(defun mm-display-elisp-inline (handle)
(mm-display-inline-fontify handle 'emacs-lisp-mode))
+;; id-signedData OBJECT IDENTIFIER ::= { iso(1) member-body(2)
+;; us(840) rsadsi(113549) pkcs(1) pkcs7(7) 2 }
+(defvar mm-pkcs7-signed-magic
+ (mm-string-as-unibyte
+ (apply 'concat
+ (mapcar 'char-to-string
+ (list ?\x30 ?\x82 ?\x01 ?\x91 ?\x06 ?\x09 ?\x2a ?\x86 ?\x48
+ ?\x86 ?\xf7 ?\x0d ?\x01 ?\x07 ?\x02)))))
+
+;; id-envelopedData OBJECT IDENTIFIER ::= { iso(1) member-body(2)
+;; us(840) rsadsi(113549) pkcs(1) pkcs7(7) 3 }
+(defvar mm-pkcs7-enveloped-magic
+ (mm-string-as-unibyte
+ (apply 'concat
+ (mapcar 'char-to-string
+ (list ?\x30 ?\x82 ?\x01 ?\x91 ?\x06 ?\x09 ?\x2a ?\x86 ?\x48
+ ?\x86 ?\xf7 ?\x0d ?\x01 ?\x07 ?\x03)))))
+
+(defun mm-view-pkcs7-get-type (handle)
+ (with-temp-buffer
+ (mm-insert-part handle)
+ (cond ((looking-at (regexp-quote mm-pkcs7-enveloped-magic))
+ 'enveloped)
+ ((looking-at (regexp-quote mm-pkcs7-signed-magic))
+ 'signed)
+ (t
+ (error "Could not identify PKCS#7 type")))))
+
+(defun mm-view-pkcs7 (handle)
+ (case (mm-view-pkcs7-get-type handle)
+ (enveloped (mm-view-pkcs7-decrypt handle))
+ (otherwise (error "Unknown or unimplemented PKCS#7 type"))))
+
+(defun mm-view-pkcs7-decrypt (handle)
+ (if (cond
+ ((eq mm-decrypt-option 'never) nil)
+ ((eq mm-decrypt-option 'always) t)
+ ((eq mm-decrypt-option 'known) t)
+ (t (y-or-n-p
+ (format "Decrypt (S/MIME) part? "))))
+ (let (res)
+ (with-temp-buffer
+ (insert-buffer (mm-handle-buffer handle))
+ (goto-char (point-min))
+ (insert "MIME-Version: 1.0\n")
+ (mm-insert-headers "application/pkcs7-mime" "base64" "smime.p7m")
+ (smime-decrypt-region
+ (point-min) (point-max)
+ (if (= (length smime-keys) 1)
+ (cadar smime-keys)
+ (smime-get-key-by-email
+ (completing-read "Decrypt this part with which key? "
+ smime-keys nil nil
+ (and (listp (car-safe smime-keys))
+ (caar smime-keys))))))
+ (setq res (buffer-string)))
+ (mm-insert-inline handle res))))
+
(provide 'mm-view)
;;; mm-view.el ends here