[bpt/emacs.git] / lisp / pgg-parse.el

;;; pgg-parse.el --- OpenPGP packet parsing

;; Copyright (C) 1999, 2002, 2003, 2004, 2005,
;;   2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.

;; Author: Daiki Ueno <ueno@unixuser.org>
;; Created: 1999/10/28
;; Keywords: PGP, OpenPGP, GnuPG
;; Package: pgg

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;;    This module is based on

;;	[OpenPGP] RFC 2440: "OpenPGP Message Format"
;;	    by John W. Noerenberg, II <jwn2@qualcomm.com>,
;;          Jon Callas <jon@pgp.com>, Lutz Donnerhacke <lutz@iks-jena.de>,
;;          Hal Finney <hal@pgp.com> and Rodney Thayer <rodney@unitran.com>
;;	    (1998/11)

;;; Code:

(eval-when-compile
  (unless (fboundp 'declare-function) (defmacro declare-function (&rest r)))
  (require 'cl))

(defgroup pgg-parse ()
  "OpenPGP packet parsing."
  :group 'pgg)

(defcustom pgg-parse-public-key-algorithm-alist
  '((1 . RSA) (2 . RSA-E) (3 . RSA-S) (16 . ELG-E) (17 . DSA) (20 . ELG))
  "Alist of the assigned number to the public key algorithm."
  :group 'pgg-parse
  :type '(repeat
	  (cons (sexp :tag "Number") (sexp :tag "Type"))))

(defcustom pgg-parse-symmetric-key-algorithm-alist
  '((1 . IDEA) (2 . 3DES) (4 . CAST5) (5 . SAFER-SK128))
  "Alist of the assigned number to the simmetric key algorithm."
  :group 'pgg-parse
  :type '(repeat
	  (cons (sexp :tag "Number") (sexp :tag "Type"))))

(defcustom pgg-parse-hash-algorithm-alist
  '((1 . MD5) (2 . SHA1) (3 . RIPEMD160) (5 . MD2) (8 . SHA256) (9 . SHA384)
    (10 . SHA512))
  "Alist of the assigned number to the cryptographic hash algorithm."
  :group 'pgg-parse
  :type '(repeat
	  (cons (sexp :tag "Number") (sexp :tag "Type"))))

(defcustom pgg-parse-compression-algorithm-alist
  '((0 . nil); Uncompressed
    (1 . ZIP)
    (2 . ZLIB))
  "Alist of the assigned number to the compression algorithm."
  :group 'pgg-parse
  :type '(repeat
	  (cons (sexp :tag "Number") (sexp :tag "Type"))))

(defcustom pgg-parse-signature-type-alist
  '((0 . "Signature of a binary document")
    (1 . "Signature of a canonical text document")
    (2 . "Standalone signature")
    (16 . "Generic certification of a User ID and Public Key packet")
    (17 . "Persona certification of a User ID and Public Key packet")
    (18 . "Casual certification of a User ID and Public Key packet")
    (19 . "Positive certification of a User ID and Public Key packet")
    (24 . "Subkey Binding Signature")
    (31 . "Signature directly on a key")
    (32 . "Key revocation signature")
    (40 . "Subkey revocation signature")
    (48 . "Certification revocation signature")
    (64 . "Timestamp signature."))
  "Alist of the assigned number to the signature type."
  :group 'pgg-parse
  :type '(repeat
	  (cons (sexp :tag "Number") (sexp :tag "Type"))))

(defcustom pgg-ignore-packet-checksum t; XXX
  "If non-nil checksum of each ascii armored packet will be ignored."
  :group 'pgg-parse
  :type 'boolean)

(defvar pgg-armor-header-lines
  '("^-----BEGIN PGP MESSAGE\\(, PART [0-9]+\\(/[0-9]+\\)?\\)?-----\r?$"
    "^-----BEGIN PGP PUBLIC KEY BLOCK-----\r?$"
    "^-----BEGIN PGP PRIVATE KEY BLOCK-----\r?$"
    "^-----BEGIN PGP SIGNATURE-----\r?$")
  "Armor headers.")

(eval-and-compile
  (defalias 'pgg-char-int (if (fboundp 'char-int)
			      'char-int
			    'identity)))

(defmacro pgg-format-key-identifier (string)
  `(mapconcat (lambda (c) (format "%02X" (pgg-char-int c)))
	      ,string "")
  ;; `(upcase (apply #'format "%02x%02x%02x%02x%02x%02x%02x%02x"
  ;;                 (string-to-number-list ,string)))
  )

(defmacro pgg-parse-time-field (bytes)
  `(list (logior (lsh (car ,bytes) 8)
		 (nth 1 ,bytes))
	 (logior (lsh (nth 2 ,bytes) 8)
		 (nth 3 ,bytes))
	 0))

(defmacro pgg-byte-after (&optional pos)
  `(pgg-char-int (char-after ,(or pos `(point)))))

(defmacro pgg-read-byte ()
  `(pgg-char-int (char-after (prog1 (point) (forward-char)))))

(defmacro pgg-read-bytes-string (nbytes)
  `(buffer-substring
    (point) (prog1 (+ ,nbytes (point))
	      (forward-char ,nbytes))))

(defmacro pgg-read-bytes (nbytes)
  `(mapcar #'pgg-char-int (pgg-read-bytes-string ,nbytes))
  ;; `(string-to-number-list (pgg-read-bytes-string ,nbytes))
  )

(defmacro pgg-read-body-string (ptag)
  `(if (nth 1 ,ptag)
       (pgg-read-bytes-string (nth 1 ,ptag))
     (pgg-read-bytes-string (- (point-max) (point)))))

(defmacro pgg-read-body (ptag)
  `(mapcar #'pgg-char-int (pgg-read-body-string ,ptag))
  ;; `(string-to-number-list (pgg-read-body-string ,ptag))
  )

(defalias 'pgg-skip-bytes 'forward-char)

(defmacro pgg-skip-header (ptag)
  `(pgg-skip-bytes (nth 2 ,ptag)))

(defmacro pgg-skip-body (ptag)
  `(pgg-skip-bytes (nth 1 ,ptag)))

(defmacro pgg-set-alist (alist key value)
  `(setq ,alist (nconc ,alist (list (cons ,key ,value)))))

(when (fboundp 'define-ccl-program)

  (define-ccl-program pgg-parse-crc24
    '(1
      ((loop
	(read r0) (r1 ^= r0) (r2 ^= 0)
	(r5 = 0)
	(loop
	 (r1 <<= 1)
	 (r1 += ((r2 >> 15) & 1))
	 (r2 <<= 1)
	 (if (r1 & 256)
	     ((r1 ^= 390) (r2 ^= 19707)))
	 (if (r5 < 7)
	     ((r5 += 1)
	      (repeat))))
	(repeat)))))

  (defvar pgg-parse-crc24)

  (defun pgg-parse-crc24-string (string)
    (let ((h (vector nil 183 1230 nil nil nil nil nil nil)))
      (ccl-execute-on-string pgg-parse-crc24 h string)
      (format "%c%c%c"
	      (logand (aref h 1) 255)
	      (logand (lsh (aref h 2) -8) 255)
	      (logand (aref h 2) 255)))))

(defmacro pgg-parse-length-type (c)
  `(cond
    ((< ,c 192) (cons ,c 1))
    ((< ,c 224)
     (cons (+ (lsh (- ,c 192) 8)
	      (pgg-byte-after (+ 2 (point)))
	      192)
	   2))
    ((= ,c 255)
     (cons (cons (logior (lsh (pgg-byte-after (+ 2 (point))) 8)
			 (pgg-byte-after (+ 3 (point))))
		 (logior (lsh (pgg-byte-after (+ 4 (point))) 8)
			 (pgg-byte-after (+ 5 (point)))))
	   5))
    (t;partial body length
     '(0 . 0))))

(defun pgg-parse-packet-header ()
  (let ((ptag (pgg-byte-after))
	length-type content-tag packet-bytes header-bytes)
    (if (zerop (logand 64 ptag));Old format
	(progn
	  (setq length-type (logand ptag 3)
		length-type (if (= 3 length-type) 0 (lsh 1 length-type))
		content-tag (logand 15 (lsh ptag -2))
		packet-bytes 0
		header-bytes (1+ length-type))
	  (dotimes (i length-type)
	    (setq packet-bytes
		  (logior (lsh packet-bytes 8)
			  (pgg-byte-after (+ 1 i (point)))))))
      (setq content-tag (logand 63 ptag)
	    length-type (pgg-parse-length-type
			 (pgg-byte-after (1+ (point))))
	    packet-bytes (car length-type)
	    header-bytes (1+ (cdr length-type))))
    (list content-tag packet-bytes header-bytes)))

(defun pgg-parse-packet (ptag)
  (case (car ptag)
    (1 ;Public-Key Encrypted Session Key Packet
     (pgg-parse-public-key-encrypted-session-key-packet ptag))
    (2 ;Signature Packet
     (pgg-parse-signature-packet ptag))
    (3 ;Symmetric-Key Encrypted Session Key Packet
     (pgg-parse-symmetric-key-encrypted-session-key-packet ptag))
    ;; 4        -- One-Pass Signature Packet
    ;; 5        -- Secret Key Packet
    (6 ;Public Key Packet
     (pgg-parse-public-key-packet ptag))
    ;; 7        -- Secret Subkey Packet
    ;; 8        -- Compressed Data Packet
    (9 ;Symmetrically Encrypted Data Packet
     (pgg-read-body-string ptag))
    (10 ;Marker Packet
     (pgg-read-body-string ptag))
    (11 ;Literal Data Packet
     (pgg-read-body-string ptag))
    ;; 12       -- Trust Packet
    (13 ;User ID Packet
     (pgg-read-body-string ptag))
    ;; 14       -- Public Subkey Packet
    ;; 60 .. 63 -- Private or Experimental Values
    ))

(defun pgg-parse-packets (&optional header-parser body-parser)
  (let ((header-parser
	 (or header-parser
	     (function pgg-parse-packet-header)))
	(body-parser
	 (or body-parser
	     (function pgg-parse-packet)))
	result ptag)
    (while (> (point-max) (1+ (point)))
      (setq ptag (funcall header-parser))
      (pgg-skip-header ptag)
      (push (cons (car ptag)
		  (save-excursion
		    (funcall body-parser ptag)))
	    result)
      (if (zerop (nth 1 ptag))
	  (goto-char (point-max))
	(forward-char (nth 1 ptag))))
    result))

(defun pgg-parse-signature-subpacket-header ()
  (let ((length-type (pgg-parse-length-type (pgg-byte-after))))
    (list (pgg-byte-after (+ (cdr length-type) (point)))
	  (1- (car length-type))
	  (1+ (cdr length-type)))))

(defun pgg-parse-signature-subpacket (ptag)
  (case (car ptag)
    (2 ;signature creation time
     (cons 'creation-time
	   (let ((bytes (pgg-read-bytes 4)))
	     (pgg-parse-time-field bytes))))
    (3 ;signature expiration time
     (cons 'signature-expiry
	   (let ((bytes (pgg-read-bytes 4)))
	     (pgg-parse-time-field bytes))))
    (4 ;exportable certification
     (cons 'exportability (pgg-read-byte)))
    (5 ;trust signature
     (cons 'trust-level (pgg-read-byte)))
    (6 ;regular expression
     (cons 'regular-expression
	   (pgg-read-body-string ptag)))
    (7 ;revocable
     (cons 'revocability (pgg-read-byte)))
    (9 ;key expiration time
     (cons 'key-expiry
	   (let ((bytes (pgg-read-bytes 4)))
	     (pgg-parse-time-field bytes))))
    ;; 10 = placeholder for backward compatibility
    (11 ;preferred symmetric algorithms
     (cons 'preferred-symmetric-key-algorithm
	   (cdr (assq (pgg-read-byte)
		      pgg-parse-symmetric-key-algorithm-alist))))
    (12 ;revocation key
     )
    (16 ;issuer key ID
     (cons 'key-identifier
	   (pgg-format-key-identifier (pgg-read-body-string ptag))))
    (20 ;notation data
     (pgg-skip-bytes 4)
     (cons 'notation
	   (let ((name-bytes (pgg-read-bytes 2))
		 (value-bytes (pgg-read-bytes 2)))
	     (cons (pgg-read-bytes-string
		    (logior (lsh (car name-bytes) 8)
			    (nth 1 name-bytes)))
		   (pgg-read-bytes-string
		    (logior (lsh (car value-bytes) 8)
			    (nth 1 value-bytes)))))))
    (21 ;preferred hash algorithms
     (cons 'preferred-hash-algorithm
	   (cdr (assq (pgg-read-byte)
		      pgg-parse-hash-algorithm-alist))))
    (22 ;preferred compression algorithms
     (cons 'preferred-compression-algorithm
	   (cdr (assq (pgg-read-byte)
		      pgg-parse-compression-algorithm-alist))))
    (23 ;key server preferences
     (cons 'key-server-preferences
	   (pgg-read-body ptag)))
    (24 ;preferred key server
     (cons 'preferred-key-server
	   (pgg-read-body-string ptag)))
    ;; 25 = primary user id
    (26 ;policy URL
     (cons 'policy-url (pgg-read-body-string ptag)))
    ;; 27 = key flags
    ;; 28 = signer's user id
    ;; 29 = reason for revocation
    ;; 100 to 110 = internal or user-defined
    ))

(defun pgg-parse-signature-packet (ptag)
  (let* ((signature-version (pgg-byte-after))
	 (result (list (cons 'version signature-version)))
	 hashed-material field n)
    (cond
     ((= signature-version 3)
      (pgg-skip-bytes 2)
      (setq hashed-material (pgg-read-bytes 5))
      (pgg-set-alist result
		     'signature-type
		     (cdr (assq (pop hashed-material)
				pgg-parse-signature-type-alist)))
      (pgg-set-alist result
		     'creation-time
		     (pgg-parse-time-field hashed-material))
      (pgg-set-alist result
		     'key-identifier
		     (pgg-format-key-identifier
		      (pgg-read-bytes-string 8)))
      (pgg-set-alist result
		     'public-key-algorithm (pgg-read-byte))
      (pgg-set-alist result
		     'hash-algorithm (pgg-read-byte)))
     ((= signature-version 4)
      (pgg-skip-bytes 1)
      (pgg-set-alist result
		     'signature-type
		     (cdr (assq (pgg-read-byte)
				pgg-parse-signature-type-alist)))
      (pgg-set-alist result
		     'public-key-algorithm
		     (pgg-read-byte))
      (pgg-set-alist result
		     'hash-algorithm (pgg-read-byte))
      (when (>= 10000 (setq n (pgg-read-bytes 2)
			    n (logior (lsh (car n) 8)
				      (nth 1 n))))
	(save-restriction
	  (narrow-to-region (point)(+ n (point)))
	  (nconc result
		 (mapcar (function cdr) ;remove packet types
			 (pgg-parse-packets
			  #'pgg-parse-signature-subpacket-header
			  #'pgg-parse-signature-subpacket)))
	  (goto-char (point-max))))
      (when (>= 10000 (setq n (pgg-read-bytes 2)
			    n (logior (lsh (car n) 8)
				      (nth 1 n))))
	(save-restriction
	  (narrow-to-region (point)(+ n (point)))
	  (nconc result
		 (mapcar (function cdr) ;remove packet types
			 (pgg-parse-packets
			  #'pgg-parse-signature-subpacket-header
			  #'pgg-parse-signature-subpacket)))))))

    (setcdr (setq field (assq 'public-key-algorithm
			      result))
	    (cdr (assq (cdr field)
		       pgg-parse-public-key-algorithm-alist)))
    (setcdr (setq field (assq 'hash-algorithm
			      result))
	    (cdr (assq (cdr field)
		       pgg-parse-hash-algorithm-alist)))
    result))

(defun pgg-parse-public-key-encrypted-session-key-packet (ptag)
  (let (result)
    (pgg-set-alist result
		   'version (pgg-read-byte))
    (pgg-set-alist result
		   'key-identifier
		   (pgg-format-key-identifier
		    (pgg-read-bytes-string 8)))
    (pgg-set-alist result
		   'public-key-algorithm
		   (cdr (assq (pgg-read-byte)
			      pgg-parse-public-key-algorithm-alist)))
    result))

(defun pgg-parse-symmetric-key-encrypted-session-key-packet (ptag)
  (let (result)
    (pgg-set-alist result
		   'version
		   (pgg-read-byte))
    (pgg-set-alist result
		   'symmetric-key-algorithm
		   (cdr (assq (pgg-read-byte)
			      pgg-parse-symmetric-key-algorithm-alist)))
    result))

(defun pgg-parse-public-key-packet (ptag)
  (let* ((key-version (pgg-read-byte))
	 (result (list (cons 'version key-version)))
	 field)
    (cond
     ((= 3 key-version)
      (pgg-set-alist result
		     'creation-time
		     (let ((bytes (pgg-read-bytes 4)))
		       (pgg-parse-time-field bytes)))
      (pgg-set-alist result
		     'key-expiry (pgg-read-bytes 2))
      (pgg-set-alist result
		     'public-key-algorithm (pgg-read-byte)))
     ((= 4 key-version)
      (pgg-set-alist result
		     'creation-time
		     (let ((bytes (pgg-read-bytes 4)))
		       (pgg-parse-time-field bytes)))
      (pgg-set-alist result
		     'public-key-algorithm (pgg-read-byte))))

    (setcdr (setq field (assq 'public-key-algorithm
			      result))
	    (cdr (assq (cdr field)
		       pgg-parse-public-key-algorithm-alist)))
    result))

;; p-d-p only calls this if it is defined, but the compiler does not
;; recognize that.
(declare-function pgg-parse-crc24-string "pgg-parse" (string))

(defun pgg-decode-packets ()
  (if (re-search-forward "^=\\([A-Za-z0-9+/]\\{4\\}\\)$" nil t)
      (let ((p (match-beginning 0))
	    (checksum (match-string 1)))
	(delete-region p (point-max))
	(if (ignore-errors (base64-decode-region (point-min) p))
	    (or (not (fboundp 'pgg-parse-crc24-string))
		pgg-ignore-packet-checksum
		(string-equal (base64-encode-string (pgg-parse-crc24-string
						     (buffer-string)))
			      checksum)
		(progn
		  (message "PGP packet checksum does not match")
		  nil))
	  (message "PGP packet contain invalid base64")
	  nil))
    (message "PGP packet checksum not found")
    nil))

(defun pgg-decode-armor-region (start end)
  (save-restriction
    (narrow-to-region start end)
    (goto-char (point-min))
    (re-search-forward "^-+BEGIN PGP" nil t)
    (delete-region (point-min)
		   (and (search-forward "\n\n")
			(match-end 0)))
    (when (pgg-decode-packets)
      (goto-char (point-min))
      (pgg-parse-packets))))

(defun pgg-parse-armor (string)
  (with-temp-buffer
    (buffer-disable-undo)
    (unless (featurep 'xemacs)
      (set-buffer-multibyte nil))
    (insert string)
    (pgg-decode-armor-region (point-min)(point))))

(eval-and-compile
  (defalias 'pgg-string-as-unibyte (if (fboundp 'string-as-unibyte)
				       'string-as-unibyte
				     'identity)))

(defun pgg-parse-armor-region (start end)
  (pgg-parse-armor (pgg-string-as-unibyte (buffer-substring start end))))

(provide 'pgg-parse)

;; arch-tag: 16c2eb82-1313-4a7c-a70f-420709b5b43e
;;; pgg-parse.el ends here
Commit	Line	Data
23f87bed MB	1	;;; pgg-parse.el --- OpenPGP packet parsing
23f87bed MB	2
aaef169d	3	;; Copyright (C) 1999, 2002, 2003, 2004, 2005,
114f9c96	4	;; 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
23f87bed MB	5
	6	;; Author: Daiki Ueno <ueno@unixuser.org>
	7	;; Created: 1999/10/28
	8	;; Keywords: PGP, OpenPGP, GnuPG
bd78fa1d	9	;; Package: pgg
23f87bed MB	10
	11	;; This file is part of GNU Emacs.
	12
eb3fa2cf	13	;; GNU Emacs is free software: you can redistribute it and/or modify
23f87bed	14	;; it under the terms of the GNU General Public License as published by
eb3fa2cf GM	15	;; the Free Software Foundation, either version 3 of the License, or
eb3fa2cf GM	16	;; (at your option) any later version.
23f87bed MB	17
	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.
	22
	23	;; You should have received a copy of the GNU General Public License
eb3fa2cf	24	;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
23f87bed MB	25
	26	;;; Commentary:
	27
	28	;; This module is based on
	29
	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>
	34	;; (1998/11)
	35
	36	;;; Code:
	37
21ee0911 MB	38	(eval-when-compile
	39	(unless (fboundp 'declare-function) (defmacro declare-function (&rest r)))
	40	(require 'cl))
23f87bed	41
23f87bed	42	(defgroup pgg-parse ()
8d764d76	43	"OpenPGP packet parsing."
23f87bed MB	44	:group 'pgg)
	45
	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."
	49	:group 'pgg-parse
	50	:type '(repeat
	51	(cons (sexp :tag "Number") (sexp :tag "Type"))))
	52
	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."
	56	:group 'pgg-parse
	57	:type '(repeat
	58	(cons (sexp :tag "Number") (sexp :tag "Type"))))
	59
	60	(defcustom pgg-parse-hash-algorithm-alist
bcc7dd61 MB	61	'((1 . MD5) (2 . SHA1) (3 . RIPEMD160) (5 . MD2) (8 . SHA256) (9 . SHA384)
bcc7dd61 MB	62	(10 . SHA512))
23f87bed MB	63	"Alist of the assigned number to the cryptographic hash algorithm."
	64	:group 'pgg-parse
	65	:type '(repeat
	66	(cons (sexp :tag "Number") (sexp :tag "Type"))))
	67
	68	(defcustom pgg-parse-compression-algorithm-alist
	69	'((0 . nil); Uncompressed
	70	(1 . ZIP)
	71	(2 . ZLIB))
	72	"Alist of the assigned number to the compression algorithm."
	73	:group 'pgg-parse
	74	:type '(repeat
	75	(cons (sexp :tag "Number") (sexp :tag "Type"))))
	76
	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."
	92	:group 'pgg-parse
	93	:type '(repeat
	94	(cons (sexp :tag "Number") (sexp :tag "Type"))))
	95
	96	(defcustom pgg-ignore-packet-checksum t; XXX
	97	"If non-nil checksum of each ascii armored packet will be ignored."
	98	:group 'pgg-parse
	99	:type 'boolean)
	100
	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?$"
	105	"^-----BEGIN PGP SIGNATURE-----\r?$")
	106	"Armor headers.")
	107
	108	(eval-and-compile
	109	(defalias 'pgg-char-int (if (fboundp 'char-int)
	110	'char-int
	111	'identity)))
	112
	113	(defmacro pgg-format-key-identifier (string)
	114	`(mapconcat (lambda (c) (format "%02X" (pgg-char-int c)))
	115	,string "")
	116	;; `(upcase (apply #'format "%02x%02x%02x%02x%02x%02x%02x%02x"
e9bd5782	117	;; (string-to-number-list ,string)))
23f87bed MB	118	)
	119
	120	(defmacro pgg-parse-time-field (bytes)
	121	`(list (logior (lsh (car ,bytes) 8)
	122	(nth 1 ,bytes))
	123	(logior (lsh (nth 2 ,bytes) 8)
	124	(nth 3 ,bytes))
	125	0))
	126
	127	(defmacro pgg-byte-after (&optional pos)
	128	`(pgg-char-int (char-after ,(or pos `(point)))))
	129
	130	(defmacro pgg-read-byte ()
	131	`(pgg-char-int (char-after (prog1 (point) (forward-char)))))
	132
	133	(defmacro pgg-read-bytes-string (nbytes)
	134	`(buffer-substring
	135	(point) (prog1 (+ ,nbytes (point))
	136	(forward-char ,nbytes))))
	137
	138	(defmacro pgg-read-bytes (nbytes)
	139	`(mapcar #'pgg-char-int (pgg-read-bytes-string ,nbytes))
e9bd5782	140	;; `(string-to-number-list (pgg-read-bytes-string ,nbytes))
23f87bed MB	141	)
	142
	143	(defmacro pgg-read-body-string (ptag)
	144	`(if (nth 1 ,ptag)
	145	(pgg-read-bytes-string (nth 1 ,ptag))
	146	(pgg-read-bytes-string (- (point-max) (point)))))
	147
	148	(defmacro pgg-read-body (ptag)
	149	`(mapcar #'pgg-char-int (pgg-read-body-string ,ptag))
e9bd5782	150	;; `(string-to-number-list (pgg-read-body-string ,ptag))
23f87bed MB	151	)
	152
	153	(defalias 'pgg-skip-bytes 'forward-char)
	154
	155	(defmacro pgg-skip-header (ptag)
	156	`(pgg-skip-bytes (nth 2 ,ptag)))
	157
	158	(defmacro pgg-skip-body (ptag)
	159	`(pgg-skip-bytes (nth 1 ,ptag)))
	160
	161	(defmacro pgg-set-alist (alist key value)
	162	`(setq ,alist (nconc ,alist (list (cons ,key ,value)))))
	163
	164	(when (fboundp 'define-ccl-program)
	165
	166	(define-ccl-program pgg-parse-crc24
	167	'(1
	168	((loop
	169	(read r0) (r1 ^= r0) (r2 ^= 0)
	170	(r5 = 0)
	171	(loop
	172	(r1 <<= 1)
	173	(r1 += ((r2 >> 15) & 1))
	174	(r2 <<= 1)
	175	(if (r1 & 256)
	176	((r1 ^= 390) (r2 ^= 19707)))
	177	(if (r5 < 7)
	178	((r5 += 1)
	179	(repeat))))
	180	(repeat)))))
	181
14ecd9e4 GM	182	(defvar pgg-parse-crc24)
14ecd9e4 GM	183
23f87bed MB	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)
	187	(format "%c%c%c"
	188	(logand (aref h 1) 255)
	189	(logand (lsh (aref h 2) -8) 255)
	190	(logand (aref h 2) 255)))))
	191
	192	(defmacro pgg-parse-length-type (c)
	193	`(cond
	194	((< ,c 192) (cons ,c 1))
	195	((< ,c 224)
	196	(cons (+ (lsh (- ,c 192) 8)
	197	(pgg-byte-after (+ 2 (point)))
	198	192)
	199	2))
	200	((= ,c 255)
	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)))))
	205	5))
	206	(t;partial body length
	207	'(0 . 0))))
	208
	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
	213	(progn
	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))
	217	packet-bytes 0
	218	header-bytes (1+ length-type))
	219	(dotimes (i length-type)
	220	(setq packet-bytes
	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)))
	229
	230	(defun pgg-parse-packet (ptag)
	231	(case (car ptag)
	232	(1 ;Public-Key Encrypted Session Key Packet
	233	(pgg-parse-public-key-encrypted-session-key-packet ptag))
	234	(2 ;Signature Packet
	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))
	246	(10 ;Marker Packet
	247	(pgg-read-body-string ptag))
248	(11 ;Literal Data Packet
249	(pgg-read-body-string ptag))
250	;; 12 -- Trust Packet
251	(13 ;User ID Packet
252	(pgg-read-body-string ptag))
253	;; 14 -- Public Subkey Packet
254	;; 60 .. 63 -- Private or Experimental Values
255	))
256
257	(defun pgg-parse-packets (&optional header-parser body-parser)
258	(let ((header-parser
259	(or header-parser
260	(function pgg-parse-packet-header)))
261	(body-parser
262	(or body-parser
263	(function pgg-parse-packet)))
264	result ptag)
265	(while (> (point-max) (1+ (point)))
266	(setq ptag (funcall header-parser))
267	(pgg-skip-header ptag)
268	(push (cons (car ptag)
269	(save-excursion
270	(funcall body-parser ptag)))
271	result)
272	(if (zerop (nth 1 ptag))
273	(goto-char (point-max))
274	(forward-char (nth 1 ptag))))
275	result))
276
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)))))
282
283	(defun pgg-parse-signature-subpacket (ptag)
284	(case (car ptag)
285	(2 ;signature creation time
286	(cons '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)))
295	(5 ;trust signature
296	(cons 'trust-level (pgg-read-byte)))
297	(6 ;regular expression
298	(cons 'regular-expression
299	(pgg-read-body-string ptag)))
300	(7 ;revocable
301	(cons 'revocability (pgg-read-byte)))
302	(9 ;key expiration time
303	(cons 'key-expiry
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))))
311	(12 ;revocation key
312	)
313	(16 ;issuer key ID
314	(cons 'key-identifier
315	(pgg-format-key-identifier (pgg-read-body-string ptag))))
316	(20 ;notation data
317	(pgg-skip-bytes 4)
318	(cons 'notation
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)
323	(nth 1 name-bytes)))
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
342	(26 ;policy URL
343	(cons 'policy-url (pgg-read-body-string ptag)))
344	;; 27 = key flags
345	;; 28 = signer's user id
346	;; 29 = reason for revocation
347	;; 100 to 110 = internal or user-defined
348	))
349
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)
354	(cond
355	((= signature-version 3)
356	(pgg-skip-bytes 2)
357	(setq hashed-material (pgg-read-bytes 5))
358	(pgg-set-alist result
359	'signature-type
360	(cdr (assq (pop hashed-material)
361	pgg-parse-signature-type-alist)))
362	(pgg-set-alist result
363	'creation-time
364	(pgg-parse-time-field hashed-material))
365	(pgg-set-alist result
366	'key-identifier
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)
374	(pgg-skip-bytes 1)
375	(pgg-set-alist result
376	'signature-type
377	(cdr (assq (pgg-read-byte)
378	pgg-parse-signature-type-alist)))
379	(pgg-set-alist result
380	'public-key-algorithm
381	(pgg-read-byte))
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)
386	(nth 1 n))))
387	(save-restriction
388	(narrow-to-region (point)(+ n (point)))
389	(nconc result
390	(mapcar (function cdr) ;remove packet types
391	(pgg-parse-packets
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)
397	(nth 1 n))))
398	(save-restriction
399	(narrow-to-region (point)(+ n (point)))
400	(nconc result
401	(mapcar (function cdr) ;remove packet types
402	(pgg-parse-packets
403	#'pgg-parse-signature-subpacket-header
404	#'pgg-parse-signature-subpacket)))))))
405
406	(setcdr (setq field (assq 'public-key-algorithm
407	result))
408	(cdr (assq (cdr field)
409	pgg-parse-public-key-algorithm-alist)))
410	(setcdr (setq field (assq 'hash-algorithm
411	result))
412	(cdr (assq (cdr field)
413	pgg-parse-hash-algorithm-alist)))
414	result))
415
416	(defun pgg-parse-public-key-encrypted-session-key-packet (ptag)
417	(let (result)
418	(pgg-set-alist result
419	'version (pgg-read-byte))
420	(pgg-set-alist result
421	'key-identifier
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)))
428	result))
429
430	(defun pgg-parse-symmetric-key-encrypted-session-key-packet (ptag)
431	(let (result)
432	(pgg-set-alist result
433	'version
434	(pgg-read-byte))
435	(pgg-set-alist result
436	'symmetric-key-algorithm
437	(cdr (assq (pgg-read-byte)
438	pgg-parse-symmetric-key-algorithm-alist)))
439	result))
440
441	(defun pgg-parse-public-key-packet (ptag)
442	(let* ((key-version (pgg-read-byte))
443	(result (list (cons 'version key-version)))
444	field)
445	(cond
446	((= 3 key-version)
447	(pgg-set-alist result
448	'creation-time
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)))
455	((= 4 key-version)
456	(pgg-set-alist result
457	'creation-time
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))))
462
463	(setcdr (setq field (assq 'public-key-algorithm
464	result))
465	(cdr (assq (cdr field)
466	pgg-parse-public-key-algorithm-alist)))
467	result))
468
14ecd9e4 GM	469	;; p-d-p only calls this if it is defined, but the compiler does not
	470	;; recognize that.
	471	(declare-function pgg-parse-crc24-string "pgg-parse" (string))
	472
23f87bed MB	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
	482	(buffer-string)))
	483	checksum)
	484	(progn
	485	(message "PGP packet checksum does not match")
	486	nil))
	487	(message "PGP packet contain invalid base64")
	488	nil))
	489	(message "PGP packet checksum not found")
	490	nil))
	491
	492	(defun pgg-decode-armor-region (start end)
	493	(save-restriction
	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")
	499	(match-end 0)))
	500	(when (pgg-decode-packets)
	501	(goto-char (point-min))
	502	(pgg-parse-packets))))
	503
	504	(defun pgg-parse-armor (string)
	505	(with-temp-buffer
	506	(buffer-disable-undo)
765d4319 KY	507	(unless (featurep 'xemacs)
765d4319 KY	508	(set-buffer-multibyte nil))
23f87bed MB	509	(insert string)
	510	(pgg-decode-armor-region (point-min)(point))))
	511
	512	(eval-and-compile
	513	(defalias 'pgg-string-as-unibyte (if (fboundp 'string-as-unibyte)
	514	'string-as-unibyte
	515	'identity)))
	516
	517	(defun pgg-parse-armor-region (start end)
	518	(pgg-parse-armor (pgg-string-as-unibyte (buffer-substring start end))))
	519
	520	(provide 'pgg-parse)
	521
cbee283d	522	;; arch-tag: 16c2eb82-1313-4a7c-a70f-420709b5b43e
23f87bed	523	;;; pgg-parse.el ends here