const char *outfile; /* Output filename */
const char *keydir; /* Directory holding private keys */
const char *keydest; /* Destination .dtb for public key */
+ const char *keyfile; /* Filename of private or public key */
const char *comment; /* Comment to add to signature node */
int require_keys; /* 1 to mark signing keys as 'required' */
int file_size; /* Total size of output file */