(Objective-C) 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 Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

#import <CkoStringBuilder.h>
#import <CkoPrivateKey.h>
#import <NSString.h>
#import <CkoJsonObject.h>
#import <CkoJws.h>

// 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.
CkoStringBuilder *sbRsaJwk = [[CkoStringBuilder alloc] init];
[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: @"}"];

CkoPrivateKey *rsaKey = [[CkoPrivateKey alloc] init];
// 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 != YES) {
    NSLog(@"%@",rsaKey.LastErrorText);
    return;
}

// ---------------------------------------------------
// Use the following ECC key loaded from JWK format.
CkoStringBuilder *sbEccJwk = [[CkoStringBuilder alloc] init];
[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: @"}"];

CkoPrivateKey *eccKey = [[CkoPrivateKey alloc] init];
// 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 != YES) {
    NSLog(@"%@",eccKey.LastErrorText);
    return;
}

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

// ---------------------------------------------------
// Prepare the headers..
// RSASSA-PKCS1-v1_5 SHA-256
CkoJsonObject *jwsProtHdr0 = [[CkoJsonObject alloc] init];
[jwsProtHdr0 AppendString: @"alg" value: @"RS256"];
CkoJsonObject *jwsUnprotHdr0 = [[CkoJsonObject alloc] init];
[jwsUnprotHdr0 AppendString: @"kid" value: @"myRsaKey"];

// ECDSA using P-256 and SHA-256
CkoJsonObject *jwsProtHdr1 = [[CkoJsonObject alloc] init];
[jwsProtHdr1 AppendString: @"alg" value: @"ES256"];
CkoJsonObject *jwsUnprotHdr1 = [[CkoJsonObject alloc] init];
[jwsUnprotHdr1 AppendString: @"kid" value: @"myEcKey"];

// HMAC using SHA-256
CkoJsonObject *jwsProtHdr2 = [[CkoJsonObject alloc] init];
[jwsProtHdr2 AppendString: @"alg" value: @"HS256"];
CkoJsonObject *jwsUnprotHdr2 = [[CkoJsonObject alloc] init];
[jwsUnprotHdr2 AppendString: @"kid" value: @"myMacKey"];

// ---------------------------------------------------
// First set the JWS headers, keys, and payload, then we'll create the JWS...
CkoJws *jws = [[CkoJws alloc] init];

[jws SetProtectedHeader: [NSNumber numberWithInt: 0] json: jwsProtHdr0];
[jws SetUnprotectedHeader: [NSNumber numberWithInt: 0] json: jwsUnprotHdr0];
[jws SetProtectedHeader: [NSNumber numberWithInt: 1] json: jwsProtHdr1];
[jws SetUnprotectedHeader: [NSNumber numberWithInt: 1] json: jwsUnprotHdr1];
[jws SetProtectedHeader: [NSNumber numberWithInt: 2] json: jwsProtHdr2];
[jws SetUnprotectedHeader: [NSNumber numberWithInt: 2] json: jwsUnprotHdr2];

[jws SetPrivateKey: [NSNumber numberWithInt: 0] privKey: rsaKey];
[jws SetPrivateKey: [NSNumber numberWithInt: 1] privKey: eccKey];
[jws SetMacKey: [NSNumber numberWithInt: 2] key: hmacKey encoding: @"base64url"];

BOOL bIncludeBom = NO;
NSString *payloadStr = @"In our village, folks say God crumbles up the old moon into stars.";
[jws SetPayload: payloadStr charset: @"utf-8" includeBom: 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.
NSString *jwsStr = [jws CreateJws];
if (jws.LastMethodSuccess != YES) {
    NSLog(@"%@",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..
CkoJsonObject *json = [[CkoJsonObject alloc] init];
[json Load: jwsStr];
json.EmitCompact = NO;
NSLog(@"%@",[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"
//     }
//   ]
// }