call-process writing to the wrong buffer

[Matthias Pfeifer <mpfeifer77@gmail.com>]

I frequently have to look into a binary file and want to translate it into
text by using an external program. I came up with this snippet from which I
had expected that it opens a new buffer, selects that buffer and writes
into it the output of this external program:

(defun mp/show-x509 ()
  (interactive)
  (let ((cert-file (buffer-file-name))
        (right-window (split-window-right))
        (openssl-buffer (generate-new-buffer (generate-new-buffer-name
"*openssl*"))))
    (select-window right-window)
    (set-window-buffer nil openssl-buffer)
    (call-process "openssl" nil t (list openssl-buffer t) "x509" "-text"
"-noout" "-in" cert-file)))

However I must have some misunderstanding here. The output of call-process
is in fact inserted into the window on the left (left when assuming there
is only one window in the frame when caling mp/show-x509). And I really do
not have a clue whats wrong.

matthias