1 ;;; pgg-parse.el --- OpenPGP packet parsing
3 ;; Copyright (C) 1999, 2002, 2003, 2004, 2005,
4 ;; 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
6 ;; Author: Daiki Ueno <ueno@unixuser.org>
8 ;; Keywords: PGP, OpenPGP, GnuPG
10 ;; This file is part of GNU Emacs.
12 ;; GNU Emacs is free software: you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation, either version 3 of the License, or
15 ;; (at your option) any later version.
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
27 ;; This module is based on
29 ;; [OpenPGP] RFC 2440: "OpenPGP Message Format"
30 ;; by John W. Noerenberg, II <jwn2@qualcomm.com>,
31 ;; Jon Callas <jon@pgp.com>, Lutz Donnerhacke <lutz@iks-jena.de>,
32 ;; Hal Finney <hal@pgp.com> and Rodney Thayer <rodney@unitran.com>
38 (unless (fboundp 'declare-function) (defmacro declare-function (&rest r)))
41 (defgroup pgg-parse ()
42 "OpenPGP packet parsing."
45 (defcustom pgg-parse-public-key-algorithm-alist
46 '((1 . RSA) (2 . RSA-E) (3 . RSA-S) (16 . ELG-E) (17 . DSA) (20 . ELG))
47 "Alist of the assigned number to the public key algorithm."
50 (cons (sexp :tag "Number") (sexp :tag "Type"))))
52 (defcustom pgg-parse-symmetric-key-algorithm-alist
53 '((1 . IDEA) (2 . 3DES) (4 . CAST5) (5 . SAFER-SK128))
54 "Alist of the assigned number to the simmetric key algorithm."
57 (cons (sexp :tag "Number") (sexp :tag "Type"))))
59 (defcustom pgg-parse-hash-algorithm-alist
60 '((1 . MD5) (2 . SHA1) (3 . RIPEMD160) (5 . MD2) (8 . SHA256) (9 . SHA384)
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-number-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-number-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-number-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 (defvar pgg-parse-crc24)
183 (defun pgg-parse-crc24-string (string)
184 (let ((h (vector nil 183 1230 nil nil nil nil nil nil)))
185 (ccl-execute-on-string pgg-parse-crc24 h string)
187 (logand (aref h 1) 255)
188 (logand (lsh (aref h 2) -8) 255)
189 (logand (aref h 2) 255)))))
191 (defmacro pgg-parse-length-type (c)
193 ((< ,c 192) (cons ,c 1))
195 (cons (+ (lsh (- ,c 192) 8)
196 (pgg-byte-after (+ 2 (point)))
200 (cons (cons (logior (lsh (pgg-byte-after (+ 2 (point))) 8)
201 (pgg-byte-after (+ 3 (point))))
202 (logior (lsh (pgg-byte-after (+ 4 (point))) 8)
203 (pgg-byte-after (+ 5 (point)))))
205 (t;partial body length
208 (defun pgg-parse-packet-header ()
209 (let ((ptag (pgg-byte-after))
210 length-type content-tag packet-bytes header-bytes)
211 (if (zerop (logand 64 ptag));Old format
213 (setq length-type (logand ptag 3)
214 length-type (if (= 3 length-type) 0 (lsh 1 length-type))
215 content-tag (logand 15 (lsh ptag -2))
217 header-bytes (1+ length-type))
218 (dotimes (i length-type)
220 (logior (lsh packet-bytes 8)
221 (pgg-byte-after (+ 1 i (point)))))))
222 (setq content-tag (logand 63 ptag)
223 length-type (pgg-parse-length-type
224 (pgg-byte-after (1+ (point))))
225 packet-bytes (car length-type)
226 header-bytes (1+ (cdr length-type))))
227 (list content-tag packet-bytes header-bytes)))
229 (defun pgg-parse-packet (ptag)
231 (1 ;Public-Key Encrypted Session Key Packet
232 (pgg-parse-public-key-encrypted-session-key-packet ptag))
234 (pgg-parse-signature-packet ptag))
235 (3 ;Symmetric-Key Encrypted Session Key Packet
236 (pgg-parse-symmetric-key-encrypted-session-key-packet ptag))
237 ;; 4 -- One-Pass Signature Packet
238 ;; 5 -- Secret Key Packet
239 (6 ;Public Key Packet
240 (pgg-parse-public-key-packet ptag))
241 ;; 7 -- Secret Subkey Packet
242 ;; 8 -- Compressed Data Packet
243 (9 ;Symmetrically Encrypted Data Packet
244 (pgg-read-body-string ptag))
246 (pgg-read-body-string ptag))
247 (11 ;Literal Data Packet
248 (pgg-read-body-string ptag))
249 ;; 12 -- Trust Packet
251 (pgg-read-body-string ptag))
252 ;; 14 -- Public Subkey Packet
253 ;; 60 .. 63 -- Private or Experimental Values
256 (defun pgg-parse-packets (&optional header-parser body-parser)
259 (function pgg-parse-packet-header)))
262 (function pgg-parse-packet)))
264 (while (> (point-max) (1+ (point)))
265 (setq ptag (funcall header-parser))
266 (pgg-skip-header ptag)
267 (push (cons (car ptag)
269 (funcall body-parser ptag)))
271 (if (zerop (nth 1 ptag))
272 (goto-char (point-max))
273 (forward-char (nth 1 ptag))))
276 (defun pgg-parse-signature-subpacket-header ()
277 (let ((length-type (pgg-parse-length-type (pgg-byte-after))))
278 (list (pgg-byte-after (+ (cdr length-type) (point)))
279 (1- (car length-type))
280 (1+ (cdr length-type)))))
282 (defun pgg-parse-signature-subpacket (ptag)
284 (2 ;signature creation time
286 (let ((bytes (pgg-read-bytes 4)))
287 (pgg-parse-time-field bytes))))
288 (3 ;signature expiration time
289 (cons 'signature-expiry
290 (let ((bytes (pgg-read-bytes 4)))
291 (pgg-parse-time-field bytes))))
292 (4 ;exportable certification
293 (cons 'exportability (pgg-read-byte)))
295 (cons 'trust-level (pgg-read-byte)))
296 (6 ;regular expression
297 (cons 'regular-expression
298 (pgg-read-body-string ptag)))
300 (cons 'revocability (pgg-read-byte)))
301 (9 ;key expiration time
303 (let ((bytes (pgg-read-bytes 4)))
304 (pgg-parse-time-field bytes))))
305 ;; 10 = placeholder for backward compatibility
306 (11 ;preferred symmetric algorithms
307 (cons 'preferred-symmetric-key-algorithm
308 (cdr (assq (pgg-read-byte)
309 pgg-parse-symmetric-key-algorithm-alist))))
313 (cons 'key-identifier
314 (pgg-format-key-identifier (pgg-read-body-string ptag))))
318 (let ((name-bytes (pgg-read-bytes 2))
319 (value-bytes (pgg-read-bytes 2)))
320 (cons (pgg-read-bytes-string
321 (logior (lsh (car name-bytes) 8)
323 (pgg-read-bytes-string
324 (logior (lsh (car value-bytes) 8)
325 (nth 1 value-bytes)))))))
326 (21 ;preferred hash algorithms
327 (cons 'preferred-hash-algorithm
328 (cdr (assq (pgg-read-byte)
329 pgg-parse-hash-algorithm-alist))))
330 (22 ;preferred compression algorithms
331 (cons 'preferred-compression-algorithm
332 (cdr (assq (pgg-read-byte)
333 pgg-parse-compression-algorithm-alist))))
334 (23 ;key server preferences
335 (cons 'key-server-preferences
336 (pgg-read-body ptag)))
337 (24 ;preferred key server
338 (cons 'preferred-key-server
339 (pgg-read-body-string ptag)))
340 ;; 25 = primary user id
342 (cons 'policy-url (pgg-read-body-string ptag)))
344 ;; 28 = signer's user id
345 ;; 29 = reason for revocation
346 ;; 100 to 110 = internal or user-defined
349 (defun pgg-parse-signature-packet (ptag)
350 (let* ((signature-version (pgg-byte-after))
351 (result (list (cons 'version signature-version)))
352 hashed-material field n)
354 ((= signature-version 3)
356 (setq hashed-material (pgg-read-bytes 5))
357 (pgg-set-alist result
359 (cdr (assq (pop hashed-material)
360 pgg-parse-signature-type-alist)))
361 (pgg-set-alist result
363 (pgg-parse-time-field hashed-material))
364 (pgg-set-alist result
366 (pgg-format-key-identifier
367 (pgg-read-bytes-string 8)))
368 (pgg-set-alist result
369 'public-key-algorithm (pgg-read-byte))
370 (pgg-set-alist result
371 'hash-algorithm (pgg-read-byte)))
372 ((= signature-version 4)
374 (pgg-set-alist result
376 (cdr (assq (pgg-read-byte)
377 pgg-parse-signature-type-alist)))
378 (pgg-set-alist result
379 'public-key-algorithm
381 (pgg-set-alist result
382 'hash-algorithm (pgg-read-byte))
383 (when (>= 10000 (setq n (pgg-read-bytes 2)
384 n (logior (lsh (car n) 8)
387 (narrow-to-region (point)(+ n (point)))
389 (mapcar (function cdr) ;remove packet types
391 #'pgg-parse-signature-subpacket-header
392 #'pgg-parse-signature-subpacket)))
393 (goto-char (point-max))))
394 (when (>= 10000 (setq n (pgg-read-bytes 2)
395 n (logior (lsh (car n) 8)
398 (narrow-to-region (point)(+ n (point)))
400 (mapcar (function cdr) ;remove packet types
402 #'pgg-parse-signature-subpacket-header
403 #'pgg-parse-signature-subpacket)))))))
405 (setcdr (setq field (assq 'public-key-algorithm
407 (cdr (assq (cdr field)
408 pgg-parse-public-key-algorithm-alist)))
409 (setcdr (setq field (assq 'hash-algorithm
411 (cdr (assq (cdr field)
412 pgg-parse-hash-algorithm-alist)))
415 (defun pgg-parse-public-key-encrypted-session-key-packet (ptag)
417 (pgg-set-alist result
418 'version (pgg-read-byte))
419 (pgg-set-alist result
421 (pgg-format-key-identifier
422 (pgg-read-bytes-string 8)))
423 (pgg-set-alist result
424 'public-key-algorithm
425 (cdr (assq (pgg-read-byte)
426 pgg-parse-public-key-algorithm-alist)))
429 (defun pgg-parse-symmetric-key-encrypted-session-key-packet (ptag)
431 (pgg-set-alist result
434 (pgg-set-alist result
435 'symmetric-key-algorithm
436 (cdr (assq (pgg-read-byte)
437 pgg-parse-symmetric-key-algorithm-alist)))
440 (defun pgg-parse-public-key-packet (ptag)
441 (let* ((key-version (pgg-read-byte))
442 (result (list (cons 'version key-version)))
446 (pgg-set-alist result
448 (let ((bytes (pgg-read-bytes 4)))
449 (pgg-parse-time-field bytes)))
450 (pgg-set-alist result
451 'key-expiry (pgg-read-bytes 2))
452 (pgg-set-alist result
453 'public-key-algorithm (pgg-read-byte)))
455 (pgg-set-alist result
457 (let ((bytes (pgg-read-bytes 4)))
458 (pgg-parse-time-field bytes)))
459 (pgg-set-alist result
460 'public-key-algorithm (pgg-read-byte))))
462 (setcdr (setq field (assq 'public-key-algorithm
464 (cdr (assq (cdr field)
465 pgg-parse-public-key-algorithm-alist)))
468 ;; p-d-p only calls this if it is defined, but the compiler does not
470 (declare-function pgg-parse-crc24-string "pgg-parse" (string))
472 (defun pgg-decode-packets ()
473 (if (re-search-forward "^=\\([A-Za-z0-9+/]\\{4\\}\\)$" nil t)
474 (let ((p (match-beginning 0))
475 (checksum (match-string 1)))
476 (delete-region p (point-max))
477 (if (ignore-errors (base64-decode-region (point-min) p))
478 (or (not (fboundp 'pgg-parse-crc24-string))
479 pgg-ignore-packet-checksum
480 (string-equal (base64-encode-string (pgg-parse-crc24-string
484 (message "PGP packet checksum does not match")
486 (message "PGP packet contain invalid base64")
488 (message "PGP packet checksum not found")
491 (defun pgg-decode-armor-region (start end)
493 (narrow-to-region start end)
494 (goto-char (point-min))
495 (re-search-forward "^-+BEGIN PGP" nil t)
496 (delete-region (point-min)
497 (and (search-forward "\n\n")
499 (when (pgg-decode-packets)
500 (goto-char (point-min))
501 (pgg-parse-packets))))
503 (defun pgg-parse-armor (string)
505 (buffer-disable-undo)
506 (if (fboundp 'set-buffer-multibyte)
507 (set-buffer-multibyte nil))
509 (pgg-decode-armor-region (point-min)(point))))
512 (defalias 'pgg-string-as-unibyte (if (fboundp 'string-as-unibyte)
516 (defun pgg-parse-armor-region (start end)
517 (pgg-parse-armor (pgg-string-as-unibyte (buffer-substring start end))))
521 ;; arch-tag: 16c2eb82-1313-4a7c-a70f-420709b5b43e
522 ;;; pgg-parse.el ends here