;;; rfc2104.el --- RFC2104 Hashed Message Authentication Codes
-;; Copyright (C) 1998,1999 Free Software Foundation, Inc.
+;; Copyright (C) 1998,1999 Free Software Foundation, Inc.
;; Author: Simon Josefsson <email@example.com>
;;; (rfc2104-hash 'md5 64 16 "Jefe" "what do ya want for nothing?")
+;;; (rfc2104-hash 'sha1-encode 64 20 "Jefe" "what do ya want for nothing?")
;;; 64 is block length of hash function (64 for MD5 and SHA), 16 is
;;; resulting hash length (16 for MD5, 20 for SHA).
;;; Tested with Emacs 20.2 and XEmacs 20.3.
+;;; Test case reference: RFC 2202.
;;; 1998-08-26 don't require hexl
;;; 1998-09-25 renamed from hmac.el to rfc2104.el, also renamed functions
;;; 1999-10-23 included in pgnus
+;;; 2000-08-15 `rfc2104-hexstring-to-bitstring'
+;;; 2000-05-12 added sha-1 example, added test case reference
(eval-when-compile (require 'cl))
(rfc2104-hex-to-int (reverse (append str nil))))
+(defun rfc2104-hexstring-to-bitstring (str)
+ (while (< 0 (length str))
+ (push (rfc2104-hex-to-int (substring str -2)) out)
+ (setq str (substring str 0 -2)))
(defun rfc2104-hash (hash block-length hash-length key text)
(let* (;; if key is longer than B, reset it to HASH(key)
(key (if (> (length key) block-length)
;; XOR key with ipad/opad into k_ipad/k_opad
(setq k_ipad (mapcar (lambda (c) (logxor c rfc2104-ipad)) k_ipad))
(setq k_opad (mapcar (lambda (c) (logxor c rfc2104-opad)) k_opad))
- (let ((first-round (funcall hash (concat k_ipad text)))
- (while (< 0 (length first-round))
- (push (rfc2104-hex-to-int (substring first-round -2)) de-hexed)
- (setq first-round (substring first-round 0 -2)))
- (funcall hash (concat k_opad de-hexed)))))
+ (funcall hash (concat k_opad (rfc2104-hexstring-to-bitstring
+ (funcall hash (concat k_ipad text)))))))