Files
chicken-scheme-hmac/hmac.scm
2011-04-16 18:51:01 -04:00

11 lines
620 B
Scheme

(use sha1 srfi-4 srfi-4-utils)
; taken from example at http://wiki.call-cc.org/drupal-xml-rpc
(define (sha1-hmac key)
(when (> (string-length key) 64) (set! key (sha1-binary-digest key)))
(set! key (string-pad-right key 64 (integer->char 0)))
(set! key (blob->u8vector (string->blob key)))
(let ((ipad (blob->string (u8vector->blob (u8vector-map (lambda (v) (bitwise-xor v #x36)) key))))
(opad (blob->string (u8vector->blob (u8vector-map (lambda (v) (bitwise-xor v #x5c)) key)))))
(lambda (message)
(sha1-binary-digest (string-append opad (sha1-binary-digest (string-append ipad message)))))))