I'm trying to pass a message from a Javascript Client to a PHP webserver. To add a layer of security I would like to sign the data object with an hash.
/* Generate signature of the data with the password */
that.signEnvelope = function(data,password)
{
return CryptoJS.SHA256(JSON.stringify(data) + password).toString();
};
This quickly falls apart on the server. The JSON.stringify function does not generate a 1:1 matching string to json_encode on the server making it impossible to verify the hash.
protected function verifySignature($remoteSignature,$data,$privateKey)
{
/* Combine json & key samen , then sha256 */
$localSignature = hash('sha256',json_encode($data) . $privateKey);
return ($localSignature === $remoteSignature);
}
Is there another algorithm that I can implement in both PHP and Javascript that will generate a hashable string ?
Conclusion
Allowing json_encode accross platforms was not a smart thing todo. There is no standard implementation.
Instead I now only allow arrays with string key/value pairs which are much easier to concat and verify.