fix digest selection for safari and add option to allow unsafe digest

Author: Retropex

src/datum_api.c

@@ -417,36 +417,38 @@ bool datum_api_check_admin_password_only(struct MHD_Connection * const connectio
 	return false;
 }
 
-static enum MHD_DigestAuthAlgorithm datum_api_pick_digest_algo(struct MHD_Connection * const connection, const bool nonce_is_stale) {
+static enum MHD_DigestAuthAlgorithm datum_api_pick_digest_algo(struct MHD_Connection * const connection) {
 	const char * const ua = MHD_lookup_connection_value(connection, MHD_HEADER_KIND, "User-Agent");
-	if (strstr(ua, "AppleWebKit/") && !(strstr(ua, "Chrome/") || strstr(ua, "Brave/") || strstr(ua, "Edge/"))) {
-		static bool safari_warned = false;
-		if (!(nonce_is_stale && safari_warned)) {
-			DLOG_WARN("Detected login request from Apple Safari. For some reason, this browser only supports obsolete and insecure MD5 digest authentication. Login at your own risk!");
-			safari_warned = true;
+	if (datum_config.api_allow_insecure_auth) {
+		if (strstr(ua, "AppleWebKit/") && !(strstr(ua, "Chrome/") || strstr(ua, "Brave/") || strstr(ua, "Edge/"))) {
+			return MHD_DIGEST_ALG_MD5;
 		}
-		return MHD_DIGEST_ALG_MD5;
 	}
 	return MHD_DIGEST_ALG_SHA256;
 }
 
 bool datum_api_check_admin_password_httponly(struct MHD_Connection * const connection, const create_response_func_t auth_failure_response_creator) {
 	int ret;
+	static bool safari_warned = false;
 
 	char * const username = MHD_digest_auth_get_username(connection);
+	const enum MHD_DigestAuthAlgorithm algo = datum_api_pick_digest_algo(connection);
 	const char * const realm = "DATUM Gateway";
 	if (username) {
-		ret = MHD_digest_auth_check2(connection, realm, username, datum_config.api_admin_password, 300, MHD_DIGEST_ALG_AUTO);
+		ret = MHD_digest_auth_check2(connection, realm, username, datum_config.api_admin_password, 300, algo);
 		free(username);
 	} else {
 		ret = MHD_NO;
 	}
+	if (algo == MHD_DIGEST_ALG_MD5 && ret == MHD_NO && !safari_warned) {
+		DLOG_WARN("Detected login request from Apple Safari. For some reason, this browser only supports obsolete and insecure MD5 digest authentication. Login at your own risk!");
+		safari_warned = true;
+	}
 	if (ret != MHD_YES) {
 		const bool nonce_is_stale = (ret == MHD_INVALID_NONCE);
 		if (username && !nonce_is_stale) {
 			DLOG_DEBUG("Wrong password in HTTP authentication");
 		}
-		const enum MHD_DigestAuthAlgorithm algo = datum_api_pick_digest_algo(connection, nonce_is_stale);
 		struct MHD_Response * const response = auth_failure_response_creator();
 		ret = MHD_queue_auth_fail_response2(connection, realm, datum_config.api_csrf_token, response, nonce_is_stale ? MHD_YES : MHD_NO, algo);
 		MHD_destroy_response(response);

src/datum_conf.c

@@ -108,6 +108,8 @@ const T_DATUM_CONFIG_ITEM datum_config_options[] = {
 		.required = false, .ptr = datum_config.api_admin_password,						.default_string[0] = "", .max_string_len = sizeof(datum_config.api_admin_password) },
 	{ .var_type = DATUM_CONF_INT, 		.category = "api",	 		.name = "listen_port",				.description = "Port to listen for API/dashboard requests (0=disabled)",
 		.required = false, .ptr = &datum_config.api_listen_port, 						.default_int = 0 },
+	{ .var_type = DATUM_CONF_BOOL, 		.category = "api", 			.name = "allow_insecure_auth",		.description = "Allow insecure authentication (required for Safari)",
+		.required = false, .ptr = &datum_config.api_allow_insecure_auth,				.default_bool = false },
 
 	// extra block submissions list
 	{ .var_type = DATUM_CONF_STRING_ARRAY, 	.category = "extra_block_submissions", 	.name = "urls",		.description = "Array of bitcoind RPC URLs to submit our blocks to directly.  Include auth info: http://user:pass@IP",

src/datum_conf.h

@@ -98,6 +98,7 @@ typedef struct {
 	size_t api_admin_password_len;
 	char api_csrf_token[65];
 	int api_listen_port;
+	bool api_allow_insecure_auth;
 
 	int extra_block_submissions_count;
 	char extra_block_submissions_urls[DATUM_MAX_BLOCK_SUBMITS][DATUM_CONFIG_MAX_STRING_ARRAY_LEN];