com.rongjih.jwt.JWT Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of rj-jwt4j Show documentation
Pure Java implementation for JSON Web Token (JWT)
The newest version!
package com.rongjih.jwt;

import java.nio.charset.StandardCharsets;

/**
 * JWT
 *
 * @author RJ
 * @since JDK1.8
 */
public final class JWT {
	public Header header;
	public Payload payload;

	public JWT(Header header, Payload payload) {
		this.header = header;
		this.payload = payload;
	}

	/**
	 * Encode this instance to JWT standard format.
	 *
	 * @param secret the signature key
	 * @return [header].[payload].[signature]
	 */
	public String generate(byte[] secret) {
		String hp = header.encode() + "." + payload.encode();
		return hp + "." + new String(
				SignerFactory.get(header.algorithm).sign(hp.getBytes(StandardCharsets.UTF_8), secret),
				StandardCharsets.UTF_8
		);
	}

	/**
	 * Encode this instance to JWT standard format.
	 *
	 * @param secret the signature key
	 * @return [header].[payload].[signature]
	 */
	public String generate(String secret) {
		return generate(secret == null ? null : secret.getBytes(StandardCharsets.UTF_8));
	}

	/**
	 * Verify whether the JWT is valid. If valid return the decoded instance.
	 *
	 * @param jwt    jwt
	 * @param secret signature key
	 * @return the decoded jwt instance
	 * @throws DecodeException if jwt is illegal
	 */
	public static JWT verify(String jwt, String secret) {
		return verify(jwt, secret == null ? null : secret.getBytes(StandardCharsets.UTF_8));
	}

	/**
	 * Validate whether the JWT is valid. If valid return the decoded instance.
	 *
	 * Follow rfc7519#section-7 to validating a JWT
	 *
	 * @param jwt    jwt
	 * @param secret signature key
	 * @return the decoded jwt instance
	 * @throws DecodeException if jwt is illegal.
	 */
	public static JWT verify(String jwt, byte[] secret) {
		// 1. verify that the jwt contains at least one period ('.') character
		if (jwt.indexOf(".") <= 0)
			throw new DecodeException("Illegal jwt: no '.' character inner");

		// verify and verify header, payload
		String[] hps = jwt.split("\\.");
		Header header = Header.decode(hps[0]);

		// a unsecured JWT is not supported this time
		if (header.algorithm == Algorithm.NONE && hps.length == 2)
			throw new DecodeException("'none' algorithm is not support.");

		// secured jwt
		if (hps.length != 3)
			throw new DecodeException("Illegal jwt: not [header].[payload].[signature] format");
		Payload payload = Payload.decode(hps[1]);

		// verify the signature
		byte[] signature = SignerFactory.get(header.algorithm)
				.sign((hps[0] + "." + hps[1]).getBytes(StandardCharsets.UTF_8), secret);
		if (!hps[2].equals(new String(signature, StandardCharsets.UTF_8))) {
			throw new DecodeException("Illegal jwt: signature not match");
		} else {
			return new JWT(header, payload);
		}
	}
}