A Clojure implementation of fernet.
Fernet's goal is to provide simple and sane authenticated symmetric encryption.
fernet-clj currently supports version 0x80 of the fernet specification.
First, if you use leiningen, add the following to your dependencies:
To encrypt some data we must generate a key:
user=> (require 'fernet.core)
nil
user=> (def k (fernet.core/generate-key))
#'user/k
user=> k
"n7i7vTDV5pXGYRyyYznsUDydOi8KJLTiIX1kUTSfxr0"Fernet keys are defined as a 128-bit signing key and a 128-bit encryption key
that have been URL-safe base64 encoded. fernet.core/generate-key returns a
randomly generated key of this form as a string.
Once you have a key you can encrypt some messages:
user=> (def m (byte-array (map byte "Hello, world!")))
#'user/m
user=> m
#<byte[] [B@5502abdb>
(def token (fernet.core/encrypt k m))
user=> (def token (fernet.core/encrypt k m))
#'user/token
user=> token
"gAAAAABSlDV-AteaTbF7zoG4IFmRxAdyXrgONgSbsQ_FHTnvv2tJCAs4WSJPXa5Ai3OnUSqjSmjX5VH8Ka5G9EOXLaRw3Er5Qg"fernet.core/encrypt returns a Fernet token which is a URL-safe base64
encoded series of bytes according to the spec and depending on version.
Generally it includes a verions identifier, followed by an iv, a timestamp,
the ciphertext, and an HMAC over the preceding fields.
They can of course be decrypted with the same key:
user=> (def out-m (fernet.core/decrypt k token))
#'user/out-m
user=> out-m
#<byte[] [B@22adc446>
user=> (String. out-m)
"Hello, world!"The timestamp contained in the Fernet token is the time at which the token
was generated. fernet.core/decrypt takes a :ttl argument which will
cause it to reject any token that is older than the specified number of
seconds.
user=> (Thread/sleep 5000)
nil
user=> (fernet.core/decrypt k token :ttl 5)
ExceptionInfo Invalid token. clojure.core/ex-info (core.clj:4327)One may also encrypt and decrypt string messages using the
fernet.core/encrypt-string and fernet.core/decrypt-to-string functions.
user=> (def m "W\u00fcrst")
#'user/m
user=> (def token (fernet.core/encrypt-string k m))
#'user/token
user=> token
"gAAAAABXMjH1bUMEHUXckPSlrAmydnnzsOzitfWHuGidq7SXxHhDieWWxgezvN3xeI4iPEgt0H_QjUP4KtqntCgpya1w74-DLQ"
user=> (fernet.core/decrypt-to-string k token)
"Würst"- encrypt/decrypt edn terms
- autodoc?
Copyright © 2013-2016 David Reid Chris Wolfe
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