stricter session ID context matching
[openssl.git] / ssl / ssl_sess.c
index 3872b419283db7e0057d3cbe11440a1a70ad65d7..6aba804faad3e0445ca980ebdd3650006a6ca3fa 100644 (file)
  * copied and put under another distribution licence
  * [including the GNU Public Licence.]
  */
+/* ====================================================================
+ * Copyright (c) 1998-2006 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+/* ====================================================================
+ * Copyright 2005 Nokia. All rights reserved.
+ *
+ * The portions of the attached software ("Contribution") is developed by
+ * Nokia Corporation and is licensed pursuant to the OpenSSL open source
+ * license.
+ *
+ * The Contribution, originally written by Mika Kousa and Pasi Eronen of
+ * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
+ * support (see RFC 4279) to OpenSSL.
+ *
+ * No patent licenses or other rights except those expressly stated in
+ * the OpenSSL open source license shall be deemed granted or received
+ * expressly, by implication, estoppel, or otherwise.
+ *
+ * No assurances are provided by Nokia that the Contribution does not
+ * infringe the patent or other intellectual property rights of any third
+ * party or that the license provides you with all the necessary rights
+ * to make use of the Contribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
+ * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
+ * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
+ * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
+ * OTHERWISE.
+ */
 
 #include <stdio.h>
 #include <openssl/lhash.h>
 static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s);
 static void SSL_SESSION_list_add(SSL_CTX *ctx,SSL_SESSION *s);
 static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lck);
-static int ssl_session_num=0;
-static STACK *ssl_session_meth=NULL;
 
-SSL_SESSION *SSL_get_session(SSL *ssl)
+SSL_SESSION *SSL_get_session(const SSL *ssl)
+/* aka SSL_get0_session; gets 0 objects, just returns a copy of the pointer */
        {
        return(ssl->session);
        }
 
-int SSL_SESSION_get_ex_new_index(long argl, char *argp, int (*new_func)(),
-            int (*dup_func)(), void (*free_func)())
-        {
-        ssl_session_num++;
-        return(CRYPTO_get_ex_new_index(ssl_session_num-1,
-               &ssl_session_meth,
-                argl,argp,new_func,dup_func,free_func));
-        }
+SSL_SESSION *SSL_get1_session(SSL *ssl)
+/* variant of SSL_get_session: caller really gets something */
+       {
+       SSL_SESSION *sess;
+       /* Need to lock this all up rather than just use CRYPTO_add so that
+        * somebody doesn't free ssl->session between when we check it's
+        * non-null and when we up the reference count. */
+       CRYPTO_w_lock(CRYPTO_LOCK_SSL_SESSION);
+       sess = ssl->session;
+       if(sess)
+               sess->references++;
+       CRYPTO_w_unlock(CRYPTO_LOCK_SSL_SESSION);
+       return(sess);
+       }
+
+int SSL_SESSION_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
+            CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
+       {
+       return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_SSL_SESSION, argl, argp,
+                       new_func, dup_func, free_func);
+       }
 
 int SSL_SESSION_set_ex_data(SSL_SESSION *s, int idx, void *arg)
        {
        return(CRYPTO_set_ex_data(&s->ex_data,idx,arg));
        }
 
-void *SSL_SESSION_get_ex_data(SSL_SESSION *s, int idx)
+void *SSL_SESSION_get_ex_data(const SSL_SESSION *s, int idx)
        {
        return(CRYPTO_get_ex_data(&s->ex_data,idx));
        }
@@ -95,7 +186,7 @@ SSL_SESSION *SSL_SESSION_new(void)
        {
        SSL_SESSION *ss;
 
-       ss=(SSL_SESSION *)Malloc(sizeof(SSL_SESSION));
+       ss=(SSL_SESSION *)OPENSSL_malloc(sizeof(SSL_SESSION));
        if (ss == NULL)
                {
                SSLerr(SSL_F_SSL_SESSION_NEW,ERR_R_MALLOC_FAILURE);
@@ -103,29 +194,85 @@ SSL_SESSION *SSL_SESSION_new(void)
                }
        memset(ss,0,sizeof(SSL_SESSION));
 
+       ss->verify_result = 1; /* avoid 0 (= X509_V_OK) just in case */
        ss->references=1;
        ss->timeout=60*5+4; /* 5 minute timeout by default */
-       ss->time=time(NULL);
+       ss->time=(unsigned long)time(NULL);
        ss->prev=NULL;
        ss->next=NULL;
        ss->compress_meth=0;
-       CRYPTO_new_ex_data(ssl_session_meth,(char *)ss,&ss->ex_data);
+#ifndef OPENSSL_NO_TLSEXT
+       ss->tlsext_hostname = NULL; 
+#ifndef OPENSSL_NO_EC
+       ss->tlsext_ecpointformatlist_length = 0;
+       ss->tlsext_ecpointformatlist = NULL;
+       ss->tlsext_ellipticcurvelist_length = 0;
+       ss->tlsext_ellipticcurvelist = NULL;
+#endif
+#endif
+       CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);
+#ifndef OPENSSL_NO_PSK
+       ss->psk_identity_hint=NULL;
+       ss->psk_identity=NULL;
+#endif
        return(ss);
        }
 
+const unsigned char *SSL_SESSION_get_id(const SSL_SESSION *s, unsigned int *len)
+       {
+       if(len)
+               *len = s->session_id_length;
+       return s->session_id;
+       }
+
+/* Even with SSLv2, we have 16 bytes (128 bits) of session ID space. SSLv3/TLSv1
+ * has 32 bytes (256 bits). As such, filling the ID with random gunk repeatedly
+ * until we have no conflict is going to complete in one iteration pretty much
+ * "most" of the time (btw: understatement). So, if it takes us 10 iterations
+ * and we still can't avoid a conflict - well that's a reasonable point to call
+ * it quits. Either the RAND code is broken or someone is trying to open roughly
+ * very close to 2^128 (or 2^256) SSL sessions to our server. How you might
+ * store that many sessions is perhaps a more interesting question ... */
+
+#define MAX_SESS_ID_ATTEMPTS 10
+static int def_generate_session_id(const SSL *ssl, unsigned char *id,
+                               unsigned int *id_len)
+{
+       unsigned int retry = 0;
+       do
+               if (RAND_pseudo_bytes(id, *id_len) <= 0)
+                       return 0;
+       while(SSL_has_matching_session_id(ssl, id, *id_len) &&
+               (++retry < MAX_SESS_ID_ATTEMPTS));
+       if(retry < MAX_SESS_ID_ATTEMPTS)
+               return 1;
+       /* else - woops a session_id match */
+       /* XXX We should also check the external cache --
+        * but the probability of a collision is negligible, and
+        * we could not prevent the concurrent creation of sessions
+        * with identical IDs since we currently don't have means
+        * to atomically check whether a session ID already exists
+        * and make a reservation for it if it does not
+        * (this problem applies to the internal cache as well).
+        */
+       return 0;
+}
+
 int ssl_get_new_session(SSL *s, int session)
        {
        /* This gets used by clients and servers. */
 
+       unsigned int tmp;
        SSL_SESSION *ss=NULL;
+       GEN_SESSION_CB cb = def_generate_session_id;
 
        if ((ss=SSL_SESSION_new()) == NULL) return(0);
 
        /* If the context has a default timeout, use it */
-       if (s->ctx->session_timeout == 0)
+       if (s->session_ctx->session_timeout == 0)
                ss->timeout=SSL_get_default_timeout(s);
        else
-               ss->timeout=s->ctx->session_timeout;
+               ss->timeout=s->session_ctx->session_timeout;
 
        if (s->session != NULL)
                {
@@ -150,35 +297,111 @@ int ssl_get_new_session(SSL *s, int session)
                        ss->ssl_version=TLS1_VERSION;
                        ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
                        }
+               else if (s->version == DTLS1_VERSION)
+                       {
+                       ss->ssl_version=DTLS1_VERSION;
+                       ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
+                       }
                else
                        {
                        SSLerr(SSL_F_SSL_GET_NEW_SESSION,SSL_R_UNSUPPORTED_SSL_VERSION);
                        SSL_SESSION_free(ss);
                        return(0);
                        }
-
-               for (;;)
+               /* Choose which callback will set the session ID */
+               CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
+               if(s->generate_session_id)
+                       cb = s->generate_session_id;
+               else if(s->session_ctx->generate_session_id)
+                       cb = s->session_ctx->generate_session_id;
+               CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
+               /* Choose a session ID */
+               tmp = ss->session_id_length;
+               if(!cb(s, ss->session_id, &tmp))
                        {
-                       SSL_SESSION *r;
-
-                       RAND_bytes(ss->session_id,ss->session_id_length);
-                       CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
-                       r=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,
-                               (char *)ss);
-                       CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
-                       if (r == NULL) break;
-                       /* else - woops a session_id match */
+                       /* The callback failed */
+                       SSLerr(SSL_F_SSL_GET_NEW_SESSION,
+                               SSL_R_SSL_SESSION_ID_CALLBACK_FAILED);
+                       SSL_SESSION_free(ss);
+                       return(0);
+                       }
+               /* Don't allow the callback to set the session length to zero.
+                * nor set it higher than it was. */
+               if(!tmp || (tmp > ss->session_id_length))
+                       {
+                       /* The callback set an illegal length */
+                       SSLerr(SSL_F_SSL_GET_NEW_SESSION,
+                               SSL_R_SSL_SESSION_ID_HAS_BAD_LENGTH);
+                       SSL_SESSION_free(ss);
+                       return(0);
                        }
+               /* If the session length was shrunk and we're SSLv2, pad it */
+               if((tmp < ss->session_id_length) && (s->version == SSL2_VERSION))
+                       memset(ss->session_id + tmp, 0, ss->session_id_length - tmp);
+               else
+                       ss->session_id_length = tmp;
+               /* Finally, check for a conflict */
+               if(SSL_has_matching_session_id(s, ss->session_id,
+                                               ss->session_id_length))
+                       {
+                       SSLerr(SSL_F_SSL_GET_NEW_SESSION,
+                               SSL_R_SSL_SESSION_ID_CONFLICT);
+                       SSL_SESSION_free(ss);
+                       return(0);
+                       }
+#ifndef OPENSSL_NO_TLSEXT
+               if (s->tlsext_hostname) {
+                       ss->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
+                       if (ss->tlsext_hostname == NULL) {
+                               SSLerr(SSL_F_SSL_GET_NEW_SESSION, ERR_R_INTERNAL_ERROR);
+                               SSL_SESSION_free(ss);
+                               return 0;
+                               }
+                       }
+#ifndef OPENSSL_NO_EC
+               if (s->tlsext_ecpointformatlist)
+                       {
+                       if (ss->tlsext_ecpointformatlist != NULL) OPENSSL_free(ss->tlsext_ecpointformatlist);
+                       if ((ss->tlsext_ecpointformatlist = OPENSSL_malloc(s->tlsext_ecpointformatlist_length)) == NULL)
+                               {
+                               SSLerr(SSL_F_SSL_GET_NEW_SESSION, ERR_R_MALLOC_FAILURE);
+                               SSL_SESSION_free(ss);
+                               return 0;
+                               }
+                       ss->tlsext_ecpointformatlist_length = s->tlsext_ecpointformatlist_length;
+                       memcpy(ss->tlsext_ecpointformatlist, s->tlsext_ecpointformatlist, s->tlsext_ecpointformatlist_length);
+                       }
+               if (s->tlsext_ellipticcurvelist)
+                       {
+                       if (ss->tlsext_ellipticcurvelist != NULL) OPENSSL_free(ss->tlsext_ellipticcurvelist);
+                       if ((ss->tlsext_ellipticcurvelist = OPENSSL_malloc(s->tlsext_ellipticcurvelist_length)) == NULL)
+                               {
+                               SSLerr(SSL_F_SSL_GET_NEW_SESSION, ERR_R_MALLOC_FAILURE);
+                               SSL_SESSION_free(ss);
+                               return 0;
+                               }
+                       ss->tlsext_ellipticcurvelist_length = s->tlsext_ellipticcurvelist_length;
+                       memcpy(ss->tlsext_ellipticcurvelist, s->tlsext_ellipticcurvelist, s->tlsext_ellipticcurvelist_length);
+                       }
+#endif
+#endif
                }
        else
                {
                ss->session_id_length=0;
                }
 
+       if (s->sid_ctx_length > sizeof ss->sid_ctx)
+               {
+               SSLerr(SSL_F_SSL_GET_NEW_SESSION, ERR_R_INTERNAL_ERROR);
+               SSL_SESSION_free(ss);
+               return 0;
+               }
        memcpy(ss->sid_ctx,s->sid_ctx,s->sid_ctx_length);
        ss->sid_ctx_length=s->sid_ctx_length;
        s->session=ss;
        ss->ssl_version=s->version;
+       ss->verify_result = X509_V_OK;
 
        return(1);
        }
@@ -188,18 +411,21 @@ int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
        /* This is used only by servers. */
 
        SSL_SESSION *ret=NULL,data;
+       int fatal = 0;
 
-       /* conn_init();*/
        data.ssl_version=s->version;
        data.session_id_length=len;
        if (len > SSL_MAX_SSL_SESSION_ID_LENGTH)
-               return(0);
+               goto err;
        memcpy(data.session_id,session_id,len);
 
-       if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_LOOKUP))
+       if (!(s->session_ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_LOOKUP))
                {
                CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
-               ret=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,(char *)&data);
+               ret=(SSL_SESSION *)lh_retrieve(s->session_ctx->sessions,&data);
+               if (ret != NULL)
+                   /* don't allow other threads to steal it: */
+                   CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
                CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
                }
 
@@ -207,35 +433,65 @@ int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
                {
                int copy=1;
        
-               s->ctx->stats.sess_miss++;
+               s->session_ctx->stats.sess_miss++;
                ret=NULL;
-               if (s->ctx->get_session_cb != NULL
-                   && (ret=s->ctx->get_session_cb(s,session_id,len,&copy))
+               if (s->session_ctx->get_session_cb != NULL
+                   && (ret=s->session_ctx->get_session_cb(s,session_id,len,&copy))
                       != NULL)
                        {
-                       s->ctx->stats.sess_cb_hit++;
-
-                       /* The following should not return 1, otherwise,
-                        * things are very strange */
-                       SSL_CTX_add_session(s->ctx,ret);
-                       /* auto free it (decrement reference count now) */
-                       if (!copy)
-                               SSL_SESSION_free(ret);
+                       s->session_ctx->stats.sess_cb_hit++;
+
+                       /* Increment reference count now if the session callback
+                        * asks us to do so (note that if the session structures
+                        * returned by the callback are shared between threads,
+                        * it must handle the reference count itself [i.e. copy == 0],
+                        * or things won't be thread-safe). */
+                       if (copy)
+                               CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
+
+                       /* Add the externally cached session to the internal
+                        * cache as well if and only if we are supposed to. */
+                       if(!(s->session_ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_STORE))
+                               /* The following should not return 1, otherwise,
+                                * things are very strange */
+                               SSL_CTX_add_session(s->session_ctx,ret);
                        }
-               if (ret == NULL) return(0);
+               if (ret == NULL)
+                       goto err;
                }
 
-       if((s->verify_mode&SSL_VERIFY_PEER)
-          && (!s->sid_ctx_length || ret->sid_ctx_length != s->sid_ctx_length
-              || memcmp(ret->sid_ctx,s->sid_ctx,ret->sid_ctx_length)))
-           {
-               if (s->sid_ctx_length)
-                       SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
-               else
-                       /* application should have used SSL[_CTX]_set_session_id_context */
-                       SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED);
-           return 0;
-           }
+       /* Now ret is non-NULL, and we own one of its reference counts. */
+
+       if (ret->sid_ctx_length != s->sid_ctx_length
+           || memcmp(ret->sid_ctx,s->sid_ctx,ret->sid_ctx_length))
+               {
+               /* We've found the session named by the client, but we don't
+                * want to use it in this context. */
+
+#if 0 /* The client cannot always know when a session is not appropriate,
+       * so we shouldn't generate an error message. */
+
+               SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
+#endif
+               goto err; /* treat like cache miss */
+               }
+       
+       if((s->verify_mode & SSL_VERIFY_PEER) && s->sid_ctx_length == 0)
+               {
+               /* We can't be sure if this session is being used out of
+                * context, which is especially important for SSL_VERIFY_PEER.
+                * The application should have used SSL[_CTX]_set_session_id_context.
+                *
+                * For this error case, we generate an error instead of treating
+                * the event like a cache miss (otherwise it would be easy for
+                * applications to effectively disable the session cache by
+                * accident without anyone noticing).
+                */
+               
+               SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED);
+               fatal = 1;
+               goto err;
+               }
 
        if (ret->cipher == NULL)
                {
@@ -250,25 +506,28 @@ int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
                else 
                        ret->cipher=ssl_get_cipher_by_char(s,&(buf[1]));
                if (ret->cipher == NULL)
-                       return(0);
+                       goto err;
                }
 
+
+#if 0 /* This is way too late. */
+
        /* If a thread got the session, then 'swaped', and another got
-        * it and then due to a time-out decided to 'Free' it we could
+        * it and then due to a time-out decided to 'OPENSSL_free' it we could
         * be in trouble.  So I'll increment it now, then double decrement
         * later - am I speaking rubbish?. */
        CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
+#endif
 
-       if ((long)(ret->time+ret->timeout) < (long)time(NULL)) /* timeout */
+       if (ret->timeout < (long)(time(NULL) - ret->time)) /* timeout */
                {
-               s->ctx->stats.sess_timeout++;
+               s->session_ctx->stats.sess_timeout++;
                /* remove it from the cache */
-               SSL_CTX_remove_session(s->ctx,ret);
-               SSL_SESSION_free(ret);          /* again to actually Free it */
-               return(0);
+               SSL_CTX_remove_session(s->session_ctx,ret);
+               goto err;
                }
 
-       s->ctx->stats.sess_hit++;
+       s->session_ctx->stats.sess_hit++;
 
        /* ret->time=time(NULL); */ /* rezero timeout? */
        /* again, just leave the session 
@@ -277,7 +536,16 @@ int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
        if (s->session != NULL)
                SSL_SESSION_free(s->session);
        s->session=ret;
+       s->verify_result = s->session->verify_result;
        return(1);
+
+ err:
+       if (ret != NULL)
+               SSL_SESSION_free(ret);
+       if (fatal)
+               return -1;
+       else
+               return 0;
        }
 
 int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *c)
@@ -285,27 +553,47 @@ int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *c)
        int ret=0;
        SSL_SESSION *s;
 
-       /* conn_init(); */
+       /* add just 1 reference count for the SSL_CTX's session cache
+        * even though it has two ways of access: each session is in a
+        * doubly linked list and an lhash */
        CRYPTO_add(&c->references,1,CRYPTO_LOCK_SSL_SESSION);
+       /* if session c is in already in cache, we take back the increment later */
 
        CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
-       s=(SSL_SESSION *)lh_insert(ctx->sessions,(char *)c);
+       s=(SSL_SESSION *)lh_insert(ctx->sessions,c);
        
-       /* Put on the end of the queue unless it is already in the cache */
+       /* s != NULL iff we already had a session with the given PID.
+        * In this case, s == c should hold (then we did not really modify
+        * ctx->sessions), or we're in trouble. */
+       if (s != NULL && s != c)
+               {
+               /* We *are* in trouble ... */
+               SSL_SESSION_list_remove(ctx,s);
+               SSL_SESSION_free(s);
+               /* ... so pretend the other session did not exist in cache
+                * (we cannot handle two SSL_SESSION structures with identical
+                * session ID in the same cache, which could happen e.g. when
+                * two threads concurrently obtain the same session from an external
+                * cache) */
+               s = NULL;
+               }
+
+       /* Put at the head of the queue unless it is already in the cache */
        if (s == NULL)
                SSL_SESSION_list_add(ctx,c);
 
-       /* If the same session if is being 're-added', Free the old
-        * one when the last person stops using it.
-        * This will also work if it is alread in the cache.
-        * The references will go up and then down :-) */
        if (s != NULL)
                {
-               SSL_SESSION_free(s);
+               /* existing cache entry -- decrement previously incremented reference
+                * count because it already takes into account the cache */
+
+               SSL_SESSION_free(s); /* s == c */
                ret=0;
                }
        else
                {
+               /* new cache entry -- remove old ones if cache has become too large */
+               
                ret=1;
 
                if (SSL_CTX_sess_get_cache_size(ctx) > 0)
@@ -338,10 +626,10 @@ static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lck)
        if ((c != NULL) && (c->session_id_length != 0))
                {
                if(lck) CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
-               r=(SSL_SESSION *)lh_delete(ctx->sessions,(char *)c);
-               if (r != NULL)
+               if ((r = (SSL_SESSION *)lh_retrieve(ctx->sessions,c)) == c)
                        {
                        ret=1;
+                       r=(SSL_SESSION *)lh_delete(ctx->sessions,c);
                        SSL_SESSION_list_remove(ctx,c);
                        }
 
@@ -380,22 +668,37 @@ void SSL_SESSION_free(SSL_SESSION *ss)
                }
 #endif
 
-       CRYPTO_free_ex_data(ssl_session_meth,(char *)ss,&ss->ex_data);
+       CRYPTO_free_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);
 
-       memset(ss->key_arg,0,SSL_MAX_KEY_ARG_LENGTH);
-       memset(ss->master_key,0,SSL_MAX_MASTER_KEY_LENGTH);
-       memset(ss->session_id,0,SSL_MAX_SSL_SESSION_ID_LENGTH);
+       OPENSSL_cleanse(ss->key_arg,sizeof ss->key_arg);
+       OPENSSL_cleanse(ss->master_key,sizeof ss->master_key);
+       OPENSSL_cleanse(ss->session_id,sizeof ss->session_id);
        if (ss->sess_cert != NULL) ssl_sess_cert_free(ss->sess_cert);
        if (ss->peer != NULL) X509_free(ss->peer);
        if (ss->ciphers != NULL) sk_SSL_CIPHER_free(ss->ciphers);
-       memset(ss,0,sizeof(*ss));
-       Free(ss);
+#ifndef OPENSSL_NO_TLSEXT
+       if (ss->tlsext_hostname != NULL) OPENSSL_free(ss->tlsext_hostname);
+#ifndef OPENSSL_NO_EC
+       ss->tlsext_ecpointformatlist_length = 0;
+       if (ss->tlsext_ecpointformatlist != NULL) OPENSSL_free(ss->tlsext_ecpointformatlist);
+       ss->tlsext_ellipticcurvelist_length = 0;
+       if (ss->tlsext_ellipticcurvelist != NULL) OPENSSL_free(ss->tlsext_ellipticcurvelist);
+#endif /* OPENSSL_NO_EC */
+#endif
+#ifndef OPENSSL_NO_PSK
+       if (ss->psk_identity_hint != NULL)
+               OPENSSL_free(ss->psk_identity_hint);
+       if (ss->psk_identity != NULL)
+               OPENSSL_free(ss->psk_identity);
+#endif
+       OPENSSL_cleanse(ss,sizeof(*ss));
+       OPENSSL_free(ss);
        }
 
 int SSL_set_session(SSL *s, SSL_SESSION *session)
        {
        int ret=0;
-       SSL_METHOD *meth;
+       const SSL_METHOD *meth;
 
        if (session != NULL)
                {
@@ -418,11 +721,23 @@ int SSL_set_session(SSL *s, SSL_SESSION *session)
                                session->timeout=s->ctx->session_timeout;
                        }
 
+#ifndef OPENSSL_NO_KRB5
+                if (s->kssl_ctx && !s->kssl_ctx->client_princ &&
+                    session->krb5_client_princ_len > 0)
+                {
+                    s->kssl_ctx->client_princ = (char *)OPENSSL_malloc(session->krb5_client_princ_len + 1);
+                    memcpy(s->kssl_ctx->client_princ,session->krb5_client_princ,
+                            session->krb5_client_princ_len);
+                    s->kssl_ctx->client_princ[session->krb5_client_princ_len] = '\0';
+                }
+#endif /* OPENSSL_NO_KRB5 */
+
                /* CRYPTO_w_lock(CRYPTO_LOCK_SSL);*/
                CRYPTO_add(&session->references,1,CRYPTO_LOCK_SSL_SESSION);
                if (s->session != NULL)
                        SSL_SESSION_free(s->session);
                s->session=session;
+               s->verify_result = s->session->verify_result;
                /* CRYPTO_w_unlock(CRYPTO_LOCK_SSL);*/
                ret=1;
                }
@@ -452,13 +767,13 @@ long SSL_SESSION_set_timeout(SSL_SESSION *s, long t)
        return(1);
        }
 
-long SSL_SESSION_get_timeout(SSL_SESSION *s)
+long SSL_SESSION_get_timeout(const SSL_SESSION *s)
        {
        if (s == NULL) return(0);
        return(s->timeout);
        }
 
-long SSL_SESSION_get_time(SSL_SESSION *s)
+long SSL_SESSION_get_time(const SSL_SESSION *s)
        {
        if (s == NULL) return(0);
        return(s->time);
@@ -480,7 +795,7 @@ long SSL_CTX_set_timeout(SSL_CTX *s, long t)
        return(l);
        }
 
-long SSL_CTX_get_timeout(SSL_CTX *s)
+long SSL_CTX_get_timeout(const SSL_CTX *s)
        {
        if (s == NULL) return(0);
        return(s->session_timeout);
@@ -499,7 +814,7 @@ static void timeout(SSL_SESSION *s, TIMEOUT_PARAM *p)
                {
                /* The reason we don't call SSL_CTX_remove_session() is to
                 * save on locking overhead */
-               lh_delete(p->cache,(char *)s);
+               lh_delete(p->cache,s);
                SSL_SESSION_list_remove(p->ctx,s);
                s->not_resumable=1;
                if (p->ctx->remove_session_cb != NULL)
@@ -508,6 +823,8 @@ static void timeout(SSL_SESSION *s, TIMEOUT_PARAM *p)
                }
        }
 
+static IMPLEMENT_LHASH_DOALL_ARG_FN(timeout, SSL_SESSION *, TIMEOUT_PARAM *)
+
 void SSL_CTX_flush_sessions(SSL_CTX *s, long t)
        {
        unsigned long i;
@@ -520,7 +837,7 @@ void SSL_CTX_flush_sessions(SSL_CTX *s, long t)
        CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
        i=tp.cache->down_load;
        tp.cache->down_load=0;
-       lh_doall_arg(tp.cache,(void (*)())timeout,(char *)&tp);
+       lh_doall_arg(tp.cache, LHASH_DOALL_ARG_FN(timeout), &tp);
        tp.cache->down_load=i;
        CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
        }
@@ -593,3 +910,72 @@ static void SSL_SESSION_list_add(SSL_CTX *ctx, SSL_SESSION *s)
                }
        }
 
+void SSL_CTX_sess_set_new_cb(SSL_CTX *ctx,
+       int (*cb)(struct ssl_st *ssl,SSL_SESSION *sess))
+       {
+       ctx->new_session_cb=cb;
+       }
+
+int (*SSL_CTX_sess_get_new_cb(SSL_CTX *ctx))(SSL *ssl, SSL_SESSION *sess)
+       {
+       return ctx->new_session_cb;
+       }
+
+void SSL_CTX_sess_set_remove_cb(SSL_CTX *ctx,
+       void (*cb)(SSL_CTX *ctx,SSL_SESSION *sess))
+       {
+       ctx->remove_session_cb=cb;
+       }
+
+void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(SSL_CTX * ctx,SSL_SESSION *sess)
+       {
+       return ctx->remove_session_cb;
+       }
+
+void SSL_CTX_sess_set_get_cb(SSL_CTX *ctx,
+       SSL_SESSION *(*cb)(struct ssl_st *ssl,
+                unsigned char *data,int len,int *copy))
+       {
+       ctx->get_session_cb=cb;
+       }
+
+SSL_SESSION * (*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(SSL *ssl,
+                unsigned char *data,int len,int *copy)
+       {
+       return ctx->get_session_cb;
+       }
+
+void SSL_CTX_set_info_callback(SSL_CTX *ctx, 
+       void (*cb)(const SSL *ssl,int type,int val))
+       {
+       ctx->info_callback=cb;
+       }
+
+void (*SSL_CTX_get_info_callback(SSL_CTX *ctx))(const SSL *ssl,int type,int val)
+       {
+       return ctx->info_callback;
+       }
+
+void SSL_CTX_set_client_cert_cb(SSL_CTX *ctx,
+       int (*cb)(SSL *ssl, X509 **x509, EVP_PKEY **pkey))
+       {
+       ctx->client_cert_cb=cb;
+       }
+
+int (*SSL_CTX_get_client_cert_cb(SSL_CTX *ctx))(SSL * ssl, X509 ** x509 , EVP_PKEY **pkey)
+       {
+       return ctx->client_cert_cb;
+       }
+
+void SSL_CTX_set_cookie_generate_cb(SSL_CTX *ctx,
+       int (*cb)(SSL *ssl, unsigned char *cookie, unsigned int *cookie_len))
+       {
+       ctx->app_gen_cookie_cb=cb;
+       }
+
+void SSL_CTX_set_cookie_verify_cb(SSL_CTX *ctx,
+       int (*cb)(SSL *ssl, unsigned char *cookie, unsigned int cookie_len))
+       {
+       ctx->app_verify_cookie_cb=cb;
+       }
+