分享：用四十种语言分别写一个MD5算法 之4 Common Lisp语言MD5算法

分享：用四十种语言分别写一个MD5算法 之4 Common Lisp语言MD5算法

(require #+sbcl 'sb-md5 #-sbcl 'md5)

(defvar +letters+ "0123456789abcdef")

(defun octets->letters (octet-vector)

(with-output-to-string (stream)

(loop for i across octet-vector

do (flet ((foo (x) (aref +letters+ (ldb (byte x (- x 4)) i))))

(princ (foo 8) stream)

(princ (foo 4) stream)))))

(defun md5 (string)

(octets->letters #+sbcl (sb-md5:md5sum-string string)

#-sbcl (with-input-from-string (stream string)

(md5:md5sum-stream stream))))</pre>

CL-USER> (md5 "foo")