Fixes for TLS server_name extension

Submitted by: Peter Sylvester

CHANGES

@@ -4,9 +4,13 @@
 
  Changes between 0.9.8a and 0.9.9  [xx XXX xxxx]
 
-  *) Add support for TLS extensions, specifically for the HostName extension
-     so far.  The SSL_SESSION, SSL_CTX, and SSL data structures now have new
-     members for HostName support.
+  *) Add initial support for TLS extensions, specifically for the server_name
+     extension so far.  The SSL_SESSION, SSL_CTX, and SSL data structures now
+     have new members for a host name.  The SSL data structure has an
+     additional member SSL_CTX *initial_ctx so that new sessions can be
+     stored in that context to allow for session resumption, even after the
+     SSL has been switched to a new SSL_CTX in reaction to a client's
+     server_name extension.
 
      New functions (subject to change):
 
@@ -21,7 +25,6 @@
          SSL_CTRL_SET_TLSEXT_SERVERNAME_ARG
                                       - SSL_CTX_set_tlsext_servername_arg()
          SSL_CTRL_SET_TLSEXT_HOSTNAME           - SSL_set_tlsext_hostname()
-         SSL_CTRL_GET_TLSEXT_HOSTNAME     [similar to SSL_get_servername()]
          SSL_CTRL_SET_TLSEXT_SERVERNAME_DONE
                                          - SSL_set_tlsext_servername_done()
 

apps/s_client.c

@@ -245,7 +245,7 @@ static int MS_CALLBACK ssl_servername_cb(SSL *s, int *ad, void *arg)
 	else 
 		BIO_printf(bio_err,"Can't use SSL_get_servername\n");
 	
-	return SSL_ERROR_NONE;
+	return 1;
 	}
 #endif
 

apps/s_server.c

@@ -540,24 +540,24 @@ static int MS_CALLBACK ssl_servername_cb(SSL *s, int *ad, void *arg)
 	{
 	tlsextctx * p = (tlsextctx *) arg;
 	const char * servername = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name);
-        if (servername) 
+        if (servername && p->biodebug) 
 		BIO_printf(p->biodebug,"Hostname in TLS extension: \"%s\"\n",servername);
         
 	if (!p->servername)
 		{
 		SSL_set_tlsext_servername_done(s,2);
-		return SSL_ERROR_NONE;
+		return 1;
 		}
 	
 	if (servername)
 		{
     		if (strcmp(servername,p->servername)) 
-			return TLS1_AD_UNRECOGNIZED_NAME;
+			return 0;
 		if (ctx2) 
 			SSL_set_SSL_CTX(s,ctx2);
 		SSL_set_tlsext_servername_done(s,1);
 		}
-	return SSL_ERROR_NONE;
+	return 1;
 }
 #endif
 
@@ -845,7 +845,6 @@ int MAIN(int argc, char *argv[])
 			{
 			if (--argc < 1) goto bad;
 			tlsextcbp.servername= *(++argv);
-			/* meth=TLSv1_server_method(); */
 			}
 		else if	(strcmp(*argv,"-cert2") == 0)
 			{

ssl/s3_lib.c

@@ -1644,19 +1644,6 @@ long ssl3_ctrl(SSL *s, int cmd, long larg, void *parg)
 		break;
 #endif /* !OPENSSL_NO_ECDH */
 #ifndef OPENSSL_NO_TLSEXT
-	case SSL_CTRL_GET_TLSEXT_HOSTNAME:	
-		if (larg != TLSEXT_NAMETYPE_host_name)
-			{
-			SSLerr(SSL_F_SSL3_CTRL, SSL_R_SSL3_EXT_INVALID_SERVERNAME_TYPE);
-			return(0);
-			}
-		/* XXX cf. SSL_get_servername() (ssl_lib.c) */
-		if (s->session && s->session->tlsext_hostname)
-			*((char **) parg) = s->session->tlsext_hostname;
-		else
-			*((char **) parg) = s->tlsext_hostname;
-		ret = 1;
-		break;
 	case SSL_CTRL_SET_TLSEXT_HOSTNAME:
  		if (larg == TLSEXT_NAMETYPE_host_name)
 			{

ssl/ssl.h

@@ -993,6 +993,7 @@ struct ssl_st
 	                          1 : prepare 2, allow last ack just after in server callback.
 	                          2 : don't call servername callback, no ack in server hello
 	                       */
+	SSL_CTX * initial_ctx; /* initial ctx, used to store sessions */
 #endif
 	};
 
@@ -1201,11 +1202,12 @@ size_t SSL_get_peer_finished(const SSL *s, void *buf, size_t count);
 #define SSL_CTRL_SET_MAX_SEND_FRAGMENT		52
 
 /* see tls.h for macros based on these */
+#ifndef OPENSSL_NO_TLSEXT
 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_CB	53
 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_ARG	54
 #define SSL_CTRL_SET_TLSEXT_HOSTNAME		55
-#define SSL_CTRL_GET_TLSEXT_HOSTNAME		56
-#define SSL_CTRL_SET_TLSEXT_SERVERNAME_DONE	57
+#define SSL_CTRL_SET_TLSEXT_SERVERNAME_DONE	56
+#endif
 
 #define SSL_session_reused(ssl) \
 	SSL_ctrl((ssl),SSL_CTRL_GET_SESSION_REUSED,0,NULL)

ssl/ssl_lib.c

@@ -307,6 +307,10 @@ SSL *SSL_new(SSL_CTX *ctx)
 
 	CRYPTO_add(&ctx->references,1,CRYPTO_LOCK_SSL_CTX);
 	s->ctx=ctx;
+#ifndef OPENSSL_NO_TLSEXT
+	CRYPTO_add(&ctx->references,1,CRYPTO_LOCK_SSL_CTX);
+	s->initial_ctx=ctx;
+#endif
 
 	s->verify_result=X509_V_OK;
 
@@ -493,6 +497,9 @@ void SSL_free(SSL *s)
 	/* Free up if allocated */
 
 	if (s->ctx) SSL_CTX_free(s->ctx);
+#ifndef OPENSSL_NO_TLSEXT
+	if (s->initial_ctx) SSL_CTX_free(s->initial_ctx);
+#endif
 
 	if (s->client_CA != NULL)
 		sk_X509_NAME_pop_free(s->client_CA,X509_NAME_free);

ssl/ssl_sess.c

@@ -114,6 +114,12 @@
 #include <openssl/rand.h>
 #include "ssl_locl.h"
 
+#ifndef OPENSSL_NO_TLSEXT
+#define session_ctx initial_ctx
+#else
+#define session_ctx ctx
+#endif
+
 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);
@@ -233,7 +239,7 @@ int ssl_get_new_session(SSL *s, int session)
 	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;
@@ -276,8 +282,8 @@ int ssl_get_new_session(SSL *s, int session)
 		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;
+		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;
@@ -347,10 +353,10 @@ int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
 		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,&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);
@@ -361,13 +367,13 @@ 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++;
+			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
@@ -379,10 +385,10 @@ int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
 
 			/* 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))
+			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->ctx,ret);
+				SSL_CTX_add_session(s->session_ctx,ret);
 			}
 		if (ret == NULL)
 			goto err;
@@ -447,13 +453,13 @@ int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len)
 
 	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_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 

ssl/tls1.h

@@ -158,9 +158,6 @@ extern "C" {
 #define TLSEXT_TYPE_trusted_ca_keys		3
 #define TLSEXT_TYPE_truncated_hmac		4
 #define TLSEXT_TYPE_status_request		5
-#if 0
-#define TLSEXT_TYPE_srp				6
-#endif
 
 /* NameType value from RFC 3546 */
 #define TLSEXT_NAMETYPE_host_name 0
@@ -181,19 +178,6 @@ SSL_CTX_ctrl(ctx,SSL_CTRL_SET_TLSEXT_SERVERNAME_ARG,0, (void *)arg)
 
 #define SSL_set_tlsext_servername_done(s,t) \
 SSL_ctrl(s,SSL_CTRL_SET_TLSEXT_SERVERNAME_DONE,t, NULL)
-
-#if 0
-#  if 0
-
-	#define SSL_get_tlsext_hostname(s,psn) \
-	SSL_ctrl(s,SSL_CTRL_GET_TLSEXT_HOSTNAME,TLSEXT_NAMETYPE_host_name, (void *)psn)
-#  else
-	/* XXX this looks weird for a macro, define a function instead? */
-	 * or just used SSL_get_servername() directly ... */
-	#define SSL_get_tlsext_hostname(s,psn) \
-	(*psn = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name),*psn != NULL)
-#  endif
-#endif
   
 #endif