Java JWT RS256

Java implementation of JSON Web Token (JWT)

Get it

Maven

<dependency>
    <groupId>com.auth0</groupId>
    <artifactId>java-jwt</artifactId>
    <version>3.10.0</version>
</dependency>

Gradle

implementation 'com.auth0:java-jwt:3.10.0'

Usage

Create and Sign a Token

• Example using RS256

//Get the key instance
RSAPublicKey publicKey = readPublicKey(new File(PUBLIC_KEY_FILE));
RSAPrivateKey privateKey = readPrivateKey(new File(PRIVATE_KEY_FILE));
try {
    Algorithm algorithm = Algorithm.RSA256(publicKey, privateKey);
    String token = JWT.create()
        .withIssuer("auth0")
        .sign(algorithm);
} catch (JWTCreationException exception){
    //Invalid Signing configuration / Couldn't convert Claims.
}

If a Claim couldn't be converted to JSON or the Key used in the signing process was invalid a JWTCreationException will raise.

Verify a Token

You'll first need to create a JWTVerifier instance by calling JWT.require() and passing the Algorithm instance. If you require the token to have specific Claim values, use the builder to define them. The instance returned by the method build() is reusable, so you can define it once and use it to verify different tokens. Finally call verifier.verify() passing the token.

• Example using RS256

String token = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXUyJ9.eyJpc3MiOiJhdXRoMCJ9.AbIJTDMFc7yUa5MhvcP03nJPyCPzZtQcGEp-zWfOkEE";
//Get the key instance
RSAPublicKey publicKey = readPublicKey(new File(PUBLIC_KEY_FILE));
RSAPrivateKey privateKey = readPrivateKey(new File(PRIVATE_KEY_FILE));
try {
    Algorithm algorithm = Algorithm.RSA256(publicKey, privateKey);
    JWTVerifier verifier = JWT.require(algorithm)
        .withIssuer("auth0")
        .build(); //Reusable verifier instance
    DecodedJWT jwt = verifier.verify(token);
} catch (JWTVerificationException exception){
    //Invalid signature/claims
}