1 files changed, 17 insertions, 4 deletions

diff --git a/tools/idevicebackup2.c b/tools/idevicebackup2.c
index 8f094c8..a0e732d 100644
--- a/tools/idevicebackup2.c
+++ b/tools/idevicebackup2.c
@@ -1258,14 +1258,15 @@ static void print_usage(int argc, char **argv)
         printf("  list\t\tlist files of last completed backup in CSV format\n");
         printf("  unback\tunpack a completed backup in DIRECTORY/_unback_/\n");
         printf("  encryption on|off [PWD]\tenable or disable backup encryption\n");
-        printf("    NOTE: if password is omitted it will be requested interactively\n");
+        printf("    NOTE: password will be requested in interactive mode if omitted\n");
         printf("  changepw [OLD NEW]  change backup password on target device\n");
-        printf("    NOTE: if no passwords are given the change will be performed interactively.\n");
+        printf("    NOTE: passwords will be requested in interactive mode if omitted\n");
         printf("\n");
         printf("options:\n");
         printf("  -d, --debug\t\tenable communication debugging\n");
         printf("  -u, --udid UDID\ttarget specific device by its 40-digit device UDID\n");
         printf("  -s, --source UDID\tuse backup data from device specified by UDID\n");
+        printf("  -i, --interactive\trequest passwords interactively\n");
         printf("  -h, --help\t\tprints usage information\n");
         printf("\n");
 }
@@ -1282,6 +1283,7 @@ int main(int argc, char *argv[])
         int is_full_backup = 0;
         int result_code = -1;
         char* backup_directory = NULL;
+        int interactive_mode = 0;
         char* backup_password = NULL;
         char* newpw = NULL;
         struct stat st;
@@ -1322,6 +1324,10 @@ int main(int argc, char *argv[])
                         source_udid = strdup(argv[i]);
                         continue;
                 }
+                else if (!strcmp(argv[i], "-i") || !strcmp(argv[i], "--interactive")) {
+                        interactive_mode = 1;
+                        continue;
+                }
                 else if (!strcmp(argv[i], "-h") || !strcmp(argv[i], "--help")) {
                         print_usage(argc, argv);
                         return 0;
@@ -1484,7 +1490,12 @@ int main(int argc, char *argv[])
 
         uint8_t is_encrypted = 0;
         char *info_path = NULL; 
-        if (cmd != CMD_CHANGEPW) {
+        if (cmd == CMD_CHANGEPW) {
+                if (!interactive_mode && (!backup_password || !newpw)) {
+                        printf("ERROR: Can't get password input in non-interactive mode. Either pass password(s) on the command line, or enable interactive mode with -i or --interactive.\n");
+                        return -1;
+                }
+        } else {
                 /* backup directory must contain an Info.plist */
                 info_path = build_path(backup_directory, source_udid, "Info.plist", NULL);
                 if (cmd == CMD_RESTORE) {
@@ -1518,7 +1529,9 @@ int main(int argc, char *argv[])
         if (is_encrypted) {
                 PRINT_VERBOSE(1, "This is an encrypted backup.\n");
                 if (backup_password == NULL) {
-                        backup_password = ask_for_password("Enter backup password", 0);
+                        if (interactive_mode) {
+                                backup_password = ask_for_password("Enter backup password", 0);
+                        }
                         if (!backup_password || (strlen(backup_password) == 0)) {
                                 if (backup_password) {
                                         free(backup_password);