+ (if (and (or name-is-key-id
+ ;; Non email user-id can be supplied through
+ ;; mml2015-signers if mml2015-encrypt-to-self is set.
+ ;; Treat it as valid, as it is user's intention.
+ (not (string-match "\\`<" name))
+ (mml2015-epg-check-user-id (car keys) name))
+ (mml2015-epg-check-sub-key (car keys) usage))
+ (setq key (car keys)
+ keys nil)
+ (setq keys (cdr keys))))
+ key))
+
+;; XXX: since gpg --list-secret-keys does not return validity of each
+;; key, `mml2015-epg-find-usable-key' defined above is not enough for
+;; secret keys. The function `mml2015-epg-find-usable-secret-key'
+;; below looks at appropriate public keys to check usability.
+(defun mml2015-epg-find-usable-secret-key (context name usage)
+ (let ((secret-keys (epg-list-keys context name t))
+ secret-key)
+ (while (and (not secret-key) secret-keys)
+ (if (mml2015-epg-find-usable-key
+ context
+ (epg-sub-key-fingerprint
+ (car (epg-key-sub-key-list
+ (car secret-keys))))
+ usage
+ t)
+ (setq secret-key (car secret-keys)
+ secret-keys nil)
+ (setq secret-keys (cdr secret-keys))))
+ secret-key))
+
+(autoload 'gnus-create-image "gnus-ems")
+
+(defun mml2015-epg-key-image (key-id)
+ "Return the image of a key, if any"
+ (with-temp-buffer
+ (mm-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 >/dev/null 2>&1"
+ (shell-quote-argument epg-gpg-program) key-id))))
+ (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 error
+ (let ((result " "))
+ (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"))