Various changes in the new TLS extension code, including the following:
[openssl.git] / ssl / ssl_sess.c
index 830f1d9b0f447dbc540ce37642729d9fd02c0d74..16162fa951de91e2562bfbafdb51deb0cbba30ef 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).
+ *
+ */
 
 #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_OF(CRYPTO_EX_DATA_FUNCS) *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);
@@ -80,21 +131,19 @@ SSL_SESSION *SSL_get1_session(SSL *ssl)
        /* 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_r_lock(CRYPTO_LOCK_SSL_SESSION);
+       CRYPTO_w_lock(CRYPTO_LOCK_SSL_SESSION);
        sess = ssl->session;
        if(sess)
                sess->references++;
-       CRYPTO_r_unlock(CRYPTO_LOCK_SSL_SESSION);
+       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)
        {
-       ssl_session_num++;
-       return(CRYPTO_get_ex_new_index(ssl_session_num-1,
-               &ssl_session_meth,
-               argl,argp,new_func,dup_func,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)
@@ -102,7 +151,7 @@ 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));
        }
@@ -122,19 +171,64 @@ SSL_SESSION *SSL_SESSION_new(void)
        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,ss,&ss->ex_data);
+#ifndef OPENSSL_NO_TLSEXT
+       ss->tlsext_hostname = NULL; 
+#endif
+       CRYPTO_new_ex_data(CRYPTO_EX_INDEX_SSL_SESSION, ss, &ss->ex_data);
        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);
 
@@ -167,31 +261,57 @@ 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->ctx->generate_session_id)
+                       cb = s->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))
+                       {
+                       /* 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))
                        {
-                       SSL_SESSION *r;
-
-                       RAND_pseudo_bytes(ss->session_id,ss->session_id_length);
-                       CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
-                       r=(SSL_SESSION *)lh_retrieve(s->ctx->sessions, ss);
-                       CRYPTO_r_unlock(CRYPTO_LOCK_SSL_CTX);
-                       if (r == NULL) break;
-                       /* 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).
-                        */
+                       SSLerr(SSL_F_SSL_GET_NEW_SESSION,
+                               SSL_R_SSL_SESSION_ID_CONFLICT);
+                       SSL_SESSION_free(ss);
+                       return(0);
                        }
                }
        else
@@ -199,6 +319,12 @@ int ssl_get_new_session(SSL *s, int session)
                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;
@@ -251,9 +377,12 @@ int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
                        if (copy)
                                CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION);
 
-                       /* The following should not return 1, otherwise,
-                        * things are very strange */
-                       SSL_CTX_add_session(s->ctx,ret);
+                       /* Add the externally cached session to the internal
+                        * cache as well if and only if we are supposed to. */
+                       if(!(s->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->ctx,ret);
                        }
                if (ret == NULL)
                        goto err;
@@ -316,7 +445,7 @@ int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
        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++;
                /* remove it from the cache */
@@ -423,10 +552,10 @@ 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,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);
                        }
 
@@ -465,22 +594,25 @@ void SSL_SESSION_free(SSL_SESSION *ss)
                }
 #endif
 
-       CRYPTO_free_ex_data(ssl_session_meth,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));
+#ifndef OPENSSL_NO_TLSEXT
+       if (ss->tlsext_hostname != NULL) OPENSSL_free(ss->tlsext_hostname);
+#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)
                {
@@ -503,6 +635,17 @@ 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 *)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)
@@ -538,13 +681,13 @@ 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);
@@ -566,7 +709,7 @@ 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);
@@ -594,6 +737,8 @@ 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;
@@ -606,7 +751,7 @@ 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, (LHASH_DOALL_ARG_FN_TYPE)timeout, &tp);
+       lh_doall_arg(tp.cache, LHASH_DOALL_ARG_FN(timeout), &tp);
        tp.cache->down_load=i;
        CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
        }