using System;

using System.Security.Cryptography;

using System.Collections.Generic;

using Jose;

using System.Text.Json;

//using System.Text.Json.Serialization;

​

​

class RrsaSignatureString {

    public static void Main() {

        Console.WriteLine("JWT RSA encryption");

        // https://www.nuget.org/packages/jose-jwt/

        // https://github.com/dvsekhvalnov/jose-jwt

        Console.WriteLine("DateTime Now: " + DateTime.Now);

        Console.WriteLine("DateTime Unix: " + DateTimeOffset.Now.ToUnixTimeSeconds());

        var payloadOrg = new Dictionary<string, object>()

        {

            { "sub", "mr.x@contoso.com" },

            { "exp", 1300819380 }

        };

        var payload = new Dictionary<string, object>()

        {

            { "sub", "mr.x@contoso.com" },

            { "exp", DateTimeOffset.Now.ToUnixTimeSeconds() + 60 } // 60 seconds valid

        };

        // getting the public key

        string publicKeyPem = loadRsaPublicKeyPem(); 

        RSA rsaAlg = RSA.Create();

        rsaAlg.ImportFromPem(publicKeyPem);

        // JWEHeader header = new JWEHeader(JWEAlgorithm.RSA_OAEP_256, EncryptionMethod.A128GCM);

        string token = Jose.JWT.Encode(payload, rsaAlg, JweAlgorithm.RSA_OAEP_256, JweEncryption.A128GCM);

        //var privateKey=new X509Certificate2("my-key.p12", "password", X509KeyStorageFlags.Exportable | X509KeyStorageFlags.MachineKeySet).PrivateKey as RSACryptoServiceProvider;

        //string token=Jose.JWT.Encode(payload, privateKey, JwsAlgorithm.RS256);

        //string token=Jose.JWT.Encode(payload, rsaAlg, JwsAlgorithm.RS256);

        Console.WriteLine("payload: " + payload);

        Console.WriteLine("token: " + token);

​

        // verify token

        // token is expired

        //token = "eyJhbGciOiJSU0EtT0FFUC0yNTYiLCJlbmMiOiJBMTI4R0NNIn0.uS9ImlYAxAiB0kUM5ZJX3Ji6k5aLcA7XiF5UPS9CQ2QdPHr1wNQUxEeFif4Mg_iPZAILr0NH2jVNX-WzO0JIyTl6fCaI-B7UXrxAOfMsNnNP_waib2LXSWTob01KkGasUYFBqiUbjZcn_lgXljaeo2gtaNViJiTCTDpWBaEcg9q6pKqhbem8Q95IYSr9S1pAOqTRMEB2fMDJNPFcQlikrcqTyXxx5ucTkwaekz3K6pF5MkoHieb1qE8nHsGPSv6thtalmxU3oDmaj9emKNoxj_u5pFIkV_YzIpmXeCF6i4f2wbcN6fUj7Br0aAWevK0NRAn_K6dPgSaZYqXsNUA6Uw.2HmE-u4hlbICEMfw.Tc12sdoqU8EpvdDLFNR7cDnpJ6pdqqiyc7xxUDmXkprVVy-jaMkW5LqK4w.07XnO1nu3m1w_J4EplexAg";

        // token is corrupted

        //token = "eyJhbGciOiJSU0EtT0FFUC0yNTYiLCJlbmMiOiJBMTI4R0NNIn0.uS9ImlYAxAiB0kUM5ZJX3Ji6k5aLcA7XiF5UPS9CQ2QdPHr1wNQUxEeFif4Mg_iPZAILr0NH2jVNX-WzO0JIyTl6fCaI-B7UXrxAOfMsNnNP_waib2LXSWTob01KkGasUYFBqiUbjZcn_lgXljaeo2gtaNViJiTCTDpWBaEcg9q6pKqhbem8Q95IYSr9S1pAOqTRMEB2fMDJNPFcQlikrcqTyXxx5ucTkwaekz3K6pF5MkoHieb1qE8nHsGPSv6thtalmxU3oDmaj9emKNoxj_u5pFIkV_YzIpmXeCF6i4f2wbcN6fUj7Br0aAWevK0NRAn_K6dPgSaZYqXsNUA6Uw.2HmE-u4hlbICEMfw.Tc12sdoqU8EpvdDLFNR7cDnpJ6pdqqiyc7xxUDmXkprVVy-jaMkW5LqK4w.07XnO1nu3m1w_J4EplexBg";

        // getting the rsa private key

        string privateKeyPem = loadRsaPrivateKeyPem();

        RSA rsaAlgd = RSA.Create();

        byte[] privateKeyByte = getRsaPrivateKeyEncodedFromPem(privateKeyPem);

        int _out;

        rsaAlgd.ImportPkcs8PrivateKey(privateKeyByte, out _out);

        string json = "";

        try {

            json = Jose.JWT.Decode(token , rsaAlgd);

            //Console.WriteLine("valid signature");

        } catch(Jose.EncryptionException) {

            Console.WriteLine("payload corrupted");

            // throws: Jose.EncryptionException: Unable to decrypt content or authentication tag do not match.

        }   

        Console.WriteLine("json: " + json);

        // check for expired

        var payloadData = JsonSerializer.Deserialize<PayloadObject>(json);

        long payloadExp = payloadData.exp;

        long dateTimeUnixNow = DateTimeOffset.Now.ToUnixTimeSeconds();

        if (payloadExp < dateTimeUnixNow) {

            Console.WriteLine("payload is expired");

        } else {

            Console.WriteLine("payload is NOT expired");

        }       

    }

​

    public static string rsaSignPssToBase64(string rsaPrivateKey, byte[] data) {

        // getting the rsa private key from xml

        RSACryptoServiceProvider RSAalg = new RSACryptoServiceProvider(2048);

        RSAalg.PersistKeyInCsp = false;

        RSAalg.FromXmlString(rsaPrivateKey);

        RSAParameters rsaParams = RSAalg.ExportParameters(true);

        RSA RSACng = RSA.Create();

        RSACng.ImportParameters(rsaParams);

        byte[] signature = RSACng.SignData(data, HashAlgorithmName.SHA256, RSASignaturePadding.Pss);

        return Base64Encoding(signature);

    }

​

    private static bool rsaVerifySignaturePssFromBase64(string rsaPublicKey, byte[] dataToSign, string signatureBase64) {

        try {

            var signature = Base64Decoding(signatureBase64);

            // getting the rsa public key from xml

            RSACryptoServiceProvider RSAalg = new RSACryptoServiceProvider(2048);

            RSAalg.PersistKeyInCsp = false;

            RSAalg.FromXmlString(rsaPublicKey);

            RSAParameters rsaParams = RSAalg.ExportParameters(false);

            RSA RSACng = RSA.Create();

            RSACng.ImportParameters(rsaParams);

            return RSACng.VerifyData(dataToSign, signature, HashAlgorithmName.SHA256, RSASignaturePadding.Pss);

        } catch(CryptographicException e) {

            Console.WriteLine(e.Message);

            return false;

        }

    }

​

    static string Base64Encoding(byte[] input) {

        return Convert.ToBase64String(input);

    }

​

    static byte[] Base64Decoding(String input) {

        return Convert.FromBase64String(input);

    }

​

    private static string loadRsaPrivateKeyXml() {

        return "<RSAKeyValue><Modulus>8EmWJUZ/Osz4vXtUU2S+0M4BP9+s423gjMjoX+qP1iCnlcRcFWxthQGN2CWSMZwR/vY9V0un/nsIxhZSWOH9iKzqUtZD4jt35jqOTeJ3PCSr48JirVDNLet7hRT37Ovfu5iieMN7ZNpkjeIG/CfT/QQl7R+kO/EnTmL3QjLKQNV/HhEbHS2/44x7PPoHqSqkOvl8GW0qtL39gTLWgAe801/w5PmcQ38CKG0oT2gdJmJqIxNmAEHkatYGHcMDtXRBpOhOSdraFj6SmPyHEmLBishaq7Jm8NPPNK9QcEQ3q+ERa5M6eM72PpF93g2p5cjKgyzzfoIV09Zb/LJ2aW2gQw==</Modulus><Exponent>AQAB</Exponent><P>/8atV5DmNxFrxF1PODDjdJPNb9pzNrDF03TiFBZWS4Q+2JazyLGjZzhg5Vv9RJ7VcIjPAbMy2Cy5BUffEFE+8ryKVWfdpPxpPYOwHCJSw4Bqqdj0Pmp/xw928ebrnUoCzdkUqYYpRWx0T7YVRoA9RiBfQiVHhuJBSDPYJPoP34k=</P><Q>8H9wLE5L8raUn4NYYRuUVMa+1k4Q1N3XBixm5cccc/Ja4LVvrnWqmFOmfFgpVd8BcTGaPSsqfA4j/oEQp7tmjZqggVFqiM2mJ2YEv18cY/5kiDUVYR7VWSkpqVOkgiX3lK3UkIngnVMGGFnoIBlfBFF9uo02rZpC5o5zebaDIms=</Q><DP>BPXecL9Pp6u/0kwY+DcCgkVHi67J4zqka4htxgP04nwLF/o8PF0tlRfj0S7qh4UpEIimsxq9lrGvWOne6psYxG5hpGxiQQvgIqBGLxV/U2lPKEIb4oYAOmUTYnefBCrmSQW3v93pOP50dwNKAFcGWTDRiB/e9j+3EmZm/7iVzDk=</DP><DQ>rBWkAC/uLDf01Ma5AJMpahfkCZhGdupdp68x2YzFkTmDSXLJ/P15GhIQ+Lxkp2swrvwdL1OpzKaZnsxfTIXNddmEq8PEBSuRjnNzRjQaLnqjGMtTBvF3G5tWkjClb/MW2q4fgWUG8cusetQqQn2k/YQKAOh2jXXqFOstOZQc9Q0=</DQ><InverseQ>BtiIiTnpBkd6hkqJnHLh6JxBLSxUopFvbhlR37Thw1JN94i65dmtgnjwluvR/OMgzcR8e8uCH2sBn5od78vzgiDXsqITF76rJgeO639ILTA4MO3Mz+O2umrJhrkmgSk8hpRKA+5Mf9aE7dwOzHrc8hbj8J102zyYJIE6pOehrGE=</InverseQ><D>hXGYfOMFzXX/vds8HYQZpISDlSF3NmbTCdyZkIsHjndcGoSOTyeEOxV93MggxIRUSjAeKNjPVzikyr2ixdHbp4fAKnjsAjvcfnOOjBp09WW4QCi3/GCfUh0w39uhRGZKPjiqIj8NzBitN06LaoYD6MPg/CtSXiezGIlFn/Hs+MuEzNFu8PFDj9DhOFhfCgQaIgEEr+IHdnl5HuUVrwTnIBrEzZA/08Q0Gv86qQZctZWoD9hPGzeAC+RSMyGVJw6Ls8zBFf0eysB4spsu4LUom/WnZMdS1ls4eqsAX+7AdqPKBRuUVpr8FNyRM3s8pJUiGns6KFsPThtJGuH6c6KVwQ==</D></RSAKeyValue>";

    }

​

    private static string loadRsaPublicKeyXml2() {

        return "<RSAKeyValue><Modulus>1EmWJUZ/Osz4vXtUU2S+0M4BP9+s423gjMjoX+qP1iCnlcRcFWxthQGN2CWSMZwR/vY9V0un/nsIxhZSWOH9iKzqUtZD4jt35jqOTeJ3PCSr48JirVDNLet7hRT37Ovfu5iieMN7ZNpkjeIG/CfT/QQl7R+kO/EnTmL3QjLKQNV/HhEbHS2/44x7PPoHqSqkOvl8GW0qtL39gTLWgAe801/w5PmcQ38CKG0oT2gdJmJqIxNmAEHkatYGHcMDtXRBpOhOSdraFj6SmPyHEmLBishaq7Jm8NPPNK9QcEQ3q+ERa5M6eM72PpF93g2p5cjKgyzzfoIV09Zb/LJ2aW2gQw==</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>";

    }

    private static string loadRsaPublicKeyXml() {

        return "<RSAKeyValue><Modulus>8EmWJUZ/Osz4vXtUU2S+0M4BP9+s423gjMjoX+qP1iCnlcRcFWxthQGN2CWSMZwR/vY9V0un/nsIxhZSWOH9iKzqUtZD4jt35jqOTeJ3PCSr48JirVDNLet7hRT37Ovfu5iieMN7ZNpkjeIG/CfT/QQl7R+kO/EnTmL3QjLKQNV/HhEbHS2/44x7PPoHqSqkOvl8GW0qtL39gTLWgAe801/w5PmcQ38CKG0oT2gdJmJqIxNmAEHkatYGHcMDtXRBpOhOSdraFj6SmPyHEmLBishaq7Jm8NPPNK9QcEQ3q+ERa5M6eM72PpF93g2p5cjKgyzzfoIV09Zb/LJ2aW2gQw==</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>";

    }

        private static byte[] getRsaPrivateKeyEncodedFromPem(string rsaPrivateKeyPem) {

        string rsaPrivateKeyHeaderPem = "-----BEGIN PRIVATE KEY-----\n";

        string rsaPrivateKeyFooterPem = "-----END PRIVATE KEY-----";

        string rsaPrivateKeyDataPem = rsaPrivateKeyPem.Replace(rsaPrivateKeyHeaderPem, "").Replace(rsaPrivateKeyFooterPem, "").Replace("\n", "");

        return Base64Decoding(rsaPrivateKeyDataPem);

    }

​

    private static string loadRsaPrivateKeyPem() {

        // this is a sample key - don't worry !

        return "-----BEGIN PRIVATE KEY-----\n" +

            "MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQDwSZYlRn86zPi9\n" +

            "e1RTZL7QzgE/36zjbeCMyOhf6o/WIKeVxFwVbG2FAY3YJZIxnBH+9j1XS6f+ewjG\n" +

            "FlJY4f2IrOpS1kPiO3fmOo5N4nc8JKvjwmKtUM0t63uFFPfs69+7mKJ4w3tk2mSN\n" +

            "4gb8J9P9BCXtH6Q78SdOYvdCMspA1X8eERsdLb/jjHs8+gepKqQ6+XwZbSq0vf2B\n" +

            "MtaAB7zTX/Dk+ZxDfwIobShPaB0mYmojE2YAQeRq1gYdwwO1dEGk6E5J2toWPpKY\n" +

            "/IcSYsGKyFqrsmbw0880r1BwRDer4RFrkzp4zvY+kX3eDanlyMqDLPN+ghXT1lv8\n" +

            "snZpbaBDAgMBAAECggEBAIVxmHzjBc11/73bPB2EGaSEg5UhdzZm0wncmZCLB453\n" +

            "XBqEjk8nhDsVfdzIIMSEVEowHijYz1c4pMq9osXR26eHwCp47AI73H5zjowadPVl\n" +

            "uEAot/xgn1IdMN/boURmSj44qiI/DcwYrTdOi2qGA+jD4PwrUl4nsxiJRZ/x7PjL\n" +

            "hMzRbvDxQ4/Q4ThYXwoEGiIBBK/iB3Z5eR7lFa8E5yAaxM2QP9PENBr/OqkGXLWV\n" +

            "qA/YTxs3gAvkUjMhlScOi7PMwRX9HsrAeLKbLuC1KJv1p2THUtZbOHqrAF/uwHaj\n" +

            "ygUblFaa/BTckTN7PKSVIhp7OihbD04bSRrh+nOilcECgYEA/8atV5DmNxFrxF1P\n" +

            "ODDjdJPNb9pzNrDF03TiFBZWS4Q+2JazyLGjZzhg5Vv9RJ7VcIjPAbMy2Cy5BUff\n" +

            "EFE+8ryKVWfdpPxpPYOwHCJSw4Bqqdj0Pmp/xw928ebrnUoCzdkUqYYpRWx0T7YV\n" +

            "RoA9RiBfQiVHhuJBSDPYJPoP34kCgYEA8H9wLE5L8raUn4NYYRuUVMa+1k4Q1N3X\n" +

            "Bixm5cccc/Ja4LVvrnWqmFOmfFgpVd8BcTGaPSsqfA4j/oEQp7tmjZqggVFqiM2m\n" +

            "J2YEv18cY/5kiDUVYR7VWSkpqVOkgiX3lK3UkIngnVMGGFnoIBlfBFF9uo02rZpC\n" +

            "5o5zebaDImsCgYAE9d5wv0+nq7/STBj4NwKCRUeLrsnjOqRriG3GA/TifAsX+jw8\n" +

            "XS2VF+PRLuqHhSkQiKazGr2Wsa9Y6d7qmxjEbmGkbGJBC+AioEYvFX9TaU8oQhvi\n" +

            "hgA6ZRNid58EKuZJBbe/3ek4/nR3A0oAVwZZMNGIH972P7cSZmb/uJXMOQKBgQCs\n" +

            "FaQAL+4sN/TUxrkAkylqF+QJmEZ26l2nrzHZjMWROYNJcsn8/XkaEhD4vGSnazCu\n" +

            "/B0vU6nMppmezF9Mhc112YSrw8QFK5GOc3NGNBoueqMYy1MG8Xcbm1aSMKVv8xba\n" +

            "rh+BZQbxy6x61CpCfaT9hAoA6HaNdeoU6y05lBz1DQKBgAbYiIk56QZHeoZKiZxy\n" +

            "4eicQS0sVKKRb24ZUd+04cNSTfeIuuXZrYJ48Jbr0fzjIM3EfHvLgh9rAZ+aHe/L\n" +

            "84Ig17KiExe+qyYHjut/SC0wODDtzM/jtrpqyYa5JoEpPIaUSgPuTH/WhO3cDsx6\n" +

            "3PIW4/CddNs8mCSBOqTnoaxh\n" +

            "-----END PRIVATE KEY-----";

    }

​

    private static string loadRsaPublicKeyPem2() { // corrupted

        // this is a sample key - don't worry !

        return "-----BEGIN PUBLIC KEY-----\n" +

            "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA8EmWJUZ/Osz4vXtUU2S+\n" +

            "0M4BP9+s423gjMjoX+qP1iCnlcRcFWxthQGN2CWSMZwR/vY9V0un/nsIxhZSWOH9\n" +

            "iKzqUtZD4jt35jqOTeJ3PCSr48JirVDNLet7hRT37Ovfu5iieMN7ZNpkjeIG/CfT\n" +

            "/QQl7R+kO/EnTmL3QjLKQNV/HhEbHS2/44x7PPoHqSqkOvl8GW0qtL39gTLWgAe8\n" +

            "01/w5PmcQ38CKG0oT2gdJmJqIxNmAEHkatYGHcMDtXRBpOhOSdraFj6SmPyHEmLB\n" +

            "sshaq7Jm8NPPNK9QcEQ3q+ERa5M6eM72PpF93g2p5cjKgyzzfoIV09Zb/LJ2aW2g\n" +

            "QwIDAQAB\n" +

            "-----END PUBLIC KEY-----";

    }

    private static string loadRsaPublicKeyPem() {

        // this is a sample key - don't worry !

        return "-----BEGIN PUBLIC KEY-----\n" +

            "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA8EmWJUZ/Osz4vXtUU2S+\n" +

            "0M4BP9+s423gjMjoX+qP1iCnlcRcFWxthQGN2CWSMZwR/vY9V0un/nsIxhZSWOH9\n" +

            "iKzqUtZD4jt35jqOTeJ3PCSr48JirVDNLet7hRT37Ovfu5iieMN7ZNpkjeIG/CfT\n" +

            "/QQl7R+kO/EnTmL3QjLKQNV/HhEbHS2/44x7PPoHqSqkOvl8GW0qtL39gTLWgAe8\n" +

            "01/w5PmcQ38CKG0oT2gdJmJqIxNmAEHkatYGHcMDtXRBpOhOSdraFj6SmPyHEmLB\n" +

            "ishaq7Jm8NPPNK9QcEQ3q+ERa5M6eM72PpF93g2p5cjKgyzzfoIV09Zb/LJ2aW2g\n" +

            "QwIDAQAB\n" +

            "-----END PUBLIC KEY-----";

    }

}

​

public class PayloadObject

{

    public string sub {get; set;}   

    public long exp {get; set;}

}   

​