jsrsasign

What is jsrsasign?

The jsrsasign npm package is a comprehensive library for cryptographic operations, including RSA/DSA/ECDSA key generation, digital signatures, X.509 certificate handling, and more. It is widely used for implementing security features in JavaScript applications.

What are jsrsasign's main functionalities?

RSA Key Generation

This feature allows you to generate RSA key pairs. The code sample demonstrates generating a 2048-bit RSA key pair using the KEYUTIL.generateKeypair method.

const rsaKeypair = KEYUTIL.generateKeypair('RSA', 2048);
console.log(rsaKeypair);

Digital Signature

This feature allows you to create digital signatures. The code sample shows how to sign a message using an RSA private key and the SHA256withRSA algorithm.

const rsa = new RSAKey();
rsa.readPrivateKeyFromPEMString('-----BEGIN PRIVATE KEY-----...');
const sig = new KJUR.crypto.Signature({alg: 'SHA256withRSA'});
sig.init(rsa);
sig.updateString('message');
const signature = sig.sign();
console.log(signature);

X.509 Certificate Handling

This feature allows you to handle X.509 certificates. The code sample demonstrates reading a PEM-encoded certificate and extracting the subject string.

const pemCert = '-----BEGIN CERTIFICATE-----...';
const x509 = new X509();
x509.readCertPEM(pemCert);
console.log(x509.getSubjectString());

JWT (JSON Web Token) Handling

This feature allows you to create and verify JSON Web Tokens (JWT). The code sample shows how to sign a JWT using the HS256 algorithm and a secret key.

const header = {alg: 'HS256', typ: 'JWT'};
const payload = {sub: '1234567890', name: 'John Doe', iat: 1516239022};
const sHeader = JSON.stringify(header);
const sPayload = JSON.stringify(payload);
const sJWT = KJUR.jws.JWS.sign('HS256', sHeader, sPayload, 'secret');
console.log(sJWT);

Other packages similar to jsrsasign

crypto

The 'crypto' module is a built-in Node.js module that provides cryptographic functionality, including a set of wrappers for OpenSSL's hash, HMAC, cipher, decipher, sign, and verify functions. It is more low-level compared to jsrsasign and is typically used for server-side cryptographic operations.

jsonwebtoken

The 'jsonwebtoken' package is a popular library for creating and verifying JSON Web Tokens (JWT). It is more specialized than jsrsasign, focusing specifically on JWT handling, and is widely used in authentication and authorization scenarios.

node-forge

The 'node-forge' package is a comprehensive library for implementing various cryptographic operations in JavaScript. It provides functionalities for key generation, digital signatures, encryption/decryption, and more. It is similar to jsrsasign in terms of the breadth of cryptographic features it offers.

README

jsrsasign

The 'jsrsasign' (RSA-Sign JavaScript Library) is an opensource free pure JavaScript cryptographic library supports RSA/RSAPSS/ECDSA/DSA signing/validation, ASN.1, PKCS#1/5/8 private/public key, X.509 certificate, CRL, CMS SignedData, TimeStamp and CAdES and JSON Web Signature(JWS)/Token(JWT)/Key(JWK).

Public page is http://kjur.github.com/jsrsasign .

DIFFERENCE WITH CRYPTO MODULE

Here is the difference between bundled 'Crypto' module and this 'jsrsasign' module.

• Crypto module
  • fast
  • works only on Node.js
  • OpenSSL based
  • lacking ASN.1 functionality
  • provides symmetric ciphers
  • lacking RSAPSS signing
• jsrsasign module
  • slow
  • implemented in pure JavaScript
  • works on both Node.js(server) and browsers(client)
  • provides ASN.1 parsing/generation functionality
  • lacking symmetric ciphers
  • provides RSAPSS signing
  • also provides support for JSON Web Signatures (JWS) and JSON Web Token (JWT)

AVAILABLE CLASSES AND METHODS

Most of the classes and methods defined in jsrsasign and jsjws are available in this jsrsasign npm module.

After loading the module,

> var r = require('jsrsasign');

You can refer name spaces, classes, methods and functions by following variables:

• r.BigInteger - BigInteger class
• r.RSAKey - RSAKey class
• r.ECDSA - KJUR.crypto.ECDSA class
• r.DSA - KJUR.crypto.DSA class
• r.Signature - KJUR.crypto.Signature class
• r.MessageDigest - KJUR.crypto.MessageDigest class
• r.Mac - KJUR.crypto.Mac class
• r.KEYUTIL - KEYUTIL class
• r.ASN1HEX - ASN1HEX class
• r.crypto - KJUR.crypto name space
• r.asn1 - KJUR.asn1 name space
• r.jws - KJUR.jws name space

Please see API reference in the above links.

EXAMPLE(1) SIGNATURE

Loading encrypted PKCS#5 private key:

> var fs = require('fs');
> var pem = fs.readFileSync('z1.prv.p5e.pem', 'binary');
> var prvKey = a.KEYUTIL.getKey(pem, 'passwd');

Sign string 'aaa' with the loaded private key:

> var sig = new a.Signature({alg: 'SHA1withRSA'});
> sig.init(prvKey);
> sig.updateString('aaa');
> var sigVal = sig.sign();
> sigVal
'd764dcacb...'