gpg-interface: do not hardcode the key string len anymore

gnupg does print the keyid followed by a space and the signer comes
next. The same pattern is also used in gpgsm, but there the key length
would be 40 instead of 16. Instead of hardcoding the expected length,
find the first space and calculate it.
Input that does not match the expected format will be ignored now,
before we jumped to found+17 which might have been behind the end of an
unexpected string.

Signed-off-by: Henning Schild <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: henning-schild

gpg-interface.c

@@ -89,10 +89,11 @@ static void parse_gpg_output(struct signature_check *sigc)
 		sigc->result = sigcheck_gpg_status[i].result;
 		/* The trust messages are not followed by key/signer information */
 		if (sigc->result != 'U') {
-			sigc->key = xmemdupz(found, 16);
+			next = strchrnul(found, ' ');
+			sigc->key = xmemdupz(found, next - found);
 			/* The ERRSIG message is not followed by signer information */
-			if (sigc-> result != 'E') {
-				found += 17;
+			if (*next && sigc-> result != 'E') {
+				found = next + 1;
 				next = strchrnul(found, '\n');
 				sigc->signer = xmemdupz(found, next - found);
 			}