clj: calculate md5 hash of a given string

md5.clj

(import 'java.security.MessageDigest
        'java.math.BigInteger)

(defn md5 [s]
  (let [algorithm (MessageDigest/getInstance "MD5")
        size (* 2 (.getDigestLength algorithm))
        raw (.digest algorithm (.getBytes s))
        sig (.toString (BigInteger. 1 raw) 16)
        padding (apply str (repeat (- size (count sig)) "0"))]
    (str padding sig)))

; for full digest support, use clj-digest: https://github.com/tebeka/clj-digest