;;; rfc2104.el --- RFC2104 Hashed Message Authentication Codes
-;; Copyright (C) 1998,1999 Free Software Foundation, Inc.
+
+;; Copyright (C) 1998, 1999, 2000, 2002, 2003, 2004,
+;; 2005 Free Software Foundation, Inc.
;; Author: Simon Josefsson <jas@pdc.kth.se>
;; Keywords: mail
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
;;; (rfc2104-hash 'md5 64 16 "Jefe" "what do ya want for nothing?")
;;; "750c783e6ab0b503eaa86e310a5db738"
;;;
+;;; (require 'sha-1)
+;;; (rfc2104-hash 'sha1-encode 64 20 "Jefe" "what do ya want for nothing?")
+;;; "effcdf6ae5eb2fa2d27416d5f184df9c259a7c79"
+;;;
;;; 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.
;;; Release history:
;;;
;;; 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
+
+;;; Code:
+
(eval-when-compile (require 'cl))
;; Magic character for inner HMAC round. 0x36 == 54 == '6'
(defconst rfc2104-zero ?\x00)
;; Alist for converting hex to decimal.
-(defconst rfc2104-hex-alist
+(defconst rfc2104-hex-alist
'((?0 . 0) (?a . 10) (?A . 10)
(?1 . 1) (?b . 11) (?B . 11)
(?2 . 2) (?c . 12) (?C . 12)
(rfc2104-hex-to-int (reverse (append str nil))))
0))
+(defun rfc2104-hexstring-to-bitstring (str)
+ (let (out)
+ (while (< 0 (length str))
+ (push (rfc2104-hex-to-int (substring str -2)) out)
+ (setq str (substring str 0 -2)))
+ (concat out)))
+
(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)
+ (key (if (> (length key) block-length)
(funcall hash key) key))
(k_ipad (append key nil))
(k_opad (append key nil)))
;; 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))
- ;; perform inner hash
- (let ((first-round (funcall hash (concat k_ipad text)))
- de-hexed)
- (while (< 0 (length first-round))
- (push (rfc2104-hex-to-int (substring first-round -2)) de-hexed)
- (setq first-round (substring first-round 0 -2)))
- ;; perform outer hash
- (funcall hash (concat k_opad de-hexed)))))
+ ;; perform outer hash
+ (funcall hash (concat k_opad (rfc2104-hexstring-to-bitstring
+ ;; perform inner hash
+ (funcall hash (concat k_ipad text)))))))
(provide 'rfc2104)