<?php 
declare(strict_types=1); 
 
if (class_exists('ParagonIE_Sodium_Core_ChaCha20', false)) { 
    return; 
} 
 
/** 
 * Class ParagonIE_Sodium_Core_ChaCha20 
 */ 
class ParagonIE_Sodium_Core_ChaCha20 extends ParagonIE_Sodium_Core_Util 
{ 
    /** 
     * Bitwise left rotation 
     * 
     * @internal You should not use this directly from another application 
     * 
     * @param int $v 
     * @param int $n 
     * @return int 
     */ 
    public static function rotate(int $v, int $n): int 
    { 
        $v &= 0xffffffff; 
        $n &= 31; 
        return ( 
            0xffffffff & ( 
                ($v << $n) 
                    | 
                ($v >> (32 - $n)) 
            ) 
        ); 
    } 
 
    /** 
     * The ChaCha20 quarter round function. Works on four 32-bit integers. 
     * 
     * @internal You should not use this directly from another application 
     * 
     * @param int $a 
     * @param int $b 
     * @param int $c 
     * @param int $d 
     * @return array<int, int> 
     */ 
    protected static function quarterRound(int $a, int $b, int $c, int $d): array 
    { 
        # a = PLUS(a,b); d = ROTATE(XOR(d,a),16); 
        /** @var int $a */ 
        $a = ($a + $b) & 0xffffffff; 
        $d = self::rotate($d ^ $a, 16); 
 
        # c = PLUS(c,d); b = ROTATE(XOR(b,c),12); 
        /** @var int $c */ 
        $c = ($c + $d) & 0xffffffff; 
        $b = self::rotate($b ^ $c, 12); 
 
        # a = PLUS(a,b); d = ROTATE(XOR(d,a), 8); 
        /** @var int $a */ 
        $a = ($a + $b) & 0xffffffff; 
        $d = self::rotate($d ^ $a, 8); 
 
        # c = PLUS(c,d); b = ROTATE(XOR(b,c), 7); 
        /** @var int $c */ 
        $c = ($c + $d) & 0xffffffff; 
        $b = self::rotate($b ^ $c, 7); 
        return array($a, $b, $c, $d); 
    } 
 
    /** 
     * @internal You should not use this directly from another application 
     * 
     * @param ParagonIE_Sodium_Core_ChaCha20_Ctx $ctx 
     * @param string $message 
     * 
     * @return string 
     * @throws TypeError 
     * @throws SodiumException 
     */ 
    public static function encryptBytes( 
        ParagonIE_Sodium_Core_ChaCha20_Ctx $ctx, 
        #[SensitiveParameter] 
        string $message = '' 
    ): string { 
        $bytes = self::strlen($message); 
 
        $j0  = (int) $ctx[0]; 
        $j1  = (int) $ctx[1]; 
        $j2  = (int) $ctx[2]; 
        $j3  = (int) $ctx[3]; 
        $j4  = (int) $ctx[4]; 
        $j5  = (int) $ctx[5]; 
        $j6  = (int) $ctx[6]; 
        $j7  = (int) $ctx[7]; 
        $j8  = (int) $ctx[8]; 
        $j9  = (int) $ctx[9]; 
        $j10 = (int) $ctx[10]; 
        $j11 = (int) $ctx[11]; 
        $j12 = (int) $ctx[12]; 
        $j13 = (int) $ctx[13]; 
        $j14 = (int) $ctx[14]; 
        $j15 = (int) $ctx[15]; 
 
        $c = ''; 
        for (;;) { 
            if ($bytes < 64) { 
                $message .= str_repeat("\x00", 64 - $bytes); 
            } 
 
            $x0 =  $j0; 
            $x1 =  $j1; 
            $x2 =  $j2; 
            $x3 =  $j3; 
            $x4 =  $j4; 
            $x5 =  $j5; 
            $x6 =  $j6; 
            $x7 =  $j7; 
            $x8 =  $j8; 
            $x9 =  $j9; 
            $x10 = $j10; 
            $x11 = $j11; 
            $x12 = $j12; 
            $x13 = $j13; 
            $x14 = $j14; 
            $x15 = $j15; 
 
            # for (i = 20; i > 0; i -= 2) { 
            for ($i = 20; $i > 0; $i -= 2) { 
                [$x0, $x4, $x8, $x12] = self::quarterRound($x0, $x4, $x8, $x12); 
                [$x1, $x5, $x9, $x13] = self::quarterRound($x1, $x5, $x9, $x13); 
                [$x2, $x6, $x10, $x14] = self::quarterRound($x2, $x6, $x10, $x14); 
                [$x3, $x7, $x11, $x15] = self::quarterRound($x3, $x7, $x11, $x15); 
 
                [$x0, $x5, $x10, $x15] = self::quarterRound($x0, $x5, $x10, $x15); 
                [$x1, $x6, $x11, $x12] = self::quarterRound($x1, $x6, $x11, $x12); 
                [$x2, $x7, $x8, $x13] = self::quarterRound($x2, $x7, $x8, $x13); 
                [$x3, $x4, $x9, $x14] = self::quarterRound($x3, $x4, $x9, $x14); 
            } 
            $x0  = ($x0 & 0xffffffff) + $j0; 
            $x1  = ($x1 & 0xffffffff) + $j1; 
            $x2  = ($x2 & 0xffffffff) + $j2; 
            $x3  = ($x3 & 0xffffffff) + $j3; 
            $x4  = ($x4 & 0xffffffff) + $j4; 
            $x5  = ($x5 & 0xffffffff) + $j5; 
            $x6  = ($x6 & 0xffffffff) + $j6; 
            $x7  = ($x7 & 0xffffffff) + $j7; 
            $x8  = ($x8 & 0xffffffff) + $j8; 
            $x9  = ($x9 & 0xffffffff) + $j9; 
            $x10 = ($x10 & 0xffffffff) + $j10; 
            $x11 = ($x11 & 0xffffffff) + $j11; 
            $x12 = ($x12 & 0xffffffff) + $j12; 
            $x13 = ($x13 & 0xffffffff) + $j13; 
            $x14 = ($x14 & 0xffffffff) + $j14; 
            $x15 = ($x15 & 0xffffffff) + $j15; 
 
            $x0  ^= self::load_4(self::substr($message, 0, 4)); 
            $x1  ^= self::load_4(self::substr($message, 4, 4)); 
            $x2  ^= self::load_4(self::substr($message, 8, 4)); 
            $x3  ^= self::load_4(self::substr($message, 12, 4)); 
            $x4  ^= self::load_4(self::substr($message, 16, 4)); 
            $x5  ^= self::load_4(self::substr($message, 20, 4)); 
            $x6  ^= self::load_4(self::substr($message, 24, 4)); 
            $x7  ^= self::load_4(self::substr($message, 28, 4)); 
            $x8  ^= self::load_4(self::substr($message, 32, 4)); 
            $x9  ^= self::load_4(self::substr($message, 36, 4)); 
            $x10 ^= self::load_4(self::substr($message, 40, 4)); 
            $x11 ^= self::load_4(self::substr($message, 44, 4)); 
            $x12 ^= self::load_4(self::substr($message, 48, 4)); 
            $x13 ^= self::load_4(self::substr($message, 52, 4)); 
            $x14 ^= self::load_4(self::substr($message, 56, 4)); 
            $x15 ^= self::load_4(self::substr($message, 60, 4)); 
 
            ++$j12; 
            if ($j12 & 0xf0000000) { 
                throw new SodiumException('Overflow'); 
            } 
 
            $block = self::store32_le(($x0  & 0xffffffff)) . 
                 self::store32_le(($x1  & 0xffffffff)) . 
                 self::store32_le(($x2  & 0xffffffff)) . 
                 self::store32_le(($x3  & 0xffffffff)) . 
                 self::store32_le(($x4  & 0xffffffff)) . 
                 self::store32_le(($x5  & 0xffffffff)) . 
                 self::store32_le(($x6  & 0xffffffff)) . 
                 self::store32_le(($x7  & 0xffffffff)) . 
                 self::store32_le(($x8  & 0xffffffff)) . 
                 self::store32_le(($x9  & 0xffffffff)) . 
                 self::store32_le(($x10 & 0xffffffff)) . 
                 self::store32_le(($x11 & 0xffffffff)) . 
                 self::store32_le(($x12 & 0xffffffff)) . 
                 self::store32_le(($x13 & 0xffffffff)) . 
                 self::store32_le(($x14 & 0xffffffff)) . 
                 self::store32_le(($x15 & 0xffffffff)); 
 
            /* Partial block */ 
            if ($bytes < 64) { 
                $c .= self::substr($block, 0, $bytes); 
                break; 
            } 
 
            /* Full block */ 
            $c .= $block; 
            $bytes -= 64; 
            if ($bytes <= 0) { 
                break; 
            } 
            $message = self::substr($message, 64); 
        } 
        /* end for(;;) loop */ 
 
        $ctx[12] = $j12; 
        $ctx[13] = $j13; 
        return $c; 
    } 
 
    /** 
     * @internal You should not use this directly from another application 
     * 
     * @param int $len 
     * @param string $nonce 
     * @param string $key 
     * @return string 
     * @throws SodiumException 
     * @throws TypeError 
     */ 
    public static function stream( 
        int $len = 64, 
        string $nonce = '', 
        #[SensitiveParameter] 
        string $key = '' 
    ): string { 
        return self::encryptBytes( 
            new ParagonIE_Sodium_Core_ChaCha20_Ctx($key, $nonce), 
            str_repeat("\x00", $len) 
        ); 
    } 
 
    /** 
     * @internal You should not use this directly from another application 
     * 
     * @param int $len 
     * @param string $nonce 
     * @param string $key 
     * @return string 
     * @throws SodiumException 
     * @throws TypeError 
     */ 
    public static function ietfStream( 
        int $len, 
        string $nonce = '', 
        #[SensitiveParameter] 
        string $key = '' 
    ): string { 
        return self::encryptBytes( 
            new ParagonIE_Sodium_Core_ChaCha20_IetfCtx($key, $nonce), 
            str_repeat("\x00", $len) 
        ); 
    } 
 
    /** 
     * @internal You should not use this directly from another application 
     * 
     * @param string $message 
     * @param string $nonce 
     * @param string $key 
     * @param string $ic 
     * @return string 
     * @throws SodiumException 
     * @throws TypeError 
     */ 
    public static function ietfStreamXorIc( 
        #[SensitiveParameter] 
        string $message, 
        string $nonce = '', 
        #[SensitiveParameter] 
        string $key = '', 
        string $ic = '' 
    ): string { 
        return self::encryptBytes( 
            new ParagonIE_Sodium_Core_ChaCha20_IetfCtx($key, $nonce, $ic), 
            $message 
        ); 
    } 
 
    /** 
     * @internal You should not use this directly from another application 
     * 
     * @param string $message 
     * @param string $nonce 
     * @param string $key 
     * @param string $ic 
     * @return string 
     * @throws SodiumException 
     * @throws TypeError 
     */ 
    public static function streamXorIc( 
        #[SensitiveParameter] 
        string $message, 
        string $nonce = '', 
        #[SensitiveParameter] 
        string $key = '', 
        string $ic = '' 
    ): string { 
        return self::encryptBytes( 
            new ParagonIE_Sodium_Core_ChaCha20_Ctx($key, $nonce, $ic), 
            $message 
        ); 
    } 
} 
 
 |