Unique DoT and DoH SSL contexts to allow for different ALPN (#1222)

gthess · web-flow · commit e4483bbbd1fa · 2025-01-20T15:43:44.000+01:00
diff --git a/daemon/daemon.c b/daemon/daemon.c
@@ -954,11 +954,12 @@ daemon_delete(struct daemon* daemon)
 	free(daemon->env);
 #ifdef HAVE_SSL
 	listen_sslctx_delete_ticket_keys();
-	SSL_CTX_free((SSL_CTX*)daemon->listen_sslctx);
-	SSL_CTX_free((SSL_CTX*)daemon->connect_sslctx);
+	SSL_CTX_free((SSL_CTX*)daemon->listen_dot_sslctx);
+	SSL_CTX_free((SSL_CTX*)daemon->listen_doh_sslctx);
+	SSL_CTX_free((SSL_CTX*)daemon->connect_dot_sslctx);
 #endif
 #ifdef HAVE_NGTCP2
-	SSL_CTX_free((SSL_CTX*)daemon->quic_sslctx);
+	SSL_CTX_free((SSL_CTX*)daemon->listen_quic_sslctx);
 #endif
 	free(daemon);
 	/* lex cleanup */
diff --git a/daemon/daemon.h b/daemon/daemon.h
@@ -97,10 +97,14 @@ struct daemon {
 	struct listen_port* rc_ports;
 	/** remote control connections management (for first worker) */
 	struct daemon_remote* rc;
-	/** ssl context for listening to dnstcp over ssl, and connecting ssl */
-	void* listen_sslctx, *connect_sslctx;
+	/** ssl context for listening to dnstcp over ssl */
+	void* listen_dot_sslctx;
+	/** ssl context for connecting to dnstcp over ssl */
+	void* connect_dot_sslctx;
+	/** ssl context for listening to DoH */
+	void* listen_doh_sslctx;
 	/** ssl context for listening to quic */
-	void* quic_sslctx;
+	void* listen_quic_sslctx;
 	/** num threads allocated */
 	int num;
 	/** num threads allocated in the previous config or 0 at first */
diff --git a/daemon/unbound.c b/daemon/unbound.c
@@ -463,6 +463,62 @@ detach(void)
 #endif /* HAVE_DAEMON */
 }
 
+/* setup a listening ssl context, fatal_exit() on any failure */
+static void
+setup_listen_sslctx(void** ctx, int is_dot, int is_doh, struct config_file* cfg)
+{
+#ifdef HAVE_SSL
+	if(!(*ctx = listen_sslctx_create(
+		cfg->ssl_service_key, cfg->ssl_service_pem, NULL,
+		cfg->tls_ciphers, cfg->tls_ciphersuites,
+		(cfg->tls_session_ticket_keys.first &&
+		cfg->tls_session_ticket_keys.first->str[0] != 0),
+		is_dot, is_doh))) {
+		fatal_exit("could not set up listen SSL_CTX");
+	}
+#else /* HAVE_SSL */
+	(void)ctx;(void)is_dot;(void)is_doh;(void)cfg;
+#endif /* HAVE_SSL */
+}
+
+/* setups the needed ssl contexts, fatal_exit() on any failure */
+static void
+setup_sslctxs(struct daemon* daemon, struct config_file* cfg)
+{
+#ifdef HAVE_SSL
+	if(!(daemon->rc = daemon_remote_create(cfg)))
+		fatal_exit("could not set up remote-control");
+	if(cfg->ssl_service_key && cfg->ssl_service_key[0]) {
+		/* setup the session keys; the callback to use them will be
+		 * attached to each sslctx separately */
+		if(cfg->tls_session_ticket_keys.first &&
+			cfg->tls_session_ticket_keys.first->str[0] != 0) {
+			if(!listen_sslctx_setup_ticket_keys(
+				cfg->tls_session_ticket_keys.first)) {
+				fatal_exit("could not set session ticket SSL_CTX");
+			}
+		}
+		(void)setup_listen_sslctx(&daemon->listen_dot_sslctx, 1, 0, cfg);
+#ifdef HAVE_NGHTTP2_NGHTTP2_H
+		if(cfg_has_https(cfg)) {
+			(void)setup_listen_sslctx(&daemon->listen_doh_sslctx, 0, 1, cfg);
+		}
+#endif
+#ifdef HAVE_NGTCP2
+		if(!(daemon->listen_quic_sslctx = quic_sslctx_create(
+			cfg->ssl_service_key, cfg->ssl_service_pem, NULL))) {
+			fatal_exit("could not set up quic SSL_CTX");
+		}
+#endif /* HAVE_NGTCP2 */
+	}
+	if(!(daemon->connect_dot_sslctx = connect_sslctx_create(NULL, NULL,
+		cfg->tls_cert_bundle, cfg->tls_win_cert)))
+		fatal_exit("could not set up connect SSL_CTX");
+#else /* HAVE_SSL */
+	(void)daemon;(void)cfg;
+#endif /* HAVE_SSL */
+}
+
 /** daemonize, drop user privileges and chroot if needed */
 static void
 perform_setup(struct daemon* daemon, struct config_file* cfg, int debug_mode,
@@ -489,43 +545,7 @@ perform_setup(struct daemon* daemon, struct config_file* cfg, int debug_mode,
 #endif
 
 	/* read ssl keys while superuser and outside chroot */
-#ifdef HAVE_SSL
-	if(!(daemon->rc = daemon_remote_create(cfg)))
-		fatal_exit("could not set up remote-control");
-	if(cfg->ssl_service_key && cfg->ssl_service_key[0]) {
-		if(!(daemon->listen_sslctx = listen_sslctx_create(
-			cfg->ssl_service_key, cfg->ssl_service_pem, NULL))) {
-			fatal_exit("could not set up listen SSL_CTX");
-		}
-		if(cfg->tls_ciphers && cfg->tls_ciphers[0]) {
-			if (!SSL_CTX_set_cipher_list(daemon->listen_sslctx, cfg->tls_ciphers)) {
-				fatal_exit("failed to set tls-cipher %s", cfg->tls_ciphers);
-			}
-		}
-#ifdef HAVE_SSL_CTX_SET_CIPHERSUITES
-		if(cfg->tls_ciphersuites && cfg->tls_ciphersuites[0]) {
-			if (!SSL_CTX_set_ciphersuites(daemon->listen_sslctx, cfg->tls_ciphersuites)) {
-				fatal_exit("failed to set tls-ciphersuites %s", cfg->tls_ciphersuites);
-			}
-		}
-#endif /* HAVE_SSL_CTX_SET_CIPHERSUITES */
-		if(cfg->tls_session_ticket_keys.first &&
-			cfg->tls_session_ticket_keys.first->str[0] != 0) {
-			if(!listen_sslctx_setup_ticket_keys(daemon->listen_sslctx, cfg->tls_session_ticket_keys.first)) {
-				fatal_exit("could not set session ticket SSL_CTX");
-			}
-		}
-#ifdef HAVE_NGTCP2
-		if(!(daemon->quic_sslctx = quic_sslctx_create(
-			cfg->ssl_service_key, cfg->ssl_service_pem, NULL))) {
-			fatal_exit("could not set up quic SSL_CTX");
-		}
-#endif /* HAVE_NGTCP2 */
-	}
-	if(!(daemon->connect_sslctx = connect_sslctx_create(NULL, NULL,
-		cfg->tls_cert_bundle, cfg->tls_win_cert)))
-		fatal_exit("could not set up connect SSL_CTX");
-#endif /* HAVE_SSL */
+	(void)setup_sslctxs(daemon, cfg);
 
 	/* init syslog (as root) if needed, before daemonize, otherwise
 	 * a fork error could not be printed since daemonize closed stderr.*/
diff --git a/daemon/worker.c b/daemon/worker.c
@@ -2173,8 +2173,9 @@ worker_init(struct worker* worker, struct config_file *cfg,
 			: cfg->tcp_idle_timeout,
 		cfg->harden_large_queries, cfg->http_max_streams,
 		cfg->http_endpoint, cfg->http_notls_downstream,
-		worker->daemon->tcl, worker->daemon->listen_sslctx,
-		worker->daemon->quic_sslctx,
+		worker->daemon->tcl, worker->daemon->listen_dot_sslctx,
+		worker->daemon->listen_doh_sslctx,
+		worker->daemon->listen_quic_sslctx,
 		dtenv, worker->daemon->doq_table, worker->env.rnd,
 		cfg, worker_handle_request, worker);
 	if(!worker->front) {
@@ -2191,7 +2192,7 @@ worker_init(struct worker* worker, struct config_file *cfg,
 		cfg->unwanted_threshold, cfg->outgoing_tcp_mss,
 		&worker_alloc_cleanup, worker,
 		cfg->do_udp || cfg->udp_upstream_without_downstream,
-		worker->daemon->connect_sslctx, cfg->delay_close,
+		worker->daemon->connect_dot_sslctx, cfg->delay_close,
 		cfg->tls_use_sni, dtenv, cfg->udp_connect,
 		cfg->max_reuse_tcp_queries, cfg->tcp_reuse_timeout,
 		cfg->tcp_auth_query_timeout);
diff --git a/dnstap/unbound-dnstap-socket.c b/dnstap/unbound-dnstap-socket.c
@@ -346,7 +346,8 @@ static struct tap_socket* tap_socket_new_tlsaccept(char* ip,
 	s->fd = -1;
 	s->ev_cb = ev_cb;
 	s->data = data;
-	s->sslctx = listen_sslctx_create(server_key, server_cert, verifypem);
+	s->sslctx = listen_sslctx_create(server_key, server_cert, verifypem,
+		NULL, NULL, 0, 0, 0);
 	if(!s->sslctx) {
 		log_err("could not create ssl context");
 		free(s->ip);
diff --git a/services/listen_dnsport.c b/services/listen_dnsport.c
@@ -1512,7 +1512,8 @@ listen_create(struct comm_base* base, struct listen_port* ports,
 	size_t bufsize, int tcp_accept_count, int tcp_idle_timeout,
 	int harden_large_queries, uint32_t http_max_streams,
 	char* http_endpoint, int http_notls, struct tcl_list* tcp_conn_limit,
-	void* sslctx, void* quic_sslctx, struct dt_env* dtenv,
+	void* dot_sslctx, void* doh_sslctx, void* quic_sslctx,
+	struct dt_env* dtenv,
 	struct doq_table* doq_table,
 	struct ub_randstate* rnd,struct config_file* cfg,
 	comm_point_callback_type* cb, void *cb_arg)
@@ -1566,7 +1567,7 @@ listen_create(struct comm_base* base, struct listen_port* ports,
 				ports->ftype, ports->pp2_enabled, cb, cb_arg,
 				ports->socket);
 			if(ports->ftype == listen_type_http) {
-				if(!sslctx && !http_notls) {
+				if(!doh_sslctx && !http_notls) {
 					log_warn("HTTPS port configured, but "
 						"no TLS tls-service-key or "
 						"tls-service-pem set");
@@ -1612,8 +1613,10 @@ listen_create(struct comm_base* base, struct listen_port* ports,
 			cp->ssl = NULL;
 		} else if(ports->ftype == listen_type_doq) {
 			cp->ssl = quic_sslctx;
+		} else if(ports->ftype == listen_type_http) {
+			cp->ssl = doh_sslctx;
 		} else {
-			cp->ssl = sslctx;
+			cp->ssl = dot_sslctx;
 		}
 		cp->dtenv = dtenv;
 		cp->do_not_close = 1;
diff --git a/services/listen_dnsport.h b/services/listen_dnsport.h
@@ -194,7 +194,8 @@ int resolve_interface_names(char** ifs, int num_ifs,
  * @param http_endpoint: HTTP endpoint to service queries on
  * @param http_notls: no TLS for http downstream
  * @param tcp_conn_limit: TCP connection limit info.
- * @param sslctx: nonNULL if ssl context.
+ * @param dot_sslctx: nonNULL if dot ssl context.
+ * @param doh_sslctx: nonNULL if doh ssl context.
  * @param quic_sslctx: nonNULL if quic ssl context.
  * @param dtenv: nonNULL if dnstap enabled.
  * @param doq_table: the doq connection table, with shared information.
@@ -210,7 +211,8 @@ listen_create(struct comm_base* base, struct listen_port* ports,
 	size_t bufsize, int tcp_accept_count, int tcp_idle_timeout,
 	int harden_large_queries, uint32_t http_max_streams,
 	char* http_endpoint, int http_notls, struct tcl_list* tcp_conn_limit,
-	void* sslctx, void* quic_sslctx, struct dt_env* dtenv,
+	void* dot_sslctx, void* doh_sslctx, void* quic_sslctx,
+	struct dt_env* dtenv,
 	struct doq_table* doq_table,
 	struct ub_randstate* rnd,struct config_file* cfg,
 	comm_point_callback_type* cb, void *cb_arg);
diff --git a/testcode/fake_event.c b/testcode/fake_event.c
@@ -938,7 +938,8 @@ listen_create(struct comm_base* base, struct listen_port* ATTR_UNUSED(ports),
 	char* ATTR_UNUSED(http_endpoint),
 	int ATTR_UNUSED(http_notls),
 	struct tcl_list* ATTR_UNUSED(tcp_conn_limit),
-	void* ATTR_UNUSED(sslctx), void* ATTR_UNUSED(quic_ssl),
+	void* ATTR_UNUSED(dot_sslctx), void* ATTR_UNUSED(doh_sslctx),
+	void* ATTR_UNUSED(quic_ssl),
 	struct dt_env* ATTR_UNUSED(dtenv),
 	struct doq_table* ATTR_UNUSED(table),
 	struct ub_randstate* ATTR_UNUSED(rnd),
diff --git a/util/net_help.c b/util/net_help.c
@@ -1162,8 +1162,29 @@ log_cert(unsigned level, const char* str, void* cert)
 }
 #endif /* HAVE_SSL */
 
+#if defined(HAVE_SSL) && defined(HAVE_SSL_CTX_SET_ALPN_SELECT_CB)
+static int
+dot_alpn_select_cb(SSL* ATTR_UNUSED(ssl), const unsigned char** out,
+	unsigned char* outlen, const unsigned char* in, unsigned int inlen,
+	void* ATTR_UNUSED(arg))
+{
+	static const unsigned char alpns[] = { 3, 'd', 'o', 't' };
+	unsigned char* tmp_out;
+	int ret;
+	ret = SSL_select_next_proto(&tmp_out, outlen, alpns, sizeof(alpns), in, inlen);
+	if(ret == OPENSSL_NPN_NO_OVERLAP) {
+		/* Client sent ALPN but no overlap. Should have been error,
+		 * but for privacy we continue without ALPN (e.g., if certain
+		 * ALPNs are blocked) */
+		return SSL_TLSEXT_ERR_NOACK;
+	}
+	*out = tmp_out;
+	return SSL_TLSEXT_ERR_OK;
+}
+#endif
+
 #if defined(HAVE_SSL) && defined(HAVE_NGHTTP2) && defined(HAVE_SSL_CTX_SET_ALPN_SELECT_CB)
-static int alpn_select_cb(SSL* ATTR_UNUSED(ssl), const unsigned char** out,
+static int doh_alpn_select_cb(SSL* ATTR_UNUSED(ssl), const unsigned char** out,
 	unsigned char* outlen, const unsigned char* in, unsigned int inlen,
 	void* ATTR_UNUSED(arg))
 {
@@ -1177,6 +1198,23 @@ static int alpn_select_cb(SSL* ATTR_UNUSED(ssl), const unsigned char** out,
 }
 #endif
 
+/* setup the callback for ticket keys */
+static int
+setup_ticket_keys_cb(void* sslctx)
+{
+#  ifdef HAVE_SSL_CTX_SET_TLSEXT_TICKET_KEY_EVP_CB
+	if(SSL_CTX_set_tlsext_ticket_key_evp_cb(sslctx, tls_session_ticket_key_cb) == 0) {
+		return 0;
+	}
+#  else
+	if(SSL_CTX_set_tlsext_ticket_key_cb(sslctx, tls_session_ticket_key_cb) == 0) {
+		return 0;
+	}
+#  endif
+	return 1;
+}
+
+
 int
 listen_sslctx_setup(void* ctxt)
 {
@@ -1248,9 +1286,6 @@ listen_sslctx_setup(void* ctxt)
 #ifdef HAVE_SSL_CTX_SET_SECURITY_LEVEL
 	SSL_CTX_set_security_level(ctx, 0);
 #endif
-#if defined(HAVE_SSL_CTX_SET_ALPN_SELECT_CB) && defined(HAVE_NGHTTP2)
-	SSL_CTX_set_alpn_select_cb(ctx, alpn_select_cb, NULL);
-#endif
 #else
 	(void)ctxt;
 #endif /* HAVE_SSL */
@@ -1285,7 +1320,10 @@ listen_sslctx_setup_2(void* ctxt)
 #endif /* HAVE_SSL */
 }
 
-void* listen_sslctx_create(char* key, char* pem, char* verifypem)
+void* listen_sslctx_create(const char* key, const char* pem,
+	const char* verifypem, const char* tls_ciphers,
+	const char* tls_ciphersuites, int set_ticket_keys_cb,
+	int is_dot, int is_doh)
 {
 #ifdef HAVE_SSL
 	SSL_CTX* ctx = SSL_CTX_new(SSLv23_server_method());
@@ -1336,11 +1374,50 @@ void* listen_sslctx_create(char* key, char* pem, char* verifypem)
 			verifypem));
 		SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER|SSL_VERIFY_FAIL_IF_NO_PEER_CERT, NULL);
 	}
+	if(tls_ciphers && tls_ciphers[0]) {
+		if (!SSL_CTX_set_cipher_list(ctx, tls_ciphers)) {
+			log_err("failed to set tls-cipher %s",
+				tls_ciphers);
+			log_crypto_err("Error in SSL_CTX_set_cipher_list");
+			SSL_CTX_free(ctx);
+			return NULL;
+		}
+	}
+#ifdef HAVE_SSL_CTX_SET_CIPHERSUITES
+	if(tls_ciphersuites && tls_ciphersuites[0]) {
+		if (!SSL_CTX_set_ciphersuites(ctx, tls_ciphersuites)) {
+			log_err("failed to set tls-ciphersuites %s",
+				tls_ciphersuites);
+			log_crypto_err("Error in SSL_CTX_set_ciphersuites");
+			SSL_CTX_free(ctx);
+			return NULL;
+		}
+	}
+#endif /* HAVE_SSL_CTX_SET_CIPHERSUITES */
+	if(set_ticket_keys_cb) {
+		if(!setup_ticket_keys_cb(ctx)) {
+			log_crypto_err("no support for TLS session ticket");
+			SSL_CTX_free(ctx);
+			return NULL;
+		}
+	}
+	/* setup ALPN */
+#if defined(HAVE_SSL_CTX_SET_ALPN_SELECT_CB)
+	if(is_dot) {
+		SSL_CTX_set_alpn_select_cb(ctx, dot_alpn_select_cb, NULL);
+	} else if(is_doh) {
+#if defined(HAVE_NGHTTP2)
+		SSL_CTX_set_alpn_select_cb(ctx, doh_alpn_select_cb, NULL);
+#endif
+	}
+#endif /* HAVE_SSL_CTX_SET_ALPN_SELECT_CB */
 	return ctx;
 #else
 	(void)key; (void)pem; (void)verifypem;
+	(void)tls_ciphers; (void)tls_ciphersuites;
+	(void)tls_session_ticket_keys;
 	return NULL;
-#endif
+#endif /* HAVE_SSL */
 }
 
 #ifdef USE_WINSOCK
@@ -1700,7 +1777,7 @@ void ub_openssl_lock_delete(void)
 #endif /* OPENSSL_THREADS */
 }
 
-int listen_sslctx_setup_ticket_keys(void* sslctx, struct config_strlist* tls_session_ticket_keys) {
+int listen_sslctx_setup_ticket_keys(struct config_strlist* tls_session_ticket_keys) {
 #ifdef HAVE_SSL
 	size_t s = 1;
 	struct config_strlist* p;
@@ -1746,24 +1823,11 @@ int listen_sslctx_setup_ticket_keys(void* sslctx, struct config_strlist* tls_ses
 	}
 	/* terminate array with NULL key name entry */
 	keys->key_name = NULL;
-#  ifdef HAVE_SSL_CTX_SET_TLSEXT_TICKET_KEY_EVP_CB
-	if(SSL_CTX_set_tlsext_ticket_key_evp_cb(sslctx, tls_session_ticket_key_cb) == 0) {
-		log_err("no support for TLS session ticket");
-		return 0;
-	}
-#  else
-	if(SSL_CTX_set_tlsext_ticket_key_cb(sslctx, tls_session_ticket_key_cb) == 0) {
-		log_err("no support for TLS session ticket");
-		return 0;
-	}
-#  endif
 	return 1;
 #else
-	(void)sslctx;
 	(void)tls_session_ticket_keys;
 	return 0;
 #endif
-
 }
 
 #ifdef HAVE_SSL
diff --git a/util/net_help.h b/util/net_help.h
