Why am I getting ' Instance of 'JWTInvalidError' for a Private Key

When I use my key to generate a token using HS256 it is fine and able to generate a token .But for RS256 it is throwing an error Instance of 'JWTInvalidError'.I have attached the screenshot below

Below Is the code I am using to generate the token import 'package:dart_jsonwebtoken/dart_jsonwebtoken.dart';

String token;

void dartJsonWebTokenGenerator() { Duration delay = new Duration(minutes: 300); final jwt = JWT( payload: { "version": "13", 'user_id': 'xxxxxxxxxxxxxxxxxx', }, audience: 'live-tv', );

// Sign it (default with HS256 algorithm) token = jwt.sign( PrivateKey( 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'), algorithm: JWTAlgorithm.RS256, expiresIn: delay); print('Signed token: $token\n'); }

The equivalent Java code I am trying to implement is :

import android.util.Log;

import java.security.GeneralSecurityException; import java.security.KeyFactory; import java.security.PrivateKey; import java.security.spec.PKCS8EncodedKeySpec; import java.util.Date; import java.util.concurrent.TimeUnit;

public class RSAKeyGenerator { private static PrivateKey getPrivateKey() throws GeneralSecurityException { String pKey = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"; KeyFactory kf = KeyFactory.getInstance("RSA"); byte[] decode; decode = android.util.Base64.decode(pKey, android.util.Base64.DEFAULT); PKCS8EncodedKeySpec keySpecPKCS8 = new PKCS8EncodedKeySpec(decode); return kf.generatePrivate(keySpecPKCS8); } public static String getJwtToken() { final long VALIDITY_MS = TimeUnit.MINUTES.toMillis(60); long nowMillis = System.currentTimeMillis(); Date now = new Date(nowMillis); Date exp = new Date(nowMillis + VALIDITY_MS); PrivateKey privateKey = null; try { privateKey = getPrivateKey(); } catch (GeneralSecurityException e) { e.printStackTrace(); } String jws = Jwts.builder() .claim("version", "13") .claim("user_id", "xxxxxxxxxxxxxxxxxxx") .setIssuedAt(now) .setExpiration(exp) .signWith(privateKey, SignatureAlgorithm.RS256) .setAudience("live-tv") .compact(); Log.d("111__", jws); SpUtil.Companion.getInstance().putString(J_TOKEN, jws); return jws; } }

Hello @Chethansmash7,

What is the structure of your RSA key ? You must give the full content of your PEM

Something like that (https://jwt.io) :

This code work perfectly :

import 'package:dart_jsonwebtoken/dart_jsonwebtoken.dart';

main() {
  String token;

  /* Sign */ {
    // Create a json web token
    final jwt = JWT(
      payload: {
        'id': 123,
        'server': {
          'id': '3e4fc296',
          'loc': 'euw-2',
        }
      },
      issuer: 'https://github.com/jonasroussel/jsonwebtoken',
    );

    // Sign it
    token = jwt.sign(
      PrivateKey(
        '''
        -----BEGIN RSA PRIVATE KEY-----
        MIIEogIBAAKCAQEAnzyis1ZjfNB0bBgKFMSvvkTtwlvBsaJq7S5wA+kzeVOVpVWw
        kWdVha4s38XM/pa/yr47av7+z3VTmvDRyAHcaT92whREFpLv9cj5lTeJSibyr/Mr
        m/YtjCZVWgaOYIhwrXwKLqPr/11inWsAkfIytvHWTxZYEcXLgAXFuUuaS3uF9gEi
        NQwzGTU1v0FqkqTBr4B8nW3HCN47XUu0t8Y0e+lf4s4OxQawWD79J9/5d3Ry0vbV
        3Am1FtGJiJvOwRsIfVChDpYStTcHTCMqtvWbV6L11BWkpzGXSW4Hv43qa+GSYOD2
        QU68Mb59oSk2OB+BtOLpJofmbGEGgvmwyCI9MwIDAQABAoIBACiARq2wkltjtcjs
        kFvZ7w1JAORHbEufEO1Eu27zOIlqbgyAcAl7q+/1bip4Z/x1IVES84/yTaM8p0go
        amMhvgry/mS8vNi1BN2SAZEnb/7xSxbflb70bX9RHLJqKnp5GZe2jexw+wyXlwaM
        +bclUCrh9e1ltH7IvUrRrQnFJfh+is1fRon9Co9Li0GwoN0x0byrrngU8Ak3Y6D9
        D8GjQA4Elm94ST3izJv8iCOLSDBmzsPsXfcCUZfmTfZ5DbUDMbMxRnSo3nQeoKGC
        0Lj9FkWcfmLcpGlSXTO+Ww1L7EGq+PT3NtRae1FZPwjddQ1/4V905kyQFLamAA5Y
        lSpE2wkCgYEAy1OPLQcZt4NQnQzPz2SBJqQN2P5u3vXl+zNVKP8w4eBv0vWuJJF+
        hkGNnSxXQrTkvDOIUddSKOzHHgSg4nY6K02ecyT0PPm/UZvtRpWrnBjcEVtHEJNp
        bU9pLD5iZ0J9sbzPU/LxPmuAP2Bs8JmTn6aFRspFrP7W0s1Nmk2jsm0CgYEAyH0X
        +jpoqxj4efZfkUrg5GbSEhf+dZglf0tTOA5bVg8IYwtmNk/pniLG/zI7c+GlTc9B
        BwfMr59EzBq/eFMI7+LgXaVUsM/sS4Ry+yeK6SJx/otIMWtDfqxsLD8CPMCRvecC
        2Pip4uSgrl0MOebl9XKp57GoaUWRWRHqwV4Y6h8CgYAZhI4mh4qZtnhKjY4TKDjx
        QYufXSdLAi9v3FxmvchDwOgn4L+PRVdMwDNms2bsL0m5uPn104EzM6w1vzz1zwKz
        5pTpPI0OjgWN13Tq8+PKvm/4Ga2MjgOgPWQkslulO/oMcXbPwWC3hcRdr9tcQtn9
        Imf9n2spL/6EDFId+Hp/7QKBgAqlWdiXsWckdE1Fn91/NGHsc8syKvjjk1onDcw0
        NvVi5vcba9oGdElJX3e9mxqUKMrw7msJJv1MX8LWyMQC5L6YNYHDfbPF1q5L4i8j
        8mRex97UVokJQRRA452V2vCO6S5ETgpnad36de3MUxHgCOX3qL382Qx9/THVmbma
        3YfRAoGAUxL/Eu5yvMK8SAt/dJK6FedngcM3JEFNplmtLYVLWhkIlNRGDwkg3I5K
        y18Ae9n7dHVueyslrb6weq7dTkYDi3iOYRW8HRkIQh06wEdbxt0shTzAJvvCQfrB
        jg/3747WSsf/zBTcHihTRBdAv6OmdhV4/dD5YBfLAkLrd+mX7iE=
        -----END RSA PRIVATE KEY-----
        ''',
      ),
      algorithm: JWTAlgorithm.RS256,
      expiresIn: Duration(minutes: 300),
    );

    print('Signed token: $token\n');
  }

  /* Verify */ {
    try {
      // Verify a token
      final jwt = JWT.verify(
        token,
        PublicKey(
          '''
          -----BEGIN PUBLIC KEY-----
          MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAnzyis1ZjfNB0bBgKFMSv
          vkTtwlvBsaJq7S5wA+kzeVOVpVWwkWdVha4s38XM/pa/yr47av7+z3VTmvDRyAHc
          aT92whREFpLv9cj5lTeJSibyr/Mrm/YtjCZVWgaOYIhwrXwKLqPr/11inWsAkfIy
          tvHWTxZYEcXLgAXFuUuaS3uF9gEiNQwzGTU1v0FqkqTBr4B8nW3HCN47XUu0t8Y0
          e+lf4s4OxQawWD79J9/5d3Ry0vbV3Am1FtGJiJvOwRsIfVChDpYStTcHTCMqtvWb
          V6L11BWkpzGXSW4Hv43qa+GSYOD2QU68Mb59oSk2OB+BtOLpJofmbGEGgvmwyCI9
          MwIDAQAB
          -----END PUBLIC KEY-----
          ''',
        ),
      );

      print('Payload: ${jwt.payload}');
    } on JWTExpiredError {
      print('jwt expired');
    } on JWTError catch (ex) {
      print(ex.message); // ex: invalid signature
    }
  }
}

Hello @Chethansmash7,

What is the structure of your RSA key ? You must give the full content of your PEM

Something like that (https://jwt.io) :

This code work perfectly :

import 'package:dart_jsonwebtoken/dart_jsonwebtoken.dart';

main() {
  String token;

  /* Sign */ {
    // Create a json web token
    final jwt = JWT(
      payload: {
        'id': 123,
        'server': {
          'id': '3e4fc296',
          'loc': 'euw-2',
        }
      },
      issuer: 'https://github.com/jonasroussel/jsonwebtoken',
    );

    // Sign it
    token = jwt.sign(
      PrivateKey(
        '''
        -----BEGIN RSA PRIVATE KEY-----
        MIIEogIBAAKCAQEAnzyis1ZjfNB0bBgKFMSvvkTtwlvBsaJq7S5wA+kzeVOVpVWw
        kWdVha4s38XM/pa/yr47av7+z3VTmvDRyAHcaT92whREFpLv9cj5lTeJSibyr/Mr
        m/YtjCZVWgaOYIhwrXwKLqPr/11inWsAkfIytvHWTxZYEcXLgAXFuUuaS3uF9gEi
        NQwzGTU1v0FqkqTBr4B8nW3HCN47XUu0t8Y0e+lf4s4OxQawWD79J9/5d3Ry0vbV
        3Am1FtGJiJvOwRsIfVChDpYStTcHTCMqtvWbV6L11BWkpzGXSW4Hv43qa+GSYOD2
        QU68Mb59oSk2OB+BtOLpJofmbGEGgvmwyCI9MwIDAQABAoIBACiARq2wkltjtcjs
        kFvZ7w1JAORHbEufEO1Eu27zOIlqbgyAcAl7q+/1bip4Z/x1IVES84/yTaM8p0go
        amMhvgry/mS8vNi1BN2SAZEnb/7xSxbflb70bX9RHLJqKnp5GZe2jexw+wyXlwaM
        +bclUCrh9e1ltH7IvUrRrQnFJfh+is1fRon9Co9Li0GwoN0x0byrrngU8Ak3Y6D9
        D8GjQA4Elm94ST3izJv8iCOLSDBmzsPsXfcCUZfmTfZ5DbUDMbMxRnSo3nQeoKGC
        0Lj9FkWcfmLcpGlSXTO+Ww1L7EGq+PT3NtRae1FZPwjddQ1/4V905kyQFLamAA5Y
        lSpE2wkCgYEAy1OPLQcZt4NQnQzPz2SBJqQN2P5u3vXl+zNVKP8w4eBv0vWuJJF+
        hkGNnSxXQrTkvDOIUddSKOzHHgSg4nY6K02ecyT0PPm/UZvtRpWrnBjcEVtHEJNp
        bU9pLD5iZ0J9sbzPU/LxPmuAP2Bs8JmTn6aFRspFrP7W0s1Nmk2jsm0CgYEAyH0X
        +jpoqxj4efZfkUrg5GbSEhf+dZglf0tTOA5bVg8IYwtmNk/pniLG/zI7c+GlTc9B
        BwfMr59EzBq/eFMI7+LgXaVUsM/sS4Ry+yeK6SJx/otIMWtDfqxsLD8CPMCRvecC
        2Pip4uSgrl0MOebl9XKp57GoaUWRWRHqwV4Y6h8CgYAZhI4mh4qZtnhKjY4TKDjx
        QYufXSdLAi9v3FxmvchDwOgn4L+PRVdMwDNms2bsL0m5uPn104EzM6w1vzz1zwKz
        5pTpPI0OjgWN13Tq8+PKvm/4Ga2MjgOgPWQkslulO/oMcXbPwWC3hcRdr9tcQtn9
        Imf9n2spL/6EDFId+Hp/7QKBgAqlWdiXsWckdE1Fn91/NGHsc8syKvjjk1onDcw0
        NvVi5vcba9oGdElJX3e9mxqUKMrw7msJJv1MX8LWyMQC5L6YNYHDfbPF1q5L4i8j
        8mRex97UVokJQRRA452V2vCO6S5ETgpnad36de3MUxHgCOX3qL382Qx9/THVmbma
        3YfRAoGAUxL/Eu5yvMK8SAt/dJK6FedngcM3JEFNplmtLYVLWhkIlNRGDwkg3I5K
        y18Ae9n7dHVueyslrb6weq7dTkYDi3iOYRW8HRkIQh06wEdbxt0shTzAJvvCQfrB
        jg/3747WSsf/zBTcHihTRBdAv6OmdhV4/dD5YBfLAkLrd+mX7iE=
        -----END RSA PRIVATE KEY-----
        ''',
      ),
      algorithm: JWTAlgorithm.RS256,
      expiresIn: Duration(minutes: 300),
    );

    print('Signed token: $token\n');
  }

  /* Verify */ {
    try {
      // Verify a token
      final jwt = JWT.verify(
        token,
        PublicKey(
          '''
          -----BEGIN PUBLIC KEY-----
          MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAnzyis1ZjfNB0bBgKFMSv
          vkTtwlvBsaJq7S5wA+kzeVOVpVWwkWdVha4s38XM/pa/yr47av7+z3VTmvDRyAHc
          aT92whREFpLv9cj5lTeJSibyr/Mrm/YtjCZVWgaOYIhwrXwKLqPr/11inWsAkfIy
          tvHWTxZYEcXLgAXFuUuaS3uF9gEiNQwzGTU1v0FqkqTBr4B8nW3HCN47XUu0t8Y0
          e+lf4s4OxQawWD79J9/5d3Ry0vbV3Am1FtGJiJvOwRsIfVChDpYStTcHTCMqtvWb
          V6L11BWkpzGXSW4Hv43qa+GSYOD2QU68Mb59oSk2OB+BtOLpJofmbGEGgvmwyCI9
          MwIDAQAB
          -----END PUBLIC KEY-----
          ''',
        ),
      );

      print('Payload: ${jwt.payload}');
    } on JWTExpiredError {
      print('jwt expired');
    } on JWTError catch (ex) {
      print(ex.message); // ex: invalid signature
    }
  }
}

Could you shed more light on what you have written in the payload section?What should I write(you can see the Java code under Jwts.builder().

Yes that is the structure of my private,as it is in yours

I juste wrote some fake data for example, payload is like claims, issuer & audience are some identification data of a jwt token

Your code is OK, I tried with the private key just above

final jwt = JWT(
  payload: {
    'version': '13',
    'user_id': 'xxxxxxxxxxxxxxxxxx',
  },
  audience: 'live-tv',
);

final token = jwt.sign(
  PrivateKey('xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'),
  algorithm: JWTAlgorithm.RS256,
  expiresIn: Duration(minutes: 300),
);

I juste wrote some fake data for example, payload is like claims, issuer & audience are some identification data of a jwt token

Your code is OK, I tried with the private key just above
final jwt = JWT(
  payload: {
    'version': '13',
    'user_id': 'xxxxxxxxxxxxxxxxxx',
  },
  audience: 'live-tv',
);

final token = jwt.sign(
  PrivateKey('xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'),
  algorithm: JWTAlgorithm.RS256,
  expiresIn: Duration(minutes: 300),
);

Yeah it is working,I tried the same code before and it was not working.The only change I did was to include the private key in this format ''' -----BEGIN PUBLIC KEY----- MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAnzyis1ZjfNB0bBgKFMSv vkTtwlvBsaJq7S5wA+kzeVOVpVWwkWdVha4s38XM/pa/yr47av7+z3VTmvDRyAHc aT92whREFpLv9cj5lTeJSibyr/Mrm/YtjCZVWgaOYIhwrXwKLqPr/11inWsAkfIy tvHWTxZYEcXLgAXFuUuaS3uF9gEiNQwzGTU1v0FqkqTBr4B8nW3HCN47XUu0t8Y0 e+lf4s4OxQawWD79J9/5d3Ry0vbV3Am1FtGJiJvOwRsIfVChDpYStTcHTCMqtvWb V6L11BWkpzGXSW4Hv43qa+GSYOD2QU68Mb59oSk2OB+BtOLpJofmbGEGgvmwyCI9 MwIDAQAB -----END PUBLIC KEY----- ''',

and boom it worked.

Thank you so much.I had been stuck for 3 days with this issue and you helped me. Perhaps in the pub.dev home page you should edit and include to try the private key in the said format also

jonasroussel / dart_jsonwebtoken

Why am I getting ' Instance of 'JWTInvalidError' for a Private Key #1