X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fssl_sess.c;h=d6755801cc6540443fecd25eac4c0bd8f20bb2bd;hp=66bd281d16cf01675a3c4abf911ca0626b22004d;hb=1eab9a1fbb6bcc3c616881da00c68bb2ef61589b;hpb=f73e07cf420ddad22b6148d8cbe28daf84ccae2d

diff --git a/ssl/ssl_sess.c b/ssl/ssl_sess.c
index 66bd281d16..d6755801cc 100644
--- a/ssl/ssl_sess.c
+++ b/ssl/ssl_sess.c
@@ -57,56 +57,63 @@
  */
 
 #include <stdio.h>
-#include "lhash.h"
-#include "rand.h"
+#include <openssl/lhash.h>
+#include <openssl/rand.h>
 #include "ssl_locl.h"
 
-#ifndef NOPROTO
 static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s);
 static void SSL_SESSION_list_add(SSL_CTX *ctx,SSL_SESSION *s);
-#else
-static void SSL_SESSION_list_remove();
-static void SSL_SESSION_list_add();
-#endif
-
+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;
+#if 1 /* traditional SSLeay behaviour */
+SSL_SESSION *SSL_get_session(SSL *ssl)
 	{
 	return(ssl->session);
 	}
+#else /* suggested change: increase reference counter so that a session
+       * can later be set in a new SSL object.
+       * Objections:
+       *   -- the modified function should have a new name (or old
+       *      applications, including s_client, leak memory);
+       *   -- the locking seems unnecessary given that SSL structures
+       *      usually cannot be safely shared between threads anyway. */
+SSL_SESSION *SSL_get_session(SSL *ssl)
+	{
+	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_r_lock(CRYPTO_LOCK_SSL_SESSION);
+	sess = ssl->session;
+	if(sess)
+		sess->references++;
+	CRYPTO_r_unlock(CRYPTO_LOCK_SSL_SESSION);
+	return(sess);
+	}
+#endif
 
-int SSL_SESSION_get_ex_new_index(argl,argp,new_func,dup_func,free_func)
-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,
+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));
-        }
+		argl,argp,new_func,dup_func,free_func));
+	}
 
-int SSL_SESSION_set_ex_data(s,idx,arg)
-SSL_SESSION *s;
-int idx;
-void *arg;
+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(s,idx)
-SSL_SESSION *s;
-int idx;
+void *SSL_SESSION_get_ex_data(SSL_SESSION *s, int idx)
 	{
 	return(CRYPTO_get_ex_data(&s->ex_data,idx));
 	}
 
-SSL_SESSION *SSL_SESSION_new()
+SSL_SESSION *SSL_SESSION_new(void)
 	{
 	SSL_SESSION *ss;
 
@@ -118,6 +125,7 @@ SSL_SESSION *SSL_SESSION_new()
 		}
 	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);
@@ -128,10 +136,10 @@ SSL_SESSION *SSL_SESSION_new()
 	return(ss);
 	}
 
-int ssl_get_new_session(s, session)
-SSL *s;
-int session;
+int ssl_get_new_session(SSL *s, int session)
 	{
+	/* This gets used by clients and servers. */
+
 	SSL_SESSION *ss=NULL;
 
 	if ((ss=SSL_SESSION_new()) == NULL) return(0);
@@ -183,6 +191,14 @@ int session;
 			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).
+			 */
 			}
 		}
 	else
@@ -194,34 +210,38 @@ int session;
 	ss->sid_ctx_length=s->sid_ctx_length;
 	s->session=ss;
 	ss->ssl_version=s->version;
+	ss->verify_result = X509_V_OK;
 
 	return(1);
 	}
 
-int ssl_get_prev_session(s,session_id,len)
-SSL *s;
-unsigned char *session_id;
-int len;
+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 copy=1;
+	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))
 		{
 		CRYPTO_r_lock(CRYPTO_LOCK_SSL_CTX);
 		ret=(SSL_SESSION *)lh_retrieve(s->ctx->sessions,(char *)&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);
 		}
 
 	if (ret == NULL)
 		{
+		int copy=1;
+	
 		s->ctx->stats.sess_miss++;
 		ret=NULL;
 		if (s->ctx->get_session_cb != NULL
@@ -230,28 +250,56 @@ int len;
 			{
 			s->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);
+
 			/* The following should not return 1, otherwise,
 			 * things are very strange */
 			SSL_CTX_add_session(s->ctx,ret);
 			}
-		if (ret == NULL) return(0);
+		if (ret == NULL)
+			goto err;
 		}
 
+	/* Now ret is non-NULL, and we own one of its reference counts. */
+
 	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)))
 	    {
-	    SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
-	    return 0;
-	    }
+		/* We've found the session named by the client, but we don't
+		 * want to use it in this context. */
+		
+		if (s->sid_ctx_length == 0)
+			{
+			/* application should have used SSL[_CTX]_set_session_id_context
+			 * -- we could tolerate this and just pretend we never heard
+			 * of this session, but then applications could 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;
+			}
+		else
+			{
+#if 0 /* The client cannot always know when a session is not appropriate,
+	   * so we shouldn't generate an error message. */
 
-	/* auto free it */
-	if (!copy)
-	    SSL_SESSION_free(ret);
+			SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
+#endif
+			goto err; /* treat like cache miss */
+			}
+		}
 
 	if (ret->cipher == NULL)
 		{
-		char buf[5],*p;
+		unsigned char buf[5],*p;
 		unsigned long l;
 
 		p=buf;
@@ -262,22 +310,25 @@ 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
 	 * 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 */
 		{
 		s->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);
+		goto err;
 		}
 
 	s->ctx->stats.sess_hit++;
@@ -289,37 +340,64 @@ 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(ctx,c)
-SSL_CTX *ctx;
-SSL_SESSION *c;
+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);
 	
-	/* 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)
@@ -327,8 +405,8 @@ SSL_SESSION *c;
 			while (SSL_CTX_sess_number(ctx) >
 				SSL_CTX_sess_get_cache_size(ctx))
 				{
-				if (!SSL_CTX_remove_session(ctx,
-					ctx->session_cache_tail))
+				if (!remove_session_lock(ctx,
+					ctx->session_cache_tail, 0))
 					break;
 				else
 					ctx->stats.sess_cache_full++;
@@ -339,16 +417,19 @@ SSL_SESSION *c;
 	return(ret);
 	}
 
-int SSL_CTX_remove_session(ctx,c)
-SSL_CTX *ctx;
-SSL_SESSION *c;
+int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *c)
+{
+	return remove_session_lock(ctx, c, 1);
+}
+
+static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lck)
 	{
 	SSL_SESSION *r;
 	int ret=0;
 
 	if ((c != NULL) && (c->session_id_length != 0))
 		{
-		CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
+		if(lck) CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
 		r=(SSL_SESSION *)lh_delete(ctx->sessions,(char *)c);
 		if (r != NULL)
 			{
@@ -356,7 +437,7 @@ SSL_SESSION *c;
 			SSL_SESSION_list_remove(ctx,c);
 			}
 
-		CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
+		if(lck) CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
 
 		if (ret)
 			{
@@ -371,8 +452,7 @@ SSL_SESSION *c;
 	return(ret);
 	}
 
-void SSL_SESSION_free(ss)
-SSL_SESSION *ss;
+void SSL_SESSION_free(SSL_SESSION *ss)
 	{
 	int i;
 
@@ -397,16 +477,14 @@ SSL_SESSION *ss;
 	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);
-	if (ss->cert != NULL) ssl_cert_free(ss->cert);
+	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);
 	}
 
-int SSL_set_session(s, session)
-SSL *s;
-SSL_SESSION *session;
+int SSL_set_session(SSL *s, SSL_SESSION *session)
 	{
 	int ret=0;
 	SSL_METHOD *meth;
@@ -459,41 +537,33 @@ SSL_SESSION *session;
 	return(ret);
 	}
 
-long SSL_SESSION_set_timeout(s,t)
-SSL_SESSION *s;
-long t;
+long SSL_SESSION_set_timeout(SSL_SESSION *s, long t)
 	{
 	if (s == NULL) return(0);
 	s->timeout=t;
 	return(1);
 	}
 
-long SSL_SESSION_get_timeout(s)
-SSL_SESSION *s;
+long SSL_SESSION_get_timeout(SSL_SESSION *s)
 	{
 	if (s == NULL) return(0);
 	return(s->timeout);
 	}
 
-long SSL_SESSION_get_time(s)
-SSL_SESSION *s;
+long SSL_SESSION_get_time(SSL_SESSION *s)
 	{
 	if (s == NULL) return(0);
 	return(s->time);
 	}
 
-long SSL_SESSION_set_time(s,t)
-SSL_SESSION *s;
-long t;
+long SSL_SESSION_set_time(SSL_SESSION *s, long t)
 	{
 	if (s == NULL) return(0);
 	s->time=t;
 	return(t);
 	}
 
-long SSL_CTX_set_timeout(s,t)
-SSL_CTX *s;
-long t;
+long SSL_CTX_set_timeout(SSL_CTX *s, long t)
 	{
 	long l;
 	if (s == NULL) return(0);
@@ -502,8 +572,7 @@ long t;
 	return(l);
 	}
 
-long SSL_CTX_get_timeout(s)
-SSL_CTX *s;
+long SSL_CTX_get_timeout(SSL_CTX *s)
 	{
 	if (s == NULL) return(0);
 	return(s->session_timeout);
@@ -516,9 +585,7 @@ typedef struct timeout_param_st
 	LHASH *cache;
 	} TIMEOUT_PARAM;
 
-static void timeout(s,p)
-SSL_SESSION *s;
-TIMEOUT_PARAM *p;
+static void timeout(SSL_SESSION *s, TIMEOUT_PARAM *p)
 	{
 	if ((p->time == 0) || (p->time > (s->time+s->timeout))) /* timeout */
 		{
@@ -533,9 +600,7 @@ TIMEOUT_PARAM *p;
 		}
 	}
 
-void SSL_CTX_flush_sessions(s,t)
-SSL_CTX *s;
-long t;
+void SSL_CTX_flush_sessions(SSL_CTX *s, long t)
 	{
 	unsigned long i;
 	TIMEOUT_PARAM tp;
@@ -552,8 +617,7 @@ long t;
 	CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
 	}
 
-int ssl_clear_bad_session(s)
-SSL *s;
+int ssl_clear_bad_session(SSL *s)
 	{
 	if (	(s->session != NULL) &&
 		!(s->shutdown & SSL_SENT_SHUTDOWN) &&
@@ -567,9 +631,7 @@ SSL *s;
 	}
 
 /* locked by SSL_CTX in the calling function */
-static void SSL_SESSION_list_remove(ctx,s)
-SSL_CTX *ctx;
-SSL_SESSION *s;
+static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *s)
 	{
 	if ((s->next == NULL) || (s->prev == NULL)) return;
 
@@ -602,9 +664,7 @@ SSL_SESSION *s;
 	s->prev=s->next=NULL;
 	}
 
-static void SSL_SESSION_list_add(ctx,s)
-SSL_CTX *ctx;
-SSL_SESSION *s;
+static void SSL_SESSION_list_add(SSL_CTX *ctx, SSL_SESSION *s)
 	{
 	if ((s->next != NULL) && (s->prev != NULL))
 		SSL_SESSION_list_remove(ctx,s);