* parse-packet.c (parse_key): Support a SHA1 checksum as per

draft-rfc2440-bis04.
* packet.h (PKT_secret_key): Add field sha1chk.
* seckey-cert.c (do_check): Check the SHA1 checksum
(protect_secret_key): And create it.
* build-packet.c (do_secret_key): Mark it as sha-1 protected.
* g10.c, options.h: New option --simple-sk-checksum.

g10/packet.h

@@ -232,6 +232,7 @@ typedef struct {
 			/* and should never be passed to a mpi_xxx() */
     struct {
 	byte algo;  /* cipher used to protect the secret information*/
+        byte sha1chk;  /* SHA1 is used instead of a 16 bit checksum */ 
 	STRING2KEY s2k;
 	byte ivlen;  /* used length of the iv */
 	byte iv[16]; /* initialization vector for CFB mode */