1 ;;; pgg-parse.el --- OpenPGP packet parsing
3 ;; Copyright (C) 1999, 2003 Free Software Foundation, Inc.
5 ;; Author: Daiki Ueno <ueno@unixuser.org>
7 ;; Keywords: PGP, OpenPGP, GnuPG
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software; you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation; either version 2, or (at your option)
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs; see the file COPYING. If not, write to the
23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24 ;; Boston, MA 02111-1307, USA.
28 ;; This module is based on
30 ;; [OpenPGP] RFC 2440: "OpenPGP Message Format"
31 ;; by John W. Noerenberg, II <jwn2@qualcomm.com>,
32 ;; Jon Callas <jon@pgp.com>, Lutz Donnerhacke <lutz@iks-jena.de>,
33 ;; Hal Finney <hal@pgp.com> and Rodney Thayer <rodney@unitran.com>
38 (eval-when-compile (require 'cl))
42 (defgroup pgg-parse ()
43 "OpenPGP packet parsing"
46 (defcustom pgg-parse-public-key-algorithm-alist
47 '((1 . RSA) (2 . RSA-E) (3 . RSA-S) (16 . ELG-E) (17 . DSA) (20 . ELG))
48 "Alist of the assigned number to the public key algorithm."
51 (cons (sexp :tag "Number") (sexp :tag "Type"))))
53 (defcustom pgg-parse-symmetric-key-algorithm-alist
54 '((1 . IDEA) (2 . 3DES) (4 . CAST5) (5 . SAFER-SK128))
55 "Alist of the assigned number to the simmetric key algorithm."
58 (cons (sexp :tag "Number") (sexp :tag "Type"))))
60 (defcustom pgg-parse-hash-algorithm-alist
61 '((1 . MD5) (2 . SHA1) (3 . RIPEMD160) (5 . MD2))
62 "Alist of the assigned number to the cryptographic hash algorithm."
65 (cons (sexp :tag "Number") (sexp :tag "Type"))))
67 (defcustom pgg-parse-compression-algorithm-alist
68 '((0 . nil); Uncompressed
71 "Alist of the assigned number to the compression algorithm."
74 (cons (sexp :tag "Number") (sexp :tag "Type"))))
76 (defcustom pgg-parse-signature-type-alist
77 '((0 . "Signature of a binary document")
78 (1 . "Signature of a canonical text document")
79 (2 . "Standalone signature")
80 (16 . "Generic certification of a User ID and Public Key packet")
81 (17 . "Persona certification of a User ID and Public Key packet")
82 (18 . "Casual certification of a User ID and Public Key packet")
83 (19 . "Positive certification of a User ID and Public Key packet")
84 (24 . "Subkey Binding Signature")
85 (31 . "Signature directly on a key")
86 (32 . "Key revocation signature")
87 (40 . "Subkey revocation signature")
88 (48 . "Certification revocation signature")
89 (64 . "Timestamp signature."))
90 "Alist of the assigned number to the signature type."
93 (cons (sexp :tag "Number") (sexp :tag "Type"))))
95 (defcustom pgg-ignore-packet-checksum t; XXX
96 "If non-nil checksum of each ascii armored packet will be ignored."
100 (defvar pgg-armor-header-lines
101 '("^-----BEGIN PGP MESSAGE\\(, PART [0-9]+\\(/[0-9]+\\)?\\)?-----\r?$"
102 "^-----BEGIN PGP PUBLIC KEY BLOCK-----\r?$"
103 "^-----BEGIN PGP PRIVATE KEY BLOCK-----\r?$"
104 "^-----BEGIN PGP SIGNATURE-----\r?$")
108 (defalias 'pgg-char-int (if (fboundp 'char-int)
112 (defmacro pgg-format-key-identifier (string)
113 `(mapconcat (lambda (c) (format "%02X" (pgg-char-int c)))
115 ;; `(upcase (apply #'format "%02x%02x%02x%02x%02x%02x%02x%02x"
116 ;; (string-to-int-list ,string)))
119 (defmacro pgg-parse-time-field (bytes)
120 `(list (logior (lsh (car ,bytes) 8)
122 (logior (lsh (nth 2 ,bytes) 8)
126 (defmacro pgg-byte-after (&optional pos)
127 `(pgg-char-int (char-after ,(or pos `(point)))))
129 (defmacro pgg-read-byte ()
130 `(pgg-char-int (char-after (prog1 (point) (forward-char)))))
132 (defmacro pgg-read-bytes-string (nbytes)
134 (point) (prog1 (+ ,nbytes (point))
135 (forward-char ,nbytes))))
137 (defmacro pgg-read-bytes (nbytes)
138 `(mapcar #'pgg-char-int (pgg-read-bytes-string ,nbytes))
139 ;; `(string-to-int-list (pgg-read-bytes-string ,nbytes))
142 (defmacro pgg-read-body-string (ptag)
144 (pgg-read-bytes-string (nth 1 ,ptag))
145 (pgg-read-bytes-string (- (point-max) (point)))))
147 (defmacro pgg-read-body (ptag)
148 `(mapcar #'pgg-char-int (pgg-read-body-string ,ptag))
149 ;; `(string-to-int-list (pgg-read-body-string ,ptag))
152 (defalias 'pgg-skip-bytes 'forward-char)
154 (defmacro pgg-skip-header (ptag)
155 `(pgg-skip-bytes (nth 2 ,ptag)))
157 (defmacro pgg-skip-body (ptag)
158 `(pgg-skip-bytes (nth 1 ,ptag)))
160 (defmacro pgg-set-alist (alist key value)
161 `(setq ,alist (nconc ,alist (list (cons ,key ,value)))))
163 (when (fboundp 'define-ccl-program)
165 (define-ccl-program pgg-parse-crc24
168 (read r0) (r1 ^= r0) (r2 ^= 0)
172 (r1 += ((r2 >> 15) & 1))
175 ((r1 ^= 390) (r2 ^= 19707)))
181 (defun pgg-parse-crc24-string (string)
182 (let ((h (vector nil 183 1230 nil nil nil nil nil nil)))
183 (ccl-execute-on-string pgg-parse-crc24 h string)
185 (logand (aref h 1) 255)
186 (logand (lsh (aref h 2) -8) 255)
187 (logand (aref h 2) 255)))))
189 (defmacro pgg-parse-length-type (c)
191 ((< ,c 192) (cons ,c 1))
193 (cons (+ (lsh (- ,c 192) 8)
194 (pgg-byte-after (+ 2 (point)))
198 (cons (cons (logior (lsh (pgg-byte-after (+ 2 (point))) 8)
199 (pgg-byte-after (+ 3 (point))))
200 (logior (lsh (pgg-byte-after (+ 4 (point))) 8)
201 (pgg-byte-after (+ 5 (point)))))
203 (t;partial body length
206 (defun pgg-parse-packet-header ()
207 (let ((ptag (pgg-byte-after))
208 length-type content-tag packet-bytes header-bytes)
209 (if (zerop (logand 64 ptag));Old format
211 (setq length-type (logand ptag 3)
212 length-type (if (= 3 length-type) 0 (lsh 1 length-type))
213 content-tag (logand 15 (lsh ptag -2))
215 header-bytes (1+ length-type))
216 (dotimes (i length-type)
218 (logior (lsh packet-bytes 8)
219 (pgg-byte-after (+ 1 i (point)))))))
220 (setq content-tag (logand 63 ptag)
221 length-type (pgg-parse-length-type
222 (pgg-byte-after (1+ (point))))
223 packet-bytes (car length-type)
224 header-bytes (1+ (cdr length-type))))
225 (list content-tag packet-bytes header-bytes)))
227 (defun pgg-parse-packet (ptag)
229 (1 ;Public-Key Encrypted Session Key Packet
230 (pgg-parse-public-key-encrypted-session-key-packet ptag))
232 (pgg-parse-signature-packet ptag))
233 (3 ;Symmetric-Key Encrypted Session Key Packet
234 (pgg-parse-symmetric-key-encrypted-session-key-packet ptag))
235 ;; 4 -- One-Pass Signature Packet
236 ;; 5 -- Secret Key Packet
237 (6 ;Public Key Packet
238 (pgg-parse-public-key-packet ptag))
239 ;; 7 -- Secret Subkey Packet
240 ;; 8 -- Compressed Data Packet
241 (9 ;Symmetrically Encrypted Data Packet
242 (pgg-read-body-string ptag))
244 (pgg-read-body-string ptag))
245 (11 ;Literal Data Packet
246 (pgg-read-body-string ptag))
247 ;; 12 -- Trust Packet
249 (pgg-read-body-string ptag))
250 ;; 14 -- Public Subkey Packet
251 ;; 60 .. 63 -- Private or Experimental Values
254 (defun pgg-parse-packets (&optional header-parser body-parser)
257 (function pgg-parse-packet-header)))
260 (function pgg-parse-packet)))
262 (while (> (point-max) (1+ (point)))
263 (setq ptag (funcall header-parser))
264 (pgg-skip-header ptag)
265 (push (cons (car ptag)
267 (funcall body-parser ptag)))
269 (if (zerop (nth 1 ptag))
270 (goto-char (point-max))
271 (forward-char (nth 1 ptag))))
274 (defun pgg-parse-signature-subpacket-header ()
275 (let ((length-type (pgg-parse-length-type (pgg-byte-after))))
276 (list (pgg-byte-after (+ (cdr length-type) (point)))
277 (1- (car length-type))
278 (1+ (cdr length-type)))))
280 (defun pgg-parse-signature-subpacket (ptag)
282 (2 ;signature creation time
284 (let ((bytes (pgg-read-bytes 4)))
285 (pgg-parse-time-field bytes))))
286 (3 ;signature expiration time
287 (cons 'signature-expiry
288 (let ((bytes (pgg-read-bytes 4)))
289 (pgg-parse-time-field bytes))))
290 (4 ;exportable certification
291 (cons 'exportability (pgg-read-byte)))
293 (cons 'trust-level (pgg-read-byte)))
294 (6 ;regular expression
295 (cons 'regular-expression
296 (pgg-read-body-string ptag)))
298 (cons 'revocability (pgg-read-byte)))
299 (9 ;key expiration time
301 (let ((bytes (pgg-read-bytes 4)))
302 (pgg-parse-time-field bytes))))
303 ;; 10 = placeholder for backward compatibility
304 (11 ;preferred symmetric algorithms
305 (cons 'preferred-symmetric-key-algorithm
306 (cdr (assq (pgg-read-byte)
307 pgg-parse-symmetric-key-algorithm-alist))))
311 (cons 'key-identifier
312 (pgg-format-key-identifier (pgg-read-body-string ptag))))
316 (let ((name-bytes (pgg-read-bytes 2))
317 (value-bytes (pgg-read-bytes 2)))
318 (cons (pgg-read-bytes-string
319 (logior (lsh (car name-bytes) 8)
321 (pgg-read-bytes-string
322 (logior (lsh (car value-bytes) 8)
323 (nth 1 value-bytes)))))))
324 (21 ;preferred hash algorithms
325 (cons 'preferred-hash-algorithm
326 (cdr (assq (pgg-read-byte)
327 pgg-parse-hash-algorithm-alist))))
328 (22 ;preferred compression algorithms
329 (cons 'preferred-compression-algorithm
330 (cdr (assq (pgg-read-byte)
331 pgg-parse-compression-algorithm-alist))))
332 (23 ;key server preferences
333 (cons 'key-server-preferences
334 (pgg-read-body ptag)))
335 (24 ;preferred key server
336 (cons 'preferred-key-server
337 (pgg-read-body-string ptag)))
338 ;; 25 = primary user id
340 (cons 'policy-url (pgg-read-body-string ptag)))
342 ;; 28 = signer's user id
343 ;; 29 = reason for revocation
344 ;; 100 to 110 = internal or user-defined
347 (defun pgg-parse-signature-packet (ptag)
348 (let* ((signature-version (pgg-byte-after))
349 (result (list (cons 'version signature-version)))
350 hashed-material field n)
352 ((= signature-version 3)
354 (setq hashed-material (pgg-read-bytes 5))
355 (pgg-set-alist result
357 (cdr (assq (pop hashed-material)
358 pgg-parse-signature-type-alist)))
359 (pgg-set-alist result
361 (pgg-parse-time-field hashed-material))
362 (pgg-set-alist result
364 (pgg-format-key-identifier
365 (pgg-read-bytes-string 8)))
366 (pgg-set-alist result
367 'public-key-algorithm (pgg-read-byte))
368 (pgg-set-alist result
369 'hash-algorithm (pgg-read-byte)))
370 ((= signature-version 4)
372 (pgg-set-alist result
374 (cdr (assq (pgg-read-byte)
375 pgg-parse-signature-type-alist)))
376 (pgg-set-alist result
377 'public-key-algorithm
379 (pgg-set-alist result
380 'hash-algorithm (pgg-read-byte))
381 (when (>= 10000 (setq n (pgg-read-bytes 2)
382 n (logior (lsh (car n) 8)
385 (narrow-to-region (point)(+ n (point)))
387 (mapcar (function cdr) ;remove packet types
389 #'pgg-parse-signature-subpacket-header
390 #'pgg-parse-signature-subpacket)))
391 (goto-char (point-max))))
392 (when (>= 10000 (setq n (pgg-read-bytes 2)
393 n (logior (lsh (car n) 8)
396 (narrow-to-region (point)(+ n (point)))
398 (mapcar (function cdr) ;remove packet types
400 #'pgg-parse-signature-subpacket-header
401 #'pgg-parse-signature-subpacket)))))))
403 (setcdr (setq field (assq 'public-key-algorithm
405 (cdr (assq (cdr field)
406 pgg-parse-public-key-algorithm-alist)))
407 (setcdr (setq field (assq 'hash-algorithm
409 (cdr (assq (cdr field)
410 pgg-parse-hash-algorithm-alist)))
413 (defun pgg-parse-public-key-encrypted-session-key-packet (ptag)
415 (pgg-set-alist result
416 'version (pgg-read-byte))
417 (pgg-set-alist result
419 (pgg-format-key-identifier
420 (pgg-read-bytes-string 8)))
421 (pgg-set-alist result
422 'public-key-algorithm
423 (cdr (assq (pgg-read-byte)
424 pgg-parse-public-key-algorithm-alist)))
427 (defun pgg-parse-symmetric-key-encrypted-session-key-packet (ptag)
429 (pgg-set-alist result
432 (pgg-set-alist result
433 'symmetric-key-algorithm
434 (cdr (assq (pgg-read-byte)
435 pgg-parse-symmetric-key-algorithm-alist)))
438 (defun pgg-parse-public-key-packet (ptag)
439 (let* ((key-version (pgg-read-byte))
440 (result (list (cons 'version key-version)))
444 (pgg-set-alist result
446 (let ((bytes (pgg-read-bytes 4)))
447 (pgg-parse-time-field bytes)))
448 (pgg-set-alist result
449 'key-expiry (pgg-read-bytes 2))
450 (pgg-set-alist result
451 'public-key-algorithm (pgg-read-byte)))
453 (pgg-set-alist result
455 (let ((bytes (pgg-read-bytes 4)))
456 (pgg-parse-time-field bytes)))
457 (pgg-set-alist result
458 'public-key-algorithm (pgg-read-byte))))
460 (setcdr (setq field (assq 'public-key-algorithm
462 (cdr (assq (cdr field)
463 pgg-parse-public-key-algorithm-alist)))
466 (defun pgg-decode-packets ()
468 (set-marker (make-marker)
469 (and (re-search-forward "^=")
470 (match-beginning 0))))
471 (checksum (buffer-substring (point) (+ 4 (point)))))
472 (delete-region marker (point-max))
473 (base64-decode-region (point-min) marker)
474 (when (fboundp 'pgg-parse-crc24-string)
475 (or pgg-ignore-packet-checksum
477 (base64-encode-string (pgg-parse-crc24-string
480 (error "PGP packet checksum does not match")))))
482 (defun pgg-decode-armor-region (start end)
484 (narrow-to-region start end)
485 (goto-char (point-min))
486 (re-search-forward "^-+BEGIN PGP" nil t)
487 (delete-region (point-min)
488 (and (search-forward "\n\n")
491 (goto-char (point-min))
492 (pgg-parse-packets)))
494 (defun pgg-parse-armor (string)
496 (buffer-disable-undo)
497 (if (fboundp 'set-buffer-multibyte)
498 (set-buffer-multibyte nil))
500 (pgg-decode-armor-region (point-min)(point))))
503 (defalias 'pgg-string-as-unibyte (if (fboundp 'string-as-unibyte)
507 (defun pgg-parse-armor-region (start end)
508 (pgg-parse-armor (pgg-string-as-unibyte (buffer-substring start end))))
512 ;;; pgg-parse.el ends here