<?php

namespace BotBlocker\Vendor\PragmaRX\Google2FA\Support;

use BotBlocker\Vendor\ParagonIE\ConstantTime\Base32 as ParagonieBase32;
use BotBlocker\Vendor\PragmaRX\Google2FA\Exceptions\IncompatibleWithGoogleAuthenticatorException;
use BotBlocker\Vendor\PragmaRX\Google2FA\Exceptions\InvalidCharactersException;
use BotBlocker\Vendor\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(
        #[\SensitiveParameter]
        $b32
    )
    {
        return strlen($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,
        #[\SensitiveParameter]
        $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(
        #[\SensitiveParameter]
        $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(
        #[\SensitiveParameter]
        $b32
    )
    {
        return (strlen($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(
        #[\SensitiveParameter]
        $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(
        #[\SensitiveParameter]
        $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(
        #[\SensitiveParameter]
        $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(
        #[\SensitiveParameter]
        $b32
    )
    {
        if ($this->enforceGoogleAuthenticatorCompatibility && $this->isCharCountNotAPowerOfTwo($b32)) {
            throw new IncompatibleWithGoogleAuthenticatorException();
        }
    }
    /**
     * Check if all secret key characters are valid.
     *
     * @param string $b32
     *
     * @throws \PragmaRX\Google2FA\Exceptions\InvalidCharactersException
     */
    protected function checkForValidCharacters(
        #[\SensitiveParameter]
        $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(
        #[\SensitiveParameter]
        $b32
    )
    {
        // Minimum = 128 bits
        // Recommended = 160 bits
        // Compatible with Google Authenticator = 256 bits
        if ($this->charCountBits($b32) < 128) {
            throw new SecretKeyTooShortException();
        }
    }
}
