slightly simplify totp code

1 files changed, 5 insertions, 10 deletions

diff --git a/kasi-totp.el b/kasi-totp.el
index 3d197d6..d14e00a 100644
--- a/kasi-totp.el
+++ b/kasi-totp.el
@@ -5,7 +5,6 @@
 (require 'bindat)
 (require 'gnutls)
 (require 'hexl)
-(require 'auth-source)
 
 (defconst base32-alphabet
   (let ((tbl (make-char-table nil)))
@@ -44,21 +43,17 @@ required for HMAC-TOTP."
          (seq-map (lambda (s) (hexl-htoi (aref s 0) (aref s 1)))
                   (seq-partition string 2))))
 
-(defun totp (string &optional time digits)
-  "Return a TOTP token using the secret hex STRING and current time.
-TIME is used as counter value instead of current time, if non-nil.
-DIGITS is the number of pin digits and defaults to 6."
+(defun totp (string)
+  "Return a TOTP token using the secret hex STRING and current time."
   (let* ((key-bytes (totp--hex-decode-string (upcase string)))
-         (counter (truncate (/ (or time (time-to-seconds)) 30)))
-         (digits (or digits 6))
-         (format-string (format "%%0%dd" digits))
+         (counter (truncate (/ (time-to-seconds) 30)))
          ;; we have to manually split the 64 bit number (u64 not supported in Emacs 27.2)
          (counter-bytes (bindat-pack  '((:high u32) (:low u32))
                                       `((:high . ,(ash counter -32)) (:low . ,(logand counter #xffffffff)))))
          (mac (gnutls-hash-mac 'SHA1 key-bytes counter-bytes))
          (offset (logand (bindat-get-field (bindat-unpack '((:offset u8)) mac 19) :offset) #xf)))
-    (format format-string
+    (format "%06d"
             (mod
              (logand (bindat-get-field (bindat-unpack '((:totp-pin u32)) mac  offset) :totp-pin)
                      #x7fffffff)
-             (expt 10 digits)))))
+             (expt 10 6)))))