extern int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz);
extern int parse_sha1_header(const char *hdr, unsigned long *sizep);
-extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);
+extern int check_object_signature(const struct object_id *oid, void *buf, unsigned long size, const char *type);
extern int finalize_object_file(const char *tmpfile, const char *filename);