JWT(JSON Web Token) Java与.Net简单编码实现

参考

• JWT（JSON WEB TOKENS）-一种无状态的认证机制
• 基于Token的WEB后台认证机制
• 各种语言版本的基于HMAC-SHA256的base64加密

Java与.Net实现实现

// java HMacsha256
private static final  String MAC_INSTANCE_NAME = "HMacSHA256";

public static String Hmacsha256(String secret, String message) throws NoSuchAlgorithmException, InvalidKeyException {
    Mac hmac_sha256 = Mac.getInstance(MAC_INSTANCE_NAME);
    SecretKeySpec key = new SecretKeySpec(secret.getBytes(), MAC_INSTANCE_NAME);
    hmac_sha256.init(key);
    byte[] buff = hmac_sha256.doFinal(message.getBytes());
    return Base64.encodeBase64URLSafeString(buff);
}

// java jwt
@Test
public void testJWT() throws InvalidKeyException, NoSuchAlgorithmException {
    String secret = "eerp";
    String header = "{"type":"JWT","alg":"HS256"}";
    String claim = "{"iss":"cnooc", "sub":"yrm", "username":"yrm", "admin":true}";

    String base64Header = Base64.encodeBase64URLSafeString(header.getBytes());
    String base64Claim = Base64.encodeBase64URLSafeString(claim.getBytes());
    String signature = ShaUtil.Hmacsha256(secret, base64Header + "." + base64Claim);

    String jwt = base64Header + "." + base64Claim  + "." + signature;
    System.out.println(jwt);
}

// c# Hmacsha256
protected String HMacSha256Hash(String key, String message)
{
    var keyBytes = Encoding.UTF8.GetBytes(key);
    using (var hmacsha256 = new HMACSHA256(keyBytes))
    {
        var buffer = hmacsha256.ComputeHash(Encoding.UTF8.GetBytes(message));
        var b64 = Base64UrlSafeString(buffer);
        return b64;
    }
}

protected String Base64UrlSafeString(Byte[] bytes)
{
    var b64 = Convert.ToBase64String(bytes);
    return b64.Replace("=", "").Replace("+", "-").Replace("/", "_");
}

// c# jwt
[Test]
public void testJWT()
{
    String secret = "eerp";
    String header = "{"type":"JWT","alg":"HS256"}";
    String claim = "{"iss":"cnooc", "sub":"yrm", "username":"yrm", "admin":true}";

    var encoding = Encoding.UTF8;
    var base64Header = Base64UrlSafeString(encoding.GetBytes(header));
    var base64Claim = Base64UrlSafeString(encoding.GetBytes(claim));
    var signature = HMacSha256Hash(secret, base64Header + "." + base64Claim);

    var jwt = base64Header + "." + base64Claim + "." + signature;
    Console.WriteLine(jwt);

}

结果:
eyJ0eXBlIjoiSldUIiwiYWxnIjoiSFMyNTYifQ.eyJpc3MiOiJjbm9vYyIsICJzdWIiOiJ5cm0iLCAidXNlcm5hbWUiOiJ5cm0iLCAiYWRtaW4iOnRydWV9.sAHcCnpnsPA0T9i-Ig9oZnVq3N0-kK_aCwlkzFOkrH8