Avoid div-by-zero error.

[elisp/epg.git] / epg.el

;;; 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:

(require 'epg-config)

(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-process-filter-running nil)
(defvar epg-pending-status-list nil)
(defvar epg-key-id nil)
(defvar epg-context 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-reason-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-reason-alist
  '((1 . "No such key")
    (2 . "Must delete secret key first")
    (3 . "Ambigious specification")))

(defconst epg-import-ok-reason-alist
  '((0 . "Not actually changed")
    (1 . "Entirely new key")
    (2 . "New user IDs")
    (4 . "New signatures")
    (8 . "New subkeys")
    (16 . "Contains private key")))

(defconst epg-import-problem-reason-alist
  '((0 . "No specific reason given")
    (1 . "Invalid Certificate")
    (2 . "Issuer Certificate missing")
    (3 . "Certificate Chain too long")
    (4 . "Error storing certificate")))

(defconst epg-no-data-reason-alist
  '((1 . "No armored data")
    (2 . "Expected a packet but did not found one")
    (3 . "Invalid packet found, this may indicate a non OpenPGP message")
    (4 . "Signature expected but not found")))

(defconst epg-unexpected-reason-alist nil)

(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-new-signature-type-alist
  '((?D . detached)
    (?C . clear)
    (?S . normal)))

(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."
  (cons 'epg-data (vector file nil)))

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

(defun epg-data-file (data)
  "Return the file of DATA."
  (unless (eq (car data) 'epg-data)
    (signal 'wrong-type-argument (list 'epg-data-p data)))
  (aref (cdr data) 0))

(defun epg-data-string (data)
  "Return the string of DATA."
  (unless (eq (car data) 'epg-data)
    (signal 'wrong-type-argument (list 'epg-data-p data)))
  (aref (cdr data) 1))

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

(defun epg-context-protocol (context)
  "Return the protocol used within CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 0))

(defun epg-context-armor (context)
  "Return t if the output shouled be ASCII armored in CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 1))

(defun epg-context-textmode (context)
  "Return t if canonical text mode should be used in CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 2))

(defun epg-context-include-certs (context)
  "Return how many certificates should be included in an S/MIME signed
message."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 3))

(defun epg-context-cipher-algorithm (context)
  "Return the cipher algorithm in CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 4))

(defun epg-context-digest-algorithm (context)
  "Return the digest algorithm in CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 5))

(defun epg-context-compress-algorithm (context)
  "Return the compress algorithm in CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 6))

(defun epg-context-passphrase-callback (context)
  "Return the function used to query passphrase."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 7))

(defun epg-context-progress-callback (context)
  "Return the function which handles progress update."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 8))

(defun epg-context-signers (context)
  "Return the list of key-id for singning."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 9))

(defun epg-context-process (context)
  "Return the process object of `epg-gpg-program'.
This function is for internal use only."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 10))

(defun epg-context-output-file (context)
  "Return the output file of `epg-gpg-program'.
This function is for internal use only."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 11))

(defun epg-context-result (context)
  "Return the result of the previous cryptographic operation."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 12))

(defun epg-context-operation (context)
  "Return the name of the current cryptographic operation."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aref (cdr context) 13))

(defun epg-context-set-protocol (context protocol)
  "Set the protocol used within CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr context) 0 protocol))

(defun epg-context-set-armor (context armor)
  "Specify if the output shouled be ASCII armored in CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr context) 1 armor))

(defun epg-context-set-textmode (context textmode)
  "Specify if canonical text mode should be used in CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr 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."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr context) 3 include-certs))

(defun epg-context-set-cipher-algorithm (context cipher-algorithm)
 "Set the cipher algorithm in CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr context) 4 cipher-algorithm))

(defun epg-context-set-digest-algorithm (context digest-algorithm)
 "Set the digest algorithm in CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr context) 5 digest-algorithm))

(defun epg-context-set-compress-algorithm (context compress-algorithm)
 "Set the compress algorithm in CONTEXT."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr context) 6 compress-algorithm))

(defun epg-context-set-passphrase-callback (context
                                                 passphrase-callback)
  "Set the function used to query passphrase."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr context) 7 passphrase-callback))

(defun epg-context-set-progress-callback (context progress-callback)
  "Set the function which handles progress update."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr context) 8 progress-callback))

(defun epg-context-set-signers (context signers)
 "Set the list of key-id for singning."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr 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."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr 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."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr context) 11 output-file))

(defun epg-context-set-result (context result)
  "Set the result of the previous cryptographic operation."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr context) 12 result))

(defun epg-context-set-operation (context operation)
  "Set the name of the current cryptographic operation."
  (unless (eq (car context) 'epg-context)
    (signal 'wrong-type-argument (list 'epg-context-p context)))
  (aset (cdr context) 13 operation))

(defun epg-make-signature (status &optional key-id)
  "Return a signature object."
  (cons 'epg-signature (vector status key-id nil nil nil nil nil nil nil nil)))

(defun epg-signature-status (signature)
  "Return the status code of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aref (cdr signature) 0))

(defun epg-signature-key-id (signature)
  "Return the key-id of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aref (cdr signature) 1))

(defun epg-signature-validity (signature)
  "Return the validity of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aref (cdr signature) 2))

(defun epg-signature-fingerprint (signature)
  "Return the fingerprint of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aref (cdr signature) 3))

(defun epg-signature-creation-time (signature)
  "Return the creation time of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aref (cdr signature) 4))

(defun epg-signature-expiration-time (signature)
  "Return the expiration time of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aref (cdr signature) 5))

(defun epg-signature-pubkey-algorithm (signature)
  "Return the public key algorithm of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aref (cdr signature) 6))

(defun epg-signature-digest-algorithm (signature)
  "Return the digest algorithm of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aref (cdr signature) 7))

(defun epg-signature-class (signature)
  "Return the class of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aref (cdr signature) 8))

(defun epg-signature-version (signature)
  "Return the version of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aref (cdr signature) 9))

(defun epg-signature-set-status (signature status)
 "Set the status code of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aset (cdr signature) 0 status))

(defun epg-signature-set-key-id (signature key-id)
 "Set the key-id of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aset (cdr signature) 1 key-id))

(defun epg-signature-set-validity (signature validity)
 "Set the validity of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aset (cdr signature) 2 validity))

(defun epg-signature-set-fingerprint (signature fingerprint)
 "Set the fingerprint of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aset (cdr signature) 3 fingerprint))

(defun epg-signature-set-creation-time (signature creation-time)
  "Set the creation time of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aset (cdr signature) 4 creation-time))

(defun epg-signature-set-expiration-time (signature expiration-time)
  "Set the expiration time of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aset (cdr signature) 5 expiration-time))

(defun epg-signature-set-pubkey-algorithm (signature pubkey-algorithm)
  "Set the public key algorithm of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aset (cdr signature) 6 pubkey-algorithm))

(defun epg-signature-set-digest-algorithm (signature digest-algorithm)
  "Set the digest algorithm of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aset (cdr signature) 7 digest-algorithm))

(defun epg-signature-set-class (signature class)
  "Set the class of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aset (cdr signature) 8 class))

(defun epg-signature-set-version (signature version)
  "Set the version of SIGNATURE."
  (unless (eq (car signature) 'epg-signature)
    (signal 'wrong-type-argument (list 'epg-signature-p signature)))
  (aset (cdr signature) 9 version))

(defun epg-make-new-signature (type pubkey-algorithm digest-algorithm
                                    class creation-time fingerprint)
  "Return a new signature object."
  (cons 'epg-new-signature (vector type pubkey-algorithm digest-algorithm
                                   class creation-time fingerprint)))

(defun epg-new-signature-type (new-signature)
  "Return the type of NEW-SIGNATURE."
  (unless (eq (car new-signature) 'epg-new-signature)
    (signal 'wrong-type-argument (list 'epg-new-signature-p new-signature)))
  (aref (cdr new-signature) 0))

(defun epg-new-signature-pubkey-algorithm (new-signature)
  "Return the public key algorithm of NEW-SIGNATURE."
  (unless (eq (car new-signature) 'epg-new-signature)
    (signal 'wrong-type-argument (list 'epg-new-signature-p new-signature)))
  (aref (cdr new-signature) 1))

(defun epg-new-signature-digest-algorithm (new-signature)
  "Return the digest algorithm of NEW-SIGNATURE."
  (unless (eq (car new-signature) 'epg-new-signature)
    (signal 'wrong-type-argument (list 'epg-new-signature-p new-signature)))
  (aref (cdr new-signature) 2))

(defun epg-new-signature-class (new-signature)
  "Return the class of NEW-SIGNATURE."
  (unless (eq (car new-signature) 'epg-new-signature)
    (signal 'wrong-type-argument (list 'epg-new-signature-p new-signature)))
  (aref (cdr new-signature) 3))

(defun epg-new-signature-creation-time (new-signature)
  "Return the creation time of NEW-SIGNATURE."
  (unless (eq (car new-signature) 'epg-new-signature)
    (signal 'wrong-type-argument (list 'epg-new-signature-p new-signature)))
  (aref (cdr new-signature) 4))

(defun epg-new-signature-fingerprint (new-signature)
  "Return the fingerprint of NEW-SIGNATURE."
  (unless (eq (car new-signature) 'epg-new-signature)
    (signal 'wrong-type-argument (list 'epg-new-signature-p new-signature)))
  (aref (cdr new-signature) 5))

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

(defun epg-key-owner-trust (key)
  "Return the owner trust of KEY."
  (unless (eq (car key) 'epg-key)
    (signal 'wrong-type-argument (list 'epg-key-p key)))
  (aref (cdr key) 0))

(defun epg-key-sub-key-list (key)
  "Return the sub key list of KEY."
  (unless (eq (car key) 'epg-key)
    (signal 'wrong-type-argument (list 'epg-key-p key)))
  (aref (cdr key) 1))

(defun epg-key-user-id-list (key)
  "Return the user ID list of KEY."
  (unless (eq (car key) 'epg-key)
    (signal 'wrong-type-argument (list 'epg-key-p key)))
  (aref (cdr key) 2))

(defun epg-key-set-sub-key-list (key sub-key-list)
  "Set the sub key list of KEY."
  (unless (eq (car key) 'epg-key)
    (signal 'wrong-type-argument (list 'epg-key-p key)))
  (aset (cdr key) 1 sub-key-list))

(defun epg-key-set-user-id-list (key user-id-list)
  "Set the user ID list of KEY."
  (unless (eq (car key) 'epg-key)
    (signal 'wrong-type-argument (list 'epg-key-p key)))
  (aset (cdr key) 2 user-id-list))

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

(defun epg-sub-key-validity (sub-key)
  "Return the validity of SUB-KEY."
  (unless (eq (car sub-key) 'epg-sub-key)
    (signal 'wrong-type-argument (list 'epg-sub-key-p sub-key)))
  (aref (cdr sub-key) 0))

(defun epg-sub-key-capability (sub-key)
  "Return the capability of SUB-KEY."
  (unless (eq (car sub-key) 'epg-sub-key)
    (signal 'wrong-type-argument (list 'epg-sub-key-p sub-key)))
  (aref (cdr sub-key) 1))

(defun epg-sub-key-secret-p (sub-key)
  "Return non-nil if SUB-KEY is a secret key."
  (unless (eq (car sub-key) 'epg-sub-key)
    (signal 'wrong-type-argument (list 'epg-sub-key-p sub-key)))
  (aref (cdr sub-key) 2))

(defun epg-sub-key-algorithm (sub-key)
  "Return the algorithm of SUB-KEY."
  (unless (eq (car sub-key) 'epg-sub-key)
    (signal 'wrong-type-argument (list 'epg-sub-key-p sub-key)))
  (aref (cdr sub-key) 3))

(defun epg-sub-key-length (sub-key)
  "Return the length of SUB-KEY."
  (unless (eq (car sub-key) 'epg-sub-key)
    (signal 'wrong-type-argument (list 'epg-sub-key-p sub-key)))
  (aref (cdr sub-key) 4))

(defun epg-sub-key-id (sub-key)
  "Return the ID of SUB-KEY."
  (unless (eq (car sub-key) 'epg-sub-key)
    (signal 'wrong-type-argument (list 'epg-sub-key-p sub-key)))
  (aref (cdr sub-key) 5))

(defun epg-sub-key-creation-time (sub-key)
  "Return the creation time of SUB-KEY."
  (unless (eq (car sub-key) 'epg-sub-key)
    (signal 'wrong-type-argument (list 'epg-sub-key-p sub-key)))
  (aref (cdr sub-key) 6))

(defun epg-sub-key-expiration-time (sub-key)
  "Return the expiration time of SUB-KEY."
  (unless (eq (car sub-key) 'epg-sub-key)
    (signal 'wrong-type-argument (list 'epg-sub-key-p sub-key)))
  (aref (cdr sub-key) 7))

(defun epg-sub-key-fingerprint (sub-key)
  "Return the fingerprint of SUB-KEY."
  (unless (eq (car sub-key) 'epg-sub-key)
    (signal 'wrong-type-argument (list 'epg-sub-key-p sub-key)))
  (aref (cdr 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."
  (unless (eq (car sub-key) 'epg-sub-key)
    (signal 'wrong-type-argument (list 'epg-sub-key-p sub-key)))
  (aset (cdr sub-key) 8 fingerprint))

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

(defun epg-user-id-validity (user-id)
  "Return the validity of USER-ID."
  (unless (eq (car user-id) 'epg-user-id)
    (signal 'wrong-type-argument (list 'epg-user-id-p user-id)))
  (aref (cdr user-id) 0))

(defun epg-user-id-string (user-id)
  "Return the name of USER-ID."
  (unless (eq (car user-id) 'epg-user-id)
    (signal 'wrong-type-argument (list 'epg-user-id-p user-id)))
  (aref (cdr user-id) 1))

(defun epg-user-id-signature-list (user-id)
  "Return the signature list of USER-ID."
  (unless (eq (car user-id) 'epg-user-id)
    (signal 'wrong-type-argument (list 'epg-user-id-p user-id)))
  (aref (cdr user-id) 2))

(defun epg-user-id-set-signature-list (user-id signature-list)
  "Set the signature list of USER-ID."
  (unless (eq (car user-id) 'epg-user-id)
    (signal 'wrong-type-argument (list 'epg-user-id-p user-id)))
  (aset (cdr user-id) 2 signature-list))

(defun epg-make-key-signature (validity pubkey-algorithm key-id creation-time
                                        expiration-time user-id class
                                        exportable-p)
  "Return a key signature object."
  (cons 'epg-key-signature
        (vector validity pubkey-algorithm key-id creation-time expiration-time
                user-id class exportable-p)))

(defun epg-key-signature-validity (key-signature)
  "Return the validity of KEY-SIGNATURE."
  (unless (eq (car key-signature) 'epg-key-signature)
    (signal 'wrong-type-argument (list 'epg-key-signature-p key-signature)))
  (aref (cdr key-signature) 0))

(defun epg-key-signature-pubkey-algorithm (key-signature)
  "Return the public key algorithm of KEY-SIGNATURE."
  (unless (eq (car key-signature) 'epg-key-signature)
    (signal 'wrong-type-argument (list 'epg-key-signature-p key-signature)))
  (aref (cdr key-signature) 1))

(defun epg-key-signature-key-id (key-signature)
  "Return the key-id of KEY-SIGNATURE."
  (unless (eq (car key-signature) 'epg-key-signature)
    (signal 'wrong-type-argument (list 'epg-key-signature-p key-signature)))
  (aref (cdr key-signature) 2))

(defun epg-key-signature-creation-time (key-signature)
  "Return the creation time of KEY-SIGNATURE."
  (unless (eq (car key-signature) 'epg-key-signature)
    (signal 'wrong-type-argument (list 'epg-key-signature-p key-signature)))
  (aref (cdr key-signature) 3))

(defun epg-key-signature-expiration-time (key-signature)
  "Return the expiration time of KEY-SIGNATURE."
  (unless (eq (car key-signature) 'epg-key-signature)
    (signal 'wrong-type-argument (list 'epg-key-signature-p key-signature)))
  (aref (cdr key-signature) 4))

(defun epg-key-signature-user-id (key-signature)
  "Return the user-id of KEY-SIGNATURE."
  (unless (eq (car key-signature) 'epg-key-signature)
    (signal 'wrong-type-argument (list 'epg-key-signature-p key-signature)))
  (aref (cdr key-signature) 5))

(defun epg-key-signature-class (key-signature)
  "Return the class of KEY-SIGNATURE."
  (unless (eq (car key-signature) 'epg-key-signature)
    (signal 'wrong-type-argument (list 'epg-key-signature-p key-signature)))
  (aref (cdr key-signature) 6))

(defun epg-key-signature-exportable-p (key-signature)
  "Return t if KEY-SIGNATURE is exportable."
  (unless (eq (car key-signature) 'epg-key-signature)
    (signal 'wrong-type-argument (list 'epg-key-signature-p key-signature)))
  (aref (cdr key-signature) 7))

(defun epg-context-result-for (context name)
  "Return the result of CONTEXT associated with NAME."
  (cdr (assq name (epg-context-result context))))

(defun epg-context-set-result-for (context name value)
  "Set the result of CONTEXT associated with NAME to 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)
  "Convert SIGNATURE to a human readable string."
  (let ((user-id (cdr (assoc (epg-signature-key-id signature)
                             epg-user-id-alist))))
    (concat
     (cond ((eq (epg-signature-status signature) 'good)
            "Good signature from ")
           ((eq (epg-signature-status signature) 'bad)
            "Bad signature from ")
           ((eq (epg-signature-status signature) 'expired)
            "Expired signature from ")
           ((eq (epg-signature-status signature) 'expired-key)
            "Signature made by expired key ")
           ((eq (epg-signature-status signature) 'revoked-key)
            "Signature made by revoked key ")
           ((eq (epg-signature-status signature) 'no-pubkey)
            "No public key for "))
     (epg-signature-key-id signature)
     (if user-id
         (concat " "
                 (if (stringp user-id)
                     user-id
                   (epg-decode-dn user-id)))
       "")
     (if (epg-signature-validity signature)
         (format " (trust %s)"  (epg-signature-validity signature))
       ""))))

(defun epg-verify-result-to-string (verify-result)
  "Convert VERIFY-RESULT to a human readable string."
  (mapconcat #'epg-signature-to-string verify-result "\n"))

(defun epg-new-signature-to-string (new-signature)
  "Convert NEW-SIGNATURE to a human readable string."
  (concat
   (cond ((eq (epg-new-signature-type new-signature) 'detached)
          "Detached signature ")
         ((eq (epg-new-signature-type new-signature) 'clear)
          "Clear text signature ")
         (t
          "Signature "))
   (cdr (assq (epg-new-signature-pubkey-algorithm new-signature)
              epg-pubkey-algorithm-alist))
   "/"
   (cdr (assq (epg-new-signature-digest-algorithm new-signature)
              epg-digest-algorithm-alist))
   " "
   (format "%02X " (epg-new-signature-class new-signature))
   (epg-new-signature-fingerprint new-signature)))

(defun epg--start (context args)
  "Start `epg-gpg-program' in a subprocess with given ARGS."
  (if (and (epg-context-process context)
           (eq (process-status (epg-context-process context)) 'run))
      (error "%s is already running in this context"
             (if (eq (epg-context-protocol context) 'CMS)
                 epg-gpgsm-program
               epg-gpg-program)))
  (let* ((args (append (list "--no-tty"
                             "--status-fd" "1"
                             "--yes"
                             "--enable-progress-filter")
                       (if epg-gpg-home-directory
                           (list "--homedir" epg-gpg-home-directory))
                       (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-process-filter-running)
      (setq epg-process-filter-running nil)
      (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)
    (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)
        (unless epg-process-filter-running
          (unwind-protect
              (progn
                (setq epg-process-filter-running t)
                (goto-char epg-read-point)
                (beginning-of-line)
                (while (looking-at ".*\n") ;the input line finished
                  (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 epg-context string))))
                  (forward-line)
                  (setq epg-read-point (point))))
            (setq epg-process-filter-running nil))))))

(defun epg-read-output (context)
  "Read the output file CONTEXT and return the content as a string."
  (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 'binary))
          (insert-file-contents (epg-context-output-file context))
          (buffer-string)))))

(defun epg-wait-for-status (context status-list)
  "Wait until one of elements in STATUS-LIST arrives."
  (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)
  "Wait until the `epg-gpg-program' process completes."
  (while (eq (process-status (epg-context-process context)) 'run)
    (accept-process-output (epg-context-process context) 1)))

(defun epg-reset (context)
  "Reset the 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)
  "Delete the output file of 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 (context 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 (context string)
  (if (string-match "\\`\\([^ ]+\\)" string)
      (setq epg-key-id (match-string 1 string))))

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

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

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

(defun epg--status-GET_BOOL (context 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 (epg-context-process context) "y\n")
        (process-send-string (epg-context-process context) "n\n"))
      (quit
       (epg-context-set-result-for
        context 'error
        (cons '(quit)
              (epg-context-result-for context 'error)))
       (delete-process (epg-context-process context))))))

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

(defun epg--status-*SIG (context status 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)))
        (epg-context-set-result-for
         context
         'verify
         (cons (epg-make-signature status key-id)
               (epg-context-result-for context 'verify)))
        (if (eq (epg-context-protocol context) 'CMS)
            (condition-case nil
                (setq user-id (epg-dn-from-string user-id))
              (error)))
        (if entry
            (setcdr entry user-id)
          (setq epg-user-id-alist
                (cons (cons key-id user-id) epg-user-id-alist))))
    (epg-context-set-result-for
     context
     'verify
     (cons (epg-make-signature status)
           (epg-context-result-for context 'verify)))))

(defun epg--status-GOODSIG (context string)
  (epg--status-*SIG context 'good string))

(defun epg--status-EXPSIG (context string)
  (epg--status-*SIG context 'expired string))

(defun epg--status-EXPKEYSIG (context string)
  (epg--status-*SIG context 'expired-key string))

(defun epg--status-REVKEYSIG (context string)
  (epg--status-*SIG context 'revoked-key string))

(defun epg--status-BADSIG (context string)
  (epg--status-*SIG context 'bad string))

(defun epg--status-NO_PUBKEY (context string)
  (let ((signature (car (epg-context-result-for context 'verify))))
    (if (and signature
             (eq (epg-signature-status signature) 'error)
             (equal (epg-signature-key-id signature) string))
        (epg-signature-set-status signature 'no-pubkey))))

(defun epg--time-from-seconds (seconds)
  (let ((number-seconds (string-to-number (concat seconds ".0"))))
    (cons (floor (/ number-seconds 65536))
          (floor (mod number-seconds 65536)))))

(defun epg--status-ERRSIG (context string)
  (if (string-match "\\`\\([^ ]+\\) \\([0-9]+\\) \\([0-9]+\\) \
\\([0-9A-Fa-f][0-9A-Fa-f]\\) \\([^ ]+\\) \\([0-9]+\\)"
                    string)
      (let ((signature (epg-make-signature 'error)))
        (epg-context-set-result-for
         context
         'verify
         (cons signature
               (epg-context-result-for context 'verify)))
        (epg-signature-set-key-id
         signature
         (match-string 1 string))
        (epg-signature-set-pubkey-algorithm
         signature
         (string-to-number (match-string 2 string)))
        (epg-signature-set-digest-algorithm
         signature
         (string-to-number (match-string 3 string)))
        (epg-signature-set-class
         signature
         (string-to-number (match-string 4 string) 16))
        (epg-signature-set-creation-time
         signature
         (epg--time-from-seconds (match-string 5 string))))))

(defun epg--status-VALIDSIG (context string)
  (let ((signature (car (epg-context-result-for context 'verify))))
    (when (and signature
               (eq (epg-signature-status signature) 'good)
               (string-match "\\`\\([^ ]+\\) [^ ]+ \\([^ ]+\\) \\([^ ]+\\) \
\\([0-9]+\\) [^ ]+ \\([0-9]+\\) \\([0-9]+\\) \\([0-9A-Fa-f][0-9A-Fa-f]\\) \
\\(.*\\)"
                           string))
      (epg-signature-set-fingerprint
       signature
       (match-string 1 string))
      (epg-signature-set-creation-time
       signature
       (epg--time-from-seconds (match-string 2 string)))
      (epg-signature-set-expiration-time
       signature
       (epg--time-from-seconds (match-string 3 string)))
      (epg-signature-set-version
       signature
       (string-to-number (match-string 4 string)))
      (epg-signature-set-pubkey-algorithm
       signature 
       (string-to-number (match-string 5 string)))
      (epg-signature-set-digest-algorithm
       signature
       (string-to-number (match-string 6 string)))
      (epg-signature-set-class
       signature
       (string-to-number (match-string 7 string) 16)))))

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

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

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

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

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

(defun epg--status-PROGRESS (context string)
  (if (string-match "\\`\\([^ ]+\\) \\([^ ]\\) \\([0-9]+\\) \\([0-9]+\\)"
                    string)
      (funcall (if (consp (epg-context-progress-callback context))
                   (car (epg-context-progress-callback context))
                 (epg-context-progress-callback context))
               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 context))
                   (cdr (epg-context-progress-callback context))))))

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

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

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

(defun epg--status-KEYEXPIRED (context string)
  (epg-context-set-result-for
   context 'error
   (cons (list 'key-expired (cons 'expiration-time
                                  (epg--time-from-seconds string)))
         (epg-context-result-for context 'error))))

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

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

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

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

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

(defun epg--status-SIG_CREATED (context string)
  (if (string-match "\\`\\([DCS]\\) \\([0-9]+\\) \\([0-9]+\\) \
\\([0-9A-Fa-F][0-9A-Fa-F]\\) \\(.*\\) " string)
      (epg-context-set-result-for
       context 'sign
       (cons (epg-make-new-signature
              (cdr (assq (aref (match-string 1 string) 0)
                         epg-new-signature-type-alist))
              (string-to-number (match-string 2 string))
              (string-to-number (match-string 3 string))
              (string-to-number (match-string 4 string) 16)
              (epg--time-from-seconds (match-string 5 string))
              (substring string (match-end 0)))
             (epg-context-result-for context 'sign)))))

(defun epg--status-KEY_CREATED (context string)
  (if (string-match "\\`\\([BPS]\\) \\([^ ]+\\)" string)
      (epg-context-set-result-for
       context 'generate-key
       (cons (list (cons 'type (string-to-char (match-string 1 string)))
                   (cons 'fingerprint (match-string 2 string)))
             (epg-context-result-for context 'generate-key)))))

(defun epg--status-KEY_NOT_CREATED (context string)
  (epg-context-set-result-for
   context 'error
   (cons '(key-not-created)
         (epg-context-result-for context 'error))))

(defun epg--status-IMPORTED (context 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)))
        (epg-context-set-result-for
         context 'import
         (cons (list (cons 'key-id key-id)
                     (cons 'user-id user-id))
               (epg-context-result-for context 'import))))))

(defun epg--status-IMPORT_OK (context string)
  (let ((result (epg-context-result-for context 'import)))
    (if (and result
             (string-match "\\`\\([0-9]+\\)\\( \\(.+\\)\\)?" string))
        (setcar result
                (append (list (cons 'reason
                                    (string-to-number
                                     (match-string 1 string))))
                        (if (match-beginning 2)
                            (list (cons 'fingerprint
                                        (match-string 3 string))))
                        (car result))))))

(defun epg--status-IMPORT_PROBLEM (context string)
  (if (string-match "\\`\\([0-9]+\\)\\( \\(.+\\)\\)?" string)
      (epg-context-set-result-for
       context 'error
       (cons (cons 'import-problem
                   (append (list (cons 'reason
                                       (string-to-number
                                        (match-string 1 string))))
                           (if (match-beginning 2)
                               (list (cons 'fingerprint
                                           (match-string 3 string))))))
             (epg-context-result-for context 'error)))))

(defun epg-passphrase-callback-function (context key-id handback)
  (if (eq key-id 'SYM)
      (read-passwd "Passphrase for symmetric encryption: "
                   (eq (epg-context-operation context) 'encrypt))
    (read-passwd
     (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 (context what char current total
                                               handback)
  (message "%s: %d%% (%d/%d)" what (if (> total 0) (/ current 1.0 total) 0)
           current total))

(defun epg--list-keys-1 (context name mode)
  (let ((args (append (if epg-gpg-home-directory
                          (list "--homedir" epg-gpg-home-directory))
                      (list "--with-colons" "--no-greeting" "--batch"
                            "--with-fingerprint"
                            "--with-fingerprint"
                            (if (memq mode '(t secret))
                                "--list-secret-keys"
                              (if (memq mode '(nil public))
                                  "--list-keys"
                                "--list-sigs")))
                      (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)
   (epg--time-from-seconds (aref line 5))
   (epg--time-from-seconds (aref line 6))))

;;;###autoload
(defun epg-list-keys (context &optional name mode)
  "Return a list of epg-key objects matched with NAME.
If MODE is nil or 'public, only public keyring should be searched.
If MODE is t or 'secret, only secret keyring should be searched. 
Otherwise, only public keyring should be searched and the key
signatures should be included."
  (let ((lines (epg--list-keys-1 context name mode))
        keys cert pointer pointer-1)
    (while lines
      (cond
       ((member (aref (car lines) 0) '("pub" "sec" "crt" "crs"))
        (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)))
       ((equal (aref (car lines) 0) "sig")
        (epg-user-id-set-signature-list
         (car (epg-key-user-id-list (car keys)))
         (cons
          (epg-make-key-signature
           (if (aref (car lines) 1)
               (cdr (assq (string-to-char (aref (car lines) 1))
                          epg-key-validity-alist)))
           (string-to-number (aref (car lines) 3))
           (aref (car lines) 4)
           (epg--time-from-seconds (aref (car lines) 5))
           (epg--time-from-seconds (aref (car lines) 6))
           (aref (car lines) 9)
           (string-to-number (aref (car lines) 10) 16)
           (eq (aref (aref (car lines) 10) 2) ?x))
          (epg-user-id-signature-list
           (car (epg-key-user-id-list (car keys))))))))
      (setq lines (cdr lines)))
    (setq keys (nreverse keys)
          pointer keys)
    (while pointer
      (epg-key-set-sub-key-list
       (car pointer)
       (nreverse (epg-key-sub-key-list (car pointer))))
      (setq pointer-1 (epg-key-set-user-id-list
                          (car pointer)
                          (nreverse (epg-key-user-id-list (car pointer)))))
      (while pointer-1
        (epg-user-id-set-signature-list
         (car pointer-1)
         (nreverse (epg-user-id-signature-list (car pointer-1))))
        (setq pointer-1 (cdr pointer-1)))
      (setq pointer (cdr pointer)))
    keys))

(if (fboundp 'make-temp-file)
    (defalias 'epg--make-temp-file 'make-temp-file)
  (defvar temporary-file-directory)
  ;; 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)
      (setq prefix (expand-file-name prefix
                                     (if (featurep 'xemacs)
                                         (temp-directory)
                                       temporary-file-directory)))
      (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))))))

(if (fboundp 'clear-string)
    (defalias 'epg--clear-string 'clear-string)
  (defun epg--clear-string (string)
    (fillarray string 0)))

;;;###autoload
(defun epg-cancel (context)
  (if (buffer-live-p (process-buffer (epg-context-process context)))
      (save-excursion
        (set-buffer (process-buffer (epg-context-process context)))
        (epg-context-set-result-for
         epg-context 'error
         (cons '(quit)
               (epg-context-result-for epg-context 'error)))))
  (if (eq (process-status (epg-context-process context)) 'run)
      (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-operation context 'decrypt)
  (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-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-operation context 'verify)
  (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)))
        (if (eq (process-status (epg-context-process context)) 'run)
            (process-send-eof (epg-context-process context))))
    ;; 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)))
      (if (eq (process-status (epg-context-process context)) 'run)
          (process-send-eof (epg-context-process context))))))

;;;###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)
;       (if (epg-context-result-for context 'error)
;           (error "Verify 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-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-wait-for-completion context)
;         (if (epg-context-result-for context 'error)
;             (error "Verify failed: %S"
;                    (epg-context-result-for context 'error)))
          (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 t or 'detached, it makes a detached signature.
If it is nil or 'normal, it makes a normal signature.
Otherwise, it makes a clear text 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-operation context 'sign)
  (epg-context-set-result context nil)
  (epg--start context
             (append (list (if (memq mode '(t detached))
                               "--detach-sign"
                             (if (memq mode '(nil normal))
                                 "--sign"
                               "--clearsign")))
                     (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")))
  (when (epg-data-string plain)
    (if (eq (process-status (epg-context-process context)) 'run)
        (process-send-string (epg-context-process context)
                             (epg-data-string plain)))
    (if (eq (process-status (epg-context-process context)) 'run)
        (process-send-eof (epg-context-process context)))))

;;;###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 t or 'detached, it makes a detached signature.
If it is nil or 'normal, it makes a normal signature.
Otherwise, it makes a clear text 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)
        (unless (epg-context-result-for context 'sign)
          (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 t or 'detached, it makes a detached signature.
If it is nil or 'normal, it makes a normal signature.
Otherwise, it makes a clear text 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-wait-for-completion context)
        (unless (epg-context-result-for context 'sign)
          (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-operation context 'encrypt)
  (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"
                                               (epg-sub-key-id
                                                (car (epg-key-sub-key-list
                                                      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"))))
  (when (epg-data-string plain)
    (if (eq (process-status (epg-context-process context)) 'run)
        (process-send-string (epg-context-process context)
                             (epg-data-string plain)))
    (if (eq (process-status (epg-context-process context)) 'run)
        (process-send-eof (epg-context-process context)))))

;;;###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 (and sign
                 (not (epg-context-result-for context 'sign)))
            (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-wait-for-completion context)
        (if (and sign
                 (not (epg-context-result-for context 'sign)))
            (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-operation context 'export-keys)
  (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-operation context 'import-keys)
  (epg-context-set-result context nil)
  (epg--start context (if (epg-data-file keys)
                          (list "--import" (epg-data-file keys))
                        (list "--import")))
  (when (epg-data-string keys)
    (if (eq (process-status (epg-context-process context)) 'run)
        (process-send-string (epg-context-process context)
                             (epg-data-string keys)))
    (if (eq (process-status (epg-context-process context)) 'run)
        (process-send-eof (epg-context-process context)))))

(defun epg--import-keys-1 (context keys)
  (unwind-protect
      (progn
        (epg-start-import-keys context keys)
        (epg-wait-for-completion context)
        (if (epg-context-result-for context 'error)
            (error "Import keys failed: %S"
                   (epg-context-result-for context 'error))))
    (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-receive-keys (context key-id-list)
  "Initiate a receive key operation.
KEY-ID-LIST is a list of key IDs.

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-generate-key-from-file' or `epg-generate-key-from-string' instead."
  (epg-context-set-operation context 'receive-keys)
  (epg-context-set-result context nil)
  (epg--start context (cons "--recv-keys" key-id-list)))

;;;###autoload
(defun epg-receive-keys (context keys)
  "Add keys from server.
KEYS is a list of key IDs"
  (unwind-protect
      (progn
        (epg-start-receive-keys context keys)
        (epg-wait-for-completion context)
        (if (epg-context-result-for context 'error)
            (error "Receive keys failed: %S"
                   (epg-context-result-for context 'error))))
    (epg-reset context)))

;;;###autoload
(defalias 'epg-import-keys-from-server 'epg-receive-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-operation context 'delete-keys)
  (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-operation context 'sign-keys)
  (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)))

;;;###autoload
(defun epg-start-generate-key (context parameters)
  "Initiate a key generation.
PARAMETERS specifies parameters for the key.

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-generate-key-from-file' or `epg-generate-key-from-string' instead."
  (epg-context-set-operation context 'generate-key)
  (epg-context-set-result context nil)
  (if (epg-data-file parameters)
      (epg--start context (list "--batch" "--genkey"
                               (epg-data-file parameters)))
    (epg--start context '("--batch" "--genkey"))
    (if (eq (process-status (epg-context-process context)) 'run)
        (process-send-string (epg-context-process context)
                             (epg-data-string parameters)))
    (if (eq (process-status (epg-context-process context)) 'run)
        (process-send-eof (epg-context-process context)))))

;;;###autoload
(defun epg-generate-key-from-file (context parameters)
  "Generate a new key pair.
PARAMETERS is a file which tells how to create the key."
  (unwind-protect
      (progn
        (epg-start-generate-key context (epg-make-data-from-file parameters))
        (epg-wait-for-completion context)
        (if (epg-context-result-for context 'error)
            (error "Generate key failed: %S"
                   (epg-context-result-for context 'error))))
    (epg-reset context)))

;;;###autoload
(defun epg-generate-key-from-string (context parameters)
  "Generate a new key pair.
PARAMETERS is a string which tells how to create the key."
  (unwind-protect
      (progn
        (epg-start-generate-key context (epg-make-data-from-string parameters))
        (epg-wait-for-completion context)
        (if (epg-context-result-for context 'error)
            (error "Generate key 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