<?php

if (class_exists('ParagonIE_Sodium_Core32_Salsa20', false)) {
    return;
}
abstract class ParagonIE_Sodium_Core32_Salsa20 extends ParagonIE_Sodium_Core32_Util
{
    const ROUNDS = 20;
    public static function core_salsa20($in, $k, $c = null)
    {
        if (self::strlen($k) < 32) {
            throw new RangeException('Key must be 32 bytes long');
        }
        if ($c === null) {
            $x0 = new ParagonIE_Sodium_Core32_Int32(array(0x6170, 0x7865));
            $x5 = new ParagonIE_Sodium_Core32_Int32(array(0x3320, 0x646e));
            $x10 = new ParagonIE_Sodium_Core32_Int32(array(0x7962, 0x2d32));
            $x15 = new ParagonIE_Sodium_Core32_Int32(array(0x6b20, 0x6574));
        } else {
            $x0 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($c, 0, 4));
            $x5 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($c, 4, 4));
            $x10 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($c, 8, 4));
            $x15 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($c, 12, 4));
        }
        $x1 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($k, 0, 4));
        $x2 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($k, 4, 4));
        $x3 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($k, 8, 4));
        $x4 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($k, 12, 4));
        $x6 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($in, 0, 4));
        $x7 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($in, 4, 4));
        $x8 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($in, 8, 4));
        $x9 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($in, 12, 4));
        $x11 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($k, 16, 4));
        $x12 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($k, 20, 4));
        $x13 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($k, 24, 4));
        $x14 = ParagonIE_Sodium_Core32_Int32::fromReverseString(self::substr($k, 28, 4));
        $j0 = clone $x0;
        $j1 = clone $x1;
        $j2 = clone $x2;
        $j3 = clone $x3;
        $j4 = clone $x4;
        $j5 = clone $x5;
        $j6 = clone $x6;
        $j7 = clone $x7;
        $j8 = clone $x8;
        $j9 = clone $x9;
        $j10 = clone $x10;
        $j11 = clone $x11;
        $j12 = clone $x12;
        $j13 = clone $x13;
        $j14 = clone $x14;
        $j15 = clone $x15;
        for ($i = self::ROUNDS; $i > 0; $i -= 2) {
            $x4 = $x4->xorInt32($x0->addInt32($x12)->rotateLeft(7));
            $x8 = $x8->xorInt32($x4->addInt32($x0)->rotateLeft(9));
            $x12 = $x12->xorInt32($x8->addInt32($x4)->rotateLeft(13));
            $x0 = $x0->xorInt32($x12->addInt32($x8)->rotateLeft(18));
            $x9 = $x9->xorInt32($x5->addInt32($x1)->rotateLeft(7));
            $x13 = $x13->xorInt32($x9->addInt32($x5)->rotateLeft(9));
            $x1 = $x1->xorInt32($x13->addInt32($x9)->rotateLeft(13));
            $x5 = $x5->xorInt32($x1->addInt32($x13)->rotateLeft(18));
            $x14 = $x14->xorInt32($x10->addInt32($x6)->rotateLeft(7));
            $x2 = $x2->xorInt32($x14->addInt32($x10)->rotateLeft(9));
            $x6 = $x6->xorInt32($x2->addInt32($x14)->rotateLeft(13));
            $x10 = $x10->xorInt32($x6->addInt32($x2)->rotateLeft(18));
            $x3 = $x3->xorInt32($x15->addInt32($x11)->rotateLeft(7));
            $x7 = $x7->xorInt32($x3->addInt32($x15)->rotateLeft(9));
            $x11 = $x11->xorInt32($x7->addInt32($x3)->rotateLeft(13));
            $x15 = $x15->xorInt32($x11->addInt32($x7)->rotateLeft(18));
            $x1 = $x1->xorInt32($x0->addInt32($x3)->rotateLeft(7));
            $x2 = $x2->xorInt32($x1->addInt32($x0)->rotateLeft(9));
            $x3 = $x3->xorInt32($x2->addInt32($x1)->rotateLeft(13));
            $x0 = $x0->xorInt32($x3->addInt32($x2)->rotateLeft(18));
            $x6 = $x6->xorInt32($x5->addInt32($x4)->rotateLeft(7));
            $x7 = $x7->xorInt32($x6->addInt32($x5)->rotateLeft(9));
            $x4 = $x4->xorInt32($x7->addInt32($x6)->rotateLeft(13));
            $x5 = $x5->xorInt32($x4->addInt32($x7)->rotateLeft(18));
            $x11 = $x11->xorInt32($x10->addInt32($x9)->rotateLeft(7));
            $x8 = $x8->xorInt32($x11->addInt32($x10)->rotateLeft(9));
            $x9 = $x9->xorInt32($x8->addInt32($x11)->rotateLeft(13));
            $x10 = $x10->xorInt32($x9->addInt32($x8)->rotateLeft(18));
            $x12 = $x12->xorInt32($x15->addInt32($x14)->rotateLeft(7));
            $x13 = $x13->xorInt32($x12->addInt32($x15)->rotateLeft(9));
            $x14 = $x14->xorInt32($x13->addInt32($x12)->rotateLeft(13));
            $x15 = $x15->xorInt32($x14->addInt32($x13)->rotateLeft(18));
        }
        $x0 = $x0->addInt32($j0);
        $x1 = $x1->addInt32($j1);
        $x2 = $x2->addInt32($j2);
        $x3 = $x3->addInt32($j3);
        $x4 = $x4->addInt32($j4);
        $x5 = $x5->addInt32($j5);
        $x6 = $x6->addInt32($j6);
        $x7 = $x7->addInt32($j7);
        $x8 = $x8->addInt32($j8);
        $x9 = $x9->addInt32($j9);
        $x10 = $x10->addInt32($j10);
        $x11 = $x11->addInt32($j11);
        $x12 = $x12->addInt32($j12);
        $x13 = $x13->addInt32($j13);
        $x14 = $x14->addInt32($j14);
        $x15 = $x15->addInt32($j15);
        return $x0->toReverseString() . $x1->toReverseString() . $x2->toReverseString() . $x3->toReverseString() . $x4->toReverseString() . $x5->toReverseString() . $x6->toReverseString() . $x7->toReverseString() . $x8->toReverseString() . $x9->toReverseString() . $x10->toReverseString() . $x11->toReverseString() . $x12->toReverseString() . $x13->toReverseString() . $x14->toReverseString() . $x15->toReverseString();
    }
    public static function salsa20($len, $nonce, $key)
    {
        if (self::strlen($key) !== 32) {
            throw new RangeException('Key must be 32 bytes long');
        }
        $kcopy = '' . $key;
        $in = self::substr($nonce, 0, 8) . str_repeat("\0", 8);
        $c = '';
        while ($len >= 64) {
            $c .= self::core_salsa20($in, $kcopy, null);
            $u = 1;
            for ($i = 8; $i < 16; ++$i) {
                $u += self::chrToInt($in[$i]);
                $in[$i] = self::intToChr($u & 0xff);
                $u >>= 8;
            }
            $len -= 64;
        }
        if ($len > 0) {
            $c .= self::substr(self::core_salsa20($in, $kcopy, null), 0, $len);
        }
        try {
            ParagonIE_Sodium_Compat::memzero($kcopy);
        } catch (SodiumException $ex) {
            $kcopy = null;
        }
        return $c;
    }
    public static function salsa20_xor_ic($m, $n, $ic, $k)
    {
        $mlen = self::strlen($m);
        if ($mlen < 1) {
            return '';
        }
        $kcopy = self::substr($k, 0, 32);
        $in = self::substr($n, 0, 8);
        $in .= ParagonIE_Sodium_Core32_Util::store64_le($ic);
        $c = '';
        while ($mlen >= 64) {
            $block = self::core_salsa20($in, $kcopy, null);
            $c .= self::xorStrings(self::substr($m, 0, 64), self::substr($block, 0, 64));
            $u = 1;
            for ($i = 8; $i < 16; ++$i) {
                $u += self::chrToInt($in[$i]);
                $in[$i] = self::intToChr($u & 0xff);
                $u >>= 8;
            }
            $mlen -= 64;
            $m = self::substr($m, 64);
        }
        if ($mlen) {
            $block = self::core_salsa20($in, $kcopy, null);
            $c .= self::xorStrings(self::substr($m, 0, $mlen), self::substr($block, 0, $mlen));
        }
        try {
            ParagonIE_Sodium_Compat::memzero($block);
            ParagonIE_Sodium_Compat::memzero($kcopy);
        } catch (SodiumException $ex) {
            $block = null;
            $kcopy = null;
        }
        return $c;
    }
    public static function salsa20_xor($message, $nonce, $key)
    {
        return self::xorStrings($message, self::salsa20(self::strlen($message), $nonce, $key));
    }
}