462         {
 463         if (s == NULL) return(0);
 464         return(s->time);
 465         }
 466
 467 long SSL_SESSION_set_time(SSL_SESSION *s, long t)
 468         {
 469         if (s == NULL) return(0);
 470         s->time=t;
 471         return(t);
 472         }
 473
 474 long SSL_CTX_set_timeout(SSL_CTX *s, long t)
 475         {
 476         long l;
 477         if (s == NULL) return(0);
 478         l=s->session_timeout;
 479         s->session_timeout=t;
 480         return(l);
 481         }
 482
 483 long SSL_CTX_get_timeout(SSL_CTX *s)
 484         {
 485         if (s == NULL) return(0);
 486         return(s->session_timeout);
 487         }
 488
 489 typedef struct timeout_param_st
 490         {
 491         SSL_CTX *ctx;
 492         long time;
 493         LHASH *cache;
 494         } TIMEOUT_PARAM;
 495
 496 static void timeout(SSL_SESSION *s, TIMEOUT_PARAM *p)
 497         {
 498         if ((p->time == 0) || (p->time > (s->time+s->timeout))) /* timeout */
 499                 {
 500                 /* The reason we don't call SSL_CTX_remove_session() is to
 501                  * save on locking overhead */
 502                 lh_delete(p->cache,(char *)s);
 503                 SSL_SESSION_list_remove(p->ctx,s);
 504                 s->not_resumable=1;
 505                 if (p->ctx->remove_session_cb != NULL)
 506                         p->ctx->remove_session_cb(p->ctx,s);
 507                 SSL_SESSION_free(s);
 508                 }
 509         }
 510
 511 void SSL_CTX_flush_sessions(SSL_CTX *s, long t)
 512         {
 513         unsigned long i;
 514         TIMEOUT_PARAM tp;
 515
 516         tp.ctx=s;
 517         tp.cache=s->sessions;
 518         if (tp.cache == NULL) return;
 519         tp.time=t;
 520         CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
 521         i=tp.cache->down_load;
 522         tp.cache->down_load=0;
 523         lh_doall_arg(tp.cache,(void (*)())timeout,(char *)&tp);
 524         tp.cache->down_load=i;
 525         CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
 526         }
 527
 528 int ssl_clear_bad_session(SSL *s)
 529         {
 530         if (    (s->session != NULL) &&
 531                 !(s->shutdown & SSL_SENT_SHUTDOWN) &&
 532                 !(SSL_in_init(s) || SSL_in_before(s)))
 533                 {
 534                 SSL_CTX_remove_session(s->ctx,s->session);
 535                 return(1);
 536                 }
 537         else
 538                 return(0);
 539         }
 540
 541 /* locked by SSL_CTX in the calling function */
 542 static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s)
 543         {
 544         if ((s->next == NULL) || (s->prev == NULL)) return;
 545
 546         if (s->next == (SSL_SESSION *)&(ctx->session_cache_tail))
 547                 { /* last element in list */
 548                 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
 549                         { /* only one element in list */
 550                         ctx->session_cache_head=NULL;
 551                         ctx->session_cache_tail=NULL;
 552                         }
 553                 else
 554                         {
 555                         ctx->session_cache_tail=s->prev;
 556                         s->prev->next=(SSL_SESSION *)&(ctx->session_cache_tail);
 557                         }
 558                 }
 559         else
 560                 {
 561                 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
 562                         { /* first element in list */
 563                         ctx->session_cache_head=s->next;
 564                         s->next->prev=(SSL_SESSION *)&(ctx->session_cache_head);
 565                         }
 566                 else
 567                         { /* middle of list */
 568                         s->next->prev=s->prev;
 569                         s->prev->next=s->next;
 570                         }
 571                 }
 572         s->prev=s->next=NULL;
 573         }
 574
 575 static void SSL_SESSION_list_add(SSL_CTX *ctx, SSL_SESSION *s)
 576         {
 577         if ((s->next != NULL) && (s->prev != NULL))
 578                 SSL_SESSION_list_remove(ctx,s);
 579
 580         if (ctx->session_cache_head == NULL)
 581                 {
 582                 ctx->session_cache_head=s;
 583                 ctx->session_cache_tail=s;
 584                 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
 585                 s->next=(SSL_SESSION *)&(ctx->session_cache_tail);
 586                 }
 587         else
 588                 {
 589                 s->next=ctx->session_cache_head;
 590                 s->next->prev=s;
 591                 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
 592                 ctx->session_cache_head=s;
 593                 }
 594         }
 595