Quick and easy Base-64 encoding and decoding

project.clj

:dependencies [[base64-clj "0.1.1"]]

util.clj

(ns project.util
  (:require [[base64-clj.core :as b64]]))

(defn b64-encode
  "Function for a safe base-64 encode that handels nils as well as converts
  any non-string argument to it's string equivalent and then encodes that.
  It's also smart enough to take a sequence of things and encode each,
  individually - returning a sequence of encoded values."
  [s]
  (cond
    (nil? s)    nil
    (string? s) (b64/encode s)
    (coll? s)   (map b64-encode s)
    :else       (b64-encode (pr-str s))))

(defn b64-decode
  "Function to safely attempt to do a base64 decoding of the argument - assuming
  it's a correct fit for the decoding. It's got to be a string, and it's got to
  have a length that's divisible by 4. If it's invalid, this function will just
  return `nil`."
  [s]
  (cond
    (string? s) (let [len (count s)]
                  (when (and (pos? len) (zero? (unchecked-remainder-int len 4)))
                    (b64/decode s)))
    (coll? s) (map b64-decode s)
    :else     nil))