2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
60 #include <openssl/lhash.h>
61 #include <openssl/rand.h>
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);
68 SSL_SESSION *SSL_get_session(SSL *ssl)
69 /* aka SSL_get0_session; gets 0 objects, just returns a copy of the pointer */
74 SSL_SESSION *SSL_get1_session(SSL *ssl)
75 /* variant of SSL_get_session: caller really gets something */
78 /* Need to lock this all up rather than just use CRYPTO_add so that
79 * somebody doesn't free ssl->session between when we check it's
80 * non-null and when we up the reference count. */
81 CRYPTO_w_lock(CRYPTO_LOCK_SSL_SESSION);
85 CRYPTO_w_unlock(CRYPTO_LOCK_SSL_SESSION);
89 int SSL_SESSION_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
90 CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
92 return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_SSL_SESSION, argl, argp,
93 new_func, dup_func, free_func);
96 int SSL_SESSION_set_ex_data(SSL_SESSION *s, int idx, void *arg)
98 return(CRYPTO_set_ex_data(&s->ex_data,idx,arg));
101 void *SSL_SESSION_get_ex_data(SSL_SESSION *s, int idx)
103 return(CRYPTO_get_ex_data(&s->ex_data,idx));
106 SSL_SESSION *SSL_SESSION_new(void)
110 ss=(SSL_SESSION *)OPENSSL_malloc(sizeof(SSL_SESSION));
113 SSLerr(SSL_F_SSL_SESSION_NEW,ERR_R_MALLOC_FAILURE);
116 memset(ss,0,sizeof(SSL_SESSION));
118 ss->verify_result = 1; /* avoid 0 (= X509_V_OK) just in case */
120 ss->timeout=60*5+4; /* 5 minute timeout by default */
125 CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);
129 /* Even with SSLv2, we have 16 bytes (128 bits) of session ID space. SSLv3/TLSv1
130 * has 32 bytes (256 bits). As such, filling the ID with random gunk repeatedly
131 * until we have no conflict is going to complete in one iteration pretty much
132 * "most" of the time (btw: understatement). So, if it takes us 10 iterations
133 * and we still can't avoid a conflict - well that's a reasonable point to call
134 * it quits. Either the RAND code is broken or someone is trying to open roughly
135 * very close to 2^128 (or 2^256) SSL sessions to our server. How you might
136 * store that many sessions is perhaps a more interesting question ... */
138 #define MAX_SESS_ID_ATTEMPTS 10
139 static int def_generate_session_id(const SSL *ssl, unsigned char *id,
140 unsigned int *id_len)
142 unsigned int retry = 0;
144 RAND_pseudo_bytes(id, *id_len);
145 while(SSL_has_matching_session_id(ssl, id, *id_len) &&
146 (++retry < MAX_SESS_ID_ATTEMPTS));
147 if(retry < MAX_SESS_ID_ATTEMPTS)
149 /* else - woops a session_id match */
150 /* XXX We should also check the external cache --
151 * but the probability of a collision is negligible, and
152 * we could not prevent the concurrent creation of sessions
153 * with identical IDs since we currently don't have means
154 * to atomically check whether a session ID already exists
155 * and make a reservation for it if it does not
156 * (this problem applies to the internal cache as well).
161 int ssl_get_new_session(SSL *s, int session)
163 /* This gets used by clients and servers. */
166 SSL_SESSION *ss=NULL;
167 GEN_SESSION_CB cb = def_generate_session_id;
169 if ((ss=SSL_SESSION_new()) == NULL) return(0);
171 /* If the context has a default timeout, use it */
172 if (s->ctx->session_timeout == 0)
173 ss->timeout=SSL_get_default_timeout(s);
175 ss->timeout=s->ctx->session_timeout;
177 if (s->session != NULL)
179 SSL_SESSION_free(s->session);
185 if (s->version == SSL2_VERSION)
187 ss->ssl_version=SSL2_VERSION;
188 ss->session_id_length=SSL2_SSL_SESSION_ID_LENGTH;
190 else if (s->version == SSL3_VERSION)
192 ss->ssl_version=SSL3_VERSION;
193 ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
195 else if (s->version == TLS1_VERSION)
197 ss->ssl_version=TLS1_VERSION;
198 ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
202 SSLerr(SSL_F_SSL_GET_NEW_SESSION,SSL_R_UNSUPPORTED_SSL_VERSION);
203 SSL_SESSION_free(ss);
206 /* Choose which callback will set the session ID */
207 CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
208 if(s->generate_session_id)
209 cb = s->generate_session_id;
210 else if(s->ctx->generate_session_id)
211 cb = s->ctx->generate_session_id;
212 CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
213 /* Choose a session ID */
214 tmp = ss->session_id_length;
215 if(!cb(s, ss->session_id, &tmp))
217 /* The callback failed */
218 SSLerr(SSL_F_SSL_GET_NEW_SESSION,
219 SSL_R_SSL_SESSION_ID_CALLBACK_FAILED);
220 SSL_SESSION_free(ss);
223 /* Don't allow the callback to set the session length to zero.
224 * nor set it higher than it was. */
225 if(!tmp || (tmp > ss->session_id_length))
227 /* The callback set an illegal length */
228 SSLerr(SSL_F_SSL_GET_NEW_SESSION,
229 SSL_R_SSL_SESSION_ID_HAS_BAD_LENGTH);
230 SSL_SESSION_free(ss);
233 /* If the session length was shrunk and we're SSLv2, pad it */
234 if((tmp < ss->session_id_length) && (s->version == SSL2_VERSION))
235 memset(ss->session_id + tmp, 0, ss->session_id_length - tmp);
237 ss->session_id_length = tmp;
238 /* Finally, check for a conflict */
239 if(SSL_has_matching_session_id(s, ss->session_id,
240 ss->session_id_length))
242 SSLerr(SSL_F_SSL_GET_NEW_SESSION,
243 SSL_R_SSL_SESSION_ID_CONFLICT);
244 SSL_SESSION_free(ss);
250 ss->session_id_length=0;
253 if (s->sid_ctx_length > sizeof ss->sid_ctx)
255 SSLerr(SSL_F_SSL_GET_NEW_SESSION, ERR_R_INTERNAL_ERROR);
256 SSL_SESSION_free(ss);
259 memcpy(ss->sid_ctx,s->sid_ctx,s->sid_ctx_length);
260 ss->sid_ctx_length=s->sid_ctx_length;
262 ss->ssl_version=s->version;
263 ss->verify_result = X509_V_OK;
268 int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
270 /* This is used only by servers. */
272 SSL_SESSION *ret=NULL,data;
275 data.ssl_version=s->version;
276 data.session_id_length=len;
277 if (len > SSL_MAX_SSL_SESSION_ID_LENGTH)
279 memcpy(data.session_id,session_id,len);
281 if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_LOOKUP))
283 CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
284 ret=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,&data);
286 /* don't allow other threads to steal it: */
287 CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
288 CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
295 s->ctx->stats.sess_miss++;
297 if (s->ctx->get_session_cb != NULL
298 && (ret=s->ctx->get_session_cb(s,session_id,len,©))
301 s->ctx->stats.sess_cb_hit++;
303 /* Increment reference count now if the session callback
304 * asks us to do so (note that if the session structures
305 * returned by the callback are shared between threads,
306 * it must handle the reference count itself [i.e. copy == 0],
307 * or things won't be thread-safe). */
309 CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
311 /* Add the externally cached session to the internal
312 * cache as well if and only if we are supposed to. */
313 if(!(s->ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_STORE))
314 /* The following should not return 1, otherwise,
315 * things are very strange */
316 SSL_CTX_add_session(s->ctx,ret);
322 /* Now ret is non-NULL, and we own one of its reference counts. */
324 if((s->verify_mode&SSL_VERIFY_PEER)
325 && (!s->sid_ctx_length || ret->sid_ctx_length != s->sid_ctx_length
326 || memcmp(ret->sid_ctx,s->sid_ctx,ret->sid_ctx_length)))
328 /* We've found the session named by the client, but we don't
329 * want to use it in this context. */
331 if (s->sid_ctx_length == 0)
333 /* application should have used SSL[_CTX]_set_session_id_context
334 * -- we could tolerate this and just pretend we never heard
335 * of this session, but then applications could effectively
336 * disable the session cache by accident without anyone noticing */
338 SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED);
344 #if 0 /* The client cannot always know when a session is not appropriate,
345 * so we shouldn't generate an error message. */
347 SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
349 goto err; /* treat like cache miss */
353 if (ret->cipher == NULL)
355 unsigned char buf[5],*p;
361 if ((ret->ssl_version>>8) == SSL3_VERSION_MAJOR)
362 ret->cipher=ssl_get_cipher_by_char(s,&(buf[2]));
364 ret->cipher=ssl_get_cipher_by_char(s,&(buf[1]));
365 if (ret->cipher == NULL)
370 #if 0 /* This is way too late. */
372 /* If a thread got the session, then 'swaped', and another got
373 * it and then due to a time-out decided to 'OPENSSL_free' it we could
374 * be in trouble. So I'll increment it now, then double decrement
375 * later - am I speaking rubbish?. */
376 CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
379 if ((long)(ret->time+ret->timeout) < (long)time(NULL)) /* timeout */
381 s->ctx->stats.sess_timeout++;
382 /* remove it from the cache */
383 SSL_CTX_remove_session(s->ctx,ret);
387 s->ctx->stats.sess_hit++;
389 /* ret->time=time(NULL); */ /* rezero timeout? */
390 /* again, just leave the session
391 * if it is the same session, we have just incremented and
392 * then decremented the reference count :-) */
393 if (s->session != NULL)
394 SSL_SESSION_free(s->session);
396 s->verify_result = s->session->verify_result;
401 SSL_SESSION_free(ret);
408 int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *c)
413 /* add just 1 reference count for the SSL_CTX's session cache
414 * even though it has two ways of access: each session is in a
415 * doubly linked list and an lhash */
416 CRYPTO_add(&c->references,1,CRYPTO_LOCK_SSL_SESSION);
417 /* if session c is in already in cache, we take back the increment later */
419 CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
420 s=(SSL_SESSION *)lh_insert(ctx->sessions,c);
422 /* s != NULL iff we already had a session with the given PID.
423 * In this case, s == c should hold (then we did not really modify
424 * ctx->sessions), or we're in trouble. */
425 if (s != NULL && s != c)
427 /* We *are* in trouble ... */
428 SSL_SESSION_list_remove(ctx,s);
430 /* ... so pretend the other session did not exist in cache
431 * (we cannot handle two SSL_SESSION structures with identical
432 * session ID in the same cache, which could happen e.g. when
433 * two threads concurrently obtain the same session from an external
438 /* Put at the head of the queue unless it is already in the cache */
440 SSL_SESSION_list_add(ctx,c);
444 /* existing cache entry -- decrement previously incremented reference
445 * count because it already takes into account the cache */
447 SSL_SESSION_free(s); /* s == c */
452 /* new cache entry -- remove old ones if cache has become too large */
456 if (SSL_CTX_sess_get_cache_size(ctx) > 0)
458 while (SSL_CTX_sess_number(ctx) >
459 SSL_CTX_sess_get_cache_size(ctx))
461 if (!remove_session_lock(ctx,
462 ctx->session_cache_tail, 0))
465 ctx->stats.sess_cache_full++;
469 CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
473 int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *c)
475 return remove_session_lock(ctx, c, 1);
478 static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lck)
483 if ((c != NULL) && (c->session_id_length != 0))
485 if(lck) CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
486 if ((r = (SSL_SESSION *)lh_retrieve(ctx->sessions,c)) == c)
489 r=(SSL_SESSION *)lh_delete(ctx->sessions,c);
490 SSL_SESSION_list_remove(ctx,c);
493 if(lck) CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
498 if (ctx->remove_session_cb != NULL)
499 ctx->remove_session_cb(ctx,r);
508 void SSL_SESSION_free(SSL_SESSION *ss)
515 i=CRYPTO_add(&ss->references,-1,CRYPTO_LOCK_SSL_SESSION);
517 REF_PRINT("SSL_SESSION",ss);
523 fprintf(stderr,"SSL_SESSION_free, bad reference count\n");
528 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);
530 OPENSSL_cleanse(ss->key_arg,sizeof ss->key_arg);
531 OPENSSL_cleanse(ss->master_key,sizeof ss->master_key);
532 OPENSSL_cleanse(ss->session_id,sizeof ss->session_id);
533 if (ss->sess_cert != NULL) ssl_sess_cert_free(ss->sess_cert);
534 if (ss->peer != NULL) X509_free(ss->peer);
535 if (ss->ciphers != NULL) sk_SSL_CIPHER_free(ss->ciphers);
536 OPENSSL_cleanse(ss,sizeof(*ss));
540 int SSL_set_session(SSL *s, SSL_SESSION *session)
547 meth=s->ctx->method->get_ssl_method(session->ssl_version);
549 meth=s->method->get_ssl_method(session->ssl_version);
552 SSLerr(SSL_F_SSL_SET_SESSION,SSL_R_UNABLE_TO_FIND_SSL_METHOD);
556 if (meth != s->method)
558 if (!SSL_set_ssl_method(s,meth))
560 if (s->ctx->session_timeout == 0)
561 session->timeout=SSL_get_default_timeout(s);
563 session->timeout=s->ctx->session_timeout;
566 #ifndef OPENSSL_NO_KRB5
567 if (s->kssl_ctx && !s->kssl_ctx->client_princ &&
568 session->krb5_client_princ_len > 0)
570 s->kssl_ctx->client_princ = (char *)malloc(session->krb5_client_princ_len + 1);
571 memcpy(s->kssl_ctx->client_princ,session->krb5_client_princ,
572 session->krb5_client_princ_len);
573 s->kssl_ctx->client_princ[session->krb5_client_princ_len] = '\0';
575 #endif /* OPENSSL_NO_KRB5 */
577 /* CRYPTO_w_lock(CRYPTO_LOCK_SSL);*/
578 CRYPTO_add(&session->references,1,CRYPTO_LOCK_SSL_SESSION);
579 if (s->session != NULL)
580 SSL_SESSION_free(s->session);
582 s->verify_result = s->session->verify_result;
583 /* CRYPTO_w_unlock(CRYPTO_LOCK_SSL);*/
588 if (s->session != NULL)
590 SSL_SESSION_free(s->session);
595 if (meth != s->method)
597 if (!SSL_set_ssl_method(s,meth))
605 long SSL_SESSION_set_timeout(SSL_SESSION *s, long t)
607 if (s == NULL) return(0);
612 long SSL_SESSION_get_timeout(SSL_SESSION *s)
614 if (s == NULL) return(0);
618 long SSL_SESSION_get_time(SSL_SESSION *s)
620 if (s == NULL) return(0);
624 long SSL_SESSION_set_time(SSL_SESSION *s, long t)
626 if (s == NULL) return(0);
631 long SSL_CTX_set_timeout(SSL_CTX *s, long t)
634 if (s == NULL) return(0);
635 l=s->session_timeout;
636 s->session_timeout=t;
640 long SSL_CTX_get_timeout(SSL_CTX *s)
642 if (s == NULL) return(0);
643 return(s->session_timeout);
646 typedef struct timeout_param_st
653 static void timeout(SSL_SESSION *s, TIMEOUT_PARAM *p)
655 if ((p->time == 0) || (p->time > (s->time+s->timeout))) /* timeout */
657 /* The reason we don't call SSL_CTX_remove_session() is to
658 * save on locking overhead */
659 lh_delete(p->cache,s);
660 SSL_SESSION_list_remove(p->ctx,s);
662 if (p->ctx->remove_session_cb != NULL)
663 p->ctx->remove_session_cb(p->ctx,s);
668 static IMPLEMENT_LHASH_DOALL_ARG_FN(timeout, SSL_SESSION *, TIMEOUT_PARAM *)
670 void SSL_CTX_flush_sessions(SSL_CTX *s, long t)
676 tp.cache=s->sessions;
677 if (tp.cache == NULL) return;
679 CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
680 i=tp.cache->down_load;
681 tp.cache->down_load=0;
682 lh_doall_arg(tp.cache, LHASH_DOALL_ARG_FN(timeout), &tp);
683 tp.cache->down_load=i;
684 CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
687 int ssl_clear_bad_session(SSL *s)
689 if ( (s->session != NULL) &&
690 !(s->shutdown & SSL_SENT_SHUTDOWN) &&
691 !(SSL_in_init(s) || SSL_in_before(s)))
693 SSL_CTX_remove_session(s->ctx,s->session);
700 /* locked by SSL_CTX in the calling function */
701 static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s)
703 if ((s->next == NULL) || (s->prev == NULL)) return;
705 if (s->next == (SSL_SESSION *)&(ctx->session_cache_tail))
706 { /* last element in list */
707 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
708 { /* only one element in list */
709 ctx->session_cache_head=NULL;
710 ctx->session_cache_tail=NULL;
714 ctx->session_cache_tail=s->prev;
715 s->prev->next=(SSL_SESSION *)&(ctx->session_cache_tail);
720 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
721 { /* first element in list */
722 ctx->session_cache_head=s->next;
723 s->next->prev=(SSL_SESSION *)&(ctx->session_cache_head);
726 { /* middle of list */
727 s->next->prev=s->prev;
728 s->prev->next=s->next;
731 s->prev=s->next=NULL;
734 static void SSL_SESSION_list_add(SSL_CTX *ctx, SSL_SESSION *s)
736 if ((s->next != NULL) && (s->prev != NULL))
737 SSL_SESSION_list_remove(ctx,s);
739 if (ctx->session_cache_head == NULL)
741 ctx->session_cache_head=s;
742 ctx->session_cache_tail=s;
743 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
744 s->next=(SSL_SESSION *)&(ctx->session_cache_tail);
748 s->next=ctx->session_cache_head;
750 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
751 ctx->session_cache_head=s;