1 ;;; pgg-parse.el --- OpenPGP packet parsing
3 ;; Copyright (C) 1999, 2002-2011 Free Software Foundation, Inc.
5 ;; Author: Daiki Ueno <ueno@unixuser.org>
7 ;; Keywords: PGP, OpenPGP, GnuPG
9 ;; Obsolete-since: 24.1
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 ;; For Emacs <22.2 and XEmacs.
40 (unless (fboundp 'declare-function) (defmacro declare-function (&rest r)))
43 (defgroup pgg-parse ()
44 "OpenPGP packet parsing."
47 (defcustom pgg-parse-public-key-algorithm-alist
48 '((1 . RSA) (2 . RSA-E) (3 . RSA-S) (16 . ELG-E) (17 . DSA) (20 . ELG))
49 "Alist of the assigned number to the public key algorithm."
52 (cons (sexp :tag "Number") (sexp :tag "Type"))))
54 (defcustom pgg-parse-symmetric-key-algorithm-alist
55 '((1 . IDEA) (2 . 3DES) (4 . CAST5) (5 . SAFER-SK128))
56 "Alist of the assigned number to the simmetric key algorithm."
59 (cons (sexp :tag "Number") (sexp :tag "Type"))))
61 (defcustom pgg-parse-hash-algorithm-alist
62 '((1 . MD5) (2 . SHA1) (3 . RIPEMD160) (5 . MD2) (8 . SHA256) (9 . SHA384)
64 "Alist of the assigned number to the cryptographic hash algorithm."
67 (cons (sexp :tag "Number") (sexp :tag "Type"))))
69 (defcustom pgg-parse-compression-algorithm-alist
70 '((0 . nil); Uncompressed
73 "Alist of the assigned number to the compression algorithm."
76 (cons (sexp :tag "Number") (sexp :tag "Type"))))
78 (defcustom pgg-parse-signature-type-alist
79 '((0 . "Signature of a binary document")
80 (1 . "Signature of a canonical text document")
81 (2 . "Standalone signature")
82 (16 . "Generic certification of a User ID and Public Key packet")
83 (17 . "Persona certification of a User ID and Public Key packet")
84 (18 . "Casual certification of a User ID and Public Key packet")
85 (19 . "Positive certification of a User ID and Public Key packet")
86 (24 . "Subkey Binding Signature")
87 (31 . "Signature directly on a key")
88 (32 . "Key revocation signature")
89 (40 . "Subkey revocation signature")
90 (48 . "Certification revocation signature")
91 (64 . "Timestamp signature."))
92 "Alist of the assigned number to the signature type."
95 (cons (sexp :tag "Number") (sexp :tag "Type"))))
97 (defcustom pgg-ignore-packet-checksum t; XXX
98 "If non-nil checksum of each ascii armored packet will be ignored."
102 (defvar pgg-armor-header-lines
103 '("^-----BEGIN PGP MESSAGE\\(, PART [0-9]+\\(/[0-9]+\\)?\\)?-----\r?$"
104 "^-----BEGIN PGP PUBLIC KEY BLOCK-----\r?$"
105 "^-----BEGIN PGP PRIVATE KEY BLOCK-----\r?$"
106 "^-----BEGIN PGP SIGNATURE-----\r?$")
110 (defalias 'pgg-char-int (if (fboundp 'char-int)
114 (defmacro pgg-format-key-identifier (string)
115 `(mapconcat (lambda (c) (format "%02X" (pgg-char-int c)))
117 ;; `(upcase (apply #'format "%02x%02x%02x%02x%02x%02x%02x%02x"
118 ;; (string-to-number-list ,string)))
121 (defmacro pgg-parse-time-field (bytes)
122 `(list (logior (lsh (car ,bytes) 8)
124 (logior (lsh (nth 2 ,bytes) 8)
128 (defmacro pgg-byte-after (&optional pos)
129 `(pgg-char-int (char-after ,(or pos `(point)))))
131 (defmacro pgg-read-byte ()
132 `(pgg-char-int (char-after (prog1 (point) (forward-char)))))
134 (defmacro pgg-read-bytes-string (nbytes)
136 (point) (prog1 (+ ,nbytes (point))
137 (forward-char ,nbytes))))
139 (defmacro pgg-read-bytes (nbytes)
140 `(mapcar #'pgg-char-int (pgg-read-bytes-string ,nbytes))
141 ;; `(string-to-number-list (pgg-read-bytes-string ,nbytes))
144 (defmacro pgg-read-body-string (ptag)
146 (pgg-read-bytes-string (nth 1 ,ptag))
147 (pgg-read-bytes-string (- (point-max) (point)))))
149 (defmacro pgg-read-body (ptag)
150 `(mapcar #'pgg-char-int (pgg-read-body-string ,ptag))
151 ;; `(string-to-number-list (pgg-read-body-string ,ptag))
154 (defalias 'pgg-skip-bytes 'forward-char)
156 (defmacro pgg-skip-header (ptag)
157 `(pgg-skip-bytes (nth 2 ,ptag)))
159 (defmacro pgg-skip-body (ptag)
160 `(pgg-skip-bytes (nth 1 ,ptag)))
162 (defmacro pgg-set-alist (alist key value)
163 `(setq ,alist (nconc ,alist (list (cons ,key ,value)))))
165 (when (fboundp 'define-ccl-program)
167 (define-ccl-program pgg-parse-crc24
170 (read r0) (r1 ^= r0) (r2 ^= 0)
174 (r1 += ((r2 >> 15) & 1))
177 ((r1 ^= 390) (r2 ^= 19707)))
183 (defvar pgg-parse-crc24)
185 (defun pgg-parse-crc24-string (string)
186 (let ((h (vector nil 183 1230 nil nil nil nil nil nil)))
187 (ccl-execute-on-string pgg-parse-crc24 h string)
189 (logand (aref h 1) 255)
190 (logand (lsh (aref h 2) -8) 255)
191 (logand (aref h 2) 255)))))
193 (defmacro pgg-parse-length-type (c)
195 ((< ,c 192) (cons ,c 1))
197 (cons (+ (lsh (- ,c 192) 8)
198 (pgg-byte-after (+ 2 (point)))
202 (cons (cons (logior (lsh (pgg-byte-after (+ 2 (point))) 8)
203 (pgg-byte-after (+ 3 (point))))
204 (logior (lsh (pgg-byte-after (+ 4 (point))) 8)
205 (pgg-byte-after (+ 5 (point)))))
207 (t;partial body length
210 (defun pgg-parse-packet-header ()
211 (let ((ptag (pgg-byte-after))
212 length-type content-tag packet-bytes header-bytes)
213 (if (zerop (logand 64 ptag));Old format
215 (setq length-type (logand ptag 3)
216 length-type (if (= 3 length-type) 0 (lsh 1 length-type))
217 content-tag (logand 15 (lsh ptag -2))
219 header-bytes (1+ length-type))
220 (dotimes (i length-type)
222 (logior (lsh packet-bytes 8)
223 (pgg-byte-after (+ 1 i (point)))))))
224 (setq content-tag (logand 63 ptag)
225 length-type (pgg-parse-length-type
226 (pgg-byte-after (1+ (point))))
227 packet-bytes (car length-type)
228 header-bytes (1+ (cdr length-type))))
229 (list content-tag packet-bytes header-bytes)))
231 (defun pgg-parse-packet (ptag)
233 (1 ;Public-Key Encrypted Session Key Packet
234 (pgg-parse-public-key-encrypted-session-key-packet ptag))
236 (pgg-parse-signature-packet ptag))
237 (3 ;Symmetric-Key Encrypted Session Key Packet
238 (pgg-parse-symmetric-key-encrypted-session-key-packet ptag))
239 ;; 4 -- One-Pass Signature Packet
240 ;; 5 -- Secret Key Packet
241 (6 ;Public Key Packet
242 (pgg-parse-public-key-packet ptag))
243 ;; 7 -- Secret Subkey Packet
244 ;; 8 -- Compressed Data Packet
245 (9 ;Symmetrically Encrypted Data Packet
246 (pgg-read-body-string ptag))
248 (pgg-read-body-string ptag))
249 (11 ;Literal Data Packet
250 (pgg-read-body-string ptag))
251 ;; 12 -- Trust Packet
253 (pgg-read-body-string ptag))
254 ;; 14 -- Public Subkey Packet
255 ;; 60 .. 63 -- Private or Experimental Values
258 (defun pgg-parse-packets (&optional header-parser body-parser)
261 (function pgg-parse-packet-header)))
264 (function pgg-parse-packet)))
266 (while (> (point-max) (1+ (point)))
267 (setq ptag (funcall header-parser))
268 (pgg-skip-header ptag)
269 (push (cons (car ptag)
271 (funcall body-parser ptag)))
273 (if (zerop (nth 1 ptag))
274 (goto-char (point-max))
275 (forward-char (nth 1 ptag))))
278 (defun pgg-parse-signature-subpacket-header ()
279 (let ((length-type (pgg-parse-length-type (pgg-byte-after))))
280 (list (pgg-byte-after (+ (cdr length-type) (point)))
281 (1- (car length-type))
282 (1+ (cdr length-type)))))
284 (defun pgg-parse-signature-subpacket (ptag)
286 (2 ;signature creation time
288 (let ((bytes (pgg-read-bytes 4)))
289 (pgg-parse-time-field bytes))))
290 (3 ;signature expiration time
291 (cons 'signature-expiry
292 (let ((bytes (pgg-read-bytes 4)))
293 (pgg-parse-time-field bytes))))
294 (4 ;exportable certification
295 (cons 'exportability (pgg-read-byte)))
297 (cons 'trust-level (pgg-read-byte)))
298 (6 ;regular expression
299 (cons 'regular-expression
300 (pgg-read-body-string ptag)))
302 (cons 'revocability (pgg-read-byte)))
303 (9 ;key expiration time
305 (let ((bytes (pgg-read-bytes 4)))
306 (pgg-parse-time-field bytes))))
307 ;; 10 = placeholder for backward compatibility
308 (11 ;preferred symmetric algorithms
309 (cons 'preferred-symmetric-key-algorithm
310 (cdr (assq (pgg-read-byte)
311 pgg-parse-symmetric-key-algorithm-alist))))
315 (cons 'key-identifier
316 (pgg-format-key-identifier (pgg-read-body-string ptag))))
320 (let ((name-bytes (pgg-read-bytes 2))
321 (value-bytes (pgg-read-bytes 2)))
322 (cons (pgg-read-bytes-string
323 (logior (lsh (car name-bytes) 8)
325 (pgg-read-bytes-string
326 (logior (lsh (car value-bytes) 8)
327 (nth 1 value-bytes)))))))
328 (21 ;preferred hash algorithms
329 (cons 'preferred-hash-algorithm
330 (cdr (assq (pgg-read-byte)
331 pgg-parse-hash-algorithm-alist))))
332 (22 ;preferred compression algorithms
333 (cons 'preferred-compression-algorithm
334 (cdr (assq (pgg-read-byte)
335 pgg-parse-compression-algorithm-alist))))
336 (23 ;key server preferences
337 (cons 'key-server-preferences
338 (pgg-read-body ptag)))
339 (24 ;preferred key server
340 (cons 'preferred-key-server
341 (pgg-read-body-string ptag)))
342 ;; 25 = primary user id
344 (cons 'policy-url (pgg-read-body-string ptag)))
346 ;; 28 = signer's user id
347 ;; 29 = reason for revocation
348 ;; 100 to 110 = internal or user-defined
351 (defun pgg-parse-signature-packet (ptag)
352 (let* ((signature-version (pgg-byte-after))
353 (result (list (cons 'version signature-version)))
354 hashed-material field n)
356 ((= signature-version 3)
358 (setq hashed-material (pgg-read-bytes 5))
359 (pgg-set-alist result
361 (cdr (assq (pop hashed-material)
362 pgg-parse-signature-type-alist)))
363 (pgg-set-alist result
365 (pgg-parse-time-field hashed-material))
366 (pgg-set-alist result
368 (pgg-format-key-identifier
369 (pgg-read-bytes-string 8)))
370 (pgg-set-alist result
371 'public-key-algorithm (pgg-read-byte))
372 (pgg-set-alist result
373 'hash-algorithm (pgg-read-byte)))
374 ((= signature-version 4)
376 (pgg-set-alist result
378 (cdr (assq (pgg-read-byte)
379 pgg-parse-signature-type-alist)))
380 (pgg-set-alist result
381 'public-key-algorithm
383 (pgg-set-alist result
384 'hash-algorithm (pgg-read-byte))
385 (when (>= 10000 (setq n (pgg-read-bytes 2)
386 n (logior (lsh (car n) 8)
389 (narrow-to-region (point)(+ n (point)))
391 (mapcar (function cdr) ;remove packet types
393 #'pgg-parse-signature-subpacket-header
394 #'pgg-parse-signature-subpacket)))
395 (goto-char (point-max))))
396 (when (>= 10000 (setq n (pgg-read-bytes 2)
397 n (logior (lsh (car n) 8)
400 (narrow-to-region (point)(+ n (point)))
402 (mapcar (function cdr) ;remove packet types
404 #'pgg-parse-signature-subpacket-header
405 #'pgg-parse-signature-subpacket)))))))
407 (setcdr (setq field (assq 'public-key-algorithm
409 (cdr (assq (cdr field)
410 pgg-parse-public-key-algorithm-alist)))
411 (setcdr (setq field (assq 'hash-algorithm
413 (cdr (assq (cdr field)
414 pgg-parse-hash-algorithm-alist)))
417 (defun pgg-parse-public-key-encrypted-session-key-packet (ptag)
419 (pgg-set-alist result
420 'version (pgg-read-byte))
421 (pgg-set-alist result
423 (pgg-format-key-identifier
424 (pgg-read-bytes-string 8)))
425 (pgg-set-alist result
426 'public-key-algorithm
427 (cdr (assq (pgg-read-byte)
428 pgg-parse-public-key-algorithm-alist)))
431 (defun pgg-parse-symmetric-key-encrypted-session-key-packet (ptag)
433 (pgg-set-alist result
436 (pgg-set-alist result
437 'symmetric-key-algorithm
438 (cdr (assq (pgg-read-byte)
439 pgg-parse-symmetric-key-algorithm-alist)))
442 (defun pgg-parse-public-key-packet (ptag)
443 (let* ((key-version (pgg-read-byte))
444 (result (list (cons 'version key-version)))
448 (pgg-set-alist result
450 (let ((bytes (pgg-read-bytes 4)))
451 (pgg-parse-time-field bytes)))
452 (pgg-set-alist result
453 'key-expiry (pgg-read-bytes 2))
454 (pgg-set-alist result
455 'public-key-algorithm (pgg-read-byte)))
457 (pgg-set-alist result
459 (let ((bytes (pgg-read-bytes 4)))
460 (pgg-parse-time-field bytes)))
461 (pgg-set-alist result
462 'public-key-algorithm (pgg-read-byte))))
464 (setcdr (setq field (assq 'public-key-algorithm
466 (cdr (assq (cdr field)
467 pgg-parse-public-key-algorithm-alist)))
470 ;; p-d-p only calls this if it is defined, but the compiler does not
472 (declare-function pgg-parse-crc24-string "pgg-parse" (string))
474 (defun pgg-decode-packets ()
475 (if (re-search-forward "^=\\([A-Za-z0-9+/]\\{4\\}\\)$" nil t)
476 (let ((p (match-beginning 0))
477 (checksum (match-string 1)))
478 (delete-region p (point-max))
479 (if (ignore-errors (base64-decode-region (point-min) p))
480 (or (not (fboundp 'pgg-parse-crc24-string))
481 pgg-ignore-packet-checksum
482 (string-equal (base64-encode-string (pgg-parse-crc24-string
486 (message "PGP packet checksum does not match")
488 (message "PGP packet contain invalid base64")
490 (message "PGP packet checksum not found")
493 (defun pgg-decode-armor-region (start end)
495 (narrow-to-region start end)
496 (goto-char (point-min))
497 (re-search-forward "^-+BEGIN PGP" nil t)
498 (delete-region (point-min)
499 (and (search-forward "\n\n")
501 (when (pgg-decode-packets)
502 (goto-char (point-min))
503 (pgg-parse-packets))))
505 (defun pgg-parse-armor (string)
507 (buffer-disable-undo)
508 (unless (featurep 'xemacs)
509 (set-buffer-multibyte nil))
511 (pgg-decode-armor-region (point-min)(point))))
514 (defalias 'pgg-string-as-unibyte (if (fboundp 'string-as-unibyte)
518 (defun pgg-parse-armor-region (start end)
519 (pgg-parse-armor (pgg-string-as-unibyte (buffer-substring start end))))
523 ;;; pgg-parse.el ends here