From: Wouter Wijngaards <wouter@nlnetlabs.nl>
Date: Thu, 29 Jun 2017 11:45:43 +0000 (+0000)
Subject: - enhancement for hardened-tls for DNS over TLS.  Removed duplicated
X-Git-Tag: release-1.6.6rc1~76
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=08a3461810709ab83102427d341cd253afd56926;p=thirdparty%2Funbound.git

- enhancement for hardened-tls for DNS over TLS.  Removed duplicated
  security settings.


git-svn-id: file:///svn/unbound/trunk@4255 be551aaa-1e26-0410-a405-d3ace91eadb9
---

diff --git a/daemon/remote.c b/daemon/remote.c
index fbfe1a1b7..74c668eec 100644
--- a/daemon/remote.c
+++ b/daemon/remote.c
@@ -229,42 +229,10 @@ daemon_remote_create(struct config_file* cfg)
 		free(rc);
 		return NULL;
 	}
-	/* no SSLv2, SSLv3 because has defects */
-	if((SSL_CTX_set_options(rc->ctx, SSL_OP_NO_SSLv2) & SSL_OP_NO_SSLv2)
-		!= SSL_OP_NO_SSLv2){
-		log_crypto_err("could not set SSL_OP_NO_SSLv2");
+	if(!listen_sslctx_setup(rc->ctx)) {
 		daemon_remote_delete(rc);
 		return NULL;
 	}
-	if((SSL_CTX_set_options(rc->ctx, SSL_OP_NO_SSLv3) & SSL_OP_NO_SSLv3)
-		!= SSL_OP_NO_SSLv3){
-		log_crypto_err("could not set SSL_OP_NO_SSLv3");
-		daemon_remote_delete(rc);
-		return NULL;
-	}
-#if defined(SSL_OP_NO_TLSv1) && defined(SSL_OP_NO_TLSv1_1)
-	/* if we have tls 1.1 disable 1.0 */
-	if((SSL_CTX_set_options(rc->ctx, SSL_OP_NO_TLSv1) & SSL_OP_NO_TLSv1)
-		!= SSL_OP_NO_TLSv1){
-		log_crypto_err("could not set SSL_OP_NO_TLSv1");
-		daemon_remote_delete(rc);
-		return NULL;
-	}
-#endif
-#if defined(SSL_OP_NO_TLSv1_1) && defined(SSL_OP_NO_TLSv1_2)
-	/* if we have tls 1.2 disable 1.1 */
-	if((SSL_CTX_set_options(rc->ctx, SSL_OP_NO_TLSv1_1) & SSL_OP_NO_TLSv1_1)
-		!= SSL_OP_NO_TLSv1_1){
-		log_crypto_err("could not set SSL_OP_NO_TLSv1_1");
-		daemon_remote_delete(rc);
-		return NULL;
-	}
-#endif
-#if defined(SHA256_DIGEST_LENGTH) && defined(USE_ECDSA)
-	/* if we have sha256, set the cipher list to have no known vulns */
-	if(!SSL_CTX_set_cipher_list(rc->ctx, "ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256"))
-		log_crypto_err("could not set cipher list with SSL_CTX_set_cipher_list");
-#endif
 
 	if (cfg->remote_control_use_cert == 0) {
 		/* No certificates are requested */
@@ -314,23 +282,7 @@ daemon_remote_create(struct config_file* cfg)
 		log_crypto_err("Error in SSL_CTX check_private_key");
 		goto setup_error;
 	}
-#if HAVE_DECL_SSL_CTX_SET_ECDH_AUTO
-	if(!SSL_CTX_set_ecdh_auto(rc->ctx,1)) {
-		log_crypto_err("Error in SSL_CTX_ecdh_auto, not enabling ECDHE");
-	}
-#elif defined(USE_ECDSA)
-	if(1) {
-		EC_KEY *ecdh = EC_KEY_new_by_curve_name (NID_X9_62_prime256v1);
-		if (!ecdh) {
-			log_crypto_err("could not find p256, not enabling ECDHE");
-		} else {
-			if (1 != SSL_CTX_set_tmp_ecdh (rc->ctx, ecdh)) {
-				log_crypto_err("Error in SSL_CTX_set_tmp_ecdh, not enabling ECDHE");
-			}
-			EC_KEY_free (ecdh);
-		}
-	}
-#endif
+	listen_sslctx_setup_2(rc->ctx);
 	if(!SSL_CTX_load_verify_locations(rc->ctx, s_cert, NULL)) {
 		log_crypto_err("Error setting up SSL_CTX verify locations");
 	setup_error:
diff --git a/doc/Changelog b/doc/Changelog
index d7f601ec2..4c167852e 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,6 +1,8 @@
 29 June 2017: Wouter
 	- Fix python example0 return module wait instead of error for pass.
 	- iana portlist update
+	- enhancement for hardened-tls for DNS over TLS.  Removed duplicated
+	  security settings.
 
 27 June 2017: Wouter
 	- Tag 1.6.4 is created with the 1.6.4rc2 contents.
diff --git a/util/net_help.c b/util/net_help.c
index 6c0d68e31..9d532852b 100644
--- a/util/net_help.c
+++ b/util/net_help.c
@@ -610,45 +610,56 @@ log_crypto_err(const char* str)
 #endif /* HAVE_SSL */
 }
 
-void* listen_sslctx_create(char* key, char* pem, char* verifypem)
+int
+listen_sslctx_setup(void* ctxt)
 {
-#ifdef HAVE_SSL
-	SSL_CTX* ctx = SSL_CTX_new(SSLv23_server_method());
-	if(!ctx) {
-		log_crypto_err("could not SSL_CTX_new");
-		return NULL;
-	}
+	SSL_CTX* ctx = (SSL_CTX*)ctxt;
 	/* no SSLv2, SSLv3 because has defects */
 	if((SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2) & SSL_OP_NO_SSLv2)
 		!= SSL_OP_NO_SSLv2){
 		log_crypto_err("could not set SSL_OP_NO_SSLv2");
-		SSL_CTX_free(ctx);
-		return NULL;
+		return 0;
 	}
 	if((SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv3) & SSL_OP_NO_SSLv3)
 		!= SSL_OP_NO_SSLv3){
 		log_crypto_err("could not set SSL_OP_NO_SSLv3");
-		SSL_CTX_free(ctx);
-		return NULL;
-	}
-	if(!SSL_CTX_use_certificate_chain_file(ctx, pem)) {
-		log_err("error for cert file: %s", pem);
-		log_crypto_err("error in SSL_CTX use_certificate_chain_file");
-		SSL_CTX_free(ctx);
-		return NULL;
+		return 0;
 	}
-	if(!SSL_CTX_use_PrivateKey_file(ctx, key, SSL_FILETYPE_PEM)) {
-		log_err("error for private key file: %s", key);
-		log_crypto_err("Error in SSL_CTX use_PrivateKey_file");
-		SSL_CTX_free(ctx);
-		return NULL;
+#if defined(SSL_OP_NO_TLSv1) && defined(SSL_OP_NO_TLSv1_1)
+	/* if we have tls 1.1 disable 1.0 */
+	if((SSL_CTX_set_options(ctx, SSL_OP_NO_TLSv1) & SSL_OP_NO_TLSv1)
+		!= SSL_OP_NO_TLSv1){
+		log_crypto_err("could not set SSL_OP_NO_TLSv1");
+		return 0;
 	}
-	if(!SSL_CTX_check_private_key(ctx)) {
-		log_err("error for key file: %s", key);
-		log_crypto_err("Error in SSL_CTX check_private_key");
-		SSL_CTX_free(ctx);
-		return NULL;
+#endif
+#if defined(SSL_OP_NO_TLSv1_1) && defined(SSL_OP_NO_TLSv1_2)
+	/* if we have tls 1.2 disable 1.1 */
+	if((SSL_CTX_set_options(ctx, SSL_OP_NO_TLSv1_1) & SSL_OP_NO_TLSv1_1)
+		!= SSL_OP_NO_TLSv1_1){
+		log_crypto_err("could not set SSL_OP_NO_TLSv1_1");
+		return 0;
 	}
+#endif
+#if defined(SHA256_DIGEST_LENGTH) && defined(USE_ECDSA)
+	/* if we have sha256, set the cipher list to have no known vulns */
+	if(!SSL_CTX_set_cipher_list(ctx, "ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256"))
+		log_crypto_err("could not set cipher list with SSL_CTX_set_cipher_list");
+#endif
+
+	SSL_CTX_set_options(ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
+
+#ifdef HAVE_SSL_CTX_SET_SECURITY_LEVEL
+	SSL_CTX_set_security_level(ctx, 0);
+#endif
+	return 1;
+}
+
+void
+listen_sslctx_setup_2(void* ctxt)
+{
+	SSL_CTX* ctx = (SSL_CTX*)ctxt;
+	(void)ctx;
 #if HAVE_DECL_SSL_CTX_SET_ECDH_AUTO
 	if(!SSL_CTX_set_ecdh_auto(ctx,1)) {
 		log_crypto_err("Error in SSL_CTX_ecdh_auto, not enabling ECDHE");
@@ -666,7 +677,39 @@ void* listen_sslctx_create(char* key, char* pem, char* verifypem)
 		}
 	}
 #endif
+}
 
+void* listen_sslctx_create(char* key, char* pem, char* verifypem)
+{
+#ifdef HAVE_SSL
+	SSL_CTX* ctx = SSL_CTX_new(SSLv23_server_method());
+	if(!ctx) {
+		log_crypto_err("could not SSL_CTX_new");
+		return NULL;
+	}
+	if(!listen_sslctx_setup(ctx)) {
+		SSL_CTX_free(ctx);
+		return NULL;
+	}
+	if(!SSL_CTX_use_certificate_chain_file(ctx, pem)) {
+		log_err("error for cert file: %s", pem);
+		log_crypto_err("error in SSL_CTX use_certificate_chain_file");
+		SSL_CTX_free(ctx);
+		return NULL;
+	}
+	if(!SSL_CTX_use_PrivateKey_file(ctx, key, SSL_FILETYPE_PEM)) {
+		log_err("error for private key file: %s", key);
+		log_crypto_err("Error in SSL_CTX use_PrivateKey_file");
+		SSL_CTX_free(ctx);
+		return NULL;
+	}
+	if(!SSL_CTX_check_private_key(ctx)) {
+		log_err("error for key file: %s", key);
+		log_crypto_err("Error in SSL_CTX check_private_key");
+		SSL_CTX_free(ctx);
+		return NULL;
+	}
+	listen_sslctx_setup_2(ctx);
 	if(verifypem && verifypem[0]) {
 		if(!SSL_CTX_load_verify_locations(ctx, verifypem, NULL)) {
 			log_crypto_err("Error in SSL_CTX verify locations");
diff --git a/util/net_help.h b/util/net_help.h
index 54f4c9c0e..f0236e533 100644
--- a/util/net_help.h
+++ b/util/net_help.h
@@ -345,6 +345,19 @@ void sock_list_merge(struct sock_list** list, struct regional* region,
  */
 void log_crypto_err(const char* str);
 
+/**
+ * Set SSL_OP_NOxxx options on SSL context to disable bad crypto
+ * @param ctxt: SSL_CTX*
+ * @return false on failure.
+ */
+int listen_sslctx_setup(void* ctxt);
+
+/**
+ * Further setup of listening SSL context, after keys loaded.
+ * @param ctxt: SSL_CTX*
+ */
+void listen_sslctx_setup_2(void* ctxt);
+
 /** 
  * create SSL listen context
  * @param key: private key file.