+(declare-function epg-key-sub-key-list "ext:epg" (key))
+(declare-function epg-sub-key-capability "ext:epg" (sub-key))
+(declare-function epg-sub-key-validity "ext:epg" (sub-key))
+
+(defun mml-smime-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 (epg-sub-key-validity (car pointer))
+ '(revoked expired))))
+ (throw 'found (car keys)))
+ (setq pointer (cdr pointer))))
+ (setq keys (cdr keys)))))
+
+(autoload 'mml-compute-boundary "mml")
+
+;; We require mm-decode, which requires mm-bodies, which autoloads
+;; message-options-get (!).
+(declare-function message-options-set "message" (symbol value))
+