;;; epg.el --- the EasyPG Library
;; Copyright (C) 1999, 2000, 2002, 2003, 2004,
;;   2005, 2006 Free Software Foundation, Inc.
;; Copyright (C) 2006 Daiki Ueno

;; Author: Daiki Ueno <ueno@unixuser.org>
;; Keywords: PGP, GnuPG

;; This file is part of EasyPG.

;; This program 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 2, or (at your option)
;; any later version.

;; This program 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; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Code:

(defgroup epg ()
  "The EasyPG Library")

(defcustom epg-gpg-program "gpg"
  "The `gpg' executable."
  :group 'epg
  :type 'string)

(defcustom epg-gpgsm-program "gpgsm"
  "The `gpgsm' executable."
  :group 'epg
  :type 'string)

(defconst epg-version-number "0.0.0")

(defvar epg-user-id nil
  "GnuPG ID of your default identity.")

(defvar epg-user-id-alist nil
  "An alist mapping from key ID to user ID.")

(defvar epg-read-point nil)
(defvar epg-pending-status-list nil)
(defvar epg-key-id nil)
(defvar epg-context nil)
(defvar epg-debug nil)
(defvar epg-debug-buffer nil)

;; from gnupg/include/cipher.h
(defconst epg-cipher-algorithm-alist
  '((0 . "NONE")
    (1 . "IDEA")
    (2 . "3DES")
    (3 . "CAST5")
    (4 . "BLOWFISH")
    (7 . "AES")
    (8 . "AES192")
    (9 . "AES256")
    (10 . "TWOFISH")
    (110 . "DUMMY")))

;; from gnupg/include/cipher.h
(defconst epg-pubkey-algorithm-alist
  '((1 . "RSA")
    (2 . "RSA_E")
    (3 . "RSA_S")
    (16 . "ELGAMAL_E")
    (17 . "DSA")
    (20 . "ELGAMAL")))

;; from gnupg/include/cipher.h
(defconst epg-digest-algorithm-alist
  '((1 . "MD5")
    (2 . "SHA1")
    (3 . "RMD160")
    (8 . "SHA256")
    (9 . "SHA384")
    (10 . "SHA512")))

;; from gnupg/include/cipher.h
(defconst epg-compress-algorithm-alist
  '((0 . "NONE")
    (1 . "ZIP")
    (2 . "ZLIB")
    (3 . "BZIP2")))

(defconst epg-invalid-recipients-alist
  '((0 . "No specific reason given")
    (1 . "Not Found")
    (2 . "Ambigious specification")
    (3 . "Wrong key usage")
    (4 . "Key revoked")
    (5 . "Key expired")
    (6 . "No CRL known")
    (7 . "CRL too old")
    (8 . "Policy mismatch")
    (9 . "Not a secret key")
    (10 . "Key not trusted")))

(defconst epg-delete-problem-alist
  '((1 . "No such key")
    (2 . "Must delete secret key first")
    (3 . "Ambigious specification")))

(defvar epg-key-validity-alist
  '((?o . unknown)
    (?i . invalid)
    (?d . disabled)
    (?r . revoked)
    (?e . expired)
    (?- . none)
    (?q . undefined)
    (?n . never)
    (?m . marginal)
    (?f . full)
    (?u . ultimate)))

(defvar epg-key-capablity-alist
  '((?e . encrypt)
    (?s . sign)
    (?c . certify)
    (?a . authentication)))

(defvar epg-dn-type-alist
  '(("1.2.840.113549.1.9.1" . "EMail")
    ("2.5.4.12" . "T")
    ("2.5.4.42" . "GN")
    ("2.5.4.4" . "SN")
    ("0.2.262.1.10.7.20" . "NameDistinguisher")
    ("2.5.4.16" . "ADDR")
    ("2.5.4.15" . "BC")
    ("2.5.4.13" . "D")
    ("2.5.4.17" . "PostalCode")
    ("2.5.4.65" . "Pseudo")
    ("2.5.4.5" . "SerialNumber")))

(defvar epg-prompt-alist nil)

(defun epg-make-data-from-file (file)
  "Make a data object from FILE."
  (vector file nil))

(defun epg-make-data-from-string (string)
  "Make a data object from STRING."
  (vector nil string))

(defun epg-data-file (data)
  "Return the file of DATA."
  (aref data 0))

(defun epg-data-string (data)
  "Return the string of DATA."
  (aref data 1))

(defun epg-make-context (&optional protocol armor textmode include-certs
				   cipher-algorithm digest-algorithm
				   compress-algorithm)
  "Return a context object."
  (vector protocol armor textmode include-certs
	  cipher-algorithm digest-algorithm compress-algorithm
	  #'epg-passphrase-callback-function
	  #'epg-progress-callback-function
	  nil nil nil nil))

(defun epg-context-protocol (context)
  "Return the protocol used within CONTEXT."
  (aref context 0))

(defun epg-context-armor (context)
  "Return t if the output shouled be ASCII armored in CONTEXT."
  (aref context 1))

(defun epg-context-textmode (context)
  "Return t if canonical text mode should be used in CONTEXT."
  (aref context 2))

(defun epg-context-include-certs (context)
  "Return how many certificates should be included in an S/MIME signed
message."
  (aref context 3))

(defun epg-context-cipher-algorithm (context)
  "Return the cipher algorithm in CONTEXT."
  (aref context 4))

(defun epg-context-digest-algorithm (context)
  "Return the digest algorithm in CONTEXT."
  (aref context 5))

(defun epg-context-compress-algorithm (context)
  "Return the compress algorithm in CONTEXT."
  (aref context 6))

(defun epg-context-passphrase-callback (context)
  "Return the function used to query passphrase."
  (aref context 7))

(defun epg-context-progress-callback (context)
  "Return the function which handles progress update."
  (aref context 8))

(defun epg-context-signers (context)
  "Return the list of key-id for singning."
  (aref context 9))

(defun epg-context-process (context)
  "Return the process object of `epg-gpg-program'.
This function is for internal use only."
  (aref context 10))

(defun epg-context-output-file (context)
  "Return the output file of `epg-gpg-program'.
This function is for internal use only."
  (aref context 11))

(defun epg-context-result (context)
  "Return the result of the previous cryptographic operation."
  (aref context 12))

(defun epg-context-set-protocol (context protocol)
  "Set the protocol used within CONTEXT."
  (aset context 0 protocol))

(defun epg-context-set-armor (context armor)
  "Specify if the output shouled be ASCII armored in CONTEXT."
  (aset context 1 armor))

(defun epg-context-set-textmode (context textmode)
  "Specify if canonical text mode should be used in CONTEXT."
  (aset context 2 textmode))

(defun epg-context-set-include-certs (context include-certs)
 "Set how many certificates should be included in an S/MIME signed message."
  (aset context 3 include-certs))

(defun epg-context-set-cipher-algorithm (context cipher-algorithm)
 "Set the cipher algorithm in CONTEXT."
  (aset context 4 cipher-algorithm))

(defun epg-context-set-digest-algorithm (context digest-algorithm)
 "Set the digest algorithm in CONTEXT."
  (aset context 5 digest-algorithm))

(defun epg-context-set-compress-algorithm (context compress-algorithm)
 "Set the compress algorithm in CONTEXT."
  (aset context 6 compress-algorithm))

(defun epg-context-set-passphrase-callback (context
						 passphrase-callback)
  "Set the function used to query passphrase."
  (aset context 7 passphrase-callback))

(defun epg-context-set-progress-callback (context progress-callback)
  "Set the function which handles progress update."
  (aset context 8 progress-callback))

(defun epg-context-set-signers (context signers)
 "Set the list of key-id for singning."
  (aset context 9 signers))

(defun epg-context-set-process (context process)
  "Set the process object of `epg-gpg-program'.
This function is for internal use only."
  (aset context 10 process))

(defun epg-context-set-output-file (context output-file)
  "Set the output file of `epg-gpg-program'.
This function is for internal use only."
  (aset context 11 output-file))

(defun epg-context-set-result (context result)
  "Set the result of the previous cryptographic operation."
  (aset context 12 result))

(defun epg-make-signature (status key-id user-id)
  "Return a signature object."
  (vector status key-id user-id nil nil))

(defun epg-signature-status (signature)
  "Return the status code of SIGNATURE."
  (aref signature 0))

(defun epg-signature-key-id (signature)
  "Return the key-id of SIGNATURE."
  (aref signature 1))

(defun epg-signature-user-id (signature)
  "Return the user-id of SIGNATURE."
  (aref signature 2))
  
(defun epg-signature-validity (signature)
  "Return the validity of SIGNATURE."
  (aref signature 3))

(defun epg-signature-fingerprint (signature)
  "Return the fingerprint of SIGNATURE."
  (aref signature 4))

(defun epg-signature-set-status (signature status)
 "Set the status code of SIGNATURE."
  (aset signature 0 status))

(defun epg-signature-set-key-id (signature key-id)
 "Set the key-id of SIGNATURE."
  (aset signature 1 key-id))

(defun epg-signature-set-user-id (signature user-id)
 "Set the user-id of SIGNATURE."
  (aset signature 2 user-id))
  
(defun epg-signature-set-validity (signature validity)
 "Set the validity of SIGNATURE."
  (aset signature 3 validity))

(defun epg-signature-set-fingerprint (signature fingerprint)
 "Set the fingerprint of SIGNATURE."
  (aset signature 4 fingerprint))

(defun epg-make-key (owner-trust)
  "Return a key object."
  (vector owner-trust nil nil))

(defun epg-key-owner-trust (key)
  "Return the owner trust of KEY."
  (aref key 0))

(defun epg-key-sub-key-list (key)
  "Return the sub key list of KEY."
  (aref key 1))

(defun epg-key-user-id-list (key)
  "Return the user ID list of KEY."
  (aref key 2))

(defun epg-key-set-sub-key-list (key sub-key-list)
  "Set the sub key list of KEY."
  (aset key 1 sub-key-list))

(defun epg-key-set-user-id-list (key user-id-list)
  "Set the user ID list of KEY."
  (aset key 2 user-id-list))

(defun epg-make-sub-key (validity capability secret algorithm length id
				  creation-time expiration-time)
  "Return a sub key object."
  (vector validity capability secret algorithm length id creation-time
	  expiration-time nil))

(defun epg-sub-key-validity (sub-key)
  "Return the validity of SUB-KEY."
  (aref sub-key 0))

(defun epg-sub-key-capability (sub-key)
  "Return the capability of SUB-KEY."
  (aref sub-key 1))

(defun epg-sub-key-secret (sub-key)
  "Return non-nil if SUB-KEY is a secret key."
  (aref sub-key 2))

(defun epg-sub-key-algorithm (sub-key)
  "Return the algorithm of SUB-KEY."
  (aref sub-key 3))

(defun epg-sub-key-length (sub-key)
  "Return the length of SUB-KEY."
  (aref sub-key 4))

(defun epg-sub-key-id (sub-key)
  "Return the ID of SUB-KEY."
  (aref sub-key 5))

(defun epg-sub-key-creation-time (sub-key)
  "Return the creation time of SUB-KEY."
  (aref sub-key 6))

(defun epg-sub-key-expiration-time (sub-key)
  "Return the expiration time of SUB-KEY."
  (aref sub-key 7))

(defun epg-sub-key-fingerprint (sub-key)
  "Return the fingerprint of SUB-KEY."
  (aref sub-key 8))

(defun epg-sub-key-set-fingerprint (sub-key fingerprint)
  "Set the fingerprint of SUB-KEY.
This function is for internal use only."
  (aset sub-key 8 fingerprint))

(defun epg-make-user-id (validity name)
  "Return a user ID object."
  (vector validity name nil))

(defun epg-user-id-validity (user-id)
  "Return the validity of USER-ID."
  (aref user-id 0))

(defun epg-user-id-name (user-id)
  "Return the name of USER-ID."
  (aref user-id 1))

(defun epg-user-id-signature-list (user-id)
  "Return the signature list of USER-ID."
  (aref user-id 2))

(defun epg-user-id-set-signature-list (user-id signature-list)
  "Set the signature list of USER-ID."
  (aset user-id 2 signature-list))

(defun epg-context-result-for (context name)
  (cdr (assq name (epg-context-result context))))

(defun epg-context-set-result-for (context name value)
  (let* ((result (epg-context-result context))
	 (entry (assq name result)))
    (if entry
	(setcdr entry value)
      (epg-context-set-result context (cons (cons name value) result)))))

(defun epg-signature-to-string (signature)
  (format "%s signature from %s %s%s"
	  (capitalize (symbol-name (epg-signature-status signature)))
	  (epg-signature-key-id signature)
	  (epg-signature-user-id signature)
	  (if (epg-signature-validity signature)
	      (format " (trust %s)"
		      (epg-signature-validity signature))
	    "")))

(defun epg-verify-result-to-string (verify-result)
  (mapconcat #'epg-signature-to-string verify-result "\n"))

(defun epg-start (context args)
  "Start `epg-gpg-program' in a subprocess with given ARGS."
  (let* ((args (append (list "--no-tty"
			     "--status-fd" "1"
			     "--yes")
		       (unless (eq (epg-context-protocol context) 'CMS)
			 (list "--command-fd" "0"))
		       (if (epg-context-armor context) '("--armor"))
		       (if (epg-context-textmode context) '("--textmode"))
		       (if (epg-context-output-file context)
			   (list "--output" (epg-context-output-file context)))
		       args))
	 (coding-system-for-write 'binary)
	 process-connection-type
	 (orig-mode (default-file-modes))
	 (buffer (generate-new-buffer " *epg*"))
	 process)
    (if epg-debug
	(save-excursion
	  (unless epg-debug-buffer
	    (setq epg-debug-buffer (generate-new-buffer " *epg-debug*")))
	  (set-buffer epg-debug-buffer)
	  (goto-char (point-max))
	  (insert (format "%s %s\n"
			  (if (eq (epg-context-protocol context) 'CMS)
			      epg-gpgsm-program
			   epg-gpg-program)
			  (mapconcat #'identity args " ")))))
    (with-current-buffer buffer
      (make-local-variable 'epg-read-point)
      (setq epg-read-point (point-min))
      (make-local-variable 'epg-pending-status-list)
      (setq epg-pending-status-list nil)
      (make-local-variable 'epg-key-id)
      (setq epg-key-id nil)
      (make-local-variable 'epg-context)
      (setq epg-context context))
    (unwind-protect
	(progn
	  (set-default-file-modes 448)
	  (setq process
		(apply #'start-process "epg" buffer
		       (if (eq (epg-context-protocol context) 'CMS)
			   epg-gpgsm-program
			 epg-gpg-program)
		       args)))
      (set-default-file-modes orig-mode))
    (set-process-filter process #'epg-process-filter)
    (set-process-sentinel process #'epg-process-sentinel)
    (epg-context-set-process context process)))

(defun epg-process-filter (process input)
  (if epg-debug
      (save-excursion
	(unless epg-debug-buffer
	  (setq epg-debug-buffer (generate-new-buffer " *epg-debug*")))
	(set-buffer epg-debug-buffer)
	(goto-char (point-max))
	(insert input)))
  (if (buffer-live-p (process-buffer process))
      (save-excursion
	(set-buffer (process-buffer process))
	(goto-char (point-max))
	(insert input)
	(goto-char epg-read-point)
	(beginning-of-line)
	(while (looking-at ".*\n")	;the input line finished
	  (save-excursion
	    (if (looking-at "\\[GNUPG:] \\([A-Z_]+\\) ?\\(.*\\)")
		(let* ((status (match-string 1))
		       (string (match-string 2))
		       (symbol (intern-soft (concat "epg-status-" status))))
		  (if (member status epg-pending-status-list)
		      (setq epg-pending-status-list nil))
		  (if (and symbol
			   (fboundp symbol))
		      (funcall symbol process string)))))
	  (forward-line))
	(setq epg-read-point (point)))))

(defun epg-process-sentinel (process status)
  (if (and (buffer-live-p (process-buffer process))
	   (not (equal status "finished\n")))
      (save-excursion
	(set-buffer (process-buffer process))
	;; gpg process exited abnormally, but we have not received an
	;; error response from it.  Set it here.
	(unless (epg-context-result-for epg-context 'error)
	  (if (string-match "\\`exited abnormally with code \\(.*\\)\n" status)
	      (epg-context-set-result-for
	       epg-context 'error
	       (list (cons 'exit (string-to-number (match-string 1 status)))))
	    (epg-context-set-result-for epg-context 'error
				    (list (cons 'signal status))))))))

(defun epg-read-output (context)
  (with-temp-buffer
    (if (fboundp 'set-buffer-multibyte)
	(set-buffer-multibyte nil))
    (if (file-exists-p (epg-context-output-file context))
	(let ((coding-system-for-read (if (epg-context-textmode context)
					  'raw-text
					'binary)))
	  (insert-file-contents (epg-context-output-file context))
	  (buffer-string)))))

(defun epg-wait-for-status (context status-list)
  (with-current-buffer (process-buffer (epg-context-process context))
    (setq epg-pending-status-list status-list)
    (while (and (eq (process-status (epg-context-process context)) 'run)
		epg-pending-status-list)
      (accept-process-output (epg-context-process context) 1))))

(defun epg-wait-for-completion (context)
  (while (eq (process-status (epg-context-process context)) 'run)
    ;; We can't use accept-process-output instead of sit-for here
    ;; because it may cause an interrupt during the sentinel execution.
    (sit-for 0.1)))

(defun epg-flush (context)
  (if (eq (process-status (epg-context-process context)) 'run)
      (process-send-eof (epg-context-process context))))

(defun epg-reset (context)
  (if (and (epg-context-process context)
	   (buffer-live-p (process-buffer (epg-context-process context))))
      (kill-buffer (process-buffer (epg-context-process context))))
  (epg-context-set-process context nil))

(defun epg-delete-output-file (context)
  (if (and (epg-context-output-file context)
	   (file-exists-p (epg-context-output-file context)))
      (delete-file (epg-context-output-file context))))

(defun epg-status-USERID_HINT (process string)
  (if (string-match "\\`\\([^ ]+\\) \\(.*\\)" string)
      (let* ((key-id (match-string 1 string))
	     (user-id (match-string 2 string))
	     (entry (assoc key-id epg-user-id-alist)))
	(if entry
	    (setcdr entry user-id)
	  (setq epg-user-id-alist (cons (cons key-id user-id)
					epg-user-id-alist))))))

(defun epg-status-NEED_PASSPHRASE (process string)
  (if (string-match "\\`\\([^ ]+\\)" string)
      (setq epg-key-id (match-string 1 string))))

(defun epg-status-NEED_PASSPHRASE_SYM (process string)
  (setq epg-key-id 'SYM))

(defun epg-status-NEED_PASSPHRASE_PIN (process string)
  (setq epg-key-id 'PIN))

(defun epg-status-GET_HIDDEN (process string)
  (if (and epg-key-id
	   (string-match "\\`passphrase\\." string))
      (let (inhibit-quit
	    passphrase
	    passphrase-with-new-line)
	(unwind-protect
	    (condition-case nil
		(progn
		  (setq passphrase
			(funcall
			 (if (consp (epg-context-passphrase-callback
				     epg-context))
			     (car (epg-context-passphrase-callback
				   epg-context))
			   (epg-context-passphrase-callback epg-context))
			 epg-key-id
			 (if (consp (epg-context-passphrase-callback
				     epg-context))
			     (cdr (epg-context-passphrase-callback
				   epg-context)))))
		  (when passphrase
		    (setq passphrase-with-new-line (concat passphrase "\n"))
		    (fillarray passphrase 0)
		    (setq passphrase nil)
		    (process-send-string process passphrase-with-new-line)))
	      (quit
	       (epg-context-set-result-for
		epg-context 'error
		(cons 'quit
		      (epg-context-result-for epg-context 'error)))
	       (delete-process process)))
	  (if passphrase
	      (fillarray passphrase 0))
	  (if passphrase-with-new-line
	      (fillarray passphrase-with-new-line 0))))))

(defun epg-status-GET_BOOL (process string)
  (let ((entry (assoc string epg-prompt-alist))
	inhibit-quit)
    (condition-case nil
      (if (y-or-n-p (if entry (cdr entry) (concat string "? ")))
	  (process-send-string process "y\n")
	(process-send-string process "n\n"))
      (quit
       (epg-context-set-result-for
	epg-context 'error
	(cons 'quit
	      (epg-context-result-for epg-context 'error)))
       (delete-process process)))))

(defun epg-status-GET_LINE (process string)
  (let ((entry (assoc string epg-prompt-alist))
	inhibit-quit)
    (condition-case nil
	(process-send-string
	 process
	 (concat (read-string (if entry (cdr entry) (concat string ": ")))
		 "\n"))
      (quit
       (epg-context-set-result-for
	epg-context 'error
	(cons 'quit
	      (epg-context-result-for epg-context 'error)))
       (delete-process process)))))

(defun epg-status-GOODSIG (process string)
  (if (string-match "\\`\\([^ ]+\\) \\(.*\\)" string)
      (epg-context-set-result-for
       epg-context
       'verify
       (cons (epg-make-signature
	      'good
	      (match-string 1 string)
	      (if (eq (epg-context-protocol epg-context) 'CMS)
		  (condition-case nil
		      (epg-dn-from-string (match-string 2 string))
		    (error (match-string 2 string)))
		(match-string 2 string)))
	     (epg-context-result-for epg-context 'verify)))))

(defun epg-status-EXPSIG (process string)
  (if (string-match "\\`\\([^ ]+\\) \\(.*\\)" string)
      (epg-context-set-result-for
       epg-context
       'verify
       (cons (epg-make-signature
	      'expired
	      (match-string 1 string)
	      (if (eq (epg-context-protocol epg-context) 'CMS)
		  (condition-case nil
		      (epg-dn-from-string (match-string 2 string))
		    (error (match-string 2 string)))
		(match-string 2 string)))
	     (epg-context-result-for epg-context 'verify)))))

(defun epg-status-EXPKEYSIG (process string)
  (if (string-match "\\`\\([^ ]+\\) \\(.*\\)" string)
      (epg-context-set-result-for
       epg-context
       'verify
       (cons (epg-make-signature
	      'expired-key
	      (match-string 1 string)
	      (if (eq (epg-context-protocol epg-context) 'CMS)
		  (condition-case nil
		      (epg-dn-from-string (match-string 2 string))
		    (error (match-string 2 string)))
		(match-string 2 string)))
	     (epg-context-result-for epg-context 'verify)))))

(defun epg-status-REVKEYSIG (process string)
  (if (string-match "\\`\\([^ ]+\\) \\(.*\\)" string)
      (epg-context-set-result-for
       epg-context
       'verify
       (cons (epg-make-signature
	      'revoked-key
	      (match-string 1 string)
	      (if (eq (epg-context-protocol epg-context) 'CMS)
		  (condition-case nil
		      (epg-dn-from-string (match-string 2 string))
		    (error (match-string 2 string)))
		(match-string 2 string)))
	     (epg-context-result-for epg-context 'verify)))))

(defun epg-status-BADSIG (process string)
  (if (string-match "\\`\\([^ ]+\\) \\(.*\\)" string)
      (epg-context-set-result-for
       epg-context
       'verify
       (cons (epg-make-signature
	      'bad
	      (match-string 1 string)
	      (if (eq (epg-context-protocol epg-context) 'CMS)
		  (condition-case nil
		      (epg-dn-from-string (match-string 2 string))
		    (error (match-string 2 string)))
		(match-string 2 string)))
	     (epg-context-result-for epg-context 'verify)))))

(defun epg-status-VALIDSIG (process string)
  (let ((signature (car (epg-context-result-for epg-context 'verify))))
    (if (and signature
	     (eq (epg-signature-status signature) 'good)
	     (string-match "\\`\\([^ ]+\\) " string))
	(epg-signature-set-fingerprint signature (match-string 1 string)))))

(defun epg-status-TRUST_UNDEFINED (process string)
  (let ((signature (car (epg-context-result-for epg-context 'verify))))
    (if (and signature
	     (eq (epg-signature-status signature) 'good))
	(epg-signature-set-validity signature 'undefined))))

(defun epg-status-TRUST_NEVER (process string)
  (let ((signature (car (epg-context-result-for epg-context 'verify))))
    (if (and signature
	     (eq (epg-signature-status signature) 'good))
	(epg-signature-set-validity signature 'never))))

(defun epg-status-TRUST_MARGINAL (process string)
  (let ((signature (car (epg-context-result-for epg-context 'verify))))
    (if (and signature
	     (eq (epg-signature-status signature) 'marginal))
	(epg-signature-set-validity signature 'marginal))))

(defun epg-status-TRUST_FULLY (process string)
  (let ((signature (car (epg-context-result-for epg-context 'verify))))
    (if (and signature
	     (eq (epg-signature-status signature) 'good))
	(epg-signature-set-validity signature 'full))))

(defun epg-status-TRUST_ULTIMATE (process string)
  (let ((signature (car (epg-context-result-for epg-context 'verify))))
    (if (and signature
	     (eq (epg-signature-status signature) 'good))
	(epg-signature-set-validity signature 'ultimate))))

(defun epg-status-PROGRESS (process string)
  (if (string-match "\\`\\([^ ]+\\) \\([^ ]\\) \\([0-9]+\\) \\([0-9]+\\)"
		    string)
      (funcall (if (consp (epg-context-progress-callback epg-context))
		   (car (epg-context-progress-callback epg-context))
		 (epg-context-progress-callback epg-context))
	       (match-string 1 string)
	       (match-string 2 string)
	       (string-to-number (match-string 3 string))
	       (string-to-number (match-string 4 string))
	       (if (consp (epg-context-progress-callback epg-context))
		   (cdr (epg-context-progress-callback epg-context))))))

(defun epg-status-DECRYPTION_FAILED (process string)
  (epg-context-set-result-for
   epg-context 'error
   (cons 'decryption-failed
	 (epg-context-result-for epg-context 'error))))

(defun epg-status-NODATA (process string)
  (epg-context-set-result-for
   epg-context 'error
   (cons (cons 'no-data (string-to-number string))
	 (epg-context-result-for epg-context 'error))))

(defun epg-status-UNEXPECTED (process string)
  (epg-context-set-result-for
   epg-context 'error
   (cons (cons 'unexpected (string-to-number string))
	 (epg-context-result-for epg-context 'error))))

(defun epg-status-KEYEXPIRED (process string)
  (epg-context-set-result-for
   epg-context 'error
   (cons (cons 'key-expired string)
	 (epg-context-result-for epg-context 'error))))

(defun epg-status-KEYREVOKED (process string)
  (epg-context-set-result-for
   epg-context 'error
   (cons 'key-revoked
	 (epg-context-result-for epg-context 'error))))

(defun epg-status-BADARMOR (process string)
  (epg-context-set-result-for
   epg-context 'error
   (cons 'bad-armor
	 (epg-context-result-for epg-context 'error))))

(defun epg-status-INV_RECP (process string)
  (if (string-match "\\`\\([0-9]+\\) \\(.*\\)" string)
      (epg-context-set-result-for
       epg-context 'error
       (cons (list 'invalid-recipient
		   (string-to-number (match-string 1 string))
		   (match-string 2 string))
	     (epg-context-result-for epg-context 'error)))))

(defun epg-status-NO_RECP (process string)
  (epg-context-set-result-for
   epg-context 'error
   (cons 'no-recipients
	 (epg-context-result-for epg-context 'error))))

(defun epg-status-DELETE_PROBLEM (process string)
  (if (string-match "\\`\\([0-9]+\\)" string)
      (epg-context-set-result-for
       epg-context 'error
       (cons (cons 'delete-problem (string-to-number (match-string 1 string)))
	     (epg-context-result-for epg-context 'error)))))

(defun epg-status-SIG_CREATED (process string)
  (if (string-match "\\`\\([DCS]\\) \\([0-9]+\\) \\([0-9]+\\) \
\\([0-9A-Fa-F][0-9A-Fa-F]\\) \\(.*\\) " string)
      (epg-context-set-result-for
       epg-context 'sign
       (cons (list (cons 'type (string-to-char (match-string 1 string)))
		   (cons 'pubkey-algorithm
			 (string-to-number (match-string 2 string)))
		   (cons 'digest-algorithm
			 (string-to-number (match-string 3 string)))
		   (cons 'class (string-to-number (match-string 4 string) 16))
		   (cons 'creation-time (match-string 5 string))
		   (cons 'fingerprint (substring string (match-end 0))))
	     (epg-context-result-for epg-context 'sign)))))

(defun epg-passphrase-callback-function (key-id handback)
  (read-passwd
   (if (eq key-id 'SYM)
       "Passphrase for symmetric encryption: "
     (if (eq key-id 'PIN)
	 "Passphrase for PIN: "
       (let ((entry (assoc key-id epg-user-id-alist)))
	 (if entry
	     (format "Passphrase for %s %s: " key-id (cdr entry))
	   (format "Passphrase for %s: " key-id)))))))

(defun epg-progress-callback-function (what char current total handback)
  (message "%s: %d%%/%d%%" what current total))

(defun epg-configuration ()
  "Return a list of internal configuration parameters of `epg-gpg-program'."
  (let (config type)
    (with-temp-buffer
      (apply #'call-process epg-gpg-program nil (list t nil) nil
	     '("--with-colons" "--list-config"))
      (goto-char (point-min))
      (while (re-search-forward "^cfg:\\([^:]+\\):\\(.*\\)" nil t)
	(setq type (intern (match-string 1))
	      config (cons (cons type
				 (if (memq type
					   '(pubkey cipher digest compress))
				     (mapcar #'string-to-number
					     (delete "" (split-string
							 (match-string 2)
							 ";")))
				   (match-string 2)))
			   config))))
    config))

(defun epg-list-keys-1 (context name mode)
  (let ((args (append (list "--with-colons" "--no-greeting" "--batch"
			    "--with-fingerprint"
			    "--with-fingerprint"
			    (if mode "--list-secret-keys" "--list-keys"))
		      (unless (eq (epg-context-protocol context) 'CMS)
			'("--fixed-list-mode"))
		      (if name (list name))))
	keys string field index)
    (with-temp-buffer
      (apply #'call-process
	     (if (eq (epg-context-protocol context) 'CMS)
		 epg-gpgsm-program
	       epg-gpg-program)
	     nil (list t nil) nil args)
      (goto-char (point-min))
      (while (re-search-forward "^[a-z][a-z][a-z]:.*" nil t)
	(setq keys (cons (make-vector 15 nil) keys)
	      string (match-string 0)
	      index 0
	      field 0)
	(while (eq index
		   (string-match "\\([^:]+\\)?:" string index))
	  (setq index (match-end 0))
	  (aset (car keys) field (match-string 1 string))
	  (setq field (1+ field))))
      (nreverse keys))))

(defun epg-make-sub-key-1 (line)
  (epg-make-sub-key
   (if (aref line 1)
       (cdr (assq (string-to-char (aref line 1)) epg-key-validity-alist)))
   (delq nil
	 (mapcar (lambda (char) (cdr (assq char epg-key-capablity-alist)))
		 (aref line 11)))
   (member (aref line 0) '("sec" "ssb"))
   (string-to-number (aref line 3))
   (string-to-number (aref line 2))
   (aref line 4)
   (aref line 5)
   (aref line 6)))

(defun epg-list-keys (context &optional name mode)
  (let ((lines (epg-list-keys-1 context name mode))
	keys cert)
    (while lines
      (cond
       ((member (aref (car lines) 0) '("pub" "sec" "crt" "crs"))
	(when (car keys)
	  (epg-key-set-sub-key-list
	   (car keys)
	   (nreverse (epg-key-sub-key-list (car keys))))
	  (epg-key-set-user-id-list
	   (car keys)
	   (nreverse (epg-key-user-id-list (car keys)))))
	(setq cert (member (aref (car lines) 0) '("crt" "crs"))
	      keys (cons (epg-make-key
			  (if (aref (car lines) 8)
			      (cdr (assq (string-to-char (aref (car lines) 8))
					 epg-key-validity-alist))))
			 keys))
	(epg-key-set-sub-key-list
	 (car keys)
	 (cons (epg-make-sub-key-1 (car lines))
	       (epg-key-sub-key-list (car keys)))))
       ((member (aref (car lines) 0) '("sub" "ssb"))
	(epg-key-set-sub-key-list
	 (car keys)
	 (cons (epg-make-sub-key-1 (car lines))
	       (epg-key-sub-key-list (car keys)))))
       ((equal (aref (car lines) 0) "uid")
	(epg-key-set-user-id-list
	 (car keys)
	 (cons (epg-make-user-id
		(if (aref (car lines) 1)
		    (cdr (assq (string-to-char (aref (car lines) 1))
			       epg-key-validity-alist)))
		(if cert
		    (condition-case nil
			(epg-dn-from-string (aref (car lines) 9))
		      (error (aref (car lines) 9)))
		  (aref (car lines) 9)))
	       (epg-key-user-id-list (car keys)))))
       ((equal (aref (car lines) 0) "fpr")
	(epg-sub-key-set-fingerprint (car (epg-key-sub-key-list (car keys)))
				     (aref (car lines) 9))))
      (setq lines (cdr lines)))
    (when (car keys)
      (epg-key-set-sub-key-list
       (car keys)
       (nreverse (epg-key-sub-key-list (car keys))))
      (epg-key-set-user-id-list
       (car keys)
       (nreverse (epg-key-user-id-list (car keys)))))
    (nreverse keys)))

(if (fboundp 'make-temp-file)
    (defalias 'epg-make-temp-file 'make-temp-file)
  ;; stolen from poe.el.
  (defun epg-make-temp-file (prefix)
    "Create a temporary file.
The returned file name (created by appending some random characters at the end
of PREFIX, and expanding against `temporary-file-directory' if necessary),
is guaranteed to point to a newly created empty file.
You can then use `write-region' to write new data into the file."
    (let (tempdir tempfile)
      (unwind-protect
	  (let (file)
	    ;; First, create a temporary directory.
	    (while (condition-case ()
		       (progn
			 (setq tempdir (make-temp-name
					(concat
					 (file-name-directory prefix)
					 "DIR")))
			 ;; return nil or signal an error.
			 (make-directory tempdir))
		     ;; let's try again.
		     (file-already-exists t)))
	    (set-file-modes tempdir 448)
	    ;; Second, create a temporary file in the tempdir.
	    ;; There *is* a race condition between `make-temp-name'
	    ;; and `write-region', but we don't care it since we are
	    ;; in a private directory now.
	    (setq tempfile (make-temp-name (concat tempdir "/EMU")))
	    (write-region "" nil tempfile nil 'silent)
	    (set-file-modes tempfile 384)
	    ;; Finally, make a hard-link from the tempfile.
	    (while (condition-case ()
		       (progn
			 (setq file (make-temp-name prefix))
			 ;; return nil or signal an error.
			 (add-name-to-file tempfile file))
		     ;; let's try again.
		     (file-already-exists t)))
	    file)
	;; Cleanup the tempfile.
	(and tempfile
	     (file-exists-p tempfile)
	     (delete-file tempfile))
	;; Cleanup the tempdir.
	(and tempdir
	     (file-directory-p tempdir)
	     (delete-directory tempdir))))))

;;;###autoload
(defun epg-cancel (context)
  (delete-process (epg-context-process context)))
  
;;;###autoload
(defun epg-start-decrypt (context cipher)
  "Initiate a decrypt operation on CIPHER.
CIPHER is a data object.

If you use this function, you will need to wait for the completion of
`epg-gpg-program' by using `epg-wait-for-completion' and call
`epg-reset' to clear a temporaly output file.
If you are unsure, use synchronous version of this function
`epg-decrypt-file' or `epg-decrypt-string' instead."
  (unless (epg-data-file cipher)
    (error "Not a file"))
  (epg-context-set-result context nil)
  (epg-start context (list "--decrypt" (epg-data-file cipher)))
  ;; `gpgsm' does not read passphrase from stdin, so waiting is not needed.
  (unless (eq (epg-context-protocol context) 'CMS)
    (epg-wait-for-status context '("BEGIN_DECRYPTION"))))

;;;###autoload
(defun epg-decrypt-file (context cipher plain)
  "Decrypt a file CIPHER and store the result to a file PLAIN.
If PLAIN is nil, it returns the result as a string."
  (unwind-protect
      (progn
	(if plain
	    (epg-context-set-output-file context plain)
	  (epg-context-set-output-file context
				       (epg-make-temp-file "epg-output")))
	(epg-start-decrypt context (epg-make-data-from-file cipher))
	(epg-wait-for-completion context)
	(if (epg-context-result-for context 'error)
	    (error "Decrypt failed: %S"
		   (epg-context-result-for context 'error)))
	(unless plain
	  (epg-read-output context)))
    (unless plain
      (epg-delete-output-file context))
    (epg-reset context)))

;;;###autoload
(defun epg-decrypt-string (context cipher)
  "Decrypt a string CIPHER and return the plain text."
  (let ((input-file (epg-make-temp-file "epg-input"))
	(coding-system-for-write 'binary))
    (unwind-protect
	(progn
	  (write-region cipher nil input-file nil 'quiet)
	  (epg-context-set-output-file context
				       (epg-make-temp-file "epg-output"))
	  (epg-start-decrypt context (epg-make-data-from-file input-file))
	  (epg-flush context)
	  (epg-wait-for-completion context)
	  (if (epg-context-result-for context 'error)
	      (error "Decrypt failed: %S"
		     (epg-context-result-for context 'error)))
	  (epg-read-output context))
      (epg-delete-output-file context)
      (if (file-exists-p input-file)
	  (delete-file input-file))
      (epg-reset context))))

;;;###autoload
(defun epg-start-verify (context signature &optional signed-text)
  "Initiate a verify operation on SIGNATURE.
SIGNATURE and SIGNED-TEXT are a data object if they are specified.

For a detached signature, both SIGNATURE and SIGNED-TEXT should be set.
For a normal or a clear text signature, SIGNED-TEXT should be nil.

If you use this function, you will need to wait for the completion of
`epg-gpg-program' by using `epg-wait-for-completion' and call
`epg-reset' to clear a temporaly output file.
If you are unsure, use synchronous version of this function
`epg-verify-file' or `epg-verify-string' instead."
  (epg-context-set-result context nil)
  (if signed-text
      ;; Detached signature.
      (if (epg-data-file signed-text)
	  (epg-start context (list "--verify" (epg-data-file signature)
				   (epg-data-file signed-text)))
	(epg-start context (list "--verify" (epg-data-file signature) "-"))
	(if (eq (process-status (epg-context-process context)) 'run)
	    (process-send-string (epg-context-process context)
				 (epg-data-string signed-text))))
    ;; Normal (or cleartext) signature.
    (if (epg-data-file signature)
	(epg-start context (list "--verify" (epg-data-file signature)))
      (epg-start context (list "--verify"))
      (if (eq (process-status (epg-context-process context)) 'run)
	  (process-send-string (epg-context-process context)
			       (epg-data-string signature))))))

;;;###autoload
(defun epg-verify-file (context signature &optional signed-text plain)
  "Verify a file SIGNATURE.
SIGNED-TEXT and PLAIN are also a file if they are specified.

For a detached signature, both SIGNATURE and SIGNED-TEXT should be string.
For a normal or a clear text signature, SIGNED-TEXT should be nil."
  (unwind-protect
      (progn
	(if plain
	    (epg-context-set-output-file context plain)
	  (epg-context-set-output-file context
				       (epg-make-temp-file "epg-output")))
	(if signed-text
	    (epg-start-verify context
			      (epg-make-data-from-file signature)
			      (epg-make-data-from-file signed-text))
	  (epg-start-verify context
			    (epg-make-data-from-file signature)))
	(epg-wait-for-completion context)
	(unless plain
	  (epg-read-output context)))
    (unless plain
      (epg-delete-output-file context))
    (epg-reset context)))

;;;###autoload
(defun epg-verify-string (context signature &optional signed-text)
  "Verify a string SIGNATURE.
SIGNED-TEXT is a string if it is specified.

For a detached signature, both SIGNATURE and SIGNED-TEXT should be string.
For a normal or a clear text signature, SIGNED-TEXT should be nil."
  (let ((coding-system-for-write 'binary)
	input-file)
    (unwind-protect
	(progn
	  (epg-context-set-output-file context
				       (epg-make-temp-file "epg-output"))
	  (if signed-text
	      (progn
		(setq input-file (epg-make-temp-file "epg-signature"))
		(write-region signature nil input-file nil 'quiet)
		(epg-start-verify context
				  (epg-make-data-from-file input-file)
				  (epg-make-data-from-string signed-text)))
	    (epg-start-verify context (epg-make-data-from-string signature)))
	  (epg-flush context)
	  (epg-wait-for-completion context)
	  (epg-read-output context))
      (epg-delete-output-file context)
      (if (and input-file
	       (file-exists-p input-file))
	  (delete-file input-file))
      (epg-reset context))))

;;;###autoload
(defun epg-start-sign (context plain &optional mode)
  "Initiate a sign operation on PLAIN.
PLAIN is a data object.

If optional 3rd argument MODE is 'clearsign, it makes a clear text signature.
If MODE is t or 'detached, it makes a detached signature.
Otherwise, it makes a normal signature.

If you use this function, you will need to wait for the completion of
`epg-gpg-program' by using `epg-wait-for-completion' and call
`epg-reset' to clear a temporaly output file.
If you are unsure, use synchronous version of this function
`epg-sign-file' or `epg-sign-string' instead."
  (epg-context-set-result context nil)
  (epg-start context
	     (append (list (if (eq mode 'clearsign)
			       "--clearsign"
			     (if (or (eq mode t) (eq mode 'detached))
				 "--detach-sign"
			       "--sign")))
		     (apply #'nconc
			    (mapcar
			     (lambda (signer)
			       (list "-u"
				     (epg-sub-key-id
				      (car (epg-key-sub-key-list signer)))))
			     (epg-context-signers context)))
		     (if (epg-data-file plain)
			 (list (epg-data-file plain)))))
  ;; `gpgsm' does not read passphrase from stdin, so waiting is not needed.
  (unless (eq (epg-context-protocol context) 'CMS)
    (epg-wait-for-status context '("BEGIN_SIGNING")))
  (if (and (epg-data-string plain)
	   (eq (process-status (epg-context-process context)) 'run))
      (process-send-string (epg-context-process context)
			   (epg-data-string plain))))

;;;###autoload
(defun epg-sign-file (context plain signature &optional mode)
  "Sign a file PLAIN and store the result to a file SIGNATURE.
If SIGNATURE is nil, it returns the result as a string.
If optional 3rd argument MODE is 'clearsign, it makes a clear text signature.
If MODE is t or 'detached, it makes a detached signature.
Otherwise, it makes a normal signature."
  (unwind-protect
      (progn
	(if signature
	    (epg-context-set-output-file context signature)
	  (epg-context-set-output-file context
				       (epg-make-temp-file "epg-output")))
	(epg-start-sign context (epg-make-data-from-file plain) mode)
	(epg-wait-for-completion context)
	(if (epg-context-result-for context 'sign)
	    (if (epg-context-result-for context 'error)
		(message "Sign warning: %S"
			 (epg-context-result-for context 'error)))
	  (if (epg-context-result-for context 'error)
	      (error "Sign failed: %S"
		     (epg-context-result-for context 'error))
	    (error "Sign failed")))
	(unless signature
	  (epg-read-output context)))
    (unless signature
      (epg-delete-output-file context))
    (epg-reset context)))

;;;###autoload
(defun epg-sign-string (context plain &optional mode)
  "Sign a string PLAIN and return the output as string.
If optional 3rd argument MODE is 'clearsign, it makes a clear text signature.
If MODE is t or 'detached, it makes a detached signature.
Otherwise, it makes a normal signature."
  (unwind-protect
      (progn
	(epg-context-set-output-file context
				     (epg-make-temp-file "epg-output"))
	(epg-start-sign context (epg-make-data-from-string plain) mode)
	(epg-flush context)
	(epg-wait-for-completion context)
	(if (epg-context-result-for context 'sign)
	    (if (epg-context-result-for context 'error)
		(message "Sign warning: %S"
			 (epg-context-result-for context 'error)))
	  (if (epg-context-result-for context 'error)
	      (error "Sign failed: %S"
		     (epg-context-result-for context 'error))
	    (error "Sign failed")))
	(epg-read-output context))
    (epg-delete-output-file context)
    (epg-reset context)))

;;;###autoload
(defun epg-start-encrypt (context plain recipients
				  &optional sign always-trust)
  "Initiate an encrypt operation on PLAIN.
PLAIN is a data object.
If RECIPIENTS is nil, it performs symmetric encryption.

If you use this function, you will need to wait for the completion of
`epg-gpg-program' by using `epg-wait-for-completion' and call
`epg-reset' to clear a temporaly output file.
If you are unsure, use synchronous version of this function
`epg-encrypt-file' or `epg-encrypt-string' instead."
  (epg-context-set-result context nil)
  (epg-start context
	     (append (if always-trust '("--always-trust"))
		     (if recipients '("--encrypt") '("--symmetric"))
		     (if sign
			 (cons "--sign"
			       (apply #'nconc
				      (mapcar (lambda (signer)
						(list "-u" signer))
					      (epg-context-signers context)))))
		     (apply #'nconc
			    (mapcar
			     (lambda (recipient)
			       (list "-r"
				     (epg-sub-key-id
				      (car (epg-key-sub-key-list recipient)))))
			     recipients))
		     (if (epg-data-file plain)
			 (list (epg-data-file plain)))))
  ;; `gpgsm' does not read passphrase from stdin, so waiting is not needed.
  (unless (eq (epg-context-protocol context) 'CMS)
    (if sign
	(epg-wait-for-status context '("BEGIN_SIGNING"))
      (epg-wait-for-status context '("BEGIN_ENCRYPTION"))))
  (if (and (epg-data-string plain)
	   (eq (process-status (epg-context-process context)) 'run))
      (process-send-string (epg-context-process context)
			   (epg-data-string plain))))

;;;###autoload
(defun epg-encrypt-file (context plain recipients
				 cipher &optional sign always-trust)
  "Encrypt a file PLAIN and store the result to a file CIPHER.
If CIPHER is nil, it returns the result as a string.
If RECIPIENTS is nil, it performs symmetric encryption."
  (unwind-protect
      (progn
	(if cipher
	    (epg-context-set-output-file context cipher)
	  (epg-context-set-output-file context
				       (epg-make-temp-file "epg-output")))
	(epg-start-encrypt context (epg-make-data-from-file plain)
			   recipients sign always-trust)
	(epg-wait-for-completion context)
	(if sign
	    (if (epg-context-result-for context 'sign)
		(if (epg-context-result-for context 'error)
		    (message "Sign warning: %S"
			     (epg-context-result-for context 'error)))
	      (if (epg-context-result-for context 'error)
		  (error "Sign failed: %S"
			 (epg-context-result-for context 'error))
		(error "Sign failed"))))
	(if (epg-context-result-for context 'error)
	    (error "Encrypt failed: %S"
		   (epg-context-result-for context 'error)))
	(unless cipher
	  (epg-read-output context)))
    (unless cipher
      (epg-delete-output-file context))
    (epg-reset context)))

;;;###autoload
(defun epg-encrypt-string (context plain recipients
				   &optional sign always-trust)
  "Encrypt a string PLAIN.
If RECIPIENTS is nil, it performs symmetric encryption."
  (unwind-protect
      (progn
	(epg-context-set-output-file context
				     (epg-make-temp-file "epg-output"))
	(epg-start-encrypt context (epg-make-data-from-string plain)
			   recipients sign always-trust)
	(epg-flush context)
	(epg-wait-for-completion context)
	(if sign
	    (if (epg-context-result-for context 'sign)
		(if (epg-context-result-for context 'error)
		    (message "Sign warning: %S"
			     (epg-context-result-for context 'error)))
	      (if (epg-context-result-for context 'error)
		  (error "Sign failed: %S"
			 (epg-context-result-for context 'error))
		(error "Sign failed"))))
	(if (epg-context-result-for context 'error)
	    (error "Encrypt failed: %S"
		   (epg-context-result-for context 'error)))
	(epg-read-output context))
    (epg-delete-output-file context)
    (epg-reset context)))

;;;###autoload
(defun epg-start-export-keys (context keys)
  "Initiate an export keys operation.

If you use this function, you will need to wait for the completion of
`epg-gpg-program' by using `epg-wait-for-completion' and call
`epg-reset' to clear a temporaly output file.
If you are unsure, use synchronous version of this function
`epg-export-keys-to-file' or `epg-export-keys-to-string' instead."
  (epg-context-set-result context nil)
  (epg-start context (cons "--export"
			   (mapcar
			    (lambda (key)
			      (epg-sub-key-id
			       (car (epg-key-sub-key-list key))))
			    keys))))

;;;###autoload
(defun epg-export-keys-to-file (context keys file)
  "Extract public KEYS."
  (unwind-protect
      (progn
	(if keys
	    (epg-context-set-output-file context file)
	  (epg-context-set-output-file context
				       (epg-make-temp-file "epg-output")))
	(epg-start-export-keys context keys)
	(epg-wait-for-completion context)
	(if (epg-context-result-for context 'error)
	    (error "Export keys failed: %S"
		   (epg-context-result-for context 'error)))
	(unless file
	  (epg-read-output context)))
    (unless file
      (epg-delete-output-file context))
    (epg-reset context)))

;;;###autoload
(defun epg-export-keys-to-string (context keys)
  "Extract public KEYS and return them as a string."
  (epg-export-keys-to-file context keys nil))

;;;###autoload
(defun epg-start-import-keys (context keys)
  "Initiate an import keys operation.
KEYS is a data object.

If you use this function, you will need to wait for the completion of
`epg-gpg-program' by using `epg-wait-for-completion' and call
`epg-reset' to clear a temporaly output file.
If you are unsure, use synchronous version of this function
`epg-import-keys-from-file' or `epg-import-keys-from-string' instead."
  (epg-context-set-result context nil)
  (epg-context-set-output-file context (epg-make-temp-file "epg-output"))
  (epg-start context (list "--import" (epg-data-file keys)))
  (if (and (epg-data-string keys)
	   (eq (process-status (epg-context-process context)) 'run))
      (process-send-string (epg-context-process context)
			   (epg-data-string keys))))
  
(defun epg-import-keys-1 (context keys)
  (unwind-protect
      (progn
	(epg-start-import-keys context keys)
	(if (epg-data-file keys)
	    (epg-flush context))
	(epg-wait-for-completion context)
	(if (epg-context-result-for context 'error)
	    (error "Import keys failed: %S"
		   (epg-context-result-for context 'error)))
	(epg-read-output context))
    (epg-reset context)))

;;;###autoload
(defun epg-import-keys-from-file (context keys)
  "Add keys from a file KEYS."
  (epg-import-keys-1 context (epg-make-data-from-file keys)))

;;;###autoload
(defun epg-import-keys-from-string (context keys)
  "Add keys from a string KEYS."
  (epg-import-keys-1 context (epg-make-data-from-string keys)))

;;;###autoload
(defun epg-start-delete-keys (context keys &optional allow-secret)
  "Initiate an delete keys operation.

If you use this function, you will need to wait for the completion of
`epg-gpg-program' by using `epg-wait-for-completion' and call
`epg-reset' to clear a temporaly output file.
If you are unsure, use synchronous version of this function
`epg-delete-keys' instead."
  (epg-context-set-result context nil)
  (epg-start context (cons (if allow-secret
			       "--delete-secret-key"
			     "--delete-key")
			   (mapcar
			    (lambda (key)
			      (epg-sub-key-id
			       (car (epg-key-sub-key-list key))))
			    keys))))

;;;###autoload
(defun epg-delete-keys (context keys &optional allow-secret)
  "Delete KEYS from the key ring."
  (unwind-protect
      (progn
	(epg-start-delete-keys context keys allow-secret)
	(epg-wait-for-completion context)
	(if (epg-context-result-for context 'error)
	    (error "Delete keys failed: %S"
		   (epg-context-result-for context 'error))))
    (epg-reset context)))

;;;###autoload
(defun epg-start-sign-keys (context keys &optional local)
  "Initiate an sign keys operation.

If you use this function, you will need to wait for the completion of
`epg-gpg-program' by using `epg-wait-for-completion' and call
`epg-reset' to clear a temporaly output file.
If you are unsure, use synchronous version of this function
`epg-sign-keys' instead."
  (epg-context-set-result context nil)
  (epg-start context (cons (if local
			       "--lsign-key"
			     "--sign-key")
			   (mapcar
			    (lambda (key)
			      (epg-sub-key-id
			       (car (epg-key-sub-key-list key))))
			    keys))))

;;;###autoload
(defun epg-sign-keys (context keys &optional local)
  "Sign KEYS from the key ring."
  (unwind-protect
      (progn
	(epg-start-sign-keys context keys local)
	(epg-wait-for-completion context)
	(if (epg-context-result-for context 'error)
	    (error "Sign keys failed: %S"
		   (epg-context-result-for context 'error))))
    (epg-reset context)))

(defun epg-decode-hexstring (string)
  (let ((index 0))
    (while (eq index (string-match "[0-9A-Fa-f][0-9A-Fa-f]" string index))
      (setq string (replace-match "\\x\\&" t nil string)
	    index (+ index 4)))
    (car (read-from-string (concat "\"" string "\"")))))

(defun epg-decode-quotedstring (string)
  (let ((index 0))
    (while (string-match "\\\\\\(\\([,=+<>#;\\\"]\\)\\|\
\\([0-9A-Fa-f][0-9A-Fa-f]\\)\\|\\(.\\)\\)"
			 string index)
      (if (match-beginning 2)
	  (setq string (replace-match "\\2" t nil string)
		index (1+ index))
	(if (match-beginning 3)
	    (setq string (replace-match "\\x\\3" t nil string)
		  index (+ index 4))
	  (setq string (replace-match "\\\\\\\\\\4" t nil string)
		index (+ index 3)))))
    (car (read-from-string (concat "\"" string "\"")))))

(defun epg-dn-from-string (string)
  "Parse STRING as LADPv3 Distinguished Names (RFC2253).
The return value is an alist mapping from types to values."
  (let ((index 0)
	(length (length string))
	alist type value group)
    (while (< index length)
      (if (eq index (string-match "[ \t\n\r]*" string index))
	  (setq index (match-end 0)))
      (if (eq index (string-match
		     "\\([0-9]+\\(\\.[0-9]+\\)*\\)\[ \t\n\r]*=[ \t\n\r]*"
		     string index))
	  (setq type (match-string 1 string)
		index (match-end 0))
	(if (eq index (string-match "\\([0-9A-Za-z]+\\)[ \t\n\r]*=[ \t\n\r]*"
				    string index))
	    (setq type (match-string 1 string)
		  index (match-end 0))))
      (unless type
	(error "Invalid type"))
      (if (eq index (string-match
		     "\\([^,=+<>#;\\\"]\\|\\\\.\\)+"
		     string index))
	  (setq index (match-end 0)
		value (epg-decode-quotedstring (match-string 0 string)))
	(if (eq index (string-match "#\\([0-9A-Fa-f]+\\)" string index))
	    (setq index (match-end 0)
		  value (epg-decode-hexstring (match-string 1 string)))
	  (if (eq index (string-match "\"\\([^\\\"]\\|\\\\.\\)*\""
				      string index))
	      (setq index (match-end 0)
		    value (epg-decode-quotedstring (match-string 0 string))))))
      (if group
	  (if (stringp (car (car alist)))
	      (setcar alist (list (cons type value) (car alist)))
	    (setcar alist (cons (cons type value) (car alist))))
	(if (consp (car (car alist)))
	    (setcar alist (nreverse (car alist))))
	(setq alist (cons (cons type value) alist)
	      type nil
	      value nil))
      (if (eq index (string-match "[ \t\n\r]*\\([,;+]\\)" string index))
	  (setq index (match-end 0)
		group (eq (aref string (match-beginning 1)) ?+))))
    (nreverse alist)))

(defun epg-decode-dn (alist)
  "Convert ALIST returned by `epg-dn-from-string' to a human readable form.
Type names are resolved using `epg-dn-type-alist'."
  (mapconcat
   (lambda (rdn)
     (if (stringp (car rdn))
	 (let ((entry (assoc (car rdn) epg-dn-type-alist)))
	   (if entry
	       (format "%s=%s" (cdr entry) (cdr rdn))
	     (format "%s=%s" (car rdn) (cdr rdn))))
       (concat "(" (epg-decode-dn rdn) ")")))
   alist
   ", "))

(provide 'epg)

;;; epg.el ends here