token_issuer.php

<?php
//require_once('vendor/autoload.php');
require __DIR__ . '/vendor/autoload.php';
require_once("config.php");
/*
 * Application setup, database connection, data sanitization and user  
 * validation routines are here.
 */

use \Firebase\JWT\JWT;
 $credentialsAreValid = 0; 
if($_POST['email']=="shishir.raven@gmail.com" && $_POST['password']=="123456")
{
    $credentialsAreValid = 1; 
    $username_id = "1";
    $username ="shishir";
}



/* For testing purposes I am setting this up. */


if ($credentialsAreValid) 
{

    $tokenId    = base64_encode(mcrypt_create_iv(32));
    $issuedAt   = time();
    $notBefore  = $issuedAt + 1;             //Adding 10 seconds
    $expire     = $notBefore + 60;            // Adding 60 seconds
    $serverName = $config['server_name']; // Retrieve the server name from config file
    
    /*
     * Create the token as an array
     */
    $data = [
        'iat'  => $issuedAt,         // Issued at: time when the token was generated
        'jti'  => $tokenId,          // Json Token Id: an unique identifier for the token
        'iss'  => $serverName,       // Issuer
        'nbf'  => $notBefore,        // Not before
        'exp'  => $expire,           // Expire
        'data' => [                  // Data related to the signer user
            'userId'   => $username_id, // userid from the users table
            'userName' => $username, // User name
        ]
    ];

     /*
      * More code here...
      */



/*
 * Code here...
 */

    /*
     * Extract the key, which is coming from the config file. 
     * 
     * Best suggestion is the key to be a binary string and 
     * store it in encoded in a config file. 
     *
     * Can be generated with base64_encode(openssl_random_pseudo_bytes(64));
     *
     * keep it secure! You'll need the exact key to verify the 
     * token later.
     */
    $secretKey = base64_decode($config['jwtKey']);
    /*
    echo $secretKey;
    exit;*/
    /*
     * Encode the array to a JWT string.
     * Second parameter is the key to encode the token.
     * 
     * The output string can be validated at http://jwt.io/
     */
    $jwt = JWT::encode(
        $data,      //Data to be encoded in the JWT
        $secretKey, // The signing key
        'HS512'     // Algorithm used to sign the token, see https://tools.ietf.org/html/draft-ietf-jose-json-web-algorithms-40#section-3
        );
        
    $unencodedArray = ['jwt' => $jwt];
    echo json_encode($unencodedArray);
} // if ($credentialsAreValid) 
else
{
    $unencodedArray = ['jwt' => "❌ error"];
        echo json_encode($unencodedArray);
}