-extern struct sha1file *sha1create(const char *fmt, ...);
-extern int sha1close(struct sha1file *);
+extern struct sha1file *sha1fd(int fd, const char *name);
+extern struct sha1file *sha1create(const char *fmt, ...) __attribute__((format (printf, 1, 2)));
+extern int sha1close(struct sha1file *, unsigned char *, int);