1 ;;; pgg-parse.el --- OpenPGP packet parsing
3 ;; Copyright (C) 1999, 2002, 2003, 2004, 2005,
4 ;; 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
6 ;; Author: Daiki Ueno <ueno@unixuser.org>
8 ;; Keywords: PGP, OpenPGP, GnuPG
11 ;; This file is part of GNU Emacs.
13 ;; GNU Emacs is free software: you can redistribute it and/or modify
14 ;; it under the terms of the GNU General Public License as published by
15 ;; the Free Software Foundation, either version 3 of the License, or
16 ;; (at your option) any later version.
18 ;; GNU Emacs is distributed in the hope that it will be useful,
19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 ;; GNU General Public License for more details.
23 ;; You should have received a copy of the GNU General Public License
24 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
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>
39 (unless (fboundp 'declare-function) (defmacro declare-function (&rest r)))
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) (8 . SHA256) (9 . SHA384)
63 "Alist of the assigned number to the cryptographic hash algorithm."
66 (cons (sexp :tag "Number") (sexp :tag "Type"))))
68 (defcustom pgg-parse-compression-algorithm-alist
69 '((0 . nil); Uncompressed
72 "Alist of the assigned number to the compression algorithm."
75 (cons (sexp :tag "Number") (sexp :tag "Type"))))
77 (defcustom pgg-parse-signature-type-alist
78 '((0 . "Signature of a binary document")
79 (1 . "Signature of a canonical text document")
80 (2 . "Standalone signature")
81 (16 . "Generic certification of a User ID and Public Key packet")
82 (17 . "Persona certification of a User ID and Public Key packet")
83 (18 . "Casual certification of a User ID and Public Key packet")
84 (19 . "Positive certification of a User ID and Public Key packet")
85 (24 . "Subkey Binding Signature")
86 (31 . "Signature directly on a key")
87 (32 . "Key revocation signature")
88 (40 . "Subkey revocation signature")
89 (48 . "Certification revocation signature")
90 (64 . "Timestamp signature."))
91 "Alist of the assigned number to the signature type."
94 (cons (sexp :tag "Number") (sexp :tag "Type"))))
96 (defcustom pgg-ignore-packet-checksum t; XXX
97 "If non-nil checksum of each ascii armored packet will be ignored."
101 (defvar pgg-armor-header-lines
102 '("^-----BEGIN PGP MESSAGE\\(, PART [0-9]+\\(/[0-9]+\\)?\\)?-----\r?$"
103 "^-----BEGIN PGP PUBLIC KEY BLOCK-----\r?$"
104 "^-----BEGIN PGP PRIVATE KEY BLOCK-----\r?$"
105 "^-----BEGIN PGP SIGNATURE-----\r?$")
109 (defalias 'pgg-char-int (if (fboundp 'char-int)
113 (defmacro pgg-format-key-identifier (string)
114 `(mapconcat (lambda (c) (format "%02X" (pgg-char-int c)))
116 ;; `(upcase (apply #'format "%02x%02x%02x%02x%02x%02x%02x%02x"
117 ;; (string-to-number-list ,string)))
120 (defmacro pgg-parse-time-field (bytes)
121 `(list (logior (lsh (car ,bytes) 8)
123 (logior (lsh (nth 2 ,bytes) 8)
127 (defmacro pgg-byte-after (&optional pos)
128 `(pgg-char-int (char-after ,(or pos `(point)))))
130 (defmacro pgg-read-byte ()
131 `(pgg-char-int (char-after (prog1 (point) (forward-char)))))
133 (defmacro pgg-read-bytes-string (nbytes)
135 (point) (prog1 (+ ,nbytes (point))
136 (forward-char ,nbytes))))
138 (defmacro pgg-read-bytes (nbytes)
139 `(mapcar #'pgg-char-int (pgg-read-bytes-string ,nbytes))
140 ;; `(string-to-number-list (pgg-read-bytes-string ,nbytes))
143 (defmacro pgg-read-body-string (ptag)
145 (pgg-read-bytes-string (nth 1 ,ptag))
146 (pgg-read-bytes-string (- (point-max) (point)))))
148 (defmacro pgg-read-body (ptag)
149 `(mapcar #'pgg-char-int (pgg-read-body-string ,ptag))
150 ;; `(string-to-number-list (pgg-read-body-string ,ptag))
153 (defalias 'pgg-skip-bytes 'forward-char)
155 (defmacro pgg-skip-header (ptag)
156 `(pgg-skip-bytes (nth 2 ,ptag)))
158 (defmacro pgg-skip-body (ptag)
159 `(pgg-skip-bytes (nth 1 ,ptag)))
161 (defmacro pgg-set-alist (alist key value)
162 `(setq ,alist (nconc ,alist (list (cons ,key ,value)))))
164 (when (fboundp 'define-ccl-program)
166 (define-ccl-program pgg-parse-crc24
169 (read r0) (r1 ^= r0) (r2 ^= 0)
173 (r1 += ((r2 >> 15) & 1))
176 ((r1 ^= 390) (r2 ^= 19707)))
182 (defvar pgg-parse-crc24)
184 (defun pgg-parse-crc24-string (string)
185 (let ((h (vector nil 183 1230 nil nil nil nil nil nil)))
186 (ccl-execute-on-string pgg-parse-crc24 h string)
188 (logand (aref h 1) 255)
189 (logand (lsh (aref h 2) -8) 255)
190 (logand (aref h 2) 255)))))
192 (defmacro pgg-parse-length-type (c)
194 ((< ,c 192) (cons ,c 1))
196 (cons (+ (lsh (- ,c 192) 8)
197 (pgg-byte-after (+ 2 (point)))
201 (cons (cons (logior (lsh (pgg-byte-after (+ 2 (point))) 8)
202 (pgg-byte-after (+ 3 (point))))
203 (logior (lsh (pgg-byte-after (+ 4 (point))) 8)
204 (pgg-byte-after (+ 5 (point)))))
206 (t;partial body length
209 (defun pgg-parse-packet-header ()
210 (let ((ptag (pgg-byte-after))
211 length-type content-tag packet-bytes header-bytes)
212 (if (zerop (logand 64 ptag));Old format
214 (setq length-type (logand ptag 3)
215 length-type (if (= 3 length-type) 0 (lsh 1 length-type))
216 content-tag (logand 15 (lsh ptag -2))
218 header-bytes (1+ length-type))
219 (dotimes (i length-type)
221 (logior (lsh packet-bytes 8)
222 (pgg-byte-after (+ 1 i (point)))))))
223 (setq content-tag (logand 63 ptag)
224 length-type (pgg-parse-length-type
225 (pgg-byte-after (1+ (point))))
226 packet-bytes (car length-type)
227 header-bytes (1+ (cdr length-type))))
228 (list content-tag packet-bytes header-bytes)))
230 (defun pgg-parse-packet (ptag)
232 (1 ;Public-Key Encrypted Session Key Packet
233 (pgg-parse-public-key-encrypted-session-key-packet ptag))
235 (pgg-parse-signature-packet ptag))
236 (3 ;Symmetric-Key Encrypted Session Key Packet
237 (pgg-parse-symmetric-key-encrypted-session-key-packet ptag))
238 ;; 4 -- One-Pass Signature Packet
239 ;; 5 -- Secret Key Packet
240 (6 ;Public Key Packet
241 (pgg-parse-public-key-packet ptag))
242 ;; 7 -- Secret Subkey Packet
243 ;; 8 -- Compressed Data Packet
244 (9 ;Symmetrically Encrypted Data Packet
245 (pgg-read-body-string ptag))
247 (pgg-read-body-string ptag))
248 (11 ;Literal Data Packet
249 (pgg-read-body-string ptag))
250 ;; 12 -- Trust Packet
252 (pgg-read-body-string ptag))
253 ;; 14 -- Public Subkey Packet
254 ;; 60 .. 63 -- Private or Experimental Values
257 (defun pgg-parse-packets (&optional header-parser body-parser)
260 (function pgg-parse-packet-header)))
263 (function pgg-parse-packet)))
265 (while (> (point-max) (1+ (point)))
266 (setq ptag (funcall header-parser))
267 (pgg-skip-header ptag)
268 (push (cons (car ptag)
270 (funcall body-parser ptag)))
272 (if (zerop (nth 1 ptag))
273 (goto-char (point-max))
274 (forward-char (nth 1 ptag))))
277 (defun pgg-parse-signature-subpacket-header ()
278 (let ((length-type (pgg-parse-length-type (pgg-byte-after))))
279 (list (pgg-byte-after (+ (cdr length-type) (point)))
280 (1- (car length-type))
281 (1+ (cdr length-type)))))
283 (defun pgg-parse-signature-subpacket (ptag)
285 (2 ;signature creation time
287 (let ((bytes (pgg-read-bytes 4)))
288 (pgg-parse-time-field bytes))))
289 (3 ;signature expiration time
290 (cons 'signature-expiry
291 (let ((bytes (pgg-read-bytes 4)))
292 (pgg-parse-time-field bytes))))
293 (4 ;exportable certification
294 (cons 'exportability (pgg-read-byte)))
296 (cons 'trust-level (pgg-read-byte)))
297 (6 ;regular expression
298 (cons 'regular-expression
299 (pgg-read-body-string ptag)))
301 (cons 'revocability (pgg-read-byte)))
302 (9 ;key expiration time
304 (let ((bytes (pgg-read-bytes 4)))
305 (pgg-parse-time-field bytes))))
306 ;; 10 = placeholder for backward compatibility
307 (11 ;preferred symmetric algorithms
308 (cons 'preferred-symmetric-key-algorithm
309 (cdr (assq (pgg-read-byte)
310 pgg-parse-symmetric-key-algorithm-alist))))
314 (cons 'key-identifier
315 (pgg-format-key-identifier (pgg-read-body-string ptag))))
319 (let ((name-bytes (pgg-read-bytes 2))
320 (value-bytes (pgg-read-bytes 2)))
321 (cons (pgg-read-bytes-string
322 (logior (lsh (car name-bytes) 8)
324 (pgg-read-bytes-string
325 (logior (lsh (car value-bytes) 8)
326 (nth 1 value-bytes)))))))
327 (21 ;preferred hash algorithms
328 (cons 'preferred-hash-algorithm
329 (cdr (assq (pgg-read-byte)
330 pgg-parse-hash-algorithm-alist))))
331 (22 ;preferred compression algorithms
332 (cons 'preferred-compression-algorithm
333 (cdr (assq (pgg-read-byte)
334 pgg-parse-compression-algorithm-alist))))
335 (23 ;key server preferences
336 (cons 'key-server-preferences
337 (pgg-read-body ptag)))
338 (24 ;preferred key server
339 (cons 'preferred-key-server
340 (pgg-read-body-string ptag)))
341 ;; 25 = primary user id
343 (cons 'policy-url (pgg-read-body-string ptag)))
345 ;; 28 = signer's user id
346 ;; 29 = reason for revocation
347 ;; 100 to 110 = internal or user-defined
350 (defun pgg-parse-signature-packet (ptag)
351 (let* ((signature-version (pgg-byte-after))
352 (result (list (cons 'version signature-version)))
353 hashed-material field n)
355 ((= signature-version 3)
357 (setq hashed-material (pgg-read-bytes 5))
358 (pgg-set-alist result
360 (cdr (assq (pop hashed-material)
361 pgg-parse-signature-type-alist)))
362 (pgg-set-alist result
364 (pgg-parse-time-field hashed-material))
365 (pgg-set-alist result
367 (pgg-format-key-identifier
368 (pgg-read-bytes-string 8)))
369 (pgg-set-alist result
370 'public-key-algorithm (pgg-read-byte))
371 (pgg-set-alist result
372 'hash-algorithm (pgg-read-byte)))
373 ((= signature-version 4)
375 (pgg-set-alist result
377 (cdr (assq (pgg-read-byte)
378 pgg-parse-signature-type-alist)))
379 (pgg-set-alist result
380 'public-key-algorithm
382 (pgg-set-alist result
383 'hash-algorithm (pgg-read-byte))
384 (when (>= 10000 (setq n (pgg-read-bytes 2)
385 n (logior (lsh (car n) 8)
388 (narrow-to-region (point)(+ n (point)))
390 (mapcar (function cdr) ;remove packet types
392 #'pgg-parse-signature-subpacket-header
393 #'pgg-parse-signature-subpacket)))
394 (goto-char (point-max))))
395 (when (>= 10000 (setq n (pgg-read-bytes 2)
396 n (logior (lsh (car n) 8)
399 (narrow-to-region (point)(+ n (point)))
401 (mapcar (function cdr) ;remove packet types
403 #'pgg-parse-signature-subpacket-header
404 #'pgg-parse-signature-subpacket)))))))
406 (setcdr (setq field (assq 'public-key-algorithm
408 (cdr (assq (cdr field)
409 pgg-parse-public-key-algorithm-alist)))
410 (setcdr (setq field (assq 'hash-algorithm
412 (cdr (assq (cdr field)
413 pgg-parse-hash-algorithm-alist)))
416 (defun pgg-parse-public-key-encrypted-session-key-packet (ptag)
418 (pgg-set-alist result
419 'version (pgg-read-byte))
420 (pgg-set-alist result
422 (pgg-format-key-identifier
423 (pgg-read-bytes-string 8)))
424 (pgg-set-alist result
425 'public-key-algorithm
426 (cdr (assq (pgg-read-byte)
427 pgg-parse-public-key-algorithm-alist)))
430 (defun pgg-parse-symmetric-key-encrypted-session-key-packet (ptag)
432 (pgg-set-alist result
435 (pgg-set-alist result
436 'symmetric-key-algorithm
437 (cdr (assq (pgg-read-byte)
438 pgg-parse-symmetric-key-algorithm-alist)))
441 (defun pgg-parse-public-key-packet (ptag)
442 (let* ((key-version (pgg-read-byte))
443 (result (list (cons 'version key-version)))
447 (pgg-set-alist result
449 (let ((bytes (pgg-read-bytes 4)))
450 (pgg-parse-time-field bytes)))
451 (pgg-set-alist result
452 'key-expiry (pgg-read-bytes 2))
453 (pgg-set-alist result
454 'public-key-algorithm (pgg-read-byte)))
456 (pgg-set-alist result
458 (let ((bytes (pgg-read-bytes 4)))
459 (pgg-parse-time-field bytes)))
460 (pgg-set-alist result
461 'public-key-algorithm (pgg-read-byte))))
463 (setcdr (setq field (assq 'public-key-algorithm
465 (cdr (assq (cdr field)
466 pgg-parse-public-key-algorithm-alist)))
469 ;; p-d-p only calls this if it is defined, but the compiler does not
471 (declare-function pgg-parse-crc24-string "pgg-parse" (string))
473 (defun pgg-decode-packets ()
474 (if (re-search-forward "^=\\([A-Za-z0-9+/]\\{4\\}\\)$" nil t)
475 (let ((p (match-beginning 0))
476 (checksum (match-string 1)))
477 (delete-region p (point-max))
478 (if (ignore-errors (base64-decode-region (point-min) p))
479 (or (not (fboundp 'pgg-parse-crc24-string))
480 pgg-ignore-packet-checksum
481 (string-equal (base64-encode-string (pgg-parse-crc24-string
485 (message "PGP packet checksum does not match")
487 (message "PGP packet contain invalid base64")
489 (message "PGP packet checksum not found")
492 (defun pgg-decode-armor-region (start end)
494 (narrow-to-region start end)
495 (goto-char (point-min))
496 (re-search-forward "^-+BEGIN PGP" nil t)
497 (delete-region (point-min)
498 (and (search-forward "\n\n")
500 (when (pgg-decode-packets)
501 (goto-char (point-min))
502 (pgg-parse-packets))))
504 (defun pgg-parse-armor (string)
506 (buffer-disable-undo)
507 (unless (featurep 'xemacs)
508 (set-buffer-multibyte nil))
510 (pgg-decode-armor-region (point-min)(point))))
513 (defalias 'pgg-string-as-unibyte (if (fboundp 'string-as-unibyte)
517 (defun pgg-parse-armor-region (start end)
518 (pgg-parse-armor (pgg-string-as-unibyte (buffer-substring start end))))
522 ;;; pgg-parse.el ends here