Clojure md5 digest

digest.clj

(defn md5
  "Generate a md5 checksum for the given string"
  [token]
  (let [hash-bytes
         (doto (java.security.MessageDigest/getInstance "MD5")
               (.reset)
               (.update (.getBytes token)))]
       (.toString
         (new java.math.BigInteger 1 (.digest hash-bytes)) ; Positive and the size of the number
         16))) ; Use base16 i.e. hex

Found this by googling, you need to 0-pad the result at the head to get exactly 32 chars results