1 ;;; pgg-parse.el --- OpenPGP packet parsing
3 ;; Copyright (C) 1999, 2002, 2003, 2004, 2005 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., 51 Franklin Street, Fifth Floor,
24 ;; Boston, MA 02110-1301, 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) (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 (defun pgg-parse-crc24-string (string)
183 (let ((h (vector nil 183 1230 nil nil nil nil nil nil)))
184 (ccl-execute-on-string pgg-parse-crc24 h string)
186 (logand (aref h 1) 255)
187 (logand (lsh (aref h 2) -8) 255)
188 (logand (aref h 2) 255)))))
190 (defmacro pgg-parse-length-type (c)
192 ((< ,c 192) (cons ,c 1))
194 (cons (+ (lsh (- ,c 192) 8)
195 (pgg-byte-after (+ 2 (point)))
199 (cons (cons (logior (lsh (pgg-byte-after (+ 2 (point))) 8)
200 (pgg-byte-after (+ 3 (point))))
201 (logior (lsh (pgg-byte-after (+ 4 (point))) 8)
202 (pgg-byte-after (+ 5 (point)))))
204 (t;partial body length
207 (defun pgg-parse-packet-header ()
208 (let ((ptag (pgg-byte-after))
209 length-type content-tag packet-bytes header-bytes)
210 (if (zerop (logand 64 ptag));Old format
212 (setq length-type (logand ptag 3)
213 length-type (if (= 3 length-type) 0 (lsh 1 length-type))
214 content-tag (logand 15 (lsh ptag -2))
216 header-bytes (1+ length-type))
217 (dotimes (i length-type)
219 (logior (lsh packet-bytes 8)
220 (pgg-byte-after (+ 1 i (point)))))))
221 (setq content-tag (logand 63 ptag)
222 length-type (pgg-parse-length-type
223 (pgg-byte-after (1+ (point))))
224 packet-bytes (car length-type)
225 header-bytes (1+ (cdr length-type))))
226 (list content-tag packet-bytes header-bytes)))
228 (defun pgg-parse-packet (ptag)
230 (1 ;Public-Key Encrypted Session Key Packet
231 (pgg-parse-public-key-encrypted-session-key-packet ptag))
233 (pgg-parse-signature-packet ptag))
234 (3 ;Symmetric-Key Encrypted Session Key Packet
235 (pgg-parse-symmetric-key-encrypted-session-key-packet ptag))
236 ;; 4 -- One-Pass Signature Packet
237 ;; 5 -- Secret Key Packet
238 (6 ;Public Key Packet
239 (pgg-parse-public-key-packet ptag))
240 ;; 7 -- Secret Subkey Packet
241 ;; 8 -- Compressed Data Packet
242 (9 ;Symmetrically Encrypted Data Packet
243 (pgg-read-body-string ptag))
245 (pgg-read-body-string ptag))
246 (11 ;Literal Data Packet
247 (pgg-read-body-string ptag))
248 ;; 12 -- Trust Packet
250 (pgg-read-body-string ptag))
251 ;; 14 -- Public Subkey Packet
252 ;; 60 .. 63 -- Private or Experimental Values
255 (defun pgg-parse-packets (&optional header-parser body-parser)
258 (function pgg-parse-packet-header)))
261 (function pgg-parse-packet)))
263 (while (> (point-max) (1+ (point)))
264 (setq ptag (funcall header-parser))
265 (pgg-skip-header ptag)
266 (push (cons (car ptag)
268 (funcall body-parser ptag)))
270 (if (zerop (nth 1 ptag))
271 (goto-char (point-max))
272 (forward-char (nth 1 ptag))))
275 (defun pgg-parse-signature-subpacket-header ()
276 (let ((length-type (pgg-parse-length-type (pgg-byte-after))))
277 (list (pgg-byte-after (+ (cdr length-type) (point)))
278 (1- (car length-type))
279 (1+ (cdr length-type)))))
281 (defun pgg-parse-signature-subpacket (ptag)
283 (2 ;signature creation time
285 (let ((bytes (pgg-read-bytes 4)))
286 (pgg-parse-time-field bytes))))
287 (3 ;signature expiration time
288 (cons 'signature-expiry
289 (let ((bytes (pgg-read-bytes 4)))
290 (pgg-parse-time-field bytes))))
291 (4 ;exportable certification
292 (cons 'exportability (pgg-read-byte)))
294 (cons 'trust-level (pgg-read-byte)))
295 (6 ;regular expression
296 (cons 'regular-expression
297 (pgg-read-body-string ptag)))
299 (cons 'revocability (pgg-read-byte)))
300 (9 ;key expiration time
302 (let ((bytes (pgg-read-bytes 4)))
303 (pgg-parse-time-field bytes))))
304 ;; 10 = placeholder for backward compatibility
305 (11 ;preferred symmetric algorithms
306 (cons 'preferred-symmetric-key-algorithm
307 (cdr (assq (pgg-read-byte)
308 pgg-parse-symmetric-key-algorithm-alist))))
312 (cons 'key-identifier
313 (pgg-format-key-identifier (pgg-read-body-string ptag))))
317 (let ((name-bytes (pgg-read-bytes 2))
318 (value-bytes (pgg-read-bytes 2)))
319 (cons (pgg-read-bytes-string
320 (logior (lsh (car name-bytes) 8)
322 (pgg-read-bytes-string
323 (logior (lsh (car value-bytes) 8)
324 (nth 1 value-bytes)))))))
325 (21 ;preferred hash algorithms
326 (cons 'preferred-hash-algorithm
327 (cdr (assq (pgg-read-byte)
328 pgg-parse-hash-algorithm-alist))))
329 (22 ;preferred compression algorithms
330 (cons 'preferred-compression-algorithm
331 (cdr (assq (pgg-read-byte)
332 pgg-parse-compression-algorithm-alist))))
333 (23 ;key server preferences
334 (cons 'key-server-preferences
335 (pgg-read-body ptag)))
336 (24 ;preferred key server
337 (cons 'preferred-key-server
338 (pgg-read-body-string ptag)))
339 ;; 25 = primary user id
341 (cons 'policy-url (pgg-read-body-string ptag)))
343 ;; 28 = signer's user id
344 ;; 29 = reason for revocation
345 ;; 100 to 110 = internal or user-defined
348 (defun pgg-parse-signature-packet (ptag)
349 (let* ((signature-version (pgg-byte-after))
350 (result (list (cons 'version signature-version)))
351 hashed-material field n)
353 ((= signature-version 3)
355 (setq hashed-material (pgg-read-bytes 5))
356 (pgg-set-alist result
358 (cdr (assq (pop hashed-material)
359 pgg-parse-signature-type-alist)))
360 (pgg-set-alist result
362 (pgg-parse-time-field hashed-material))
363 (pgg-set-alist result
365 (pgg-format-key-identifier
366 (pgg-read-bytes-string 8)))
367 (pgg-set-alist result
368 'public-key-algorithm (pgg-read-byte))
369 (pgg-set-alist result
370 'hash-algorithm (pgg-read-byte)))
371 ((= signature-version 4)
373 (pgg-set-alist result
375 (cdr (assq (pgg-read-byte)
376 pgg-parse-signature-type-alist)))
377 (pgg-set-alist result
378 'public-key-algorithm
380 (pgg-set-alist result
381 'hash-algorithm (pgg-read-byte))
382 (when (>= 10000 (setq n (pgg-read-bytes 2)
383 n (logior (lsh (car n) 8)
386 (narrow-to-region (point)(+ n (point)))
388 (mapcar (function cdr) ;remove packet types
390 #'pgg-parse-signature-subpacket-header
391 #'pgg-parse-signature-subpacket)))
392 (goto-char (point-max))))
393 (when (>= 10000 (setq n (pgg-read-bytes 2)
394 n (logior (lsh (car n) 8)
397 (narrow-to-region (point)(+ n (point)))
399 (mapcar (function cdr) ;remove packet types
401 #'pgg-parse-signature-subpacket-header
402 #'pgg-parse-signature-subpacket)))))))
404 (setcdr (setq field (assq 'public-key-algorithm
406 (cdr (assq (cdr field)
407 pgg-parse-public-key-algorithm-alist)))
408 (setcdr (setq field (assq 'hash-algorithm
410 (cdr (assq (cdr field)
411 pgg-parse-hash-algorithm-alist)))
414 (defun pgg-parse-public-key-encrypted-session-key-packet (ptag)
416 (pgg-set-alist result
417 'version (pgg-read-byte))
418 (pgg-set-alist result
420 (pgg-format-key-identifier
421 (pgg-read-bytes-string 8)))
422 (pgg-set-alist result
423 'public-key-algorithm
424 (cdr (assq (pgg-read-byte)
425 pgg-parse-public-key-algorithm-alist)))
428 (defun pgg-parse-symmetric-key-encrypted-session-key-packet (ptag)
430 (pgg-set-alist result
433 (pgg-set-alist result
434 'symmetric-key-algorithm
435 (cdr (assq (pgg-read-byte)
436 pgg-parse-symmetric-key-algorithm-alist)))
439 (defun pgg-parse-public-key-packet (ptag)
440 (let* ((key-version (pgg-read-byte))
441 (result (list (cons 'version key-version)))
445 (pgg-set-alist result
447 (let ((bytes (pgg-read-bytes 4)))
448 (pgg-parse-time-field bytes)))
449 (pgg-set-alist result
450 'key-expiry (pgg-read-bytes 2))
451 (pgg-set-alist result
452 'public-key-algorithm (pgg-read-byte)))
454 (pgg-set-alist result
456 (let ((bytes (pgg-read-bytes 4)))
457 (pgg-parse-time-field bytes)))
458 (pgg-set-alist result
459 'public-key-algorithm (pgg-read-byte))))
461 (setcdr (setq field (assq 'public-key-algorithm
463 (cdr (assq (cdr field)
464 pgg-parse-public-key-algorithm-alist)))
467 (defun pgg-decode-packets ()
468 (if (re-search-forward "^=\\([A-Za-z0-9+/]\\{4\\}\\)$" nil t)
469 (let ((p (match-beginning 0))
470 (checksum (match-string 1)))
471 (delete-region p (point-max))
472 (if (ignore-errors (base64-decode-region (point-min) p))
473 (or (not (fboundp 'pgg-parse-crc24-string))
474 pgg-ignore-packet-checksum
475 (string-equal (base64-encode-string (pgg-parse-crc24-string
479 (message "PGP packet checksum does not match")
481 (message "PGP packet contain invalid base64")
483 (message "PGP packet checksum not found")
486 (defun pgg-decode-armor-region (start end)
488 (narrow-to-region start end)
489 (goto-char (point-min))
490 (re-search-forward "^-+BEGIN PGP" nil t)
491 (delete-region (point-min)
492 (and (search-forward "\n\n")
494 (when (pgg-decode-packets)
495 (goto-char (point-min))
496 (pgg-parse-packets))))
498 (defun pgg-parse-armor (string)
500 (buffer-disable-undo)
501 (if (fboundp 'set-buffer-multibyte)
502 (set-buffer-multibyte nil))
504 (pgg-decode-armor-region (point-min)(point))))
507 (defalias 'pgg-string-as-unibyte (if (fboundp 'string-as-unibyte)
511 (defun pgg-parse-armor-region (start end)
512 (pgg-parse-armor (pgg-string-as-unibyte (buffer-substring start end))))
516 ;;; arch-tag: 16c2eb82-1313-4a7c-a70f-420709b5b43e
517 ;;; pgg-parse.el ends here