jsSHA

A JavaScript implementation of the complete Secure Hash Standard family (SHA-1, SHA-224, SHA-256, SHA-384, and SHA-512) as well as HMAC by Brian Turek

About

jsSHA is a javaScript implementation of the complete Secure Hash Algorithm family as defined by FIPS PUB 180-2 (http://csrc.nist.gov/publications/fips/fips180-2/fips180-2withchangenotice.pdf).

It also includes the HMAC algorithm with SHA support as defined by FIPS PUB 198-1 (http://csrc.nist.gov/publications/fips/fips198-1/FIPS-198-1_final.pdf)

With the slow phasing out of MD5 as the standard hash to use in web applications, a client-side implementation of the complete Secure Hash Standard family was needed. Due to SHA-384 and SHA-512's use of 64-bit values throughout the algorithm, JavaScript can not easily natively support the calculation of these hashes. As a result, a bit of hacking had to be done to make sure the values behaved themselves. SHA-224 was added to the Secure Hash Standard family on 25 February 2004 so it was also included in this package.

Files

src/sha_dev.js

A commented implementation of the entire SHA family of hashes. Not to be used in production.

src/sha.js

A Google Closure Compiler optimized version of the entire library

src/sha1.js

A Google Closure Compiler optimized version the library with non SHA-1 functionality removed

src/sha256.js

A Google Closure Compiler optimized version the library with non SHA-224/SHA-256 functionality removed

src/sha512.js

A Google Closure Compiler optimized version the library with non SHA-384/SHA-512 functionality removed

test/test.html

A test page that calculates various hashes and has their correct values

test/genHashRounds.py

A Python2 script that generates multi-round hash values

build/make-release

A Bash script that runs the various Google Closure Compiler commands to build a release

build/externs.js

File needed solely to make the Google Closure Compilter work

Usage

Browser

Include the desired JavaScript file (sha.js, sha1.js, sha256.js, or sha512.js) in your header (sha.js used below):

<script type="text/javascript" src="/path/to/sha.js"></script>

Instantiate a new jsSHA object with your string to be hashed and its format (HEX or TEXT) as the parameters. Then, call getHash with the desired hash variant (SHA-1, SHA-224, SHA-256, SHA-384, or SHA-512) and output type (HEX or B64).

In the example below, "This is a Test" and "SHA-512" were used as the string to be hashed and variant respectively. Also, the HMAC using TEXT key "SecretKey" and hashing algorithm SHA-512 was calculated.

var shaObj = new jsSHA("This is a Test", "TEXT");
var hash = shaObj.getHash("SHA-512", "HEX");
var hmac = shaObj.getHMAC("SecretKey", "TEXT", "SHA-512", "HEX");

The constructor takes an optional parameter, encoding, that specifies the encoding used to encode TEXT-type inputs. Valid options are "UTF8", "UTF16BE", and "UTF16LE", it defaults to "UTF8"

getHash takes two optional parameters, a numRounds integer and an outputFormatOpts hashlist. numRounds controls the number of hashing iterations/rounds performed and defaults to a value of "1" if not specified. outputFormatOpts dictates some formatting options for the output. By default, outputFormatOpts = {"outputUpper" : false, "b64Pad" : "="}. These options are intelligently interpreted based upon the chosen output format.

getHMAC also takes an optional outputFormatOpts hashlist which operates the exact same way as above.

Node.js

jsSHA is available through NPM and be installed by simply doing

npm install jssha

To use the module, first require it using:

jsSHA = require("jssha");

The rest of the instructions are identical to the Browser section above.

Compiling

This library makes use of the Google Closure Compiler (https://developers.google.com/closure/compiler) to both boost performance and reduce filesizes. To compile sha_dev.js into a customized output file, use a command like the following:

java -jar compiler.jar --define="SUPPORTED_ALGS=<FLAG>" \
	--externs /path/to/build/externs.js --warning_level VERBOSE \
	--compilation_level ADVANCED_OPTIMIZATIONS \
	--js /path/to/sha_dev.js --js_output_file /path/to/sha.js

where FLAG is a bitwise OR of the following values:

• 4 for SHA-384/SHA-512
• 2 for SHA-224/256
• 1 for SHA-1

Contact Info

The project's website is located at http://caligatio.github.com/jsSHA/