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 /* The following should not return 1, otherwise,
313 * things are very strange */
314 SSL_CTX_add_session(s->ctx,ret);
320 /* Now ret is non-NULL, and we own one of its reference counts. */
322 if((s->verify_mode&SSL_VERIFY_PEER)
323 && (!s->sid_ctx_length || ret->sid_ctx_length != s->sid_ctx_length
324 || memcmp(ret->sid_ctx,s->sid_ctx,ret->sid_ctx_length)))
326 /* We've found the session named by the client, but we don't
327 * want to use it in this context. */
329 if (s->sid_ctx_length == 0)
331 /* application should have used SSL[_CTX]_set_session_id_context
332 * -- we could tolerate this and just pretend we never heard
333 * of this session, but then applications could effectively
334 * disable the session cache by accident without anyone noticing */
336 SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED);
342 #if 0 /* The client cannot always know when a session is not appropriate,
343 * so we shouldn't generate an error message. */
345 SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
347 goto err; /* treat like cache miss */
351 if (ret->cipher == NULL)
353 unsigned char buf[5],*p;
359 if ((ret->ssl_version>>8) == SSL3_VERSION_MAJOR)
360 ret->cipher=ssl_get_cipher_by_char(s,&(buf[2]));
362 ret->cipher=ssl_get_cipher_by_char(s,&(buf[1]));
363 if (ret->cipher == NULL)
368 #if 0 /* This is way too late. */
370 /* If a thread got the session, then 'swaped', and another got
371 * it and then due to a time-out decided to 'OPENSSL_free' it we could
372 * be in trouble. So I'll increment it now, then double decrement
373 * later - am I speaking rubbish?. */
374 CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
377 if ((long)(ret->time+ret->timeout) < (long)time(NULL)) /* timeout */
379 s->ctx->stats.sess_timeout++;
380 /* remove it from the cache */
381 SSL_CTX_remove_session(s->ctx,ret);
385 s->ctx->stats.sess_hit++;
387 /* ret->time=time(NULL); */ /* rezero timeout? */
388 /* again, just leave the session
389 * if it is the same session, we have just incremented and
390 * then decremented the reference count :-) */
391 if (s->session != NULL)
392 SSL_SESSION_free(s->session);
394 s->verify_result = s->session->verify_result;
399 SSL_SESSION_free(ret);
406 int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *c)
411 /* add just 1 reference count for the SSL_CTX's session cache
412 * even though it has two ways of access: each session is in a
413 * doubly linked list and an lhash */
414 CRYPTO_add(&c->references,1,CRYPTO_LOCK_SSL_SESSION);
415 /* if session c is in already in cache, we take back the increment later */
417 CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
418 s=(SSL_SESSION *)lh_insert(ctx->sessions,c);
420 /* s != NULL iff we already had a session with the given PID.
421 * In this case, s == c should hold (then we did not really modify
422 * ctx->sessions), or we're in trouble. */
423 if (s != NULL && s != c)
425 /* We *are* in trouble ... */
426 SSL_SESSION_list_remove(ctx,s);
428 /* ... so pretend the other session did not exist in cache
429 * (we cannot handle two SSL_SESSION structures with identical
430 * session ID in the same cache, which could happen e.g. when
431 * two threads concurrently obtain the same session from an external
436 /* Put at the head of the queue unless it is already in the cache */
438 SSL_SESSION_list_add(ctx,c);
442 /* existing cache entry -- decrement previously incremented reference
443 * count because it already takes into account the cache */
445 SSL_SESSION_free(s); /* s == c */
450 /* new cache entry -- remove old ones if cache has become too large */
454 if (SSL_CTX_sess_get_cache_size(ctx) > 0)
456 while (SSL_CTX_sess_number(ctx) >
457 SSL_CTX_sess_get_cache_size(ctx))
459 if (!remove_session_lock(ctx,
460 ctx->session_cache_tail, 0))
463 ctx->stats.sess_cache_full++;
467 CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
471 int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *c)
473 return remove_session_lock(ctx, c, 1);
476 static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lck)
481 if ((c != NULL) && (c->session_id_length != 0))
483 if(lck) CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
484 if ((r = (SSL_SESSION *)lh_retrieve(ctx->sessions,c)) == c)
487 r=(SSL_SESSION *)lh_delete(ctx->sessions,c);
488 SSL_SESSION_list_remove(ctx,c);
491 if(lck) CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
496 if (ctx->remove_session_cb != NULL)
497 ctx->remove_session_cb(ctx,r);
506 void SSL_SESSION_free(SSL_SESSION *ss)
513 i=CRYPTO_add(&ss->references,-1,CRYPTO_LOCK_SSL_SESSION);
515 REF_PRINT("SSL_SESSION",ss);
521 fprintf(stderr,"SSL_SESSION_free, bad reference count\n");
526 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);
528 memset(ss->key_arg,0,SSL_MAX_KEY_ARG_LENGTH);
529 memset(ss->master_key,0,SSL_MAX_MASTER_KEY_LENGTH);
530 memset(ss->session_id,0,SSL_MAX_SSL_SESSION_ID_LENGTH);
531 if (ss->sess_cert != NULL) ssl_sess_cert_free(ss->sess_cert);
532 if (ss->peer != NULL) X509_free(ss->peer);
533 if (ss->ciphers != NULL) sk_SSL_CIPHER_free(ss->ciphers);
534 memset(ss,0,sizeof(*ss));
538 int SSL_set_session(SSL *s, SSL_SESSION *session)
545 meth=s->ctx->method->get_ssl_method(session->ssl_version);
547 meth=s->method->get_ssl_method(session->ssl_version);
550 SSLerr(SSL_F_SSL_SET_SESSION,SSL_R_UNABLE_TO_FIND_SSL_METHOD);
554 if (meth != s->method)
556 if (!SSL_set_ssl_method(s,meth))
558 if (s->ctx->session_timeout == 0)
559 session->timeout=SSL_get_default_timeout(s);
561 session->timeout=s->ctx->session_timeout;
564 #ifndef OPENSSL_NO_KRB5
565 if (s->kssl_ctx && !s->kssl_ctx->client_princ &&
566 session->krb5_client_princ_len > 0)
568 s->kssl_ctx->client_princ = (char *)malloc(session->krb5_client_princ_len + 1);
569 memcpy(s->kssl_ctx->client_princ,session->krb5_client_princ,
570 session->krb5_client_princ_len);
571 s->kssl_ctx->client_princ[session->krb5_client_princ_len] = '\0';
573 #endif /* OPENSSL_NO_KRB5 */
575 /* CRYPTO_w_lock(CRYPTO_LOCK_SSL);*/
576 CRYPTO_add(&session->references,1,CRYPTO_LOCK_SSL_SESSION);
577 if (s->session != NULL)
578 SSL_SESSION_free(s->session);
580 s->verify_result = s->session->verify_result;
581 /* CRYPTO_w_unlock(CRYPTO_LOCK_SSL);*/
586 if (s->session != NULL)
588 SSL_SESSION_free(s->session);
593 if (meth != s->method)
595 if (!SSL_set_ssl_method(s,meth))
603 long SSL_SESSION_set_timeout(SSL_SESSION *s, long t)
605 if (s == NULL) return(0);
610 long SSL_SESSION_get_timeout(SSL_SESSION *s)
612 if (s == NULL) return(0);
616 long SSL_SESSION_get_time(SSL_SESSION *s)
618 if (s == NULL) return(0);
622 long SSL_SESSION_set_time(SSL_SESSION *s, long t)
624 if (s == NULL) return(0);
629 long SSL_CTX_set_timeout(SSL_CTX *s, long t)
632 if (s == NULL) return(0);
633 l=s->session_timeout;
634 s->session_timeout=t;
638 long SSL_CTX_get_timeout(SSL_CTX *s)
640 if (s == NULL) return(0);
641 return(s->session_timeout);
644 typedef struct timeout_param_st
651 static void timeout(SSL_SESSION *s, TIMEOUT_PARAM *p)
653 if ((p->time == 0) || (p->time > (s->time+s->timeout))) /* timeout */
655 /* The reason we don't call SSL_CTX_remove_session() is to
656 * save on locking overhead */
657 lh_delete(p->cache,s);
658 SSL_SESSION_list_remove(p->ctx,s);
660 if (p->ctx->remove_session_cb != NULL)
661 p->ctx->remove_session_cb(p->ctx,s);
666 static IMPLEMENT_LHASH_DOALL_ARG_FN(timeout, SSL_SESSION *, TIMEOUT_PARAM *)
668 void SSL_CTX_flush_sessions(SSL_CTX *s, long t)
674 tp.cache=s->sessions;
675 if (tp.cache == NULL) return;
677 CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
678 i=tp.cache->down_load;
679 tp.cache->down_load=0;
680 lh_doall_arg(tp.cache, LHASH_DOALL_ARG_FN(timeout), &tp);
681 tp.cache->down_load=i;
682 CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
685 int ssl_clear_bad_session(SSL *s)
687 if ( (s->session != NULL) &&
688 !(s->shutdown & SSL_SENT_SHUTDOWN) &&
689 !(SSL_in_init(s) || SSL_in_before(s)))
691 SSL_CTX_remove_session(s->ctx,s->session);
698 /* locked by SSL_CTX in the calling function */
699 static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s)
701 if ((s->next == NULL) || (s->prev == NULL)) return;
703 if (s->next == (SSL_SESSION *)&(ctx->session_cache_tail))
704 { /* last element in list */
705 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
706 { /* only one element in list */
707 ctx->session_cache_head=NULL;
708 ctx->session_cache_tail=NULL;
712 ctx->session_cache_tail=s->prev;
713 s->prev->next=(SSL_SESSION *)&(ctx->session_cache_tail);
718 if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
719 { /* first element in list */
720 ctx->session_cache_head=s->next;
721 s->next->prev=(SSL_SESSION *)&(ctx->session_cache_head);
724 { /* middle of list */
725 s->next->prev=s->prev;
726 s->prev->next=s->next;
729 s->prev=s->next=NULL;
732 static void SSL_SESSION_list_add(SSL_CTX *ctx, SSL_SESSION *s)
734 if ((s->next != NULL) && (s->prev != NULL))
735 SSL_SESSION_list_remove(ctx,s);
737 if (ctx->session_cache_head == NULL)
739 ctx->session_cache_head=s;
740 ctx->session_cache_tail=s;
741 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
742 s->next=(SSL_SESSION *)&(ctx->session_cache_tail);
746 s->next=ctx->session_cache_head;
748 s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
749 ctx->session_cache_head=s;