Make PGP macros global

This commit moves the macros PGP_SIGNATURE and PGP_MESSAGE to gpg-interface.h to
make them publicly reachable, which is necessary for RFC3161 time-stamping.

When verifying an RFC3161 time-stamp signature, a SHA-1 hash has to be generated
over the git object excluding a possible PGP signature, which makes it necessary
to detect the beginning of this PGP signature.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>

gpg-interface.c

@@ -7,9 +7,6 @@
 static char *configured_signing_key;
 static const char *gpg_program = "gpg";
 
-#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
-#define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
-
 void signature_check_clear(struct signature_check *sigc)
 {
 	free(sigc->payload);

gpg-interface.h

@@ -4,6 +4,9 @@
 #define GPG_VERIFY_VERBOSE	1
 #define GPG_VERIFY_RAW		2
 
+#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
+#define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
+
 struct signature_check {
 	char *payload;
 	char *gpg_output;