emacs/lisp/gnus/mml2015.el

1014 lines
33 KiB
EmacsLisp

;;; mml2015.el --- MIME Security with Pretty Good Privacy (PGP) -*- lexical-binding: t; -*-
;; Copyright (C) 2000-2024 Free Software Foundation, Inc.
;; Author: Shenghuo Zhu <zsh@cs.rochester.edu>
;; Keywords: PGP MIME MML
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;; RFC 2015 is updated by RFC 3156, this file should be compatible
;; with both.
;;; Code:
(eval-when-compile (require 'cl-lib))
(require 'mm-decode)
(require 'mm-util)
(require 'mml)
(require 'mml-sec)
(require 'epg-config)
(defvar mc-pgp-always-sign)
(declare-function epg-check-configuration "ext:epg-config"
(config &optional minimum-version))
(declare-function epg-configuration "ext:epg-config" ())
;; Maybe this should be in eg mml-sec.el (and have a different name).
;; Then mml1991 would not need to require mml2015, and mml1991-use
;; could be removed.
(defvar mml2015-use 'epg
"The package used for PGP/MIME.
Valid packages include `epg', and `mailcrypt'.")
;; Something is not RFC2015.
(defvar mml2015-function-alist
'((mailcrypt mml2015-mailcrypt-sign
mml2015-mailcrypt-encrypt
mml2015-mailcrypt-verify
mml2015-mailcrypt-decrypt
mml2015-mailcrypt-clear-verify
mml2015-mailcrypt-clear-decrypt)
(pgg mml2015-pgg-sign
mml2015-pgg-encrypt
mml2015-pgg-verify
mml2015-pgg-decrypt
mml2015-pgg-clear-verify
mml2015-pgg-clear-decrypt)
(epg mml2015-epg-sign
mml2015-epg-encrypt
mml2015-epg-verify
mml2015-epg-decrypt
mml2015-epg-clear-verify
mml2015-epg-clear-decrypt))
"Alist of PGP/MIME functions.")
(defvar mml2015-result-buffer nil)
(defcustom mml2015-unabbrev-trust-alist
'(("TRUST_UNDEFINED" . nil)
("TRUST_NEVER" . nil)
("TRUST_MARGINAL" . t)
("TRUST_FULLY" . t)
("TRUST_ULTIMATE" . t))
"Map GnuPG trust output values to a boolean saying if you trust the key."
:version "22.1"
:group 'mime-security
:type '(repeat (cons (regexp :tag "GnuPG output regexp")
(boolean :tag "Trust key"))))
(defcustom mml2015-cache-passphrase mml-secure-cache-passphrase
"If t, cache passphrase."
:group 'mime-security
:type 'boolean)
(make-obsolete-variable 'mml2015-cache-passphrase
'mml-secure-cache-passphrase
"25.1")
(defcustom mml2015-passphrase-cache-expiry mml-secure-passphrase-cache-expiry
"How many seconds the passphrase is cached.
Whether the passphrase is cached at all is controlled by
`mml2015-cache-passphrase'."
:group 'mime-security
:type 'integer)
(make-obsolete-variable 'mml2015-passphrase-cache-expiry
'mml-secure-passphrase-cache-expiry
"25.1")
(defcustom mml2015-signers nil
"A list of your own key ID(s) which will be used to sign a message.
If set, it overrides the setting of `mml2015-sign-with-sender'."
:group 'mime-security
:type '(repeat (string :tag "Key ID")))
(defcustom mml2015-sign-with-sender nil
"If t, use message sender so find a key to sign with."
:group 'mime-security
:type 'boolean
:version "24.1")
(defcustom mml2015-encrypt-to-self nil
"If t, add your own key ID to recipient list when encryption."
:group 'mime-security
:type 'boolean)
(defcustom mml2015-always-trust t
"If t, GnuPG skip key validation on encryption."
:group 'mime-security
:type 'boolean)
(defcustom mml2015-maximum-key-image-dimension 64
"The maximum dimension (width or height) of any key images."
:version "24.4"
:group 'mime-security
:type 'integer)
(defcustom mml2015-display-key-image t
"If t, try to display key images."
:version "24.5"
:group 'mime-security
:type 'boolean)
;; Extract plaintext from cleartext signature. IMO, this kind of task
;; should be done by GnuPG rather than Elisp, but older PGP backends
;; (such as Mailcrypt, and PGG) discard the output from GnuPG.
(defun mml2015-extract-cleartext-signature ()
;; Daiki Ueno in
;; <54a15d860801080142l70b95d7dkac4bf51a86196011@mail.gmail.com>: ``I still
;; believe that the right way is to use the plaintext output from GnuPG as
;; it is, and mml2015-extract-cleartext-signature is just a kludge for
;; misdesigned libraries like PGG, which have no ability to do that. So, I
;; think it should not have descriptive documentation.''
;;
;; This function doesn't handle NotDashEscaped correctly. EasyPG handles it
;; correctly.
;; http://thread.gmane.org/gmane.emacs.gnus.general/66062/focus=66082 [dead link]
;; http://thread.gmane.org/gmane.emacs.gnus.general/65087/focus=65109 [dead link]
(goto-char (point-min))
(forward-line)
;; We need to be careful not to strip beyond the armor headers.
;; Previously, an attacker could replace the text inside our
;; markup with trailing garbage by injecting whitespace into the
;; message.
(while (looking-at "Hash:") ; The only header allowed in cleartext
(forward-line)) ; signatures according to RFC2440.
(when (looking-at "[\t ]*$")
(forward-line))
(delete-region (point-min) (point))
(if (re-search-forward "^-----BEGIN PGP SIGNATURE-----" nil t)
(delete-region (match-beginning 0) (point-max)))
(goto-char (point-min))
(while (re-search-forward "^- " nil t)
(replace-match "" t t)
(forward-line 1)))
;;; mailcrypt wrapper
(autoload 'mailcrypt-decrypt "mailcrypt")
(autoload 'mailcrypt-verify "mailcrypt")
(autoload 'mc-pgp-always-sign "mailcrypt")
(autoload 'mc-encrypt-generic "mc-toplev")
(autoload 'mc-cleanup-recipient-headers "mc-toplev")
(autoload 'mc-sign-generic "mc-toplev")
(defvar mml2015-decrypt-function 'mailcrypt-decrypt)
(defvar mml2015-verify-function 'mailcrypt-verify)
(defun mml2015-format-error (err)
(if (stringp (cadr err))
(cadr err)
(format "%S" (cdr err))))
(defun mml2015-mailcrypt-decrypt (handle _ctl)
(catch 'error
(let (child handles result)
(unless (setq child (mm-find-part-by-type
(cdr handle)
"application/octet-stream" nil t))
(mm-sec-error 'gnus-info "Corrupted")
(throw 'error handle))
(with-temp-buffer
(mm-insert-part child)
(setq result
(condition-case err
(funcall mml2015-decrypt-function)
(error
(mm-sec-error 'gnus-details (mml2015-format-error err))
nil)
(quit
(mm-sec-error 'gnus-details "Quit.")
nil)))
(unless (car result)
(mm-sec-error 'gnus-info "Failed")
(throw 'error handle))
(setq handles (mm-dissect-buffer t)))
(mm-destroy-parts handle)
(mm-sec-status
'gnus-info
(concat "OK"
(let ((sig (with-current-buffer mml2015-result-buffer
(mml2015-gpg-extract-signature-details))))
(concat ", Signer: " sig))))
(if (listp (car handles))
handles
(list handles)))))
(defun mml2015-gpg-pretty-print-fpr (fingerprint)
(let* ((result "")
(fpr-length (string-width fingerprint))
(n-slice 0)
slice)
(setq fingerprint (string-to-list fingerprint))
(while fingerprint
(setq fpr-length (- fpr-length 4))
(setq slice (butlast fingerprint fpr-length))
(setq fingerprint (nthcdr 4 fingerprint))
(setq n-slice (1+ n-slice))
(setq result
(concat
result
(cl-case n-slice
(1 slice)
(otherwise (concat " " slice))))))
result))
(defun mml2015-gpg-extract-signature-details ()
(goto-char (point-min))
(let* ((expired (re-search-forward
"^\\[GNUPG:\\] SIGEXPIRED$"
nil t))
(signer (and (re-search-forward
"^\\[GNUPG:\\] GOODSIG \\([0-9A-Za-z]*\\) \\(.*\\)$"
nil t)
(cons (match-string 1) (match-string 2))))
(fprint (and (re-search-forward
"^\\[GNUPG:\\] VALIDSIG \\([0-9a-zA-Z]*\\) "
nil t)
(match-string 1)))
(trust (and (re-search-forward
"^\\[GNUPG:\\] \\(TRUST_.*\\)$"
nil t)
(match-string 1)))
(trust-good-enough-p
(cdr (assoc trust mml2015-unabbrev-trust-alist))))
(cond ((and signer fprint)
(concat (cdr signer)
(unless trust-good-enough-p
(concat "\nUntrusted, Fingerprint: "
(mml2015-gpg-pretty-print-fpr fprint)))
(when expired
(format "\nWARNING: Signature from expired key (%s)"
(car signer)))))
((re-search-forward
"^\\(gpg: \\)?Good signature from \"\\(.*\\)\"$" nil t)
(match-string 2))
(t
"From unknown user"))))
(defun mml2015-mailcrypt-clear-decrypt ()
(let (result)
(setq result
(condition-case err
(funcall mml2015-decrypt-function)
(error
(mm-sec-error 'gnus-details (mml2015-format-error err))
nil)
(quit
(mm-sec-error 'gnus-details "Quit.")
nil)))
(if (car result)
(mm-sec-status 'gnus-info "OK")
(mm-sec-error 'gnus-info "Failed"))))
(defun mml2015-fix-micalg (alg)
(and alg
;; Mutt/1.2.5i has seen sending micalg=php-sha1
(upcase (if (string-match "^p[gh]p-" alg)
(substring alg (match-end 0))
alg))))
(autoload 'gnus-get-buffer-create "gnus")
(defun mml2015-mailcrypt-verify (handle ctl)
(catch 'error
(let (part)
(unless (setq part (mm-find-raw-part-by-type
ctl (or (mm-handle-multipart-ctl-parameter
ctl 'protocol)
"application/pgp-signature")
t))
(mm-sec-error 'gnus-info "Corrupted")
(throw 'error handle))
(with-temp-buffer
(insert "-----BEGIN PGP SIGNED MESSAGE-----\n")
(insert (format "Hash: %s\n\n"
(or (mml2015-fix-micalg
(mm-handle-multipart-ctl-parameter
ctl 'micalg))
"SHA1")))
(save-restriction
(narrow-to-region (point) (point))
(insert part "\n")
(goto-char (point-min))
(while (not (eobp))
(if (looking-at "^-")
(insert "- "))
(forward-line)))
(unless (setq part (mm-find-part-by-type
(cdr handle) "application/pgp-signature" nil t))
(mm-sec-error 'gnus-info "Corrupted")
(throw 'error handle))
(save-restriction
(narrow-to-region (point) (point))
(mm-insert-part part)
(goto-char (point-min))
(if (re-search-forward "^-----BEGIN PGP [^-]+-----\r?$" nil t)
(replace-match "-----BEGIN PGP SIGNATURE-----" t t))
(if (re-search-forward "^-----END PGP [^-]+-----\r?$" nil t)
(replace-match "-----END PGP SIGNATURE-----" t t)))
(let ((mc-gpg-debug-buffer (gnus-get-buffer-create " *gnus gpg debug*")))
(unless (condition-case err
(prog1
(funcall mml2015-verify-function)
(if (get-buffer " *mailcrypt stderr temp")
(mm-sec-error
'gnus-details
(with-current-buffer " *mailcrypt stderr temp"
(buffer-string))))
(if (get-buffer " *mailcrypt stdout temp")
(kill-buffer " *mailcrypt stdout temp"))
(if (get-buffer " *mailcrypt stderr temp")
(kill-buffer " *mailcrypt stderr temp"))
(if (get-buffer " *mailcrypt status temp")
(kill-buffer " *mailcrypt status temp"))
(if (get-buffer mc-gpg-debug-buffer)
(kill-buffer mc-gpg-debug-buffer)))
(error
(mm-sec-error 'gnus-details (mml2015-format-error err))
nil)
(quit
(mm-sec-error 'gnus-details "Quit.")
nil))
(mm-sec-error 'gnus-info "Failed")
(throw 'error handle))))
(mm-sec-status 'gnus-info "OK")
handle)))
(defun mml2015-mailcrypt-clear-verify ()
(let ((mc-gpg-debug-buffer (gnus-get-buffer-create " *gnus gpg debug*")))
(if (condition-case err
(prog1
(funcall mml2015-verify-function)
(if (get-buffer " *mailcrypt stderr temp")
(mm-sec-error
'gnus-details
(with-current-buffer " *mailcrypt stderr temp"
(buffer-string))))
(if (get-buffer " *mailcrypt stdout temp")
(kill-buffer " *mailcrypt stdout temp"))
(if (get-buffer " *mailcrypt stderr temp")
(kill-buffer " *mailcrypt stderr temp"))
(if (get-buffer " *mailcrypt status temp")
(kill-buffer " *mailcrypt status temp"))
(if (get-buffer mc-gpg-debug-buffer)
(kill-buffer mc-gpg-debug-buffer)))
(error
(mm-sec-error 'gnus-details (mml2015-format-error err))
nil)
(quit
(mm-sec-error 'gnus-details "Quit.")
nil))
(mm-sec-status 'gnus-info "OK")
(mm-sec-error 'gnus-info "Failed")))
(mml2015-extract-cleartext-signature))
(defun mml2015-mailcrypt-sign (cont)
(mc-sign-generic (message-options-get 'message-sender)
nil nil nil nil)
(let ((boundary (mml-compute-boundary cont))
hash point)
(goto-char (point-min))
(unless (re-search-forward "^-----BEGIN PGP SIGNED MESSAGE-----\r?$" nil t)
(error "Cannot find signed begin line"))
(goto-char (match-beginning 0))
(forward-line 1)
(unless (looking-at "Hash:[ \t]*\\([a-zA-Z0-9]+\\)")
(error "Cannot not find PGP hash"))
(setq hash (match-string 1))
(unless (re-search-forward "^$" nil t)
(error "Cannot not find PGP message"))
(forward-line 1)
(delete-region (point-min) (point))
(insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
boundary))
(insert (format "\tmicalg=pgp-%s; protocol=\"application/pgp-signature\"\n"
(downcase hash)))
(insert (format "\n--%s\n" boundary))
(setq point (point))
(goto-char (point-max))
(unless (re-search-backward "^-----END PGP SIGNATURE-----\r?$" nil t)
(error "Cannot find signature part"))
(replace-match "-----END PGP MESSAGE-----" t t)
(goto-char (match-beginning 0))
(unless (re-search-backward "^-----BEGIN PGP SIGNATURE-----\r?$"
nil t)
(error "Cannot find signature part"))
(replace-match "-----BEGIN PGP MESSAGE-----" t t)
(goto-char (match-beginning 0))
(save-restriction
(narrow-to-region point (point))
(goto-char point)
(while (re-search-forward "^- -" nil t)
(replace-match "-" t t))
(goto-char (point-max)))
(insert (format "--%s\n" boundary))
(insert "Content-Type: application/pgp-signature\n\n")
(goto-char (point-max))
(insert (format "--%s--\n" boundary))
(goto-char (point-max))))
;; We require mm-decode, which requires mm-bodies, which autoloads
;; message-options-get (!).
(declare-function message-options-set "message" (symbol value))
(defun mml2015-mailcrypt-encrypt (cont &optional sign)
(let ((mc-pgp-always-sign
(or mc-pgp-always-sign
sign
(eq t (or (message-options-get 'message-sign-encrypt)
(message-options-set
'message-sign-encrypt
(or (y-or-n-p "Sign the message? ")
'not))))
'never)))
(insert
(with-temp-buffer
(set-buffer-multibyte nil)
(mc-encrypt-generic
(or (message-options-get 'message-recipients)
(message-options-set 'message-recipients
(mc-cleanup-recipient-headers
(read-string "Recipients: "))))
nil nil nil
(message-options-get 'message-sender))
(buffer-string))))
(goto-char (point-min))
(unless (looking-at "-----BEGIN PGP MESSAGE-----")
(error "Fail to encrypt the message"))
(let ((boundary (mml-compute-boundary cont)))
(insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
boundary))
(insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
(insert (format "--%s\n" boundary))
(insert "Content-Type: application/pgp-encrypted\n\n")
(insert "Version: 1\n\n")
(insert (format "--%s\n" boundary))
(insert "Content-Type: application/octet-stream\n\n")
(goto-char (point-max))
(insert (format "--%s--\n" boundary))
(goto-char (point-max))))
;;; pgg wrapper
(defvar pgg-default-user-id)
(defvar pgg-errors-buffer)
(defvar pgg-output-buffer)
(defvar pgg-text-mode)
(autoload 'pgg-decrypt-region "pgg")
(autoload 'pgg-verify-region "pgg")
(autoload 'pgg-sign-region "pgg")
(autoload 'pgg-encrypt-region "pgg")
(autoload 'pgg-parse-armor "pgg-parse")
(defun mml2015-pgg-decrypt (handle _ctl)
(catch 'error
(let ((pgg-errors-buffer mml2015-result-buffer)
child handles decrypt-status) ;; result
(unless (setq child (mm-find-part-by-type
(cdr handle)
"application/octet-stream" nil t))
(mm-sec-error 'gnus-info "Corrupted")
(throw 'error handle))
(with-temp-buffer
(mm-insert-part child)
(if (condition-case err
(prog1
(pgg-decrypt-region (point-min) (point-max))
(setq decrypt-status
(with-current-buffer mml2015-result-buffer
(buffer-string)))
(mm-sec-status 'gnus-details decrypt-status))
(error
(mm-sec-error 'gnus-details (mml2015-format-error err))
nil)
(quit
(mm-sec-error 'gnus-details "Quit.")
nil))
(with-current-buffer pgg-output-buffer
(goto-char (point-min))
(while (search-forward "\r\n" nil t)
(replace-match "\n" t t))
(setq handles (mm-dissect-buffer t))
(mm-destroy-parts handle)
(mm-sec-status 'gnus-info "OK"
'gnus-details
(concat decrypt-status
(when (stringp (car handles))
"\n" (mm-handle-multipart-ctl-parameter
handles 'gnus-details))))
(if (listp (car handles))
handles
(list handles)))
(mm-sec-error 'gnus-info "Failed")
(throw 'error handle))))))
(defun mml2015-pgg-clear-decrypt ()
(let ((pgg-errors-buffer mml2015-result-buffer))
(if (prog1
(pgg-decrypt-region (point-min) (point-max))
(mm-sec-status
'gnus-details
(with-current-buffer mml2015-result-buffer
(buffer-string))))
(progn
(erase-buffer)
;; Treat data which pgg returns as a unibyte string.
(mm-disable-multibyte)
(insert-buffer-substring pgg-output-buffer)
(goto-char (point-min))
(while (search-forward "\r\n" nil t)
(replace-match "\n" t t))
(mm-sec-status 'gnus-info "OK"))
(mm-sec-error 'gnus-info "Failed"))))
(defun mml2015-pgg-verify (handle ctl)
(let ((pgg-errors-buffer mml2015-result-buffer)
signature-file part signature)
(if (or (null (setq part (mm-find-raw-part-by-type
ctl (or (mm-handle-multipart-ctl-parameter
ctl 'protocol)
"application/pgp-signature")
t)))
(null (setq signature
(mm-find-part-by-type
(cdr handle) "application/pgp-signature" nil t))))
(progn
(mm-sec-error 'gnus-info "Corrupted")
handle)
(with-temp-buffer
(insert part)
;; Convert <LF> to <CR><LF> in signed text. If --textmode is
;; specified when signing, the conversion is not necessary.
(goto-char (point-min))
(end-of-line)
(while (not (eobp))
(unless (eq (char-before) ?\r)
(insert "\r"))
(forward-line)
(end-of-line))
(with-temp-file (setq signature-file (make-temp-file "pgg"))
(mm-insert-part signature))
(if (condition-case err
(prog1
(pgg-verify-region (point-min) (point-max)
signature-file t)
(goto-char (point-min))
(while (search-forward "\r\n" nil t)
(replace-match "\n" t t))
(mm-sec-status
'gnus-details
(concat (with-current-buffer pgg-output-buffer
(buffer-string))
(with-current-buffer pgg-errors-buffer
(buffer-string)))))
(error
(mm-sec-error 'gnus-details (mml2015-format-error err))
nil)
(quit
(mm-sec-error 'gnus-details "Quit.")
nil))
(progn
(delete-file signature-file)
(mm-sec-error
'gnus-info
(with-current-buffer pgg-errors-buffer
(mml2015-gpg-extract-signature-details))))
(delete-file signature-file)
(mm-sec-error 'gnus-info "Failed")))))
handle)
(defun mml2015-pgg-clear-verify ()
(let ((pgg-errors-buffer mml2015-result-buffer)
(text (buffer-string))
(coding-system buffer-file-coding-system))
(if (condition-case err
(prog1
(mm-with-unibyte-buffer
(insert (encode-coding-string text coding-system))
(pgg-verify-region (point-min) (point-max) nil t))
(goto-char (point-min))
(while (search-forward "\r\n" nil t)
(replace-match "\n" t t))
(mm-sec-status
'gnus-details
(concat (with-current-buffer pgg-output-buffer
(buffer-string))
(with-current-buffer pgg-errors-buffer
(buffer-string)))))
(error
(mm-sec-error 'gnus-details (mml2015-format-error err))
nil)
(quit
(mm-sec-error 'gnus-details "Quit.")
nil))
(mm-sec-status
'gnus-info
(with-current-buffer pgg-errors-buffer
(mml2015-gpg-extract-signature-details)))
(mm-sec-error 'gnus-info "Failed")))
(mml2015-extract-cleartext-signature))
(defun mml2015-pgg-sign (cont)
(let ((pgg-errors-buffer mml2015-result-buffer)
(boundary (mml-compute-boundary cont))
(pgg-default-user-id (or (message-options-get 'mml-sender)
pgg-default-user-id))
(pgg-text-mode t)
entry)
(unless (pgg-sign-region (point-min) (point-max))
(pop-to-buffer mml2015-result-buffer)
(error "Sign error"))
(goto-char (point-min))
(insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
boundary))
(if (setq entry (assq 2 (pgg-parse-armor
(with-current-buffer pgg-output-buffer
(buffer-string)))))
(setq entry (assq 'hash-algorithm (cdr entry))))
(insert (format "\tmicalg=%s; "
(if (cdr entry)
(downcase (format "pgp-%s" (cdr entry)))
"pgp-sha1")))
(insert "protocol=\"application/pgp-signature\"\n")
(insert (format "\n--%s\n" boundary))
(goto-char (point-max))
(insert (format "\n--%s\n" boundary))
(insert "Content-Type: application/pgp-signature\n\n")
(insert-buffer-substring pgg-output-buffer)
(goto-char (point-max))
(insert (format "--%s--\n" boundary))
(goto-char (point-max))))
(defun mml2015-pgg-encrypt (cont &optional sign)
(let ((pgg-errors-buffer mml2015-result-buffer)
(pgg-text-mode t)
(boundary (mml-compute-boundary cont)))
(unless (pgg-encrypt-region (point-min) (point-max)
(split-string
(or
(message-options-get 'message-recipients)
(message-options-set 'message-recipients
(read-string "Recipients: ")))
"[ \f\t\n\r\v,]+")
sign)
(pop-to-buffer mml2015-result-buffer)
(error "Encrypt error"))
(delete-region (point-min) (point-max))
(goto-char (point-min))
(insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
boundary))
(insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
(insert (format "--%s\n" boundary))
(insert "Content-Type: application/pgp-encrypted\n\n")
(insert "Version: 1\n\n")
(insert (format "--%s\n" boundary))
(insert "Content-Type: application/octet-stream\n\n")
(insert-buffer-substring pgg-output-buffer)
(goto-char (point-max))
(insert (format "--%s--\n" boundary))
(goto-char (point-max))))
;;; epg wrapper
(defvar epg-user-id-alist)
(defvar epg-digest-algorithm-alist)
(defvar epg-gpg-program)
(autoload 'epg-make-context "epg")
(autoload 'epg-context-set-armor "epg")
(autoload 'epg-context-set-textmode "epg")
(autoload 'epg-context-set-signers "epg")
(autoload 'epg-context-result-for "epg")
(autoload 'epg-new-signature-digest-algorithm "epg")
(autoload 'epg-list-keys "epg")
(autoload 'epg-decrypt-string "epg")
(autoload 'epg-verify-string "epg")
(autoload 'epg-sign-string "epg")
(autoload 'epg-encrypt-string "epg")
(autoload 'epg-context-set-passphrase-callback "epg")
(autoload 'epg-key-sub-key-list "epg")
(autoload 'epg-sub-key-capability "epg")
(autoload 'epg-sub-key-validity "epg")
(autoload 'epg-sub-key-fingerprint "epg")
(autoload 'epg-signature-key-id "epg")
(autoload 'epg-signature-to-string "epg")
(autoload 'epg-key-user-id-list "epg")
(autoload 'epg-user-id-string "epg")
(autoload 'epg-user-id-validity "epg")
(autoload 'epg-configuration "epg-config")
(autoload 'epg-expand-group "epg-config")
(autoload 'epa-select-keys "epa")
(autoload 'gnus-create-image "gnus-util")
(defun mml2015-epg-key-image (key-id)
"Return the image of a key, if any."
(with-temp-buffer
(set-buffer-multibyte nil)
(let* ((coding-system-for-write 'binary)
(coding-system-for-read 'binary)
(data (shell-command-to-string
(format "%s --list-options no-show-photos --attribute-fd 3 --list-keys %s 3>&1 >%s 2>&1"
(shell-quote-argument epg-gpg-program)
key-id null-device))))
(when (> (length data) 0)
(insert (substring data 16))
(condition-case nil
(gnus-create-image (buffer-string) nil t)
(error))))))
(autoload 'gnus-rescale-image "gnus-util")
(defun mml2015-epg-key-image-to-string (key-id)
"Return a string with the image of a key, if any."
(let ((key-image (mml2015-epg-key-image key-id)))
(if (not key-image)
""
(condition-case nil
(let ((result (copy-sequence " ")))
(put-text-property
1 2 'display
(gnus-rescale-image key-image
(cons mml2015-maximum-key-image-dimension
mml2015-maximum-key-image-dimension))
result)
result)
(error "")))))
(defun mml2015-epg-signature-to-string (signature)
(concat (epg-signature-to-string signature)
(when mml2015-display-key-image
(mml2015-epg-key-image-to-string (epg-signature-key-id signature)))))
(defun mml2015-epg-verify-result-to-string (verify-result)
(mapconcat #'mml2015-epg-signature-to-string verify-result "\n"))
(defun mml2015-epg-decrypt (handle _ctl)
(catch 'error
(let (context plain child handles) ;; decrypt-status result
(unless (setq child (mm-find-part-by-type
(cdr handle)
"application/octet-stream" nil t))
(mm-sec-error 'gnus-info "Corrupted")
(throw 'error handle))
(setq context (epg-make-context))
(if (or mml2015-cache-passphrase mml-secure-cache-passphrase)
(epg-context-set-passphrase-callback
context
(cons 'mml-secure-passphrase-callback 'OpenPGP)))
(condition-case error
(setq plain (epg-decrypt-string context (mm-get-part child))
mml-secure-secret-key-id-list nil)
(error
(mml-secure-clear-secret-key-id-list)
(mm-sec-error 'gnus-info "Failed")
(if (eq (car error) 'quit)
(mm-sec-status 'gnus-details "Quit.")
(mm-sec-status 'gnus-details (mml2015-format-error error)))
(throw 'error handle)))
(with-temp-buffer
(insert plain)
(goto-char (point-min))
(while (search-forward "\r\n" nil t)
(replace-match "\n" t t))
(setq handles (mm-dissect-buffer t))
(mm-destroy-parts handle)
(if (epg-context-result-for context 'verify)
(mm-sec-status
'gnus-info
(concat "OK\n"
(mml2015-epg-verify-result-to-string
(epg-context-result-for context 'verify))))
(mm-sec-status 'gnus-info "OK"))
(if (stringp (car handles))
(mm-sec-status
'gnus-details
(mm-handle-multipart-ctl-parameter handles 'gnus-details))))
(if (listp (car handles))
handles
(list handles)))))
(defun mml2015-epg-clear-decrypt ()
(let ((context (epg-make-context))
plain)
(if (or mml2015-cache-passphrase mml-secure-cache-passphrase)
(epg-context-set-passphrase-callback
context
(cons 'mml-secure-passphrase-callback 'OpenPGP)))
(condition-case error
(setq plain (epg-decrypt-string context (buffer-string))
mml-secure-secret-key-id-list nil)
(error
(mml-secure-clear-secret-key-id-list)
(mm-sec-error 'gnus-info "Failed")
(if (eq (car error) 'quit)
(mm-sec-status 'gnus-details "Quit.")
(mm-sec-status 'gnus-details (mml2015-format-error error)))))
(when plain
(erase-buffer)
;; Treat data which epg returns as a unibyte string.
(mm-disable-multibyte)
(insert plain)
(goto-char (point-min))
(while (search-forward "\r\n" nil t)
(replace-match "\n" t t))
(mm-sec-status 'gnus-info "OK")
(if (epg-context-result-for context 'verify)
(mm-sec-status
'gnus-details
(mml2015-epg-verify-result-to-string
(epg-context-result-for context 'verify)))))))
(defun mml2015-epg-verify (handle ctl)
(catch 'error
(let (context part signature) ;; plain signature-file
(when (or (null (setq part (mm-find-raw-part-by-type
ctl (or (mm-handle-multipart-ctl-parameter
ctl 'protocol)
"application/pgp-signature")
t)))
(null (setq signature (mm-find-part-by-type
(cdr handle) "application/pgp-signature"
nil t))))
(mm-sec-error 'gnus-info "Corrupted")
(throw 'error handle))
(setq part (string-replace "\n" "\r\n" part)
signature (mm-get-part signature)
context (epg-make-context))
(condition-case error
;; (setq plain
(epg-verify-string context signature part) ;;)
(error
(mm-sec-error 'gnus-info "Failed")
(mm-sec-status 'gnus-details (if (eq (car error) 'quit)
"Quit."
(mml2015-format-error error)))
(throw 'error handle)))
(mm-sec-status 'gnus-info
(mml2015-epg-verify-result-to-string
(epg-context-result-for context 'verify)))
handle)))
(defun mml2015-epg-clear-verify ()
(let ((context (epg-make-context))
(signature (encode-coding-string (buffer-string)
coding-system-for-write))
plain)
(condition-case error
(setq plain (epg-verify-string context signature))
(error
(mm-sec-error 'gnus-info "Failed")
(if (eq (car error) 'quit)
(mm-sec-status 'gnus-details "Quit.")
(mm-sec-status 'gnus-details (mml2015-format-error error)))))
(if plain
(progn
(mm-sec-status
'gnus-info
(mml2015-epg-verify-result-to-string
(epg-context-result-for context 'verify)))
(delete-region (point-min) (point-max))
(insert (decode-coding-string plain coding-system-for-read)))
(mml2015-extract-cleartext-signature))))
(defun mml2015-epg-sign (cont)
(let ((boundary (mml-compute-boundary cont)))
;; Signed data must end with a newline (RFC 3156, 5).
(goto-char (point-max))
(unless (bolp)
(insert "\n"))
(let* ((pair (mml-secure-epg-sign 'OpenPGP t))
(signature (car pair))
(micalg (cdr pair)))
(unless (stringp signature)
(error "Signature failed"))
(goto-char (point-min))
(insert (format "Content-Type: multipart/signed; boundary=\"%s\";\n"
boundary))
(if micalg
(insert (format "\tmicalg=pgp-%s; "
(downcase
(cdr (assq micalg
epg-digest-algorithm-alist))))))
(insert "protocol=\"application/pgp-signature\"\n")
(insert (format "\n--%s\n" boundary))
(goto-char (point-max))
(insert (format "\n--%s\n" boundary))
(insert "Content-Type: application/pgp-signature; name=\"signature.asc\"\n\n")
(insert signature)
(goto-char (point-max))
(insert (format "--%s--\n" boundary))
(goto-char (point-max)))))
(defun mml2015-epg-encrypt (cont &optional sign)
(let* ((boundary (mml-compute-boundary cont))
(cipher (mml-secure-epg-encrypt 'OpenPGP cont sign)))
(delete-region (point-min) (point-max))
(goto-char (point-min))
(insert (format "Content-Type: multipart/encrypted; boundary=\"%s\";\n"
boundary))
(insert "\tprotocol=\"application/pgp-encrypted\"\n\n")
(insert (format "--%s\n" boundary))
(insert "Content-Type: application/pgp-encrypted\n\n")
(insert "Version: 1\n\n")
(insert (format "--%s\n" boundary))
(insert "Content-Type: application/octet-stream\n\n")
(insert cipher)
(goto-char (point-max))
(insert (format "--%s--\n" boundary))
(goto-char (point-max))))
;;; General wrapper
(autoload 'gnus-buffer-live-p "gnus-util")
(defun mml2015-clean-buffer ()
(if (gnus-buffer-live-p mml2015-result-buffer)
(with-current-buffer mml2015-result-buffer
(erase-buffer)
t)
(setq mml2015-result-buffer
(gnus-get-buffer-create " *MML2015 Result*"))
nil))
(defsubst mml2015-clear-decrypt-function ()
(nth 6 (assq mml2015-use mml2015-function-alist)))
(defsubst mml2015-clear-verify-function ()
(nth 5 (assq mml2015-use mml2015-function-alist)))
;;;###autoload
(defun mml2015-decrypt (handle ctl)
(mml2015-clean-buffer)
(let ((func (nth 4 (assq mml2015-use mml2015-function-alist))))
(if func
(funcall func handle ctl)
handle)))
;;;###autoload
(defun mml2015-decrypt-test (_handle _ctl)
mml2015-use)
;;;###autoload
(defun mml2015-verify (handle ctl)
(mml2015-clean-buffer)
(let ((func (nth 3 (assq mml2015-use mml2015-function-alist))))
(if func
(funcall func handle ctl)
handle)))
;;;###autoload
(defun mml2015-verify-test (_handle _ctl)
mml2015-use)
;;;###autoload
(defun mml2015-encrypt (cont &optional sign)
(mml2015-clean-buffer)
(let ((func (nth 2 (assq mml2015-use mml2015-function-alist))))
(if func
(funcall func cont sign)
(error "Cannot find encrypt function"))))
;;;###autoload
(defun mml2015-sign (cont)
(mml2015-clean-buffer)
(let ((func (nth 1 (assq mml2015-use mml2015-function-alist))))
(if func
(funcall func cont)
(error "Cannot find sign function"))))
;;;###autoload
(defun mml2015-self-encrypt ()
(mml2015-encrypt nil))
(provide 'mml2015)
;;; mml2015.el ends here