PLIVO v3 validation not able to verify signature using PLIVO SDK

Question

I am trying to validate the request received from the plivo to my application server. For this I am using the sample code provided by the plivo in the documentation.

<?php
require 'vendor/autoload.php';
use Plivo\Exceptions\PlivoValidationException;
use Plivo\Util\v3SignatureValidation;
use Plivo\XML\Response;

if (preg_match('/speak/', $_SERVER["REQUEST_URI"])) {
    $auth_token = "<auth_token>";
    $signature = @$_SERVER["X-Plivo-Signature-V3"] ?: 'signature';
    $nonce = @$_SERVER["X-Plivo-Signature-V3-Nonce"] ?: 'nonce';
    $url = 'http' . (isset($_SERVER['HTTPS']) ? 's' : '') . '://' . "{$_SERVER['HTTP_HOST']}{$_SERVER['REQUEST_URI']}";
    $method = $_SERVER['REQUEST_METHOD'];
    $SVUtil = new v3SignatureValidation();
    if ($method == "GET") {
        try {
            $valid = $SVUtil->validateV3Signature($method, $url, $nonce, $auth_token, $signature);
        } catch (PlivoValidationException $e) {
            echo("error");
        }
    } else {
        $body = file_get_contents("php://input");
        $params = json_decode($body, true);
        try {
            $valid = $SVUtil->validateV3Signature($method, $url, $nonce, $auth_token, $signature, $params);
        } catch (PlivoValidationException $e) {
            echo("error");
        }
    }
    echo $valid;
    $body = 'Hi, Calling from Plivo';
    $attributes = array(
        'loop' => 3,
    );
    $r = new Response();
    $r->addSpeak($body, $attributes);
    echo($r->toXML());
} else {
    echo "<p>Welcome to Plivo</p>";
}

But I am getting this error

Invalid argument supplied for foreach() in code/plivo/vendor/plivo/plivo-php/src/Plivo/Util/v3SignatureValidation.php on line 13

I am debugging, but not able to find the solution. One thing I noticed that nothing is being received in json from the PLIVO server. Can anyone help, as There is not enough documentation available for Plivo Request Validation.

Answer 1

Plivo's Developer Evangelist here. Please try the below code instead.

<?php
require 'vendor/autoload.php';
use Plivo\Exceptions\PlivoValidationException;
use Plivo\Util\v3SignatureValidation;
use Plivo\XML\Response;

if (preg_match('/speak/', $_SERVER["REQUEST_URI"]))
{
    $auth_token = "<auth_token>";
    $signature = @$_SERVER["HTTP_X_PLIVO_SIGNATURE_V3"] ? : 'signature';
    $nonce = @$_SERVER["HTTP_X_PLIVO_SIGNATURE_V3_NONCE"] ? : 'nonce';
    $url = $_SERVER['HTTP_REFERER'];
    $method = $_SERVER['REQUEST_METHOD'];
    $SVUtil = new v3SignatureValidation();
    if ($method == "GET")
    {
        try
        {
            $valid = $SVUtil->validateV3Signature($method, $url, $nonce, $auth_token, $signature);
        }
        catch(PlivoValidationException $e)
        {
            echo ("error");
        }
    }
    else
    {
        $body = file_get_contents("php://input", true);
        parse_str($body, $get_array);
        try
        {
            $valid = $SVUtil->validateV3Signature($method, $url, $nonce, $auth_token, $signature, $get_array);
        }
        catch(PlivoValidationException $e)
        {
            echo ("error");
        }
    }
    error_log(print_r($valid, true));
    $body = 'Hi, Calling from Plivo';
    $attributes = array(
        'loop' => 3,
    );
    $r = new Response();
    $r->addSpeak($body, $attributes);
    echo ($r->toXML());
}
else
{
    echo "<p>Welcome to Plivo</p>";
}

And run the below command

php -S localhost:5000

In case if you still face any issues, please free to contact our support team

src: https://www.plivo.com/docs/voice/concepts/signature-validation#code