pandect

pandect is a fast and easy-to-use Message Digest, Checksum, HMAC and Signature library for Clojure.

Usage

Note that - for versions 0.6.0 and up - to use functions based on the BouncyCastle crypto provider, you have to manually include a version of the org.bouncycastle/bcprov-jdk15on artifact. Additionally, you need to take special care when trying to create an uberjar (see here).

REPL

(require '[pandect.algo.sha1 :refer :all])

(sha1 "Hello World!")                      ;; => "2ef7bde608ce5404e97d5f042f95f89f1c232871"
(sha1 (.getBytes "Hello World!" "UTF-8"))  ;; => "2ef7bde608ce5404e97d5f042f95f89f1c232871"
(sha1 (File. "project.clj"))               ;; => "ff3b4565652aeb835edf2715b2a28586929ea4cc"
(sha1 (FileInputStream. "project.clj"))    ;; => "ff3b4565652aeb835edf2715b2a28586929ea4cc"

;; more variants
(sha1-bytes "Hello World!")                ;; => #<byte[] [B@5293b95>
(sha1-file "project.clj")                  ;; => "ff3b4565652aeb835edf2715b2a28586929ea4cc"
(sha1-file-bytes "project.clj")            ;; => #<byte[] [B@e2606c7>

HMAC functions take an additional key:

(sha1-hmac "Hello World!" "secret-key")       ;; => "399fc3d94f6df2213f92fcf2a8b6669279ef7d20"
(sha1-hmac-bytes "Hello World!" "secret-key") ;; => #<byte[] [B@602bd522>

Signing functions expect a java.security.PrivateKey, while verification works with java.security.PublicKey or java.security.cert.Certificate:

(sha1-rsa "Hello World!" private-key)                 ;; => "5866..."
(sha1-rsa-verify "Hello World!" "5866..." public-key) ;; => true

You can tune stream processing using pandect.buffer/with-buffer-size (default is 2KB):

(require '[pandect.buffer :refer [with-buffer-size]])

(with-open [in (io/input-stream "shootout/data/1mb.txt")]
  (with-buffer-size (* 512 1024)
    (sha256 in)))

If you want to hash a String using a specific encoding, you should create the respective byte array manually:

(sha1 "Hällo World!")                          ;; => "f19c05a67c3d0f297b62e868657cf177913ce02a"
(sha1 (.getBytes "Hällo World!" "ISO-8859-1")) ;; => "cfe670bd6845020f5754b19a3c0eee602043eb89"

The namespace pandect.core contains all available algorithms but for better startup/compile times, using algorithm-specific ones is recommended.

Supported Algorithms

See the generated documentation for the available functions and their parameters.

Checksum	MDx	SHA	SHA-3	RIPEMD	BLAKE2	Others
Adler32*	MD2*	SHA-1	SHA3-224	RIPEMD-128	BLAKE2b-160	SipHash-2-4+
CRC-32*	MD4	SHA-256	SHA3-256	RIPEMD-160	BLAKE2b-256	SipHash-4-8+
	MD5	SHA-384	SHA3-384	RIPEMD-256	BLAKE2b-384	Tiger192,3
		SHA-512	SHA3-512	RIPEMD-320	BLAKE2b-512	Whirlpool

* not available as MAC
⁺ only available as MAC

Uberjars and BouncyCastle

The BouncyCastle JAR has been signed to prevent tampering - and JCE won't allow usage of any of its functions if that signature is not present. This poses a problem when creating an Uberjar since all needed class files will be extracted from their JARs and repackaged into a single one - removing any existing signature.

You'll see, for example, the following exceptions in that case:

java.security.NoSuchAlgorithmException: Algorithm (...) not available
java.security.NoSuchProviderException: JCE cannot authenticate the provider BC

Primarily, this means you have to prevent the BouncyCastle files ending up within the JAR which can be accomplished using the :provided profile in you project.clj:

:profiles
{:provided
 {:dependencies [[org.bouncycastle/bcprov-jdk15on "1.54"]}}

Now you can build your uberjar but you have to make sure that the BouncyCastle JAR is on your classpath when running it, i.e. assuming they are both in the same directory:

java -cp bcprov-jdk15on-1.54.jar:app-standalone.jar app.core

Before version 0.6.0, pandect accessed the BouncyCastle functionality directly (i.e. not via MessageDigest/getInstance or Mac/getInstance but using actual constructor calls), meaning these limitations did not apply. It is, thus, strongly recommended to do it right and upgrade to 0.6.0.

Benchmarks

You can run benchmarks on the following Message Digest implementations:

• pandect (obviously)
• clj-digest 1.4.3
• clj-message-digest 1.0.0

Use the following command:

lein benchmark {pandect|clj-digest|clj-message-digest}\
               {--md2|--md5|--sha1|--sha256|--sha384|--sha512}\
               [--file <Path>]

If a file is supplied a benchmark will be run hashing its contents; if no file is given, the simple string "Hello, World!" will be hashed.

Benchmark Results

Benchmarks are run using Criterium on an Intel Core i7 2.7GHz/8GB RAM machine with Oracle JDK 1.7.0u67 (64-bit).

Results obtained using pandect 0.5.0.

Input: "Hello, World!"

Library	md2	md5	sha1	sha256	sha384	sha512	adler32	crc32
pandect	4.27µs	910ns	1.07µs	1.27µs	1.68µs	1.74µs	302ns	315ns
clj-digest	5.92µs	2.62µs	3.47µs	4.36µs	5.65µs	7.09µs	-	-
clj-message-digest	28.2µs	25µs	30.2µs	44.7µs	66.4µs	80.9µs	-	-

Input: 1KB file (times include I/O)

Library	md2	md5	sha1	sha256	sha384	sha512	adler32	crc32
pandect	122µs	13.7µs	14.9µs	17.9µs	16.5µs	16.3µs	9.19µs	9.12µs
clj-digest	128µs	19.1µs	20.5µs	24.8µs	25.1µs	26.1µs	-	-
clj-message-digest	259µs	149µs	155µs	160µs	203µs	221µs	-	-

Input: 1MB file (times include I/O)

Library	md2	md5	sha1	sha256	sha384	sha512	adler32	crc32
pandect	112ms	3.14ms	4.57ms	6.74ms	5.1ms	5.11ms	582µs	833µs
clj-digest	113ms	4.18ms	5.81ms	7.87ms	6.15ms	6.23ms	-	-
clj-message-digest	112ms	3.07ms	4.59ms	6.73ms	5.17ms	5.19ms	-	-

Contributors

• Yannick Scherer (@xsc)
• Toshiki Takeuchi (@totakke)
• Jan Stępień (@jstepien)
• Tom Crayford (@tcrayford)
• Alexander Kiel (@alexanderkiel)

License

MIT License

Copyright (c) 2014-2021 Yannick Scherer

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
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