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>
65 static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s);
66 static void SSL_SESSION_list_add(SSL_CTX *ctx,SSL_SESSION *s);
67 static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lck);
69 SSL_SESSION *SSL_get_session(SSL *ssl)
70 /* aka SSL_get0_session; gets 0 objects, just returns a copy of the pointer */
75 SSL_SESSION *SSL_get1_session(SSL *ssl)
76 /* variant of SSL_get_session: caller really gets something */
79 /* Need to lock this all up rather than just use CRYPTO_add so that
80 * somebody doesn't free ssl->session between when we check it's
81 * non-null and when we up the reference count. */
82 CRYPTO_r_lock(CRYPTO_LOCK_SSL_SESSION);
86 CRYPTO_r_unlock(CRYPTO_LOCK_SSL_SESSION);
90 int SSL_SESSION_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
91 CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
93 return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_SSL_SESSION, argl, argp,
94 new_func, dup_func, free_func);
97 int SSL_SESSION_set_ex_data(SSL_SESSION *s, int idx, void *arg)
99 return(CRYPTO_set_ex_data(&s->ex_data,idx,arg));
102 void *SSL_SESSION_get_ex_data(SSL_SESSION *s, int idx)
104 return(CRYPTO_get_ex_data(&s->ex_data,idx));
107 SSL_SESSION *SSL_SESSION_new(void)
111 ss=(SSL_SESSION *)OPENSSL_malloc(sizeof(SSL_SESSION));
114 SSLerr(SSL_F_SSL_SESSION_NEW,ERR_R_MALLOC_FAILURE);
117 memset(ss,0,sizeof(SSL_SESSION));
119 ss->verify_result = 1; /* avoid 0 (= X509_V_OK) just in case */
121 ss->timeout=60*5+4; /* 5 minute timeout by default */
126 CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);
130 /* Even with SSLv2, we have 16 bytes (128 bits) of session ID space. SSLv3/TLSv1
131 * has 32 bytes (256 bits). As such, filling the ID with random gunk repeatedly
132 * until we have no conflict is going to complete in one iteration pretty much
133 * "most" of the time (btw: understatement). So, if it takes us 10 iterations
134 * and we still can't avoid a conflict - well that's a reasonable point to call
135 * it quits. Either the RAND code is broken or someone is trying to open roughly
136 * very close to 2^128 (or 2^256) SSL sessions to our server. How you might
137 * store that many sessions is perhaps a more interesting question ... */
139 #define MAX_SESS_ID_ATTEMPTS 10
140 static int def_generate_session_id(const SSL *ssl, unsigned char *id,
141 unsigned int *id_len)
143 unsigned int retry = 0;
145 RAND_pseudo_bytes(id, *id_len);
146 while(SSL_has_matching_session_id(ssl, id, *id_len) &&
147 (++retry < MAX_SESS_ID_ATTEMPTS));
148 if(retry < MAX_SESS_ID_ATTEMPTS)
150 /* else - woops a session_id match */
151 /* XXX We should also check the external cache --
152 * but the probability of a collision is negligible, and
153 * we could not prevent the concurrent creation of sessions
154 * with identical IDs since we currently don't have means
155 * to atomically check whether a session ID already exists
156 * and make a reservation for it if it does not
157 * (this problem applies to the internal cache as well).
162 int ssl_get_new_session(SSL *s, int session)
164 /* This gets used by clients and servers. */
167 SSL_SESSION *ss=NULL;
168 GEN_SESSION_CB cb = def_generate_session_id;
170 if ((ss=SSL_SESSION_new()) == NULL) return(0);
172 /* If the context has a default timeout, use it */
173 if (s->ctx->session_timeout == 0)
174 ss->timeout=SSL_get_default_timeout(s);
176 ss->timeout=s->ctx->session_timeout;
178 if (s->session != NULL)
180 SSL_SESSION_free(s->session);
186 if (s->version == SSL2_VERSION)
188 ss->ssl_version=SSL2_VERSION;
189 ss->session_id_length=SSL2_SSL_SESSION_ID_LENGTH;
191 else if (s->version == SSL3_VERSION)
193 ss->ssl_version=SSL3_VERSION;
194 ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
196 else if (s->version == TLS1_VERSION)
198 ss->ssl_version=TLS1_VERSION;
199 ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
203 SSLerr(SSL_F_SSL_GET_NEW_SESSION,SSL_R_UNSUPPORTED_SSL_VERSION);
204 SSL_SESSION_free(ss);
207 /* Choose which callback will set the session ID */
208 CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
209 if(s->generate_session_id)
210 cb = s->generate_session_id;
211 else if(s->ctx->generate_session_id)
212 cb = s->ctx->generate_session_id;
213 CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
214 /* Choose a session ID */
215 tmp = ss->session_id_length;
216 if(!cb(s, ss->session_id, &tmp))
218 /* The callback failed */
219 SSLerr(SSL_F_SSL_GET_NEW_SESSION,
220 SSL_R_SSL_SESSION_ID_CALLBACK_FAILED);
221 SSL_SESSION_free(ss);
224 /* Don't allow the callback to set the session length to zero.
225 * nor set it higher than it was. */
226 if(!tmp || (tmp > ss->session_id_length))
228 /* The callback set an illegal length */
229 SSLerr(SSL_F_SSL_GET_NEW_SESSION,
230 SSL_R_SSL_SESSION_ID_HAS_BAD_LENGTH);
231 SSL_SESSION_free(ss);
234 /* If the session length was shrunk and we're SSLv2, pad it */
235 if((tmp < ss->session_id_length) && (s->version == SSL2_VERSION))
236 memset(ss->session_id + tmp, 0, ss->session_id_length - tmp);
238 ss->session_id_length = tmp;
239 /* Finally, check for a conflict */
240 if(SSL_has_matching_session_id(s, ss->session_id,
241 ss->session_id_length))
243 SSLerr(SSL_F_SSL_GET_NEW_SESSION,
244 SSL_R_SSL_SESSION_ID_CONFLICT);
245 SSL_SESSION_free(ss);
251 ss->session_id_length=0;
254 if (s->sid_ctx_length > sizeof ss->sid_ctx)
256 SSLerr(SSL_F_SSL_GET_NEW_SESSION, ERR_R_INTERNAL_ERROR);
257 SSL_SESSION_free(ss);
260 memcpy(ss->sid_ctx,s->sid_ctx,s->sid_ctx_length);
261 ss->sid_ctx_length=s->sid_ctx_length;
263 ss->ssl_version=s->version;
264 ss->verify_result = X509_V_OK;
269 int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
271 /* This is used only by servers. */
273 SSL_SESSION *ret=NULL,data;
276 data.ssl_version=s->version;
277 data.session_id_length=len;
278 if (len > SSL_MAX_SSL_SESSION_ID_LENGTH)
280 memcpy(data.session_id,session_id,len);
282 if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_LOOKUP))
284 CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
285 ret=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,&data);
287 /* don't allow other threads to steal it: */
288 CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
289 CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
296 s->ctx->stats.sess_miss++;
298 if (s->ctx->get_session_cb != NULL
299 && (ret=s->ctx->get_session_cb(s,session_id,len,©))
302 s->ctx->stats.sess_cb_hit++;
304 /* Increment reference count now if the session callback
305 * asks us to do so (note that if the session structures
306 * returned by the callback are shared between threads,
307 * it must handle the reference count itself [i.e. copy == 0],
308 * or things won't be thread-safe). */
310 CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
312 /* Add the externally cached session to the internal
313 * cache as well if and only if we are supposed to. */
314 if(!(s->ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_STORE))
315 /* The following should not return 1, otherwise,
316 * things are very strange */
317 SSL_CTX_add_session(s->ctx,ret);
323 /* Now ret is non-NULL, and we own one of its reference counts. */
325 if((s->verify_mode&SSL_VERIFY_PEER)
326 && (!s->sid_ctx_length || ret->sid_ctx_length != s->sid_ctx_length
327 || memcmp(ret->sid_ctx,s->sid_ctx,ret->sid_ctx_length)))
329 /* We've found the session named by the client, but we don't
330 * want to use it in this context. */
332 if (s->sid_ctx_length == 0)
334 /* application should have used SSL[_CTX]_set_session_id_context
335 * -- we could tolerate this and just pretend we never heard
336 * of this session, but then applications could effectively
337 * disable the session cache by accident without anyone noticing */
339 SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED);
345 #if 0 /* The client cannot always know when a session is not appropriate,
346 * so we shouldn't generate an error message. */
348 SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
350 goto err; /* treat like cache miss */
354 if (ret->cipher == NULL)
356 unsigned char buf[5],*p;
362 if ((ret->ssl_version>>8) == SSL3_VERSION_MAJOR)
363 ret->cipher=ssl_get_cipher_by_char(s,&(buf[2]));
365 ret->cipher=ssl_get_cipher_by_char(s,&(buf[1]));
366 if (ret->cipher == NULL)
371 #if 0 /* This is way too late. */
373 /* If a thread got the session, then 'swaped', and another got
374 * it and then due to a time-out decided to 'OPENSSL_free' it we could
375 * be in trouble. So I'll increment it now, then double decrement
376 * later - am I speaking rubbish?. */
377 CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
380 if ((long)(ret->time+ret->timeout) < (long)time(NULL)) /* timeout */
382 s->ctx->stats.sess_timeout++;
383 /* remove it from the cache */
384 SSL_CTX_remove_session(s->ctx,ret);
388 s->ctx->stats.sess_hit++;
390 /* ret->time=time(NULL); */ /* rezero timeout? */
391 /* again, just leave the session
392 * if it is the same session, we have just incremented and
393 * then decremented the reference count :-) */
394 if (s->session != NULL)
395 SSL_SESSION_free(s->session);
397 s->verify_result = s->session->verify_result;
402 SSL_SESSION_free(ret);
409 int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *c)
414 /* add just 1 reference count for the SSL_CTX's session cache
415 * even though it has two ways of access: each session is in a
416 * doubly linked list and an lhash */
417 CRYPTO_add(&c->references,1,CRYPTO_LOCK_SSL_SESSION);
418 /* if session c is in already in cache, we take back the increment later */
420 CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
421 s=(SSL_SESSION *)lh_insert(ctx->sessions,c);
423 /* s != NULL iff we already had a session with the given PID.
424 * In this case, s == c should hold (then we did not really modify
425 * ctx->sessions), or we're in trouble. */
426 if (s != NULL && s != c)
428 /* We *are* in trouble ... */
429 SSL_SESSION_list_remove(ctx,s);
431 /* ... so pretend the other session did not exist in cache
432 * (we cannot handle two SSL_SESSION structures with identical
433 * session ID in the same cache, which could happen e.g. when
434 * two threads concurrently obtain the same session from an external
439 /* Put at the head of the queue unless it is already in the cache */
441 SSL_SESSION_list_add(ctx,c);
445 /* existing cache entry -- decrement previously incremented reference
446 * count because it already takes into account the cache */
448 SSL_SESSION_free(s); /* s == c */
453 /* new cache entry -- remove old ones if cache has become too large */
457 if (SSL_CTX_sess_get_cache_size(ctx) > 0)
459 while (SSL_CTX_sess_number(ctx) >
460 SSL_CTX_sess_get_cache_size(ctx))
462 if (!remove_session_lock(ctx,
463 ctx->session_cache_tail, 0))
466 ctx->stats.sess_cache_full++;
470 CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
474 int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *c)
476 return remove_session_lock(ctx, c, 1);
479 static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lck)
484 if ((c != NULL) && (c->session_id_length != 0))
486 if(lck) CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
487 if ((r = (SSL_SESSION *)lh_retrieve(ctx->sessions,c)) == c)
490 r=(SSL_SESSION *)lh_delete(ctx->sessions,c);
491 SSL_SESSION_list_remove(ctx,c);
494 if(lck) CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
499 if (ctx->remove_session_cb != NULL)
500 ctx->remove_session_cb(ctx,r);
509 void SSL_SESSION_free(SSL_SESSION *ss)
516 i=CRYPTO_add(&ss->references,-1,CRYPTO_LOCK_SSL_SESSION);
518 REF_PRINT("SSL_SESSION",ss);
524 fprintf(stderr,"SSL_SESSION_free, bad reference count\n");
529 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);
531 OPENSSL_cleanse(ss->key_arg,sizeof ss->key_arg);
532 OPENSSL_cleanse(ss->master_key,sizeof ss->master_key);
533 OPENSSL_cleanse(ss->session_id,sizeof ss->session_id);
534 if (ss->sess_cert != NULL) ssl_sess_cert_free(ss->sess_cert);
535 if (ss->peer != NULL) X509_free(ss->peer);
536 if (ss->ciphers != NULL) sk_SSL_CIPHER_free(ss->ciphers);
537 OPENSSL_cleanse(ss,sizeof(*ss));
541 int SSL_set_session(SSL *s, SSL_SESSION *session)
548 meth=s->ctx->method->get_ssl_method(session->ssl_version);
550 meth=s->method->get_ssl_method(session->ssl_version);
553 SSLerr(SSL_F_SSL_SET_SESSION,SSL_R_UNABLE_TO_FIND_SSL_METHOD);
557 if (meth != s->method)
559 if (!SSL_set_ssl_method(s,meth))
561 if (s->ctx->session_timeout == 0)
562 session->timeout=SSL_get_default_timeout(s);
564 session->timeout=s->ctx->session_timeout;
567 #ifndef OPENSSL_NO_KRB5
568 if (s->kssl_ctx && !s->kssl_ctx->client_princ &&
569 session->krb5_client_princ_len > 0)
571 s->kssl_ctx->client_princ = (char *)malloc(session->krb5_client_princ_len + 1);
572 memcpy(s->kssl_ctx->client_princ,session->krb5_client_princ,
573 session->krb5_client_princ_len);
574 s->kssl_ctx->client_princ[session->krb5_client_princ_len] = '\0';
576 #endif /* OPENSSL_NO_KRB5 */
578 /* CRYPTO_w_lock(CRYPTO_LOCK_SSL);*/
579 CRYPTO_add(&session->references,1,CRYPTO_LOCK_SSL_SESSION);
580 if (s->session != NULL)
581 SSL_SESSION_free(s->session);
583 s->verify_result = s->session->verify_result;
584 /* CRYPTO_w_unlock(CRYPTO_LOCK_SSL);*/
589 if (s->session != NULL)
591 SSL_SESSION_free(s->session);
596 if (meth != s->method)
598 if (!SSL_set_ssl_method(s,meth))
606 long SSL_SESSION_set_timeout(SSL_SESSION *s, long t)
608 if (s == NULL) return(0);
613 long SSL_SESSION_get_timeout(SSL_SESSION *s)
615 if (s == NULL) return(0);
619 long SSL_SESSION_get_time(SSL_SESSION *s)
621 if (s == NULL) return(0);
625 long SSL_SESSION_set_time(SSL_SESSION *s, long t)
627 if (s == NULL) return(0);
632 long SSL_CTX_set_timeout(SSL_CTX *s, long t)
635 if (s == NULL) return(0);
636 l=s->session_timeout;
637 s->session_timeout=t;
641 long SSL_CTX_get_timeout(SSL_CTX *s)
643 if (s == NULL) return(0);
644 return(s->session_timeout);
647 typedef struct timeout_param_st
654 static void timeout(SSL_SESSION *s, TIMEOUT_PARAM *p)
656 if ((p->time == 0) || (p->time > (s->time+s->timeout))) /* timeout */
658 /* The reason we don't call SSL_CTX_remove_session() is to
659 * save on locking overhead */
660 lh_delete(p->cache,s);
661 SSL_SESSION_list_remove(p->ctx,s);
663 if (p->ctx->remove_session_cb != NULL)
664 p->ctx->remove_session_cb(p->ctx,s);
669 static IMPLEMENT_LHASH_DOALL_ARG_FN(timeout, SSL_SESSION *, TIMEOUT_PARAM *)
671 void SSL_CTX_flush_sessions(SSL_CTX *s, long t)
677 tp.cache=s->sessions;
678 if (tp.cache == NULL) return;
680 CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
681 i=tp.cache->down_load;
682 tp.cache->down_load=0;
683 lh_doall_arg(tp.cache, LHASH_DOALL_ARG_FN(timeout), &tp);
684 tp.cache->down_load=i;
685 CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
688 int ssl_clear_bad_session(SSL *s)
690 if ( (s->session != NULL) &&
691 !(s->shutdown & SSL_SENT_SHUTDOWN) &&
692 !(SSL_in_init(s) || SSL_in_before(s)))
694 SSL_CTX_remove_session(s->ctx,s->session);
701 /* locked by SSL_CTX in the calling function */
702 static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s)
704 if ((s->next == NULL) || (s->prev == NULL)) return;
706 if (s->next == (SSL_SESSION *)&(ctx->session_cache_tail))
707 { /* last element in list */
708 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
709 { /* only one element in list */
710 ctx->session_cache_head=NULL;
711 ctx->session_cache_tail=NULL;
715 ctx->session_cache_tail=s->prev;
716 s->prev->next=(SSL_SESSION *)&(ctx->session_cache_tail);
721 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
722 { /* first element in list */
723 ctx->session_cache_head=s->next;
724 s->next->prev=(SSL_SESSION *)&(ctx->session_cache_head);
727 { /* middle of list */
728 s->next->prev=s->prev;
729 s->prev->next=s->next;
732 s->prev=s->next=NULL;
735 static void SSL_SESSION_list_add(SSL_CTX *ctx, SSL_SESSION *s)
737 if ((s->next != NULL) && (s->prev != NULL))
738 SSL_SESSION_list_remove(ctx,s);
740 if (ctx->session_cache_head == NULL)
742 ctx->session_cache_head=s;
743 ctx->session_cache_tail=s;
744 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
745 s->next=(SSL_SESSION *)&(ctx->session_cache_tail);
749 s->next=ctx->session_cache_head;
751 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
752 ctx->session_cache_head=s;