PHP Classes

File: src/Core/AEGIS/State256.php

Recommend this page to a friend!
  Classes of Scott Arciszewski   PHP Sodium Compat   src/Core/AEGIS/State256.php   Download  
File: src/Core/AEGIS/State256.php
Role: Class source
Content type: text/plain
Description: Class source
Class: PHP Sodium Compat
Cryptographic functions of libsodium in pure PHP
Author: By
Last change:
Date: 27 days ago
Size: 6,799 bytes
 

Contents

Class file image Download
<?php
declare(strict_types=1);

if (
class_exists('ParagonIE_Sodium_Core_AEGIS_State256', false)) {
    return;
}

if (!
defined('SODIUM_COMPAT_AEGIS_C0')) {
   
define('SODIUM_COMPAT_AEGIS_C0', "\x00\x01\x01\x02\x03\x05\x08\x0d\x15\x22\x37\x59\x90\xe9\x79\x62");
}
if (!
defined('SODIUM_COMPAT_AEGIS_C1')) {
   
define('SODIUM_COMPAT_AEGIS_C1', "\xdb\x3d\x18\x55\x6d\xc2\x2f\xf1\x20\x11\x31\x42\x73\xb5\x28\xdd");
}

class
ParagonIE_Sodium_Core_AEGIS_State256
{
   
/** @var array<int, string> $state */
   
protected array $state;

    public function
__construct()
    {
       
$this->state = array_fill(0, 6, '');
    }

   
/**
     * @internal Only use this for unit tests!
     * @return string[]
     */
   
public function getState(): array
    {
        return
array_values($this->state);
    }

   
/**
     * @param array $input
     * @return self
     * @throws SodiumException
     *
     * @internal Only for unit tests
     */
   
public static function initForUnitTests(array $input): self
   
{
        if (
count($input) < 6) {
            throw new
SodiumException('invalid input');
        }
       
$state = new self();
        for (
$i = 0; $i < 6; ++$i) {
           
$state->state[$i] = $input[$i];
        }
        return
$state;
    }

   
/**
     * @param string $key
     * @param string $nonce
     * @return self
     */
   
public static function init(
       
#[SensitiveParameter]
       
string $key,
       
string $nonce
   
): self {
       
$state = new self();
       
$k0 = ParagonIE_Sodium_Core_Util::substr($key, 0, 16);
       
$k1 = ParagonIE_Sodium_Core_Util::substr($key, 16, 16);
       
$n0 = ParagonIE_Sodium_Core_Util::substr($nonce, 0, 16);
       
$n1 = ParagonIE_Sodium_Core_Util::substr($nonce, 16, 16);

       
// S0 = k0 ^ n0
        // S1 = k1 ^ n1
        // S2 = C1
        // S3 = C0
        // S4 = k0 ^ C0
        // S5 = k1 ^ C1
       
$k0_n0 = $k0 ^ $n0;
       
$k1_n1 = $k1 ^ $n1;
       
$state->state[0] = $k0_n0;
       
$state->state[1] = $k1_n1;
       
$state->state[2] = SODIUM_COMPAT_AEGIS_C1;
       
$state->state[3] = SODIUM_COMPAT_AEGIS_C0;
       
$state->state[4] = $k0 ^ SODIUM_COMPAT_AEGIS_C0;
       
$state->state[5] = $k1 ^ SODIUM_COMPAT_AEGIS_C1;

       
// Repeat(4,
        // Update(k0)
        // Update(k1)
        // Update(k0 ^ n0)
        // Update(k1 ^ n1)
        // )
       
for ($i = 0; $i < 4; ++$i) {
           
$state->update($k0);
           
$state->update($k1);
           
$state->update($k0 ^ $n0);
           
$state->update($k1 ^ $n1);
        }
        return
$state;
    }

   
/**
     * @param string $ai
     * @return static
     * @throws SodiumException
     */
   
public function absorb(string $ai): static
    {
        if (
ParagonIE_Sodium_Core_Util::strlen($ai) !== 16) {
            throw new
SodiumException('Input must be an AES block in size');
        }
        return
$this->update($ai);
    }

   
/**
     * @param string $ci
     * @return string
     * @throws SodiumException
     */
   
public function dec(string $ci): string
   
{
        if (
ParagonIE_Sodium_Core_Util::strlen($ci) !== 16) {
            throw new
SodiumException('Input must be an AES block in size');
        }
       
// z = S1 ^ S4 ^ S5 ^ (S2 & S3)
       
$z = $this->state[1]
            ^
$this->state[4]
            ^
$this->state[5]
            ^
ParagonIE_Sodium_Core_Util::andStrings($this->state[2], $this->state[3]);
       
$xi = $ci ^ $z;
       
$this->update($xi);
        return
$xi;
    }

   
/**
     * @param string $cn
     * @return string
     *
     * @throws SodiumException
     */
   
public function decPartial(string $cn): string
   
{
       
$len = ParagonIE_Sodium_Core_Util::strlen($cn);
       
// z = S1 ^ S4 ^ S5 ^ (S2 & S3)
       
$z = $this->state[1]
            ^
$this->state[4]
            ^
$this->state[5]
            ^
ParagonIE_Sodium_Core_Util::andStrings($this->state[2], $this->state[3]);

       
// t = ZeroPad(cn, 128)
       
$t = str_pad($cn, 16, "\0");

       
// out = t ^ z
       
$out = $t ^ $z;

       
// xn = Truncate(out, |cn|)
       
$xn = ParagonIE_Sodium_Core_Util::substr($out, 0, $len);

       
// v = ZeroPad(xn, 128)
       
$v = str_pad($xn, 16, "\0");
       
// Update(v)
       
$this->update($v);

       
// return xn
       
return $xn;
    }

   
/**
     * @param string $xi
     * @return string
     * @throws SodiumException
     */
   
public function enc(
       
#[SensitiveParameter]
       
string $xi
   
): string {
        if (
ParagonIE_Sodium_Core_Util::strlen($xi) !== 16) {
            throw new
SodiumException('Input must be an AES block in size');
        }
       
// z = S1 ^ S4 ^ S5 ^ (S2 & S3)
       
$z = $this->state[1]
            ^
$this->state[4]
            ^
$this->state[5]
            ^
ParagonIE_Sodium_Core_Util::andStrings($this->state[2], $this->state[3]);
       
$this->update($xi);
        return
$xi ^ $z;
    }

   
/**
     * @param int $ad_len_bits
     * @param int $msg_len_bits
     * @return string
     */
   
public function finalize(
       
int $ad_len_bits,
       
int $msg_len_bits
   
): string {
       
$encoded = ParagonIE_Sodium_Core_Util::store64_le($ad_len_bits) .
           
ParagonIE_Sodium_Core_Util::store64_le($msg_len_bits);
       
$t = $this->state[3] ^ $encoded;

        for (
$i = 0; $i < 7; ++$i) {
           
$this->update($t);
        }

        return (
$this->state[0] ^ $this->state[1] ^ $this->state[2]) .
            (
$this->state[3] ^ $this->state[4] ^ $this->state[5]);
    }

   
/**
     * @param string $m
     * @return static
     */
   
public function update(string $m): static
    {
       
/*
            S'0 = AESRound(S5, S0 ^ M)
            S'1 = AESRound(S0, S1)
            S'2 = AESRound(S1, S2)
            S'3 = AESRound(S2, S3)
            S'4 = AESRound(S3, S4)
            S'5 = AESRound(S4, S5)
         */
       
list($s_0, $s_1) = ParagonIE_Sodium_Core_AES::doubleRound(
           
$this->state[5],$this->state[0] ^ $m,
           
$this->state[0], $this->state[1]
        );

        list(
$s_2, $s_3) = ParagonIE_Sodium_Core_AES::doubleRound(
           
$this->state[1], $this->state[2],
           
$this->state[2], $this->state[3]
        );
        list(
$s_4, $s_5) = ParagonIE_Sodium_Core_AES::doubleRound(
           
$this->state[3], $this->state[4],
           
$this->state[4], $this->state[5]
        );

       
/*
            S0 = S'0
            S1 = S'1
            S2 = S'2
            S3 = S'3
            S4 = S'4
            S5 = S'5
         */
       
$this->state[0] = $s_0;
       
$this->state[1] = $s_1;
       
$this->state[2] = $s_2;
       
$this->state[3] = $s_3;
       
$this->state[4] = $s_4;
       
$this->state[5] = $s_5;
        return
$this;
    }
}