xref: /freebsd/crypto/openssl/ssl/ssl_sess.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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 
68 SSL_SESSION *SSL_get_session(const SSL *ssl)
69 /* aka SSL_get0_session; gets 0 objects, just returns a copy of the pointer */
70 	{
71 	return(ssl->session);
72 	}
73 
74 SSL_SESSION *SSL_get1_session(SSL *ssl)
75 /* variant of SSL_get_session: caller really gets something */
76 	{
77 	SSL_SESSION *sess;
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);
82 	sess = ssl->session;
83 	if(sess)
84 		sess->references++;
85 	CRYPTO_w_unlock(CRYPTO_LOCK_SSL_SESSION);
86 	return(sess);
87 	}
88 
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)
91 	{
92 	return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_SSL_SESSION, argl, argp,
93 			new_func, dup_func, free_func);
94 	}
95 
96 int SSL_SESSION_set_ex_data(SSL_SESSION *s, int idx, void *arg)
97 	{
98 	return(CRYPTO_set_ex_data(&s->ex_data,idx,arg));
99 	}
100 
101 void *SSL_SESSION_get_ex_data(const SSL_SESSION *s, int idx)
102 	{
103 	return(CRYPTO_get_ex_data(&s->ex_data,idx));
104 	}
105 
106 SSL_SESSION *SSL_SESSION_new(void)
107 	{
108 	SSL_SESSION *ss;
109 
110 	ss=(SSL_SESSION *)OPENSSL_malloc(sizeof(SSL_SESSION));
111 	if (ss == NULL)
112 		{
113 		SSLerr(SSL_F_SSL_SESSION_NEW,ERR_R_MALLOC_FAILURE);
114 		return(0);
115 		}
116 	memset(ss,0,sizeof(SSL_SESSION));
117 
118 	ss->verify_result = 1; /* avoid 0 (= X509_V_OK) just in case */
119 	ss->references=1;
120 	ss->timeout=60*5+4; /* 5 minute timeout by default */
121 	ss->time=(unsigned long)time(NULL);
122 	ss->prev=NULL;
123 	ss->next=NULL;
124 	ss->compress_meth=0;
125 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);
126 	return(ss);
127 	}
128 
129 const unsigned char *SSL_SESSION_get_id(const SSL_SESSION *s, unsigned int *len)
130 	{
131 	if(len)
132 		*len = s->session_id_length;
133 	return s->session_id;
134 	}
135 
136 /* Even with SSLv2, we have 16 bytes (128 bits) of session ID space. SSLv3/TLSv1
137  * has 32 bytes (256 bits). As such, filling the ID with random gunk repeatedly
138  * until we have no conflict is going to complete in one iteration pretty much
139  * "most" of the time (btw: understatement). So, if it takes us 10 iterations
140  * and we still can't avoid a conflict - well that's a reasonable point to call
141  * it quits. Either the RAND code is broken or someone is trying to open roughly
142  * very close to 2^128 (or 2^256) SSL sessions to our server. How you might
143  * store that many sessions is perhaps a more interesting question ... */
144 
145 #define MAX_SESS_ID_ATTEMPTS 10
146 static int def_generate_session_id(const SSL *ssl, unsigned char *id,
147 				unsigned int *id_len)
148 {
149 	unsigned int retry = 0;
150 	do
151 		if (RAND_pseudo_bytes(id, *id_len) <= 0)
152 			return 0;
153 	while(SSL_has_matching_session_id(ssl, id, *id_len) &&
154 		(++retry < MAX_SESS_ID_ATTEMPTS));
155 	if(retry < MAX_SESS_ID_ATTEMPTS)
156 		return 1;
157 	/* else - woops a session_id match */
158 	/* XXX We should also check the external cache --
159 	 * but the probability of a collision is negligible, and
160 	 * we could not prevent the concurrent creation of sessions
161 	 * with identical IDs since we currently don't have means
162 	 * to atomically check whether a session ID already exists
163 	 * and make a reservation for it if it does not
164 	 * (this problem applies to the internal cache as well).
165 	 */
166 	return 0;
167 }
168 
169 int ssl_get_new_session(SSL *s, int session)
170 	{
171 	/* This gets used by clients and servers. */
172 
173 	unsigned int tmp;
174 	SSL_SESSION *ss=NULL;
175 	GEN_SESSION_CB cb = def_generate_session_id;
176 
177 	if ((ss=SSL_SESSION_new()) == NULL) return(0);
178 
179 	/* If the context has a default timeout, use it */
180 	if (s->ctx->session_timeout == 0)
181 		ss->timeout=SSL_get_default_timeout(s);
182 	else
183 		ss->timeout=s->ctx->session_timeout;
184 
185 	if (s->session != NULL)
186 		{
187 		SSL_SESSION_free(s->session);
188 		s->session=NULL;
189 		}
190 
191 	if (session)
192 		{
193 		if (s->version == SSL2_VERSION)
194 			{
195 			ss->ssl_version=SSL2_VERSION;
196 			ss->session_id_length=SSL2_SSL_SESSION_ID_LENGTH;
197 			}
198 		else if (s->version == SSL3_VERSION)
199 			{
200 			ss->ssl_version=SSL3_VERSION;
201 			ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
202 			}
203 		else if (s->version == TLS1_VERSION)
204 			{
205 			ss->ssl_version=TLS1_VERSION;
206 			ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
207 			}
208 		else if (s->version == DTLS1_VERSION)
209 			{
210 			ss->ssl_version=DTLS1_VERSION;
211 			ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
212 			}
213 		else
214 			{
215 			SSLerr(SSL_F_SSL_GET_NEW_SESSION,SSL_R_UNSUPPORTED_SSL_VERSION);
216 			SSL_SESSION_free(ss);
217 			return(0);
218 			}
219 		/* Choose which callback will set the session ID */
220 		CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
221 		if(s->generate_session_id)
222 			cb = s->generate_session_id;
223 		else if(s->ctx->generate_session_id)
224 			cb = s->ctx->generate_session_id;
225 		CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
226 		/* Choose a session ID */
227 		tmp = ss->session_id_length;
228 		if(!cb(s, ss->session_id, &tmp))
229 			{
230 			/* The callback failed */
231 			SSLerr(SSL_F_SSL_GET_NEW_SESSION,
232 				SSL_R_SSL_SESSION_ID_CALLBACK_FAILED);
233 			SSL_SESSION_free(ss);
234 			return(0);
235 			}
236 		/* Don't allow the callback to set the session length to zero.
237 		 * nor set it higher than it was. */
238 		if(!tmp || (tmp > ss->session_id_length))
239 			{
240 			/* The callback set an illegal length */
241 			SSLerr(SSL_F_SSL_GET_NEW_SESSION,
242 				SSL_R_SSL_SESSION_ID_HAS_BAD_LENGTH);
243 			SSL_SESSION_free(ss);
244 			return(0);
245 			}
246 		/* If the session length was shrunk and we're SSLv2, pad it */
247 		if((tmp < ss->session_id_length) && (s->version == SSL2_VERSION))
248 			memset(ss->session_id + tmp, 0, ss->session_id_length - tmp);
249 		else
250 			ss->session_id_length = tmp;
251 		/* Finally, check for a conflict */
252 		if(SSL_has_matching_session_id(s, ss->session_id,
253 						ss->session_id_length))
254 			{
255 			SSLerr(SSL_F_SSL_GET_NEW_SESSION,
256 				SSL_R_SSL_SESSION_ID_CONFLICT);
257 			SSL_SESSION_free(ss);
258 			return(0);
259 			}
260 		}
261 	else
262 		{
263 		ss->session_id_length=0;
264 		}
265 
266 	if (s->sid_ctx_length > sizeof ss->sid_ctx)
267 		{
268 		SSLerr(SSL_F_SSL_GET_NEW_SESSION, ERR_R_INTERNAL_ERROR);
269 		SSL_SESSION_free(ss);
270 		return 0;
271 		}
272 	memcpy(ss->sid_ctx,s->sid_ctx,s->sid_ctx_length);
273 	ss->sid_ctx_length=s->sid_ctx_length;
274 	s->session=ss;
275 	ss->ssl_version=s->version;
276 	ss->verify_result = X509_V_OK;
277 
278 	return(1);
279 	}
280 
281 int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
282 	{
283 	/* This is used only by servers. */
284 
285 	SSL_SESSION *ret=NULL,data;
286 	int fatal = 0;
287 
288 	data.ssl_version=s->version;
289 	data.session_id_length=len;
290 	if (len > SSL_MAX_SSL_SESSION_ID_LENGTH)
291 		goto err;
292 	memcpy(data.session_id,session_id,len);
293 
294 	if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_LOOKUP))
295 		{
296 		CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
297 		ret=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,&data);
298 		if (ret != NULL)
299 		    /* don't allow other threads to steal it: */
300 		    CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
301 		CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
302 		}
303 
304 	if (ret == NULL)
305 		{
306 		int copy=1;
307 
308 		s->ctx->stats.sess_miss++;
309 		ret=NULL;
310 		if (s->ctx->get_session_cb != NULL
311 		    && (ret=s->ctx->get_session_cb(s,session_id,len,&copy))
312 		       != NULL)
313 			{
314 			s->ctx->stats.sess_cb_hit++;
315 
316 			/* Increment reference count now if the session callback
317 			 * asks us to do so (note that if the session structures
318 			 * returned by the callback are shared between threads,
319 			 * it must handle the reference count itself [i.e. copy == 0],
320 			 * or things won't be thread-safe). */
321 			if (copy)
322 				CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
323 
324 			/* Add the externally cached session to the internal
325 			 * cache as well if and only if we are supposed to. */
326 			if(!(s->ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_STORE))
327 				/* The following should not return 1, otherwise,
328 				 * things are very strange */
329 				SSL_CTX_add_session(s->ctx,ret);
330 			}
331 		if (ret == NULL)
332 			goto err;
333 		}
334 
335 	/* Now ret is non-NULL, and we own one of its reference counts. */
336 
337 	if((s->verify_mode&SSL_VERIFY_PEER)
338 	   && (!s->sid_ctx_length || ret->sid_ctx_length != s->sid_ctx_length
339 	       || memcmp(ret->sid_ctx,s->sid_ctx,ret->sid_ctx_length)))
340 	    {
341 		/* We've found the session named by the client, but we don't
342 		 * want to use it in this context. */
343 
344 		if (s->sid_ctx_length == 0)
345 			{
346 			/* application should have used SSL[_CTX]_set_session_id_context
347 			 * -- we could tolerate this and just pretend we never heard
348 			 * of this session, but then applications could effectively
349 			 * disable the session cache by accident without anyone noticing */
350 
351 			SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED);
352 			fatal = 1;
353 			goto err;
354 			}
355 		else
356 			{
357 #if 0 /* The client cannot always know when a session is not appropriate,
358 	   * so we shouldn't generate an error message. */
359 
360 			SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
361 #endif
362 			goto err; /* treat like cache miss */
363 			}
364 		}
365 
366 	if (ret->cipher == NULL)
367 		{
368 		unsigned char buf[5],*p;
369 		unsigned long l;
370 
371 		p=buf;
372 		l=ret->cipher_id;
373 		l2n(l,p);
374 		if ((ret->ssl_version>>8) == SSL3_VERSION_MAJOR)
375 			ret->cipher=ssl_get_cipher_by_char(s,&(buf[2]));
376 		else
377 			ret->cipher=ssl_get_cipher_by_char(s,&(buf[1]));
378 		if (ret->cipher == NULL)
379 			goto err;
380 		}
381 
382 
383 #if 0 /* This is way too late. */
384 
385 	/* If a thread got the session, then 'swaped', and another got
386 	 * it and then due to a time-out decided to 'OPENSSL_free' it we could
387 	 * be in trouble.  So I'll increment it now, then double decrement
388 	 * later - am I speaking rubbish?. */
389 	CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
390 #endif
391 
392 	if (ret->timeout < (long)(time(NULL) - ret->time)) /* timeout */
393 		{
394 		s->ctx->stats.sess_timeout++;
395 		/* remove it from the cache */
396 		SSL_CTX_remove_session(s->ctx,ret);
397 		goto err;
398 		}
399 
400 	s->ctx->stats.sess_hit++;
401 
402 	/* ret->time=time(NULL); */ /* rezero timeout? */
403 	/* again, just leave the session
404 	 * if it is the same session, we have just incremented and
405 	 * then decremented the reference count :-) */
406 	if (s->session != NULL)
407 		SSL_SESSION_free(s->session);
408 	s->session=ret;
409 	s->verify_result = s->session->verify_result;
410 	return(1);
411 
412  err:
413 	if (ret != NULL)
414 		SSL_SESSION_free(ret);
415 	if (fatal)
416 		return -1;
417 	else
418 		return 0;
419 	}
420 
421 int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *c)
422 	{
423 	int ret=0;
424 	SSL_SESSION *s;
425 
426 	/* add just 1 reference count for the SSL_CTX's session cache
427 	 * even though it has two ways of access: each session is in a
428 	 * doubly linked list and an lhash */
429 	CRYPTO_add(&c->references,1,CRYPTO_LOCK_SSL_SESSION);
430 	/* if session c is in already in cache, we take back the increment later */
431 
432 	CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
433 	s=(SSL_SESSION *)lh_insert(ctx->sessions,c);
434 
435 	/* s != NULL iff we already had a session with the given PID.
436 	 * In this case, s == c should hold (then we did not really modify
437 	 * ctx->sessions), or we're in trouble. */
438 	if (s != NULL && s != c)
439 		{
440 		/* We *are* in trouble ... */
441 		SSL_SESSION_list_remove(ctx,s);
442 		SSL_SESSION_free(s);
443 		/* ... so pretend the other session did not exist in cache
444 		 * (we cannot handle two SSL_SESSION structures with identical
445 		 * session ID in the same cache, which could happen e.g. when
446 		 * two threads concurrently obtain the same session from an external
447 		 * cache) */
448 		s = NULL;
449 		}
450 
451  	/* Put at the head of the queue unless it is already in the cache */
452 	if (s == NULL)
453 		SSL_SESSION_list_add(ctx,c);
454 
455 	if (s != NULL)
456 		{
457 		/* existing cache entry -- decrement previously incremented reference
458 		 * count because it already takes into account the cache */
459 
460 		SSL_SESSION_free(s); /* s == c */
461 		ret=0;
462 		}
463 	else
464 		{
465 		/* new cache entry -- remove old ones if cache has become too large */
466 
467 		ret=1;
468 
469 		if (SSL_CTX_sess_get_cache_size(ctx) > 0)
470 			{
471 			while (SSL_CTX_sess_number(ctx) >
472 				SSL_CTX_sess_get_cache_size(ctx))
473 				{
474 				if (!remove_session_lock(ctx,
475 					ctx->session_cache_tail, 0))
476 					break;
477 				else
478 					ctx->stats.sess_cache_full++;
479 				}
480 			}
481 		}
482 	CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
483 	return(ret);
484 	}
485 
486 int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *c)
487 {
488 	return remove_session_lock(ctx, c, 1);
489 }
490 
491 static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lck)
492 	{
493 	SSL_SESSION *r;
494 	int ret=0;
495 
496 	if ((c != NULL) && (c->session_id_length != 0))
497 		{
498 		if(lck) CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
499 		if ((r = (SSL_SESSION *)lh_retrieve(ctx->sessions,c)) == c)
500 			{
501 			ret=1;
502 			r=(SSL_SESSION *)lh_delete(ctx->sessions,c);
503 			SSL_SESSION_list_remove(ctx,c);
504 			}
505 
506 		if(lck) CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
507 
508 		if (ret)
509 			{
510 			r->not_resumable=1;
511 			if (ctx->remove_session_cb != NULL)
512 				ctx->remove_session_cb(ctx,r);
513 			SSL_SESSION_free(r);
514 			}
515 		}
516 	else
517 		ret=0;
518 	return(ret);
519 	}
520 
521 void SSL_SESSION_free(SSL_SESSION *ss)
522 	{
523 	int i;
524 
525 	if(ss == NULL)
526 	    return;
527 
528 	i=CRYPTO_add(&ss->references,-1,CRYPTO_LOCK_SSL_SESSION);
529 #ifdef REF_PRINT
530 	REF_PRINT("SSL_SESSION",ss);
531 #endif
532 	if (i > 0) return;
533 #ifdef REF_CHECK
534 	if (i < 0)
535 		{
536 		fprintf(stderr,"SSL_SESSION_free, bad reference count\n");
537 		abort(); /* ok */
538 		}
539 #endif
540 
541 	CRYPTO_free_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);
542 
543 	OPENSSL_cleanse(ss->key_arg,sizeof ss->key_arg);
544 	OPENSSL_cleanse(ss->master_key,sizeof ss->master_key);
545 	OPENSSL_cleanse(ss->session_id,sizeof ss->session_id);
546 	if (ss->sess_cert != NULL) ssl_sess_cert_free(ss->sess_cert);
547 	if (ss->peer != NULL) X509_free(ss->peer);
548 	if (ss->ciphers != NULL) sk_SSL_CIPHER_free(ss->ciphers);
549 	OPENSSL_cleanse(ss,sizeof(*ss));
550 	OPENSSL_free(ss);
551 	}
552 
553 int SSL_set_session(SSL *s, SSL_SESSION *session)
554 	{
555 	int ret=0;
556 	SSL_METHOD *meth;
557 
558 	if (session != NULL)
559 		{
560 		meth=s->ctx->method->get_ssl_method(session->ssl_version);
561 		if (meth == NULL)
562 			meth=s->method->get_ssl_method(session->ssl_version);
563 		if (meth == NULL)
564 			{
565 			SSLerr(SSL_F_SSL_SET_SESSION,SSL_R_UNABLE_TO_FIND_SSL_METHOD);
566 			return(0);
567 			}
568 
569 		if (meth != s->method)
570 			{
571 			if (!SSL_set_ssl_method(s,meth))
572 				return(0);
573 			if (s->ctx->session_timeout == 0)
574 				session->timeout=SSL_get_default_timeout(s);
575 			else
576 				session->timeout=s->ctx->session_timeout;
577 			}
578 
579 #ifndef OPENSSL_NO_KRB5
580                 if (s->kssl_ctx && !s->kssl_ctx->client_princ &&
581                     session->krb5_client_princ_len > 0)
582                 {
583                     s->kssl_ctx->client_princ = (char *)OPENSSL_malloc(session->krb5_client_princ_len + 1);
584                     memcpy(s->kssl_ctx->client_princ,session->krb5_client_princ,
585                             session->krb5_client_princ_len);
586                     s->kssl_ctx->client_princ[session->krb5_client_princ_len] = '\0';
587                 }
588 #endif /* OPENSSL_NO_KRB5 */
589 
590 		/* CRYPTO_w_lock(CRYPTO_LOCK_SSL);*/
591 		CRYPTO_add(&session->references,1,CRYPTO_LOCK_SSL_SESSION);
592 		if (s->session != NULL)
593 			SSL_SESSION_free(s->session);
594 		s->session=session;
595 		s->verify_result = s->session->verify_result;
596 		/* CRYPTO_w_unlock(CRYPTO_LOCK_SSL);*/
597 		ret=1;
598 		}
599 	else
600 		{
601 		if (s->session != NULL)
602 			{
603 			SSL_SESSION_free(s->session);
604 			s->session=NULL;
605 			}
606 
607 		meth=s->ctx->method;
608 		if (meth != s->method)
609 			{
610 			if (!SSL_set_ssl_method(s,meth))
611 				return(0);
612 			}
613 		ret=1;
614 		}
615 	return(ret);
616 	}
617 
618 long SSL_SESSION_set_timeout(SSL_SESSION *s, long t)
619 	{
620 	if (s == NULL) return(0);
621 	s->timeout=t;
622 	return(1);
623 	}
624 
625 long SSL_SESSION_get_timeout(const SSL_SESSION *s)
626 	{
627 	if (s == NULL) return(0);
628 	return(s->timeout);
629 	}
630 
631 long SSL_SESSION_get_time(const SSL_SESSION *s)
632 	{
633 	if (s == NULL) return(0);
634 	return(s->time);
635 	}
636 
637 long SSL_SESSION_set_time(SSL_SESSION *s, long t)
638 	{
639 	if (s == NULL) return(0);
640 	s->time=t;
641 	return(t);
642 	}
643 
644 long SSL_CTX_set_timeout(SSL_CTX *s, long t)
645 	{
646 	long l;
647 	if (s == NULL) return(0);
648 	l=s->session_timeout;
649 	s->session_timeout=t;
650 	return(l);
651 	}
652 
653 long SSL_CTX_get_timeout(const SSL_CTX *s)
654 	{
655 	if (s == NULL) return(0);
656 	return(s->session_timeout);
657 	}
658 
659 typedef struct timeout_param_st
660 	{
661 	SSL_CTX *ctx;
662 	long time;
663 	LHASH *cache;
664 	} TIMEOUT_PARAM;
665 
666 static void timeout(SSL_SESSION *s, TIMEOUT_PARAM *p)
667 	{
668 	if ((p->time == 0) || (p->time > (s->time+s->timeout))) /* timeout */
669 		{
670 		/* The reason we don't call SSL_CTX_remove_session() is to
671 		 * save on locking overhead */
672 		lh_delete(p->cache,s);
673 		SSL_SESSION_list_remove(p->ctx,s);
674 		s->not_resumable=1;
675 		if (p->ctx->remove_session_cb != NULL)
676 			p->ctx->remove_session_cb(p->ctx,s);
677 		SSL_SESSION_free(s);
678 		}
679 	}
680 
681 static IMPLEMENT_LHASH_DOALL_ARG_FN(timeout, SSL_SESSION *, TIMEOUT_PARAM *)
682 
683 void SSL_CTX_flush_sessions(SSL_CTX *s, long t)
684 	{
685 	unsigned long i;
686 	TIMEOUT_PARAM tp;
687 
688 	tp.ctx=s;
689 	tp.cache=s->sessions;
690 	if (tp.cache == NULL) return;
691 	tp.time=t;
692 	CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
693 	i=tp.cache->down_load;
694 	tp.cache->down_load=0;
695 	lh_doall_arg(tp.cache, LHASH_DOALL_ARG_FN(timeout), &tp);
696 	tp.cache->down_load=i;
697 	CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
698 	}
699 
700 int ssl_clear_bad_session(SSL *s)
701 	{
702 	if (	(s->session != NULL) &&
703 		!(s->shutdown & SSL_SENT_SHUTDOWN) &&
704 		!(SSL_in_init(s) || SSL_in_before(s)))
705 		{
706 		SSL_CTX_remove_session(s->ctx,s->session);
707 		return(1);
708 		}
709 	else
710 		return(0);
711 	}
712 
713 /* locked by SSL_CTX in the calling function */
714 static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s)
715 	{
716 	if ((s->next == NULL) || (s->prev == NULL)) return;
717 
718 	if (s->next == (SSL_SESSION *)&(ctx->session_cache_tail))
719 		{ /* last element in list */
720 		if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
721 			{ /* only one element in list */
722 			ctx->session_cache_head=NULL;
723 			ctx->session_cache_tail=NULL;
724 			}
725 		else
726 			{
727 			ctx->session_cache_tail=s->prev;
728 			s->prev->next=(SSL_SESSION *)&(ctx->session_cache_tail);
729 			}
730 		}
731 	else
732 		{
733 		if (s->prev == (SSL_SESSION *)&(ctx->session_cache_head))
734 			{ /* first element in list */
735 			ctx->session_cache_head=s->next;
736 			s->next->prev=(SSL_SESSION *)&(ctx->session_cache_head);
737 			}
738 		else
739 			{ /* middle of list */
740 			s->next->prev=s->prev;
741 			s->prev->next=s->next;
742 			}
743 		}
744 	s->prev=s->next=NULL;
745 	}
746 
747 static void SSL_SESSION_list_add(SSL_CTX *ctx, SSL_SESSION *s)
748 	{
749 	if ((s->next != NULL) && (s->prev != NULL))
750 		SSL_SESSION_list_remove(ctx,s);
751 
752 	if (ctx->session_cache_head == NULL)
753 		{
754 		ctx->session_cache_head=s;
755 		ctx->session_cache_tail=s;
756 		s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
757 		s->next=(SSL_SESSION *)&(ctx->session_cache_tail);
758 		}
759 	else
760 		{
761 		s->next=ctx->session_cache_head;
762 		s->next->prev=s;
763 		s->prev=(SSL_SESSION *)&(ctx->session_cache_head);
764 		ctx->session_cache_head=s;
765 		}
766 	}
767 
768 void SSL_CTX_sess_set_new_cb(SSL_CTX *ctx,
769 	int (*cb)(struct ssl_st *ssl,SSL_SESSION *sess))
770 	{
771 	ctx->new_session_cb=cb;
772 	}
773 
774 int (*SSL_CTX_sess_get_new_cb(SSL_CTX *ctx))(SSL *ssl, SSL_SESSION *sess)
775 	{
776 	return ctx->new_session_cb;
777 	}
778 
779 void SSL_CTX_sess_set_remove_cb(SSL_CTX *ctx,
780 	void (*cb)(SSL_CTX *ctx,SSL_SESSION *sess))
781 	{
782 	ctx->remove_session_cb=cb;
783 	}
784 
785 void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(SSL_CTX * ctx,SSL_SESSION *sess)
786 	{
787 	return ctx->remove_session_cb;
788 	}
789 
790 void SSL_CTX_sess_set_get_cb(SSL_CTX *ctx,
791 	SSL_SESSION *(*cb)(struct ssl_st *ssl,
792 	         unsigned char *data,int len,int *copy))
793 	{
794 	ctx->get_session_cb=cb;
795 	}
796 
797 SSL_SESSION * (*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(SSL *ssl,
798 	         unsigned char *data,int len,int *copy)
799 	{
800 	return ctx->get_session_cb;
801 	}
802 
803 void SSL_CTX_set_info_callback(SSL_CTX *ctx,
804 	void (*cb)(const SSL *ssl,int type,int val))
805 	{
806 	ctx->info_callback=cb;
807 	}
808 
809 void (*SSL_CTX_get_info_callback(SSL_CTX *ctx))(const SSL *ssl,int type,int val)
810 	{
811 	return ctx->info_callback;
812 	}
813 
814 void SSL_CTX_set_client_cert_cb(SSL_CTX *ctx,
815 	int (*cb)(SSL *ssl, X509 **x509, EVP_PKEY **pkey))
816 	{
817 	ctx->client_cert_cb=cb;
818 	}
819 
820 int (*SSL_CTX_get_client_cert_cb(SSL_CTX *ctx))(SSL * ssl, X509 ** x509 , EVP_PKEY **pkey)
821 	{
822 	return ctx->client_cert_cb;
823 	}
824 
825 void SSL_CTX_set_cookie_generate_cb(SSL_CTX *ctx,
826 	int (*cb)(SSL *ssl, unsigned char *cookie, unsigned int *cookie_len))
827 	{
828 	ctx->app_gen_cookie_cb=cb;
829 	}
830 
831 void SSL_CTX_set_cookie_verify_cb(SSL_CTX *ctx,
832 	int (*cb)(SSL *ssl, unsigned char *cookie, unsigned int cookie_len))
833 	{
834 	ctx->app_verify_cookie_cb=cb;
835 	}
836 
837