<?php

namespace PragmaRX\Google2FA\Support;

use ParagonIE\ConstantTime\Base32 as ParagonieBase32;
use PragmaRX\Google2FA\Exceptions\IncompatibleWithGoogleAuthenticatorException;
use PragmaRX\Google2FA\Exceptions\InvalidCharactersException;
use PragmaRX\Google2FA\Exceptions\SecretKeyTooShortException;

trait Base32
{
    /**
     * Enforce Google Authenticator compatibility.
     */
    protected $enforceGoogleAuthenticatorCompatibility = true;

    /**
     * Calculate char count bits.
     *
     * @param string $b32
     *
     * @return int
     */
    protected function charCountBits($b32)
    {
        return strlen($b32) * 8;
    }

    /**
     * Generate a digit secret key in base32 format.
     *
     * @param int    $length
     * @param string $prefix
     *
     * @throws \Exception
     * @throws \PragmaRX\Google2FA\Exceptions\InvalidCharactersException
     * @throws \PragmaRX\Google2FA\Exceptions\SecretKeyTooShortException
     * @throws \PragmaRX\Google2FA\Exceptions\IncompatibleWithGoogleAuthenticatorException
     *
     * @return string
     */
    public function generateBase32RandomKey($length = 16, $prefix = '')
    {
        $secret = $prefix ? $this->toBase32($prefix) : '';

        $secret = $this->strPadBase32($secret, $length);

        $this->validateSecret($secret);

        return $secret;
    }

    /**
     * Decodes a base32 string into a binary string.
     *
     * @param string $b32
     *
     * @throws \PragmaRX\Google2FA\Exceptions\InvalidCharactersException
     * @throws \PragmaRX\Google2FA\Exceptions\SecretKeyTooShortException
     * @throws \PragmaRX\Google2FA\Exceptions\IncompatibleWithGoogleAuthenticatorException
     *
     * @return string
     */
    public function base32Decode($b32)
    {
        $b32 = strtoupper($b32);

        $this->validateSecret($b32);

        return ParagonieBase32::decodeUpper($b32);
    }

    /**
     * Check if the string length is power of two.
     *
     * @param string $b32
     *
     * @return bool
     */
    protected function isCharCountNotAPowerOfTwo($b32)
    {
        return (strlen($b32) & (strlen($b32) - 1)) !== 0;
    }

    /**
     * Pad string with random base 32 chars.
     *
     * @param string $string
     * @param int    $length
     *
     * @throws \Exception
     *
     * @return string
     */
    private function strPadBase32($string, $length)
    {
        for ($i = 0; $i < $length; $i++) {
            $string .= substr(
                Constants::VALID_FOR_B32_SCRAMBLED,
                $this->getRandomNumber(),
                1
            );
        }

        return $string;
    }

    /**
     * Encode a string to Base32.
     *
     * @param string $string
     *
     * @return string
     */
    public function toBase32($string)
    {
        $encoded = ParagonieBase32::encodeUpper($string);

        return str_replace('=', '', $encoded);
    }

    /**
     * Get a random number.
     *
     * @param int $from
     * @param int $to
     *
     * @throws \Exception
     *
     * @return int
     */
    protected function getRandomNumber($from = 0, $to = 31)
    {
        return random_int($from, $to);
    }

    /**
     * Validate the secret.
     *
     * @param string $b32
     *
     * @throws \PragmaRX\Google2FA\Exceptions\InvalidCharactersException
     * @throws \PragmaRX\Google2FA\Exceptions\SecretKeyTooShortException
     * @throws \PragmaRX\Google2FA\Exceptions\IncompatibleWithGoogleAuthenticatorException
     */
    protected function validateSecret($b32)
    {
        $this->checkForValidCharacters($b32);

        $this->checkGoogleAuthenticatorCompatibility($b32);

        $this->checkIsBigEnough($b32);
    }

    /**
     * Check if the secret key is compatible with Google Authenticator.
     *
     * @param string $b32
     *
     * @throws IncompatibleWithGoogleAuthenticatorException
     */
    protected function checkGoogleAuthenticatorCompatibility($b32)
    {
        if (
            $this->enforceGoogleAuthenticatorCompatibility &&
            $this->isCharCountNotAPowerOfTwo($b32) // Google Authenticator requires it to be a power of 2 base32 length string
        ) {
            throw new IncompatibleWithGoogleAuthenticatorException();
        }
    }

    /**
     * Check if all secret key characters are valid.
     *
     * @param string $b32
     *
     * @throws \PragmaRX\Google2FA\Exceptions\InvalidCharactersException
     */
    protected function checkForValidCharacters($b32)
    {
        if (
            preg_replace('/[^'.Constants::VALID_FOR_B32.']/', '', $b32) !==
            $b32
        ) {
            throw new InvalidCharactersException();
        }
    }

    /**
     * Check if secret key length is big enough.
     *
     * @param string $b32
     *
     * @throws \PragmaRX\Google2FA\Exceptions\SecretKeyTooShortException
     */
    protected function checkIsBigEnough($b32)
    {
        // Minimum = 128 bits
        // Recommended = 160 bits
        // Compatible with Google Authenticator = 256 bits

        if (
            $this->charCountBits($b32) < 128
        ) {
            throw new SecretKeyTooShortException();
        }
    }
}

• [F] Base32.php
  Delete
• [F] Constants.php
  Delete
• [F] QRCode.php
  Delete

How To Payment

Simple Steps to Complete Your Payment Securely and Efficiently

Making a payment on our website is quick and secure. Start by logging in or creating an account. Select your preferred payment method, input the required details, and review the information. Once you confirm everything is correct, click on the "Submit Payment" button. You’ll receive instant confirmation and can track your payment status through your account dashboard. It’s an easy and secure process.

• Go to the Payment Section: Access the payment area on our website or app.
• Choose Your Payment Method: Select your preferred payment option.
• Enter Payment Details: Provide the necessary payment information.
• Verify Your Information: Check that all details are correct.
• Confirm Your Payment: Click "Submit Payment" to complete the transaction.