(C# UWP/WinRT) Create JWS with Multiple Signatures using the General JSON Serialization Format

Creates a JSON Web Signature (JWS) containing 3 signatures and output using the general JSON serialization format.

Chilkat supports all of the following JWS algorithms:

   +--------------+-------------------------------+--------------------+
   | "alg" Param  | Digital Signature or MAC      | Implementation     |
   | Value        | Algorithm                     | Requirements       |
   +--------------+-------------------------------+--------------------+
   | HS256        | HMAC using SHA-256            | Required           |
   | HS384        | HMAC using SHA-384            | Optional           |
   | HS512        | HMAC using SHA-512            | Optional           |
   | RS256        | RSASSA-PKCS1-v1_5 using       | Recommended        |
   |              | SHA-256                       |                    |
   | RS384        | RSASSA-PKCS1-v1_5 using       | Optional           |
   |              | SHA-384                       |                    |
   | RS512        | RSASSA-PKCS1-v1_5 using       | Optional           |
   |              | SHA-512                       |                    |
   | ES256        | ECDSA using P-256 and SHA-256 | Recommended+       |
   | ES384        | ECDSA using P-384 and SHA-384 | Optional           |
   | ES512        | ECDSA using P-521 and SHA-512 | Optional           |
   | PS256        | RSASSA-PSS using SHA-256 and  | Optional           |
   |              | MGF1 with SHA-256             |                    |
   | PS384        | RSASSA-PSS using SHA-384 and  | Optional           |
   |              | MGF1 with SHA-384             |                    |
   | PS512        | RSASSA-PSS using SHA-512 and  | Optional           |
   |              | MGF1 with SHA-512             |                    |
   +--------------+-------------------------------+--------------------+

Note: This example requires Chilkat v9.5.0.66 or greater.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

// This requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Note: This example requires Chilkat v9.5.0.66 or greater.

// The JWS to be created will contain three signatures.
// The 1st will use an ECC key, the 2nd an RSA key, and the 3rd an HMAC key.

// Prepare each key..

// ---------------------------------------------------
// Use the following RSA key loaded from JWK format.
Chilkat.StringBuilder sbRsaJwk = new Chilkat.StringBuilder();
sbRsaJwk.Append("{\"kty\":\"RSA\",");
sbRsaJwk.Append("\"n\":\"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx");
sbRsaJwk.Append("HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs");
sbRsaJwk.Append("D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH");
sbRsaJwk.Append("SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV");
sbRsaJwk.Append("MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8");
sbRsaJwk.Append("NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ\",");
sbRsaJwk.Append("\"e\":\"AQAB\",");
sbRsaJwk.Append("\"d\":\"Eq5xpGnNCivDflJsRQBXHx1hdR1k6Ulwe2JZD50LpXyWPEAeP88vLNO97I");
sbRsaJwk.Append("jlA7_GQ5sLKMgvfTeXZx9SE-7YwVol2NXOoAJe46sui395IW_GO-pWJ1O0");
sbRsaJwk.Append("BkTGoVEn2bKVRUCgu-GjBVaYLU6f3l9kJfFNS3E0QbVdxzubSu3Mkqzjkn");
sbRsaJwk.Append("439X0M_V51gfpRLI9JYanrC4D4qAdGcopV_0ZHHzQlBjudU2QvXt4ehNYT");
sbRsaJwk.Append("CBr6XCLQUShb1juUO1ZdiYoFaFQT5Tw8bGUl_x_jTj3ccPDVZFD9pIuhLh");
sbRsaJwk.Append("BOneufuBiB4cS98l2SR_RQyGWSeWjnczT0QU91p1DhOVRuOopznQ\",");
sbRsaJwk.Append("\"p\":\"4BzEEOtIpmVdVEZNCqS7baC4crd0pqnRH_5IB3jw3bcxGn6QLvnEtfdUdi");
sbRsaJwk.Append("YrqBdss1l58BQ3KhooKeQTa9AB0Hw_Py5PJdTJNPY8cQn7ouZ2KKDcmnPG");
sbRsaJwk.Append("BY5t7yLc1QlQ5xHdwW1VhvKn-nXqhJTBgIPgtldC-KDV5z-y2XDwGUc\",");
sbRsaJwk.Append("\"q\":\"uQPEfgmVtjL0Uyyx88GZFF1fOunH3-7cepKmtH4pxhtCoHqpWmT8YAmZxa");
sbRsaJwk.Append("ewHgHAjLYsp1ZSe7zFYHj7C6ul7TjeLQeZD_YwD66t62wDmpe_HlB-TnBA");
sbRsaJwk.Append("-njbglfIsRLtXlnDzQkv5dTltRJ11BKBBypeeF6689rjcJIDEz9RWdc\",");
sbRsaJwk.Append("\"dp\":\"BwKfV3Akq5_MFZDFZCnW-wzl-CCo83WoZvnLQwCTeDv8uzluRSnm71I3Q");
sbRsaJwk.Append("CLdhrqE2e9YkxvuxdBfpT_PI7Yz-FOKnu1R6HsJeDCjn12Sk3vmAktV2zb");
sbRsaJwk.Append("34MCdy7cpdTh_YVr7tss2u6vneTwrA86rZtu5Mbr1C1XsmvkxHQAdYo0\",");
sbRsaJwk.Append("\"dq\":\"h_96-mK1R_7glhsum81dZxjTnYynPbZpHziZjeeHcXYsXaaMwkOlODsWa");
sbRsaJwk.Append("7I9xXDoRwbKgB719rrmI2oKr6N3Do9U0ajaHF-NKJnwgjMd2w9cjz3_-ky");
sbRsaJwk.Append("NlxAr2v4IKhGNpmM5iIgOS1VZnOZ68m6_pbLBSp3nssTdlqvd0tIiTHU\",");
sbRsaJwk.Append("\"qi\":\"IYd7DHOhrWvxkwPQsRM2tOgrjbcrfvtQJipd-DlcxyVuuM9sQLdgjVk2o");
sbRsaJwk.Append("y26F0EmpScGLq2MowX7fhd_QJQ3ydy5cY7YIBi87w93IKLEdfnbJtoOPLU");
sbRsaJwk.Append("W0ITrJReOgo1cq9SbsxYawBgfp_gh6A5603k2-ZQwVK0JKSHuLFkuQ3U\"");
sbRsaJwk.Append("}");

Chilkat.PrivateKey rsaKey = new Chilkat.PrivateKey();
// Note: This example loads the RSA key from JWK format.  Any format can be loaded
// into the private key object. (See the online reference documentation..)
bool success = rsaKey.LoadJwk(sbRsaJwk.GetAsString());
if (success != true) {
    Debug.WriteLine(rsaKey.LastErrorText);
    return;
}

// ---------------------------------------------------
// Use the following ECC key loaded from JWK format.
Chilkat.StringBuilder sbEccJwk = new Chilkat.StringBuilder();
sbEccJwk.Append("{\"kty\":\"EC\",");
sbEccJwk.Append("\"crv\":\"P-256\",");
sbEccJwk.Append("\"x\":\"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU\",");
sbEccJwk.Append("\"y\":\"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0\",");
sbEccJwk.Append("\"d\":\"jpsQnnGQmL-YBIffH1136cspYG6-0iY7X1fCE9-E9LI\"");
sbEccJwk.Append("}");

Chilkat.PrivateKey eccKey = new Chilkat.PrivateKey();
// Note: This example loads the ECDSA key from JWK format.  Any format can be loaded
// into the private key object. (See the online reference documentation..)
success = eccKey.LoadJwk(sbEccJwk.GetAsString());
if (success != true) {
    Debug.WriteLine(eccKey.LastErrorText);
    return;
}

// ---------------------------------------------------
// The HMAC key (in base64url format)
string hmacKey = "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow";

// ---------------------------------------------------
// Prepare the headers..
// RSASSA-PKCS1-v1_5 SHA-256
Chilkat.JsonObject jwsProtHdr0 = new Chilkat.JsonObject();
jwsProtHdr0.AppendString("alg","RS256");
Chilkat.JsonObject jwsUnprotHdr0 = new Chilkat.JsonObject();
jwsUnprotHdr0.AppendString("kid","myRsaKey");

// ECDSA using P-256 and SHA-256
Chilkat.JsonObject jwsProtHdr1 = new Chilkat.JsonObject();
jwsProtHdr1.AppendString("alg","ES256");
Chilkat.JsonObject jwsUnprotHdr1 = new Chilkat.JsonObject();
jwsUnprotHdr1.AppendString("kid","myEcKey");

// HMAC using SHA-256
Chilkat.JsonObject jwsProtHdr2 = new Chilkat.JsonObject();
jwsProtHdr2.AppendString("alg","HS256");
Chilkat.JsonObject jwsUnprotHdr2 = new Chilkat.JsonObject();
jwsUnprotHdr2.AppendString("kid","myMacKey");

// ---------------------------------------------------
// First set the JWS headers, keys, and payload, then we'll create the JWS...
Chilkat.Jws jws = new Chilkat.Jws();

jws.SetProtectedHeader(0,jwsProtHdr0);
jws.SetUnprotectedHeader(0,jwsUnprotHdr0);
jws.SetProtectedHeader(1,jwsProtHdr1);
jws.SetUnprotectedHeader(1,jwsUnprotHdr1);
jws.SetProtectedHeader(2,jwsProtHdr2);
jws.SetUnprotectedHeader(2,jwsUnprotHdr2);

jws.SetPrivateKey(0,rsaKey);
jws.SetPrivateKey(1,eccKey);
jws.SetMacKey(2,hmacKey,"base64url");

bool bIncludeBom = false;
string payloadStr = "In our village, folks say God crumbles up the old moon into stars.";
jws.SetPayload(payloadStr,"utf-8",bIncludeBom);

// ---------------------------------------------------
// Create the JWS.
// Givent that multiple signatures will exist, only the general JSON serialization 
// format is possible, and that is what will be produced.
string jwsStr = jws.CreateJws();
if (jws.LastMethodSuccess != true) {
    Debug.WriteLine(jws.LastErrorText);
    return;
}

// The jwsStr is contains JSON in the smallest possible size, which is a single line.
// To get in human-readable format, load into a Chilkat JSON object and emit..
Chilkat.JsonObject json = new Chilkat.JsonObject();
json.Load(jwsStr);
json.EmitCompact = false;
Debug.WriteLine(json.Emit());

// Sample output:

// { 
//   "payload": "SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu",
//   "signatures": [
//     { 
//       "protected": "eyJhbGciOiJSUzI1NiJ9",
//       "header": { 
//         "kid": "myRsaKey"
//       },
//       "signature": "B04c24gSnpVm1Z-_bemfyNMCpZm6Knj1yB-yzaIOvijsWfDgoF_mSJccTIbzapNgwJudnobr5iDOfZWiRR9iqCyDJLe5M1S40vFF7MFEI3JecYRgrRc6n1lTkYLMRyVq48BwbQlmKgPqmK9drun3agklsr0FmgNx65pfmcnlYdXsgwxf8WbgppefrlrMImp-98-dNtBcUL8ce1aOjbcyVFjGMCzpm3JerQqIzWQvEwBstnMEQle73KHcyx_nsTmlzY70CaydbRTsciOATL7WfiMwuX1q9Y2NIpTg3CbOTWKdwjh7iyfiAKQxNBaF2mApnqj9hjpf8GwR-CfxAzJtPg"
//     },
//     { 
//       "protected": "eyJhbGciOiJFUzI1NiJ9",
//       "header": { 
//         "kid": "myEcKey"
//       },
//       "signature": "2cbugKq0ERaQMh01n2B-86EZFYleeMf8bsccaQMxzOxAg14PxfjR3IImvodTJYqkmfBJYW203etz2-7ZtJUOGw"
//     },
//     { 
//       "protected": "eyJhbGciOiJIUzI1NiJ9",
//       "header": { 
//         "kid": "myMacKey"
//       },
//       "signature": "e7R9gjx0RsUNa3c7qd8k9mQGEhtcG8vsN1W7jbLb2MA"
//     }
//   ]
// }