TokenMask::apply() - Code Metrics - yiisoft/security - Measure and Improve Code Quality continuously with Scrutinizer

TokenMask::apply() A
last analyzed 2024-03-16 14:08 UTC

↳ Parent: TokenMask

Complexity

Conditions	1
Paths	1

Size

Total Lines	6
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	3
CRAP Score	1

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
cc	1
eloc	2
c	1
b	0
f	0
nc	1
nop	1
dl	0
loc	6
ccs	3
cts	3
cp	1
crap	1
rs	10

<?php

declare(strict_types=1);

namespace Yiisoft\Security;

use Yiisoft\Strings\StringHelper;

/**
 * TokenMask helps to mitigate BREACH attack by randomizing how token is outputted on each request.
 * A random mask is applied to the token making the string always unique.
 */
final class TokenMask
{
    /**
     * Masks a token to make it incompressible.
     * Applies a random mask to the token and prepends the mask used to the result making the string always unique.
     *
     * @param string $token An unmasked token.
     *
     * @throws \Exception if unable to securely generate random bytes
     *
     * @return string A masked token.
     */
    public static function apply(string $token): string
    {
        // The number of bytes in a mask is always equal to the number of bytes in a token.
        /** @psalm-suppress ArgumentTypeCoercion */
        $mask = random_bytes(StringHelper::byteLength($token));
        return StringHelper::base64UrlEncode($mask . ($mask ^ $token));
    }

    /**
     * Unmasks a token previously masked by `mask`.
     *
     * @param string $maskedToken A masked token.
     *
     * @return string An unmasked token, or an empty string in case of token format is invalid.
     */
    public static function remove(string $maskedToken): string
    {
        $decoded = StringHelper::base64UrlDecode($maskedToken);
        $length = StringHelper::byteLength($decoded) / 2;
        // Check if the masked token has an even length.
        if (!is_int($length)) {

            return '';
        }

        return StringHelper::byteSubstring($decoded, $length, $length) ^ StringHelper::byteSubstring($decoded, 0, $length);
    }
}


1		<?php
2
3		declare(strict_types=1);
4
5		namespace Yiisoft\Security;
6
7		use Yiisoft\Strings\StringHelper;
8
9		/**
10		* TokenMask helps to mitigate BREACH attack by randomizing how token is outputted on each request.
11		* A random mask is applied to the token making the string always unique.
12		*/
13		final class TokenMask
14		{
15		/**
16		* Masks a token to make it incompressible.
17		* Applies a random mask to the token and prepends the mask used to the result making the string always unique.
18		*
19		* @param string $token An unmasked token.
20		*
21		* @throws \Exception if unable to securely generate random bytes
22		*
23		* @return string A masked token.
24		*/
25	5	public static function apply(string $token): string
26		{
27		// The number of bytes in a mask is always equal to the number of bytes in a token.
28		/** @psalm-suppress ArgumentTypeCoercion */
29	5	$mask = random_bytes(StringHelper::byteLength($token));
30	4	return StringHelper::base64UrlEncode($mask . ($mask ^ $token));
31		}
32
33		/**
34		* Unmasks a token previously masked by `mask`.
35		*
36		* @param string $maskedToken A masked token.
37		*
38		* @return string An unmasked token, or an empty string in case of token format is invalid.
39		*/
40	6	public static function remove(string $maskedToken): string
41		{
42	6	$decoded = StringHelper::base64UrlDecode($maskedToken);
43	6	$length = StringHelper::byteLength($decoded) / 2;
44		// Check if the masked token has an even length.
45	6	if (!is_int($length)) {
		0 ignored issues – show introduced 2019-06-27 22:30 UTC by Report Bug Copy Issue Report The condition `is_int($length)` is always `true`. Loading history...
46	1	return '';
47		}
48
49	5	return StringHelper::byteSubstring($decoded, $length, $length) ^ StringHelper::byteSubstring($decoded, 0, $length);
50		}
51		}
52

yiisoft / security

TokenMask::apply() A last analyzed 2024-03-16 14:08 UTC

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TokenMask::apply() A
last analyzed 2024-03-16 14:08 UTC