+;;; epg wrapper
+
+(defvar epg-user-id-alist)
+(defvar epg-digest-algorithm-alist)
+(defvar inhibit-redisplay)
+
+(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-verify-result-to-string "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-passphrase-callback-function "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-configuration "epg-config")
+(autoload 'epg-expand-group "epg-config")
+(autoload 'epa-select-keys "epa")
+
+(defvar mml2015-epg-secret-key-id-list nil)
+
+(defun mml2015-epg-passphrase-callback (context key-id ignore)
+ (if (eq key-id 'SYM)
+ (epg-passphrase-callback-function context key-id nil)
+ (let* ((password-cache-key-id
+ (if (eq key-id 'PIN)
+ "PIN"
+ key-id))
+ entry
+ (passphrase
+ (password-read
+ (if (eq key-id 'PIN)
+ "Passphrase for PIN: "
+ (if (setq entry (assoc key-id epg-user-id-alist))
+ (format "Passphrase for %s %s: " key-id (cdr entry))
+ (format "Passphrase for %s: " key-id)))
+ password-cache-key-id)))
+ (when passphrase
+ (let ((password-cache-expiry mml2015-passphrase-cache-expiry))
+ (password-cache-add password-cache-key-id passphrase))
+ (setq mml2015-epg-secret-key-id-list
+ (cons password-cache-key-id mml2015-epg-secret-key-id-list))
+ (copy-sequence passphrase)))))
+
+(defun mml2015-epg-find-usable-key (keys usage)
+ (catch 'found
+ (while keys
+ (let ((pointer (epg-key-sub-key-list (car keys))))
+ (while pointer
+ (if (and (memq usage (epg-sub-key-capability (car pointer)))
+ (not (memq 'disabled (epg-sub-key-capability (car pointer))))
+ (not (memq (epg-sub-key-validity (car pointer))
+ '(revoked expired))))
+ (throw 'found (car keys)))
+ (setq pointer (cdr pointer))))
+ (setq keys (cdr keys)))))
+
+(defun mml2015-epg-decrypt (handle ctl)
+ (catch 'error
+ (let ((inhibit-redisplay t)
+ context plain child handles result decrypt-status)
+ (unless (setq child (mm-find-part-by-type
+ (cdr handle)
+ "application/octet-stream" nil t))
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-info "Corrupted")
+ (throw 'error handle))
+ (setq context (epg-make-context))
+ (if mml2015-cache-passphrase
+ (epg-context-set-passphrase-callback
+ context
+ #'mml2015-epg-passphrase-callback))
+ (condition-case error
+ (setq plain (epg-decrypt-string context (mm-get-part child))
+ mml2015-epg-secret-key-id-list nil)
+ (error
+ (while mml2015-epg-secret-key-id-list
+ (password-cache-remove (car mml2015-epg-secret-key-id-list))
+ (setq mml2015-epg-secret-key-id-list
+ (cdr mml2015-epg-secret-key-id-list)))
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-info "Failed")
+ (if (eq (car error) 'quit)
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-details "Quit.")
+ (mm-set-handle-multipart-parameter
+ mm-security-handle '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-set-handle-multipart-parameter
+ mm-security-handle 'gnus-info
+ (concat "OK\n"
+ (epg-verify-result-to-string
+ (epg-context-result-for context 'verify))))
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-info "OK"))
+ (if (stringp (car handles))
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-details
+ (mm-handle-multipart-ctl-parameter handles 'gnus-details))))
+ (if (listp (car handles))
+ handles
+ (list handles)))))
+
+(defun mml2015-epg-clear-decrypt ()
+ (let ((inhibit-redisplay t)
+ (context (epg-make-context))
+ plain)
+ (if mml2015-cache-passphrase
+ (epg-context-set-passphrase-callback
+ context
+ #'mml2015-epg-passphrase-callback))
+ (condition-case error
+ (setq plain (epg-decrypt-string context (buffer-string))
+ mml2015-epg-secret-key-id-list nil)
+ (error
+ (while mml2015-epg-secret-key-id-list
+ (password-cache-remove (car mml2015-epg-secret-key-id-list))
+ (setq mml2015-epg-secret-key-id-list
+ (cdr mml2015-epg-secret-key-id-list)))
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-info "Failed")
+ (if (eq (car error) 'quit)
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-details "Quit.")
+ (mm-set-handle-multipart-parameter
+ mm-security-handle '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-set-handle-multipart-parameter
+ mm-security-handle 'gnus-info "OK")
+ (if (epg-context-result-for context 'verify)
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-details
+ (epg-verify-result-to-string
+ (epg-context-result-for context 'verify)))))))
+
+(defun mml2015-epg-verify (handle ctl)
+ (catch 'error
+ (let ((inhibit-redisplay t)
+ context plain signature-file part signature)
+ (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-set-handle-multipart-parameter
+ mm-security-handle 'gnus-info "Corrupted")
+ (throw 'error handle))
+ (setq part (mm-replace-in-string part "\n" "\r\n" t)
+ signature (mm-get-part signature)
+ context (epg-make-context))
+ (condition-case error
+ (setq plain (epg-verify-string context signature part))
+ (error
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-info "Failed")
+ (if (eq (car error) 'quit)
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-details "Quit.")
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-details (mml2015-format-error error)))
+ (throw 'error handle)))
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-info
+ (epg-verify-result-to-string (epg-context-result-for context 'verify)))
+ handle)))
+
+(defun mml2015-epg-clear-verify ()
+ (let ((inhibit-redisplay t)
+ (context (epg-make-context))
+ (signature (mm-encode-coding-string (buffer-string)
+ coding-system-for-write))
+ plain)
+ (condition-case error
+ (setq plain (epg-verify-string context signature))
+ (error
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-info "Failed")
+ (if (eq (car error) 'quit)
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-details "Quit.")
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-details (mml2015-format-error error)))))
+ (if plain
+ (progn
+ (mm-set-handle-multipart-parameter
+ mm-security-handle 'gnus-info
+ (epg-verify-result-to-string
+ (epg-context-result-for context 'verify)))
+ (delete-region (point-min) (point-max))
+ (insert (mm-decode-coding-string plain coding-system-for-read)))
+ (mml2015-extract-cleartext-signature))))
+
+(defun mml2015-epg-sign (cont)
+ (let* ((inhibit-redisplay t)
+ (context (epg-make-context))
+ (boundary (mml-compute-boundary cont))
+ (sender (message-options-get 'message-sender))
+ signer-key
+ (signers
+ (or (message-options-get 'mml2015-epg-signers)
+ (message-options-set
+ 'mml2015-epg-signers
+ (if (eq mm-sign-option 'guided)
+ (epa-select-keys context "\
+Select keys for signing.
+If no one is selected, default secret key is used. "
+ (cons sender mml2015-signers) t)
+ (if (or sender mml2015-signers)
+ (delq nil
+ (mapcar
+ (lambda (signer)
+ (setq signer-key (mml2015-epg-find-usable-key
+ (epg-list-keys context signer t)
+ 'sign))
+ (unless (or signer-key
+ (y-or-n-p
+ (format
+ "No secret key for %s; skip it? "
+ signer)))
+ (error "No secret key for %s" signer))
+ signer-key)
+ (cons sender mml2015-signers))))))))
+ signature micalg)
+ (epg-context-set-armor context t)
+ (epg-context-set-textmode context t)
+ (epg-context-set-signers context signers)
+ (if mml2015-cache-passphrase
+ (epg-context-set-passphrase-callback
+ context
+ #'mml2015-epg-passphrase-callback))
+ (condition-case error
+ (setq signature (epg-sign-string context (buffer-string) t)
+ mml2015-epg-secret-key-id-list nil)
+ (error
+ (while mml2015-epg-secret-key-id-list
+ (password-cache-remove (car mml2015-epg-secret-key-id-list))
+ (setq mml2015-epg-secret-key-id-list
+ (cdr mml2015-epg-secret-key-id-list)))
+ (signal (car error) (cdr error))))
+ (if (epg-context-result-for context 'sign)
+ (setq micalg (epg-new-signature-digest-algorithm
+ (car (epg-context-result-for context 'sign)))))
+ (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\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 ((inhibit-redisplay t)
+ (context (epg-make-context))
+ (config (epg-configuration))
+ (sender (message-options-get 'message-sender))
+ (recipients (message-options-get 'mml2015-epg-recipients))
+ cipher signers
+ (boundary (mml-compute-boundary cont))
+ recipient-key signer-key)
+ (unless recipients
+ (setq recipients
+ (apply #'nconc
+ (mapcar
+ (lambda (recipient)
+ (or (epg-expand-group config recipient)
+ (list (concat "<" recipient ">"))))
+ (split-string
+ (or (message-options-get 'message-recipients)
+ (message-options-set 'message-recipients
+ (read-string "Recipients: ")))
+ "[ \f\t\n\r\v,]+"))))
+ (when mml2015-encrypt-to-self
+ (unless (or sender mml2015-signers)
+ (error "Message sender and mml2015-signers not set"))
+ (setq recipients (nconc recipients (cons sender mml2015-signers))))
+ (if (eq mm-encrypt-option 'guided)
+ (setq recipients
+ (epa-select-keys context "\
+Select recipients for encryption.
+If no one is selected, symmetric encryption will be performed. "
+ recipients))
+ (setq recipients
+ (delq nil
+ (mapcar
+ (lambda (recipient)
+ (setq recipient-key (mml2015-epg-find-usable-key
+ (epg-list-keys context recipient)
+ 'encrypt))
+ (unless (or recipient-key
+ (y-or-n-p
+ (format "No public key for %s; skip it? "
+ recipient)))
+ (error "No public key for %s" recipient))
+ recipient-key)
+ recipients)))
+ (unless recipients
+ (error "No recipient specified")))
+ (message-options-set 'mml2015-epg-recipients recipients))
+ (when sign
+ (setq signers
+ (or (message-options-get 'mml2015-epg-signers)
+ (message-options-set
+ 'mml2015-epg-signers
+ (if (eq mm-sign-option 'guided)
+ (epa-select-keys context "\
+Select keys for signing.
+If no one is selected, default secret key is used. "
+ (cons sender mml2015-signers) t)
+ (if (or sender mml2015-signers)
+ (delq nil
+ (mapcar
+ (lambda (signer)
+ (setq signer-key (mml2015-epg-find-usable-key
+ (epg-list-keys context signer t)
+ 'sign))
+ (unless (or signer-key
+ (y-or-n-p
+ (format
+ "No secret key for %s; skip it? "
+ signer)))
+ (error "No secret key for %s" signer))
+ signer-key)
+ (cons sender mml2015-signers))))))))
+ (epg-context-set-signers context signers))
+ (epg-context-set-armor context t)
+ (epg-context-set-textmode context t)
+ (if mml2015-cache-passphrase
+ (epg-context-set-passphrase-callback
+ context
+ #'mml2015-epg-passphrase-callback))
+ (condition-case error
+ (setq cipher
+ (epg-encrypt-string context (buffer-string) recipients sign
+ mml2015-always-trust)
+ mml2015-epg-secret-key-id-list nil)
+ (error
+ (while mml2015-epg-secret-key-id-list
+ (password-cache-remove (car mml2015-epg-secret-key-id-list))
+ (setq mml2015-epg-secret-key-id-list
+ (cdr mml2015-epg-secret-key-id-list)))
+ (signal (car error) (cdr 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 cipher)
+ (goto-char (point-max))
+ (insert (format "--%s--\n" boundary))
+ (goto-char (point-max))))
+