C#
C#
Validate JWS with Multiple Signatures using the General JSON Serialization Format
See more JSON Web Signatures (JWS) Examples
Validates and recovers data and headers from a JSON Web Signature (JWS) containing 3 signatures.Note: 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 | | +--------------+-------------------------------+--------------------+
Chilkat C# Downloads
bool success = false;
// This requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
// First, prepare the public keys that will be needed for each signature.
// ---------------------------------------------------
// 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("}");
Chilkat.PublicKey rsaKey = new Chilkat.PublicKey();
success = rsaKey.LoadFromString(sbRsaJwk.GetAsString());
if (success == false) {
Debug.WriteLine(rsaKey.LastErrorText);
return;
}
// ---------------------------------------------------
// Use the following ECC public 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("}");
Chilkat.PublicKey eccKey = new Chilkat.PublicKey();
success = eccKey.LoadFromString(sbEccJwk.GetAsString());
if (success == false) {
Debug.WriteLine(eccKey.LastErrorText);
return;
}
// ---------------------------------------------------
// The HMAC key (in base64url format)
string hmacKey = "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow";
// The code below will verify each of the signatures in this JWS:
// {
// "payload": "SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu",
// "signatures": [
// {
// "protected": "eyJhbGciOiJSUzI1NiIsImtpZCI6Im15UnNhS2V5In0",
// "signature": "IPMQ02niTQDwLzsRZSCaEm9VEyAX_AVe3HWjniNt9kW-a8d6ZVbd2k6jGae8s1yIh0cgxDnXQ6-p6_sBI0cnMO0xpuJANhh2vFtNJl5lisad94-H3mB3lSfafRqxeYp5D8bh39BPv7y3PrUNVMQdKEJp_D5oJ0ROPTIYx3EG8eJQOx1HO0KqhcUo401XR6KSsIyFm5joBLNKTVzxZUTT1RRZZtwTdeZkbGevugIOX_9gHAtARpV6WaFA4Vvjnq8X9wPgqjWNCQRupadhTPz0JAsa-wy5vXQjsFlXAn43mDPpMfna5Ab3F5pS4yDwkbX6nRn7XBxH1SnnNJRFholQZw"
// },
// {
// "protected": "eyJhbGciOiJFUzI1NiIsImtpZCI6Im15RWNLZXkifQ",
// "signature": "1OQtaT3pgZmkDxvlfghvxL_8kX16WIen6u1MadEq1pA4qytA0--_EwZDNk00GDPWFpoJtKznibMZzLOg_UhHIw"
// },
// {
// "protected": "eyJhbGciOiJIUzI1NiIsImtpZCI6Im15TWFjS2V5In0",
// "signature": "YY8yVjmJJfy7YJOn3uUydG8WCY2PEuCvOLil5Ks5lnw"
// }
// ]
// }
Chilkat.StringBuilder sbJws = new Chilkat.StringBuilder();
sbJws.Append("{ ");
sbJws.Append(" \"payload\": \"SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu\",");
sbJws.Append(" \"signatures\": [");
sbJws.Append(" { ");
sbJws.Append(" \"protected\": \"eyJhbGciOiJSUzI1NiIsImtpZCI6Im15UnNhS2V5In0\",");
sbJws.Append(" \"signature\": \"IPMQ02niTQDwLzsRZSCaEm9VEyAX_AVe3HWjniNt9kW-a8d6ZVbd2k6jGae8s1yIh0cgxDnXQ6-p6_sBI0cnMO0xpuJANhh2vFtNJl5lisad94-H3mB3lSfafRqxeYp5D8bh39BPv7y3PrUNVMQdKEJp_D5oJ0ROPTIYx3EG8eJQOx1HO0KqhcUo401XR6KSsIyFm5joBLNKTVzxZUTT1RRZZtwTdeZkbGevugIOX_9gHAtARpV6WaFA4Vvjnq8X9wPgqjWNCQRupadhTPz0JAsa-wy5vXQjsFlXAn43mDPpMfna5Ab3F5pS4yDwkbX6nRn7XBxH1SnnNJRFholQZw\"");
sbJws.Append(" },");
sbJws.Append(" { ");
sbJws.Append(" \"protected\": \"eyJhbGciOiJFUzI1NiIsImtpZCI6Im15RWNLZXkifQ\",");
sbJws.Append(" \"signature\": \"1OQtaT3pgZmkDxvlfghvxL_8kX16WIen6u1MadEq1pA4qytA0--_EwZDNk00GDPWFpoJtKznibMZzLOg_UhHIw\"");
sbJws.Append(" },");
sbJws.Append(" { ");
sbJws.Append(" \"protected\": \"eyJhbGciOiJIUzI1NiIsImtpZCI6Im15TWFjS2V5In0\",");
sbJws.Append(" \"signature\": \"YY8yVjmJJfy7YJOn3uUydG8WCY2PEuCvOLil5Ks5lnw\"");
sbJws.Append(" }");
sbJws.Append(" ]");
sbJws.Append("}");
Chilkat.Jws jws = new Chilkat.Jws();
success = jws.LoadJwsSb(sbJws);
if (success == false) {
Debug.WriteLine(jws.LastErrorText);
return;
}
// The payload is easily accessible:
Debug.WriteLine("Payload: " + jws.GetPayload("utf-8"));
Chilkat.StringBuilder sbKeyId = new Chilkat.StringBuilder();
bool bCaseSensitive = false;
Chilkat.JsonObject protHeader = new Chilkat.JsonObject();
int numSignatures = jws.NumSignatures;
int i = 0;
while (i < numSignatures) {
success = jws.GetProtectedH(i,protHeader);
if (success == false) {
Debug.WriteLine(jws.LastErrorText);
return;
}
Debug.WriteLine("--------------------------");
Debug.WriteLine(Convert.ToString(i) + ": ");
// Get the protected header.
protHeader.EmitCompact = false;
Debug.WriteLine(protHeader.Emit());
// Get the key ID ("kid") member.
// Note: In this example, the "kid" values are contained in the protected headers.
// They could've just as easily been located in unprotected headers. In that case,
// we would've called GetUnprotectedH instead of GetProtectedH(i).
sbKeyId.Clear();
sbKeyId.Append(protHeader.StringOf("kid"));
// Set the key based on key ID.
if (sbKeyId.ContentsEqual("myRsaKey",bCaseSensitive) == true) {
jws.SetPublicKey(i,rsaKey);
}
if (sbKeyId.ContentsEqual("myEcKey",bCaseSensitive) == true) {
jws.SetPublicKey(i,eccKey);
}
if (sbKeyId.ContentsEqual("myMacKey",bCaseSensitive) == true) {
jws.SetMacKey(i,hmacKey,"base64url");
}
// Validate this signature.
int v = jws.Validate(i);
if (v < 0) {
// Perhaps Chilkat was not unlocked or the trial expired..
Debug.WriteLine("Validate failed for some other reason.");
Debug.WriteLine(jws.LastErrorText);
}
else {
if (v == 0) {
Debug.WriteLine("Invalid signature. The key was incorrect, the JWS was invalid, or both.");
}
else {
Debug.WriteLine("Signature validated.");
}
}
i = i + 1;
}
// The output of this program is:
// Payload: In our village, folks say God crumbles up the old moon into stars.
// --------------------------
// 0:
// {
// "alg": "RS256",
// "kid": "myRsaKey"
// }
//
// Signature validated.
// --------------------------
// 1:
// {
// "alg": "ES256",
// "kid": "myEcKey"
// }
//
// Signature validated.
// --------------------------
// 2:
// {
// "alg": "HS256",
// "kid": "myMacKey"
// }
//
// Signature validated.