sm.js

SM series cryptography in javascript implementation.

SM2 signature and SM3 hash are implemented.

install

sm.js is available in npm.

npm install sm.js

Usage

SM2 key pair

Generate a key pair

var sm2 = require("sm.js").sm2

var key = sm2.genKeyPair()

The public key can be converted to a string or a byte array, for storing or transmitting on network.

var pubKeyString = key.pubToString()
var pubKeyBytes = key.pubToBytes("compress")

Note that there are 3 conversion modes: compress, nocompress and mex. The default mode is nocompress.

To parse the public key string/array, simply use the key pair constructor

var key = new sm2.SM2KeyPair(pubKeyString);

SM2 signature

The key pair can be used to sign message or verify the signature.

var msg = "abc"
var signature = key.sign(msg)

if (key.verify(msg, signature.r, signature.s)) {
  console.log("PASS")
}

Note that key.pri should not be null when signing, as well as key.pub for verifying.

sign will combine the input message with extra infos(a constant ID, the curve parameters and the public key), and use SM3 as the hash algorithm. While there is a function pair signRaw and verifyRaw which do not use the extra infos. Also there is a function pair signDigest and verifyDigest use the message digest as the input, allowing for custom hashing.

SM3 hash algorithm

The sm3 module is used to generate digest using SM3 hash algorithm.

var sm3 = require("sm.js").sm3

var msg = "abc"
var hash = new sm3()
var digest = hash.sum(msg)