PHP Requires Chilkat v11.0.0+

Create a JWS Using ECDSA P-256 SHA-256

See more JSON Web Signatures (JWS) Examples

Creates and validates a JSON Web Signature (JWS) that uses ECDSA P-256 SHA-256 Chilkat2 PHP

<?php

use Chilkat2\JsonObject;
use Chilkat2\Jws;
use Chilkat2\PrivateKey;
use Chilkat2\PublicKey;
use Chilkat2\StringBuilder;

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

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

$eccKey = new 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..)
try {
    $eccKey->LoadJwk($sbJwk->GetAsString());

    // Create the JWS Protected Header
    $jwsProtHdr = new JsonObject();
    $jwsProtHdr->AppendString('alg', 'ES256');

    $jws = new Jws();

    // Set the protected header:
    $signatureIndex = 0;
    $jws->SetProtectedHeader($signatureIndex, $jwsProtHdr);

    // Set the ECC key:
    $jws->SetPrivateKey($signatureIndex, $eccKey);

    // Set the payload.
    $bIncludeBom = false;
    $payloadStr = 'In our village, folks say God crumbles up the old moon into stars.';
    $jws->SetPayload($payloadStr, 'utf-8', $bIncludeBom);

    // Create the JWS
    // By default, the compact serialization is used.
    $jwsCompact = $jws->CreateJws();
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo 'JWS: ', $jwsCompact, "\n";

// Note: ECC signatures use random values, so the output will be different each time a signature is produced.
// sample output:
// JWS: eyJhbGciOiJFUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.J6EGTNkeuEjehHHBu0SOKzifm8r35wbx49A5964pxzB7gannyZZPMkK7vmlaPJ-K8Xmm8cZsQySAPC12Xd8avw

// Now load the JWS, validate, and recover the original text.
$jws2 = new Jws();

// Load the JWS.
$jws2->LoadJws($jwsCompact);

$eccPubKey = new PublicKey();
$eccKey->ToPublicKey($eccPubKey);

// Set the ECC public key used for validation.
$signatureIndex = 0;
$jws2->SetPublicKey($signatureIndex, $eccPubKey);

// Validate the 1st (and only) signature at index 0..
$v = $jws2->Validate($signatureIndex);
if ($v < 0) {
    // Perhaps Chilkat was not unlocked or the trial expired..
    echo "Method call failed for some other reason.\n";
    echo $jws2->LastErrorText, "\n";
    exit;
}

if ($v == 0) {
    echo "Invalid signature.  The ECC key was incorrect, the JWS was invalid, or both.\n";
    exit;
}

// If we get here, the signature was validated..
echo "Signature validated.\n";

// Recover the original content:
echo $jws2->GetPayload('utf-8'), "\n";

// Examine the protected header:
$joseHeader = new JsonObject();
$jws2->GetProtectedH($signatureIndex, $joseHeader);
$joseHeader->EmitCompact = false;

echo "Protected (JOSE) header:\n";
echo $joseHeader->Emit(), "\n";

// Output:

// Signature validated.
// In our village, folks say God crumbles up the old moon into stars.
// Protected (JOSE) header:
// {
//   "alg": "ES256"
// }