--- /dev/null
+;;; hmac-def.el --- A macro for defining HMAC functions.
+
+;; Copyright (C) 1999, 2001, 2007 Free Software Foundation, Inc.
+
+;; Author: Shuhei KOBAYASHI <shuhei@aqua.ocn.ne.jp>
+;; Keywords: HMAC, RFC 2104
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; 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., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
+
+;;; Commentary:
+
+;; This program is implemented from RFC 2104,
+;; "HMAC: Keyed-Hashing for Message Authentication".
+
+;;; Code:
+
+(defmacro define-hmac-function (name H B L &optional bit)
+ "Define a function NAME(TEXT KEY) which computes HMAC with function H.
+
+HMAC function is H(KEY XOR opad, H(KEY XOR ipad, TEXT)):
+
+H is a cryptographic hash function, such as SHA1 and MD5, which takes
+a string and return a digest of it (in binary form).
+B is a byte-length of a block size of H. (B=64 for both SHA1 and MD5.)
+L is a byte-length of hash outputs. (L=16 for MD5, L=20 for SHA1.)
+If BIT is non-nil, truncate output to specified bits."
+ `(defun ,name (text key)
+ ,(concat "Compute "
+ (upcase (symbol-name name))
+ " over TEXT with KEY.")
+ (let ((key-xor-ipad (make-string ,B ?\x36))
+ (key-xor-opad (make-string ,B ?\x5C))
+ (len (length key))
+ (pos 0))
+ (unwind-protect
+ (progn
+ ;; if `key' is longer than the block size, apply hash function
+ ;; to `key' and use the result as a real `key'.
+ (if (> len ,B)
+ (setq key (,H key)
+ len ,L))
+ (while (< pos len)
+ (aset key-xor-ipad pos (logxor (aref key pos) ?\x36))
+ (aset key-xor-opad pos (logxor (aref key pos) ?\x5C))
+ (setq pos (1+ pos)))
+ (setq key-xor-ipad (unwind-protect
+ (concat key-xor-ipad text)
+ (fillarray key-xor-ipad 0))
+ key-xor-ipad (unwind-protect
+ (,H key-xor-ipad)
+ (fillarray key-xor-ipad 0))
+ key-xor-opad (unwind-protect
+ (concat key-xor-opad key-xor-ipad)
+ (fillarray key-xor-opad 0))
+ key-xor-opad (unwind-protect
+ (,H key-xor-opad)
+ (fillarray key-xor-opad 0)))
+ ;; now `key-xor-opad' contains
+ ;; H(KEY XOR opad, H(KEY XOR ipad, TEXT)).
+ ,(if (and bit (< (/ bit 8) L))
+ `(substring key-xor-opad 0 ,(/ bit 8))
+ ;; return a copy of `key-xor-opad'.
+ `(concat key-xor-opad)))
+ ;; cleanup.
+ (fillarray key-xor-ipad 0)
+ (fillarray key-xor-opad 0)))))
+
+(provide 'hmac-def)
+
+;;; arch-tag: 645adcef-b835-4900-a10a-11f636c982b9
+;;; hmac-def.el ends here
--- /dev/null
+;;; hmac-md5.el --- Compute HMAC-MD5.
+
+;; Copyright (C) 1999, 2001, 2007 Free Software Foundation, Inc.
+
+;; Author: Shuhei KOBAYASHI <shuhei@aqua.ocn.ne.jp>
+;; Keywords: HMAC, RFC 2104, HMAC-MD5, MD5, KEYED-MD5, CRAM-MD5
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; 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., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
+
+;;; Commentary:
+
+;; Test cases from RFC 2202, "Test Cases for HMAC-MD5 and HMAC-SHA-1".
+;;
+;; (encode-hex-string (hmac-md5 "Hi There" (make-string 16 ?\x0b)))
+;; => "9294727a3638bb1c13f48ef8158bfc9d"
+;;
+;; (encode-hex-string (hmac-md5 "what do ya want for nothing?" "Jefe"))
+;; => "750c783e6ab0b503eaa86e310a5db738"
+;;
+;; (encode-hex-string (hmac-md5 (make-string 50 ?\xdd) (make-string 16 ?\xaa)))
+;; => "56be34521d144c88dbb8c733f0e8b3f6"
+;;
+;; (encode-hex-string
+;; (hmac-md5
+;; (make-string 50 ?\xcd)
+;; (decode-hex-string "0102030405060708090a0b0c0d0e0f10111213141516171819")))
+;; => "697eaf0aca3a3aea3a75164746ffaa79"
+;;
+;; (encode-hex-string
+;; (hmac-md5 "Test With Truncation" (make-string 16 ?\x0c)))
+;; => "56461ef2342edc00f9bab995690efd4c"
+;;
+;; (encode-hex-string
+;; (hmac-md5-96 "Test With Truncation" (make-string 16 ?\x0c)))
+;; => "56461ef2342edc00f9bab995"
+;;
+;; (encode-hex-string
+;; (hmac-md5
+;; "Test Using Larger Than Block-Size Key - Hash Key First"
+;; (make-string 80 ?\xaa)))
+;; => "6b1ab7fe4bd7bf8f0b62e6ce61b9d0cd"
+;;
+;; (encode-hex-string
+;; (hmac-md5
+;; "Test Using Larger Than Block-Size Key and Larger Than One Block-Size Data"
+;; (make-string 80 ?\xaa)))
+;; => "6f630fad67cda0ee1fb1f562db3aa53e"
+
+;;; Code:
+
+(eval-when-compile (require 'hmac-def))
+(require 'hex-util) ; (decode-hex-string STRING)
+(require 'md5) ; expects (md5 STRING)
+
+(defun md5-binary (string)
+ "Return the MD5 of STRING in binary form."
+ (if (condition-case nil
+ ;; `md5' of v21 takes 4th arg CODING (and 5th arg NOERROR).
+ (md5 "" nil nil 'binary) ; => "d41d8cd98f00b204e9800998ecf8427e"
+ (wrong-number-of-arguments nil))
+ (decode-hex-string (md5 string nil nil 'binary))
+ (decode-hex-string (md5 string))))
+
+(define-hmac-function hmac-md5 md5-binary 64 16) ; => (hmac-md5 TEXT KEY)
+(define-hmac-function hmac-md5-96 md5-binary 64 16 96)
+
+(provide 'hmac-md5)
+
+;;; arch-tag: 0ab3f4f6-3d4b-4167-a9fa-635b7fed7f27
+;;; hmac-md5.el ends here