Add support to crypto/tls for client cert and CA cert from smartcard

src/crypto/tls.h

@@ -63,7 +63,10 @@ struct tls_config {
  * @engine_id: engine id string (this is OpenSSL specific for now)
  * @ppin: pointer to the pin variable in the configuration
  * (this is OpenSSL specific for now)
- * @key_id: the private key's key id (this is OpenSSL specific for now)
+ * @key_id: the private key's id when using engine (this is OpenSSL
+ * specific for now)
+ * @cert_id: the certificate's id when using engine
+ * @ca_cert_id: the CA certificate's id when using engine
  * @tls_ia: Whether to enable TLS/IA (for EAP-TTLSv1)
  *
  * TLS connection parameters to be configured with tls_connection_set_params()
@@ -98,6 +101,8 @@ struct tls_connection_params {
 	const char *engine_id;
 	const char *pin;
 	const char *key_id;
+	const char *cert_id;
+	const char *ca_cert_id;
 };
 
 

src/crypto/tls_openssl.c

@@ -777,7 +777,8 @@ void tls_deinit(void *ssl_ctx)
 
 
 static int tls_engine_init(struct tls_connection *conn, const char *engine_id,
-			   const char *pin, const char *key_id)
+			   const char *pin, const char *key_id,
+			   const char *cert_id, const char *ca_cert_id)
 {
 #ifndef OPENSSL_NO_ENGINE
 	int ret = -1;
@@ -814,6 +815,7 @@ static int tls_engine_init(struct tls_connection *conn, const char *engine_id,
 			   ERR_error_string(ERR_get_error(), NULL));
 		goto err;
 	}
+	/* load private key first in-case PIN is required for cert */
 	conn->private_key = ENGINE_load_private_key(conn->engine,
 						    key_id, NULL, NULL);
 	if (!conn->private_key) {
@@ -823,6 +825,21 @@ static int tls_engine_init(struct tls_connection *conn, const char *engine_id,
 		ret = TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED;
 		goto err;
 	}
+
+	/* handle a certificate and/or CA certificate */
+	if (cert_id || ca_cert_id) {
+		const char *cmd_name = "LOAD_CERT_CTRL";
+
+		/* test if the engine supports a LOAD_CERT_CTRL */
+		if (!ENGINE_ctrl(conn->engine, ENGINE_CTRL_GET_CMD_FROM_NAME,
+				 0, (void *)cmd_name, NULL)) {
+			wpa_printf(MSG_ERROR, "ENGINE: engine does not support"
+				   " loading certificates");
+			ret = TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED;
+			goto err;
+		}
+	}
+
 	return 0;
 
 err:
@@ -1495,6 +1512,112 @@ static int tls_read_pkcs12_blob(SSL_CTX *ssl_ctx, SSL *ssl,
 }
 
 
+static int tls_engine_get_cert(struct tls_connection *conn,
+			       const char *cert_id,
+			       X509 **cert)
+{
+#ifndef OPENSSL_NO_ENGINE
+	/* this runs after the private key is loaded so no PIN is required */
+	struct {
+		const char *cert_id;
+		X509 *cert;
+	} params;
+	params.cert_id = cert_id;
+	params.cert = NULL;
+
+	if (!ENGINE_ctrl_cmd(conn->engine, "LOAD_CERT_CTRL",
+			     0, &params, NULL, 1)) {
+		wpa_printf(MSG_ERROR, "ENGINE: cannot load client cert with id"
+			   " '%s' [%s]", cert_id,
+			   ERR_error_string(ERR_get_error(), NULL));
+		return TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED;
+	}
+	if (!params.cert) {
+		wpa_printf(MSG_ERROR, "ENGINE: did not properly cert with id"
+			   " '%s'", cert_id);
+		return TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED;
+	}
+	*cert = params.cert;
+	return 0;
+#else /* OPENSSL_NO_ENGINE */
+	return -1;
+#endif /* OPENSSL_NO_ENGINE */
+}
+
+
+static int tls_connection_engine_client_cert(struct tls_connection *conn,
+					     const char *cert_id)
+{
+#ifndef OPENSSL_NO_ENGINE
+	X509 *cert;
+
+	if (tls_engine_get_cert(conn, cert_id, &cert))
+		return -1;
+
+	if (!SSL_use_certificate(conn->ssl, cert)) {
+		tls_show_errors(MSG_ERROR, __func__,
+				"SSL_use_certificate failed");
+                X509_free(cert);
+		return -1;
+	}
+	X509_free(cert);
+	wpa_printf(MSG_DEBUG, "ENGINE: SSL_use_certificate --> "
+		   "OK");
+	return 0;
+
+#else /* OPENSSL_NO_ENGINE */
+	return -1;
+#endif /* OPENSSL_NO_ENGINE */
+}
+
+
+static int tls_connection_engine_ca_cert(void *_ssl_ctx,
+					 struct tls_connection *conn,
+					 const char *ca_cert_id)
+{
+#ifndef OPENSSL_NO_ENGINE
+	X509 *cert;
+	SSL_CTX *ssl_ctx = _ssl_ctx;
+
+	if (tls_engine_get_cert(conn, ca_cert_id, &cert))
+		return -1;
+
+	/* start off the same as tls_connection_ca_cert */
+	X509_STORE_free(ssl_ctx->cert_store);
+	ssl_ctx->cert_store = X509_STORE_new();
+	if (ssl_ctx->cert_store == NULL) {
+		wpa_printf(MSG_DEBUG, "OpenSSL: %s - failed to allocate new "
+			   "certificate store", __func__);
+		X509_free(cert);
+		return -1;
+	}
+	if (!X509_STORE_add_cert(ssl_ctx->cert_store, cert)) {
+		unsigned long err = ERR_peek_error();
+		tls_show_errors(MSG_WARNING, __func__,
+				"Failed to add CA certificate from engine "
+				"to certificate store");
+		if (ERR_GET_LIB(err) == ERR_LIB_X509 &&
+		    ERR_GET_REASON(err) == X509_R_CERT_ALREADY_IN_HASH_TABLE) {
+			wpa_printf(MSG_DEBUG, "OpenSSL: %s - ignoring cert"
+				   " already in hash table error",
+				   __func__);
+		} else {
+			X509_free(cert);
+			return -1;
+		}
+	}
+	X509_free(cert);
+	wpa_printf(MSG_DEBUG, "OpenSSL: %s - added CA certificate from engine "
+		   "to certificate store", __func__);
+	SSL_set_verify(conn->ssl, SSL_VERIFY_PEER, tls_verify_cb);
+	return 0;
+
+#else /* OPENSSL_NO_ENGINE */
+	return -1;
+#endif /* OPENSSL_NO_ENGINE */
+}
+
+
 static int tls_connection_engine_private_key(struct tls_connection *conn)
 {
 #ifndef OPENSSL_NO_ENGINE
@@ -2233,26 +2356,39 @@ int tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,
 			   __func__, ERR_error_string(err, NULL));
 	}
 
+	if (params->engine) {
+		wpa_printf(MSG_DEBUG, "SSL: Initializing TLS engine");
+		ret = tls_engine_init(conn, params->engine_id, params->pin,
+				      params->key_id, params->cert_id,
+				      params->ca_cert_id);
+		if (ret)
+			return ret;
+	}
 	if (tls_connection_set_subject_match(conn,
 					     params->subject_match,
 					     params->altsubject_match))
 		return -1;
-	if (tls_connection_ca_cert(tls_ctx, conn, params->ca_cert,
+
+	if (params->engine && params->ca_cert_id) {
+		if (tls_connection_engine_ca_cert(tls_ctx, conn,
+						  params->ca_cert_id))
+			return TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED;
+	} else if (tls_connection_ca_cert(tls_ctx, conn, params->ca_cert,
 					  params->ca_cert_blob,
 					  params->ca_cert_blob_len,
 					  params->ca_path))
 		return -1;
-	if (tls_connection_client_cert(conn, params->client_cert,
+
+	if (params->engine && params->cert_id) {
+		if (tls_connection_engine_client_cert(conn, params->cert_id))
+			return TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED;
+	} else if (tls_connection_client_cert(conn, params->client_cert,
 					      params->client_cert_blob,
 					      params->client_cert_blob_len))
 		return -1;
 
-	if (params->engine) {
+	if (params->engine && params->key_id) {
-		wpa_printf(MSG_DEBUG, "SSL: Initializing TLS engine");
+		wpa_printf(MSG_DEBUG, "TLS: Using private key from engine");
-		ret = tls_engine_init(conn, params->engine_id, params->pin,
-				      params->key_id);
-		if (ret)
-			return ret;
 		if (tls_connection_engine_private_key(conn))
 			return TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED;
 	} else if (tls_connection_private_key(tls_ctx, conn,