Change cipher defaults

Switch cipher defaults to HIGH:!aNULL:@STRENGTH (OpenSSL) or
SECURE128 (GnuTLS).

INSTALL

@@ -12,11 +12,18 @@
 I. Upgrade Information
 ~~~~~~~~~~~~~~~~~~~~~~
 
+Differences to previous version 
+
+- Starting with ngIRCd 21, the ciphers used by SSL are configurable and
+  default to HIGH:!aNULL:@STRENGTH (OpenSSL) or SECURE128 (GnuTLS).
+  Previous version were using the OpenSSL or GnuTLS defaults, DEFAULT
+  and NORMAL respectively.
+
 Differences to version 19.x
 
 - Starting with ngIRCd 20, users can "cloak" their hostname only when the
   configuration variable "CloakHostModeX" (introduced in 19.2) is set.
-  Otherwise, only IRC opertators, other servers, and services are allowed to
+  Otherwise, only IRC operators, other servers, and services are allowed to
   set mode +x. This prevents regular users from changing their hostmask to
   the name of the IRC server itself, which confused quite a few people ;-)
 

doc/sample-ngircd.conf.tmpl

@@ -249,11 +249,9 @@
 	;CertFile = :ETCDIR:/ssl/server-cert.pem
 
 	# Select cipher suites allowed for SSL/TLS connections. This defaults
-	# to the empty string, so all supported ciphers are allowed. Please
+	# to HIGH:!aNULL:@STRENGTH (OpenSSL) or SECURE128 (GnuTLS).
-	# see 'man 1ssl ciphers' (OpenSSL) and 'man 3 gnutls_priority_init'
+	# See 'man 1ssl ciphers' (OpenSSL) or 'man 3 gnutls_priority_init'
 	# (GnuTLS) for details.
-	# For example, this setting allows only "high strength" cipher suites,
-	# disables the ones without authentication, and sorts by strength:
 	# For OpenSSL:
 	;CipherList = HIGH:!aNULL:@STRENGTH
 	# For GnuTLS:

man/ngircd.conf.5.tmpl

@@ -367,13 +367,10 @@ when it is compiled with support for SSL using OpenSSL or GnuTLS!
 SSL Certificate file of the private server key.
 .TP
 \fBCipherList\fR (string)
-Select cipher suites allowed for SSL/TLS connections. This defaults to the
+Select cipher suites allowed for SSL/TLS connections.  This defaults to
-empty string, so all supported ciphers are allowed.
+"HIGH:!aNULL:@STRENGTH" (OpenSSL) or "SECURE128" (GnuTLS).
 Please see 'man 1ssl ciphers' (OpenSSL) and 'man 3 gnutls_priority_init'
 (GnuTLS) for details.
-For example, this setting allows only "high strength" cipher suites, disables
-the ones without authentication, and sorts by strength:
-"HIGH:!aNULL:@STRENGTH" (OpenSSL), "SECURE128" (GnuTLS).
 .TP
 \fBDHFile\fR (string)
 Name of the Diffie-Hellman Parameter file. Can be created with GnuTLS

src/ngircd/conf.c

@@ -93,6 +93,12 @@ static void Init_Server_Struct PARAMS(( CONF_SERVER *Server ));
 #define DEFAULT_LISTEN_ADDRSTR "0.0.0.0"
 #endif
 
+#ifdef HAVE_LIBSSL
+#define DEFAULT_CIPHERS		"HIGH:!aNULL:@STRENGTH"
+#endif
+#ifdef HAVE_LIBGNUTLS
+#define DEFAULT_CIPHERS		"SECURE128"
+#endif
 
 #ifdef SSL_SUPPORT
 
@@ -435,8 +441,8 @@ Conf_Test( void )
 	puts("[SSL]");
 	printf("  CertFile = %s\n", Conf_SSLOptions.CertFile
 					? Conf_SSLOptions.CertFile : "");
-	printf("  CipherList = %s\n", Conf_SSLOptions.CipherList
+	printf("  CipherList = %s\n", Conf_SSLOptions.CipherList ?
-					? Conf_SSLOptions.CipherList : "");
+	       Conf_SSLOptions.CipherList : DEFAULT_CIPHERS);
 	printf("  DHFile = %s\n", Conf_SSLOptions.DHFile
 					? Conf_SSLOptions.DHFile : "");
 	printf("  KeyFile = %s\n", Conf_SSLOptions.KeyFile
@@ -1032,6 +1038,10 @@ Read_Config(bool TestOnly, bool IsStarting)
 	CheckFileReadable("CertFile", Conf_SSLOptions.CertFile);
 	CheckFileReadable("DHFile", Conf_SSLOptions.DHFile);
 	CheckFileReadable("KeyFile", Conf_SSLOptions.KeyFile);
+
+	/* Set the default ciphers if none were configured */
+	if (!Conf_SSLOptions.CipherList)
+		Conf_SSLOptions.CipherList = strdup_warn(DEFAULT_CIPHERS);
 #endif
 
 	return true;

src/ngircd/conn-ssl.c

@@ -306,17 +306,10 @@ ConnSSL_InitLibrary( void )
 	if (!ConnSSL_LoadServerKey_openssl(newctx))
 		goto out;
 
-	if(Conf_SSLOptions.CipherList && *Conf_SSLOptions.CipherList) {
+	if (SSL_CTX_set_cipher_list(newctx, Conf_SSLOptions.CipherList) == 0) {
-		if(SSL_CTX_set_cipher_list(newctx, Conf_SSLOptions.CipherList) == 0 ) {
+		Log(LOG_ERR, "Failed to apply OpenSSL cipher list \"%s\"!",
-			Log(LOG_ERR,
-			    "Failed to apply OpenSSL cipher list \"%s\"!",
 		    Conf_SSLOptions.CipherList);
 		goto out;
-		} else {
-			Log(LOG_INFO,
-			    "Successfully applied OpenSSL cipher list \"%s\".",
-			    Conf_SSLOptions.CipherList);
-		}
 	}
 
 	SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2);
@@ -352,26 +345,13 @@ out:
 	if (!ConnSSL_LoadServerKey_gnutls())
 		goto out;
 
-	if(Conf_SSLOptions.CipherList && *Conf_SSLOptions.CipherList) {
+	if (gnutls_priority_init(&priorities_cache, Conf_SSLOptions.CipherList,
-		err = gnutls_priority_init(&priorities_cache,
+				 NULL) != GNUTLS_E_SUCCESS) {
-					   Conf_SSLOptions.CipherList, NULL);
-		if (err != GNUTLS_E_SUCCESS) {
 		Log(LOG_ERR,
 		    "Failed to apply GnuTLS cipher list \"%s\"!",
 		    Conf_SSLOptions.CipherList);
 		goto out;
 	}
-		Log(LOG_INFO,
-		    "Successfully applied GnuTLS cipher list \"%s\".",
-		    Conf_SSLOptions.CipherList);
-	} else {
-		err = gnutls_priority_init(&priorities_cache, "NORMAL", NULL);
-		if (err != GNUTLS_E_SUCCESS) {
-			Log(LOG_ERR,
-			    "Failed to apply GnuTLS cipher list \"NORMAL\"!");
-			goto out;
-		}
-	}
 
 	Log(LOG_INFO, "GnuTLS %s initialized.", gnutls_check_version(NULL));
 	initialized = true;
@@ -505,7 +485,7 @@ ConnSSL_Init_SSL(CONNECTION *c)
 #ifdef HAVE_LIBGNUTLS
 	Conn_OPTION_ADD(c, CONN_SSL);
 	ret = gnutls_priority_set(c->ssl_state.gnutls_session, priorities_cache);
-	if (ret != 0) {
+	if (ret != GNUTLS_E_SUCCESS) {
 		Log(LOG_ERR, "Failed to set GnuTLS session priorities: %s",
 		    gnutls_strerror(ret));
 		ConnSSL_Free(c);