| 1 | ;;; mml1991.el --- Old PGP message format (RFC 1991) support for MML |
| 2 | |
| 3 | ;; Copyright (C) 1998-2014 Free Software Foundation, Inc. |
| 4 | |
| 5 | ;; Author: Sascha Lüdecke <sascha@meta-x.de>, |
| 6 | ;; Simon Josefsson <simon@josefsson.org> (Mailcrypt interface, Gnus glue) |
| 7 | ;; Keywords: PGP |
| 8 | |
| 9 | ;; This file is part of GNU Emacs. |
| 10 | |
| 11 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
| 12 | ;; it under the terms of the GNU General Public License as published by |
| 13 | ;; the Free Software Foundation, either version 3 of the License, or |
| 14 | ;; (at your option) any later version. |
| 15 | |
| 16 | ;; GNU Emacs is distributed in the hope that it will be useful, |
| 17 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 19 | ;; GNU General Public License for more details. |
| 20 | |
| 21 | ;; You should have received a copy of the GNU General Public License |
| 22 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
| 23 | |
| 24 | ;;; Commentary: |
| 25 | |
| 26 | ;;; Code: |
| 27 | |
| 28 | (eval-and-compile |
| 29 | (if (locate-library "password-cache") |
| 30 | (require 'password-cache) |
| 31 | (require 'password))) |
| 32 | |
| 33 | (eval-when-compile |
| 34 | (require 'cl) |
| 35 | (require 'mm-util)) |
| 36 | |
| 37 | (require 'mm-encode) |
| 38 | (require 'mml-sec) |
| 39 | |
| 40 | (defvar mc-pgp-always-sign) |
| 41 | |
| 42 | (autoload 'quoted-printable-decode-region "qp") |
| 43 | (autoload 'quoted-printable-encode-region "qp") |
| 44 | |
| 45 | (autoload 'mm-decode-content-transfer-encoding "mm-bodies") |
| 46 | (autoload 'mm-encode-content-transfer-encoding "mm-bodies") |
| 47 | (autoload 'message-options-get "message") |
| 48 | (autoload 'message-options-set "message") |
| 49 | |
| 50 | (require 'mml2015) |
| 51 | |
| 52 | (defvar mml1991-use mml2015-use |
| 53 | "The package used for PGP.") |
| 54 | |
| 55 | (defvar mml1991-function-alist |
| 56 | '((mailcrypt mml1991-mailcrypt-sign |
| 57 | mml1991-mailcrypt-encrypt) |
| 58 | (pgg mml1991-pgg-sign |
| 59 | mml1991-pgg-encrypt) |
| 60 | (epg mml1991-epg-sign |
| 61 | mml1991-epg-encrypt)) |
| 62 | "Alist of PGP functions.") |
| 63 | |
| 64 | (defvar mml1991-cache-passphrase mml-secure-cache-passphrase |
| 65 | "If t, cache passphrase.") |
| 66 | |
| 67 | (defvar mml1991-passphrase-cache-expiry mml-secure-passphrase-cache-expiry |
| 68 | "How many seconds the passphrase is cached. |
| 69 | Whether the passphrase is cached at all is controlled by |
| 70 | `mml1991-cache-passphrase'.") |
| 71 | |
| 72 | (defvar mml1991-signers nil |
| 73 | "A list of your own key ID which will be used to sign a message.") |
| 74 | |
| 75 | (defvar mml1991-encrypt-to-self nil |
| 76 | "If t, add your own key ID to recipient list when encryption.") |
| 77 | |
| 78 | ;;; mailcrypt wrapper |
| 79 | |
| 80 | (autoload 'mc-sign-generic "mc-toplev") |
| 81 | |
| 82 | (defvar mml1991-decrypt-function 'mailcrypt-decrypt) |
| 83 | (defvar mml1991-verify-function 'mailcrypt-verify) |
| 84 | |
| 85 | (defun mml1991-mailcrypt-sign (cont) |
| 86 | (let ((text (current-buffer)) |
| 87 | headers signature |
| 88 | (result-buffer (get-buffer-create "*GPG Result*"))) |
| 89 | ;; Save MIME Content[^ ]+: headers from signing |
| 90 | (goto-char (point-min)) |
| 91 | (while (looking-at "^Content[^ ]+:") (forward-line)) |
| 92 | (unless (bobp) |
| 93 | (setq headers (buffer-string)) |
| 94 | (delete-region (point-min) (point))) |
| 95 | (goto-char (point-max)) |
| 96 | (unless (bolp) |
| 97 | (insert "\n")) |
| 98 | (quoted-printable-decode-region (point-min) (point-max)) |
| 99 | (with-temp-buffer |
| 100 | (setq signature (current-buffer)) |
| 101 | (insert-buffer-substring text) |
| 102 | (unless (mc-sign-generic (message-options-get 'message-sender) |
| 103 | nil nil nil nil) |
| 104 | (unless (> (point-max) (point-min)) |
| 105 | (pop-to-buffer result-buffer) |
| 106 | (error "Sign error"))) |
| 107 | (goto-char (point-min)) |
| 108 | (while (re-search-forward "\r+$" nil t) |
| 109 | (replace-match "" t t)) |
| 110 | (quoted-printable-encode-region (point-min) (point-max)) |
| 111 | (set-buffer text) |
| 112 | (delete-region (point-min) (point-max)) |
| 113 | (if headers (insert headers)) |
| 114 | (insert "\n") |
| 115 | (insert-buffer-substring signature) |
| 116 | (goto-char (point-max))))) |
| 117 | |
| 118 | (declare-function mc-encrypt-generic "ext:mc-toplev" |
| 119 | (&optional recipients scheme start end from sign)) |
| 120 | |
| 121 | (defun mml1991-mailcrypt-encrypt (cont &optional sign) |
| 122 | (let ((text (current-buffer)) |
| 123 | (mc-pgp-always-sign |
| 124 | (or mc-pgp-always-sign |
| 125 | sign |
| 126 | (eq t (or (message-options-get 'message-sign-encrypt) |
| 127 | (message-options-set |
| 128 | 'message-sign-encrypt |
| 129 | (or (y-or-n-p "Sign the message? ") |
| 130 | 'not)))) |
| 131 | 'never)) |
| 132 | cipher |
| 133 | (result-buffer (get-buffer-create "*GPG Result*"))) |
| 134 | ;; Strip MIME Content[^ ]: headers since it will be ASCII ARMORED |
| 135 | (goto-char (point-min)) |
| 136 | (while (looking-at "^Content[^ ]+:") (forward-line)) |
| 137 | (unless (bobp) |
| 138 | (delete-region (point-min) (point))) |
| 139 | (with-temp-buffer |
| 140 | (inline (mm-disable-multibyte)) |
| 141 | (setq cipher (current-buffer)) |
| 142 | (insert-buffer-substring text) |
| 143 | (unless (mc-encrypt-generic |
| 144 | (or |
| 145 | (message-options-get 'message-recipients) |
| 146 | (message-options-set 'message-recipients |
| 147 | (read-string "Recipients: "))) |
| 148 | nil |
| 149 | (point-min) (point-max) |
| 150 | (message-options-get 'message-sender) |
| 151 | 'sign) |
| 152 | (unless (> (point-max) (point-min)) |
| 153 | (pop-to-buffer result-buffer) |
| 154 | (error "Encrypt error"))) |
| 155 | (goto-char (point-min)) |
| 156 | (while (re-search-forward "\r+$" nil t) |
| 157 | (replace-match "" t t)) |
| 158 | (set-buffer text) |
| 159 | (delete-region (point-min) (point-max)) |
| 160 | ;;(insert "Content-Type: application/pgp-encrypted\n\n") |
| 161 | ;;(insert "Version: 1\n\n") |
| 162 | (insert "\n") |
| 163 | (insert-buffer-substring cipher) |
| 164 | (goto-char (point-max))))) |
| 165 | |
| 166 | ;; pgg wrapper |
| 167 | |
| 168 | (autoload 'pgg-sign-region "pgg") |
| 169 | (autoload 'pgg-encrypt-region "pgg") |
| 170 | |
| 171 | (defvar pgg-default-user-id) |
| 172 | (defvar pgg-errors-buffer) |
| 173 | (defvar pgg-output-buffer) |
| 174 | |
| 175 | (defun mml1991-pgg-sign (cont) |
| 176 | (let ((pgg-text-mode t) |
| 177 | (pgg-default-user-id (or (message-options-get 'mml-sender) |
| 178 | pgg-default-user-id)) |
| 179 | headers cte) |
| 180 | ;; Don't sign headers. |
| 181 | (goto-char (point-min)) |
| 182 | (when (re-search-forward "^$" nil t) |
| 183 | (setq headers (buffer-substring (point-min) (point))) |
| 184 | (save-restriction |
| 185 | (narrow-to-region (point-min) (point)) |
| 186 | (setq cte (mail-fetch-field "content-transfer-encoding"))) |
| 187 | (forward-line 1) |
| 188 | (delete-region (point-min) (point)) |
| 189 | (when cte |
| 190 | (setq cte (intern (downcase cte))) |
| 191 | (mm-decode-content-transfer-encoding cte))) |
| 192 | (unless (pgg-sign-region (point-min) (point-max) t) |
| 193 | (pop-to-buffer pgg-errors-buffer) |
| 194 | (error "Encrypt error")) |
| 195 | (delete-region (point-min) (point-max)) |
| 196 | (mm-with-unibyte-current-buffer |
| 197 | (insert-buffer-substring pgg-output-buffer) |
| 198 | (goto-char (point-min)) |
| 199 | (while (re-search-forward "\r+$" nil t) |
| 200 | (replace-match "" t t)) |
| 201 | (when cte |
| 202 | (mm-encode-content-transfer-encoding cte)) |
| 203 | (goto-char (point-min)) |
| 204 | (when headers |
| 205 | (insert headers)) |
| 206 | (insert "\n")) |
| 207 | t)) |
| 208 | |
| 209 | (defun mml1991-pgg-encrypt (cont &optional sign) |
| 210 | (goto-char (point-min)) |
| 211 | (when (re-search-forward "^$" nil t) |
| 212 | (let ((cte (save-restriction |
| 213 | (narrow-to-region (point-min) (point)) |
| 214 | (mail-fetch-field "content-transfer-encoding")))) |
| 215 | ;; Strip MIME headers since it will be ASCII armored. |
| 216 | (forward-line 1) |
| 217 | (delete-region (point-min) (point)) |
| 218 | (when cte |
| 219 | (mm-decode-content-transfer-encoding (intern (downcase cte)))))) |
| 220 | (unless (let ((pgg-text-mode t)) |
| 221 | (pgg-encrypt-region |
| 222 | (point-min) (point-max) |
| 223 | (split-string |
| 224 | (or |
| 225 | (message-options-get 'message-recipients) |
| 226 | (message-options-set 'message-recipients |
| 227 | (read-string "Recipients: "))) |
| 228 | "[ \f\t\n\r\v,]+") |
| 229 | sign)) |
| 230 | (pop-to-buffer pgg-errors-buffer) |
| 231 | (error "Encrypt error")) |
| 232 | (delete-region (point-min) (point-max)) |
| 233 | (insert "\n") |
| 234 | (insert-buffer-substring pgg-output-buffer) |
| 235 | t) |
| 236 | |
| 237 | ;; epg wrapper |
| 238 | |
| 239 | (defvar epg-user-id-alist) |
| 240 | |
| 241 | (autoload 'epg-make-context "epg") |
| 242 | (autoload 'epg-passphrase-callback-function "epg") |
| 243 | (autoload 'epa-select-keys "epa") |
| 244 | (autoload 'epg-list-keys "epg") |
| 245 | (autoload 'epg-context-set-armor "epg") |
| 246 | (autoload 'epg-context-set-textmode "epg") |
| 247 | (autoload 'epg-context-set-signers "epg") |
| 248 | (autoload 'epg-context-set-passphrase-callback "epg") |
| 249 | (autoload 'epg-key-sub-key-list "epg") |
| 250 | (autoload 'epg-sub-key-capability "epg") |
| 251 | (autoload 'epg-sub-key-validity "epg") |
| 252 | (autoload 'epg-sub-key-fingerprint "epg") |
| 253 | (autoload 'epg-sign-string "epg") |
| 254 | (autoload 'epg-encrypt-string "epg") |
| 255 | (autoload 'epg-configuration "epg-config") |
| 256 | (autoload 'epg-expand-group "epg-config") |
| 257 | |
| 258 | (defvar mml1991-epg-secret-key-id-list nil) |
| 259 | |
| 260 | (defun mml1991-epg-passphrase-callback (context key-id ignore) |
| 261 | (if (eq key-id 'SYM) |
| 262 | (epg-passphrase-callback-function context key-id nil) |
| 263 | (let* ((entry (assoc key-id epg-user-id-alist)) |
| 264 | (passphrase |
| 265 | (password-read |
| 266 | (format "GnuPG passphrase for %s: " |
| 267 | (if entry |
| 268 | (cdr entry) |
| 269 | key-id)) |
| 270 | (if (eq key-id 'PIN) |
| 271 | "PIN" |
| 272 | key-id)))) |
| 273 | (when passphrase |
| 274 | (let ((password-cache-expiry mml1991-passphrase-cache-expiry)) |
| 275 | (password-cache-add key-id passphrase)) |
| 276 | (setq mml1991-epg-secret-key-id-list |
| 277 | (cons key-id mml1991-epg-secret-key-id-list)) |
| 278 | (copy-sequence passphrase))))) |
| 279 | |
| 280 | (defun mml1991-epg-find-usable-key (keys usage) |
| 281 | (catch 'found |
| 282 | (while keys |
| 283 | (let ((pointer (epg-key-sub-key-list (car keys)))) |
| 284 | ;; The primary key will be marked as disabled, when the entire |
| 285 | ;; key is disabled (see 12 Field, Format of colon listings, in |
| 286 | ;; gnupg/doc/DETAILS) |
| 287 | (unless (memq 'disabled (epg-sub-key-capability (car pointer))) |
| 288 | (while pointer |
| 289 | (if (and (memq usage (epg-sub-key-capability (car pointer))) |
| 290 | (not (memq (epg-sub-key-validity (car pointer)) |
| 291 | '(revoked expired)))) |
| 292 | (throw 'found (car keys))) |
| 293 | (setq pointer (cdr pointer))))) |
| 294 | (setq keys (cdr keys))))) |
| 295 | |
| 296 | ;; XXX: since gpg --list-secret-keys does not return validity of each |
| 297 | ;; key, `mml1991-epg-find-usable-key' defined above is not enough for |
| 298 | ;; secret keys. The function `mml1991-epg-find-usable-secret-key' |
| 299 | ;; below looks at appropriate public keys to check usability. |
| 300 | (defun mml1991-epg-find-usable-secret-key (context name usage) |
| 301 | (let ((secret-keys (epg-list-keys context name t)) |
| 302 | secret-key) |
| 303 | (while (and (not secret-key) secret-keys) |
| 304 | (if (mml1991-epg-find-usable-key |
| 305 | (epg-list-keys context (epg-sub-key-fingerprint |
| 306 | (car (epg-key-sub-key-list |
| 307 | (car secret-keys))))) |
| 308 | usage) |
| 309 | (setq secret-key (car secret-keys) |
| 310 | secret-keys nil) |
| 311 | (setq secret-keys (cdr secret-keys)))) |
| 312 | secret-key)) |
| 313 | |
| 314 | (defun mml1991-epg-sign (cont) |
| 315 | (let ((context (epg-make-context)) |
| 316 | headers cte signer-key signers signature) |
| 317 | (if (eq mm-sign-option 'guided) |
| 318 | (setq signers (epa-select-keys context "Select keys for signing. |
| 319 | If no one is selected, default secret key is used. " |
| 320 | mml1991-signers t)) |
| 321 | (if mml1991-signers |
| 322 | (setq signers (delq nil |
| 323 | (mapcar |
| 324 | (lambda (name) |
| 325 | (setq signer-key |
| 326 | (mml1991-epg-find-usable-secret-key |
| 327 | context name 'sign)) |
| 328 | (unless (or signer-key |
| 329 | (y-or-n-p |
| 330 | (format |
| 331 | "No secret key for %s; skip it? " |
| 332 | name))) |
| 333 | (error "No secret key for %s" name)) |
| 334 | signer-key) |
| 335 | mml1991-signers))))) |
| 336 | (epg-context-set-armor context t) |
| 337 | (epg-context-set-textmode context t) |
| 338 | (epg-context-set-signers context signers) |
| 339 | (if mml1991-cache-passphrase |
| 340 | (epg-context-set-passphrase-callback |
| 341 | context |
| 342 | #'mml1991-epg-passphrase-callback)) |
| 343 | ;; Don't sign headers. |
| 344 | (goto-char (point-min)) |
| 345 | (when (re-search-forward "^$" nil t) |
| 346 | (setq headers (buffer-substring (point-min) (point))) |
| 347 | (save-restriction |
| 348 | (narrow-to-region (point-min) (point)) |
| 349 | (setq cte (mail-fetch-field "content-transfer-encoding"))) |
| 350 | (forward-line 1) |
| 351 | (delete-region (point-min) (point)) |
| 352 | (when cte |
| 353 | (setq cte (intern (downcase cte))) |
| 354 | (mm-decode-content-transfer-encoding cte))) |
| 355 | (condition-case error |
| 356 | (setq signature (epg-sign-string context (buffer-string) 'clear) |
| 357 | mml1991-epg-secret-key-id-list nil) |
| 358 | (error |
| 359 | (while mml1991-epg-secret-key-id-list |
| 360 | (password-cache-remove (car mml1991-epg-secret-key-id-list)) |
| 361 | (setq mml1991-epg-secret-key-id-list |
| 362 | (cdr mml1991-epg-secret-key-id-list))) |
| 363 | (signal (car error) (cdr error)))) |
| 364 | (delete-region (point-min) (point-max)) |
| 365 | (mm-with-unibyte-current-buffer |
| 366 | (insert signature) |
| 367 | (goto-char (point-min)) |
| 368 | (while (re-search-forward "\r+$" nil t) |
| 369 | (replace-match "" t t)) |
| 370 | (when cte |
| 371 | (mm-encode-content-transfer-encoding cte)) |
| 372 | (goto-char (point-min)) |
| 373 | (when headers |
| 374 | (insert headers)) |
| 375 | (insert "\n")) |
| 376 | t)) |
| 377 | |
| 378 | (defun mml1991-epg-encrypt (cont &optional sign) |
| 379 | (goto-char (point-min)) |
| 380 | (when (re-search-forward "^$" nil t) |
| 381 | (let ((cte (save-restriction |
| 382 | (narrow-to-region (point-min) (point)) |
| 383 | (mail-fetch-field "content-transfer-encoding")))) |
| 384 | ;; Strip MIME headers since it will be ASCII armored. |
| 385 | (forward-line 1) |
| 386 | (delete-region (point-min) (point)) |
| 387 | (when cte |
| 388 | (mm-decode-content-transfer-encoding (intern (downcase cte)))))) |
| 389 | (let ((context (epg-make-context)) |
| 390 | (recipients |
| 391 | (if (message-options-get 'message-recipients) |
| 392 | (split-string |
| 393 | (message-options-get 'message-recipients) |
| 394 | "[ \f\t\n\r\v,]+"))) |
| 395 | recipient-key signer-key cipher signers config) |
| 396 | (when mml1991-encrypt-to-self |
| 397 | (unless mml1991-signers |
| 398 | (error "mml1991-signers is not set")) |
| 399 | (setq recipients (nconc recipients mml1991-signers))) |
| 400 | ;; We should remove this check if epg-0.0.6 is released. |
| 401 | (if (and (condition-case nil |
| 402 | (require 'epg-config) |
| 403 | (error)) |
| 404 | (functionp #'epg-expand-group)) |
| 405 | (setq config (epg-configuration) |
| 406 | recipients |
| 407 | (apply #'nconc |
| 408 | (mapcar (lambda (recipient) |
| 409 | (or (epg-expand-group config recipient) |
| 410 | (list recipient))) |
| 411 | recipients)))) |
| 412 | (if (eq mm-encrypt-option 'guided) |
| 413 | (setq recipients |
| 414 | (epa-select-keys context "Select recipients for encryption. |
| 415 | If no one is selected, symmetric encryption will be performed. " |
| 416 | recipients)) |
| 417 | (setq recipients |
| 418 | (delq nil (mapcar |
| 419 | (lambda (name) |
| 420 | (setq recipient-key (mml1991-epg-find-usable-key |
| 421 | (epg-list-keys context name) |
| 422 | 'encrypt)) |
| 423 | (unless (or recipient-key |
| 424 | (y-or-n-p |
| 425 | (format "No public key for %s; skip it? " |
| 426 | name))) |
| 427 | (error "No public key for %s" name)) |
| 428 | recipient-key) |
| 429 | recipients))) |
| 430 | (unless recipients |
| 431 | (error "No recipient specified"))) |
| 432 | (when sign |
| 433 | (if (eq mm-sign-option 'guided) |
| 434 | (setq signers (epa-select-keys context "Select keys for signing. |
| 435 | If no one is selected, default secret key is used. " |
| 436 | mml1991-signers t)) |
| 437 | (if mml1991-signers |
| 438 | (setq signers (delq nil |
| 439 | (mapcar |
| 440 | (lambda (name) |
| 441 | (mml1991-epg-find-usable-secret-key |
| 442 | context name 'sign)) |
| 443 | mml1991-signers))))) |
| 444 | (epg-context-set-signers context signers)) |
| 445 | (epg-context-set-armor context t) |
| 446 | (epg-context-set-textmode context t) |
| 447 | (if mml1991-cache-passphrase |
| 448 | (epg-context-set-passphrase-callback |
| 449 | context |
| 450 | #'mml1991-epg-passphrase-callback)) |
| 451 | (condition-case error |
| 452 | (setq cipher |
| 453 | (epg-encrypt-string context (buffer-string) recipients sign) |
| 454 | mml1991-epg-secret-key-id-list nil) |
| 455 | (error |
| 456 | (while mml1991-epg-secret-key-id-list |
| 457 | (password-cache-remove (car mml1991-epg-secret-key-id-list)) |
| 458 | (setq mml1991-epg-secret-key-id-list |
| 459 | (cdr mml1991-epg-secret-key-id-list))) |
| 460 | (signal (car error) (cdr error)))) |
| 461 | (delete-region (point-min) (point-max)) |
| 462 | (insert "\n" cipher)) |
| 463 | t) |
| 464 | |
| 465 | ;;;###autoload |
| 466 | (defun mml1991-encrypt (cont &optional sign) |
| 467 | (let ((func (nth 2 (assq mml1991-use mml1991-function-alist)))) |
| 468 | (if func |
| 469 | (funcall func cont sign) |
| 470 | (error "Cannot find encrypt function")))) |
| 471 | |
| 472 | ;;;###autoload |
| 473 | (defun mml1991-sign (cont) |
| 474 | (let ((func (nth 1 (assq mml1991-use mml1991-function-alist)))) |
| 475 | (if func |
| 476 | (funcall func cont) |
| 477 | (error "Cannot find sign function")))) |
| 478 | |
| 479 | (provide 'mml1991) |
| 480 | |
| 481 | ;; Local Variables: |
| 482 | ;; coding: utf-8 |
| 483 | ;; End: |
| 484 | |
| 485 | ;;; mml1991.el ends here |