auth-worker: Fix potential crash when importing passdb/userdb fields …

…without value.

These were being converted to NULL values in auth-worker, while elsewhere they were
converted to "". Changed to "" here as well and added asserts to make sure they
won't happen again.

Most of the NULL values would have been fine, but overriding any IP/port
fields would have caused a crash when trying to parse the value.

src/auth/auth-request.c

@@ -356,6 +356,8 @@ void auth_request_export(struct auth_request *request, string_t *dest)
 bool auth_request_import_info(struct auth_request *request,
 			      const char *key, const char *value)
 {
+	i_assert(value != NULL);
+
 	/* authentication and user lookups may set these */
 	if (strcmp(key, "service") == 0)
 		request->service = p_strdup(request->pool, value);
@@ -399,6 +401,8 @@ bool auth_request_import_info(struct auth_request *request,
 bool auth_request_import_auth(struct auth_request *request,
 			      const char *key, const char *value)
 {
+	i_assert(value != NULL);
+
 	if (auth_request_import_info(request, key, value))
 		return TRUE;
 
@@ -429,6 +433,8 @@ bool auth_request_import_master(struct auth_request *request,
 {
 	pid_t pid;
 
+	i_assert(value != NULL);
+
 	/* master request lookups may set these */
 	if (strcmp(key, "session_pid") == 0) {
 		if (str_to_pid(value, &pid) == 0)
@@ -443,6 +449,8 @@ bool auth_request_import_master(struct auth_request *request,
 bool auth_request_import(struct auth_request *request,
 			 const char *key, const char *value)
 {
+	i_assert(value != NULL);
+
 	if (auth_request_import_auth(request, key, value))
 		return TRUE;
 

src/auth/auth-worker-client.c

@@ -92,7 +92,7 @@ worker_auth_request_new(struct auth_worker_client *client, unsigned int id,
 	for (; *args != NULL; args++) {
 		value = strchr(*args, '=');
 		if (value == NULL)
-			(void)auth_request_import(auth_request, *args, NULL);
+			(void)auth_request_import(auth_request, *args, "");
 		else {
 			key = t_strdup_until(*args, value++);
 			(void)auth_request_import(auth_request, key, value);