JWE Key ID not found in encrypted request message!

[zzggs]

Hi all,

We want to convert Java code to C#, Java code sample:

`private JWSObject signMessage(String messagePayload, KeyStore ks, String keyAlias, String keyPw)
throws UnrecoverableKeyException, KeyStoreException, NoSuchAlgorithmException, JOSEException {
#1 Payload payload = new Payload(messagePayload);

#2 JWSHeader header = new JWSHeader.Builder(JWSAlgorithm.RS256).keyID("0001").build();
#3 JWSObject jwsObject = new JWSObject(header, payload);

#4 PrivateKey privateKey = (PrivateKey) ks.getKey(keyAlias, keyPw.toCharArray());
JWSSigner signer = new RSASSASigner(privateKey);
#5 jwsObject.sign(signer);

return jwsObject;

}`

1. Prepare your Message Payload, that is, the plain json request message
2. Create JWS Header using RS256 signing algorithm and JWS keyID, in this case, 0001
3. Create JWS Object by combining JWS Header and Message Payload
4. Retrieve your Private Key as the signer
5. Create Signed JWS Object by signing it with the Private Key

Next, you are going to Encrypt the Signed JWS Object:
`private JWEObject getEncryptedJWEObject(JWSObject jwsObject, RSAPublicKey key)
throws JOSEException {
#1 Payload jwepayload = new Payload(jwsObject.serialize());

#2 JWEHeader jweheader = new JWEHeader.Builder(JWEAlgorithm.RSA_OAEP_256, EncryptionMethod.A128GCM).keyID("0002").build();
#3 JWEObject jweObject = new JWEObject(jweheader, jwepayload);

#4 JWEEncrypter encrypter = new RSAEncrypter(key);
#5 jweObject.encrypt(encrypter);

return jweObject;

}`
1.Prepare your JWE Payload, that is, the Signed JWS Object
2.Create JWE Header. The algorithm used to encrypt the message body is A128GCM while the algorithm used to encrypt the encryption key is RSA_OAEP_256. JWE keyID is 0002.
3.Create JWE Object by combining JWE Header and JWE Payload
4.Retrieve HSBC's Public Key as the encrypter
5.Create Encrypted JWE Object by encrypted it with HSBC's Public Key

C# Code:
var signedtoken= ""; var requestpayload = "..."; var header = "..."; var cert = "..."; using (var privatekey = cert.PrivateKey as RSACryptoServiceProvider) { if (privatekey != null) { signedtoken = JWT.Encode(requestpayload, privatekey, JwsAlgorithm.RS256, extraHeaders: header); } }
Next step to encrypt token
`using (RSA publickey = hsbccert.GetRSAPublicKey())
{
if (publickey != null)
{

    var hsbcheader = ...
    var encrypttoken = Jose.JWT.Encode(signedtoken, fpspk, JweAlgorithm.RSA_OAEP_256, JweEncryption.A128GCM, hsbcheader);
    //PaymentHelper.LogArchInfo("FPS JWE Token : ", "FPS", encrypttoken, DateTime.Now);
}

}`

The post response : JWE Key ID not found in encrypted request message!

It seems signature is not generated. When we use following code to read this signed token, no security key in this JWT token:
var handler = new JwtSecurityTokenHandler(); var tokenData = handler.ReadJwtToken(signedtoken);

How to resolve this issue?