ParagonIE_Sodium_Core32_ChaCha20::quarterRound( ParagonIE_Sodium_Core32_Int32 $a, ParagonIE_Sodium_Core32_Int32 $b, ParagonIE_Sodium_Core32_Int32 $c, ParagonIE_Sodium_Core32_Int32 $d ): array<int,

25    protected static function quarterRound(26        ParagonIE_Sodium_Core32_Int32 $a,27        ParagonIE_Sodium_Core32_Int32 $b,28        ParagonIE_Sodium_Core32_Int32 $c,29        ParagonIE_Sodium_Core32_Int32 $d30    ) {31        /** @var ParagonIE_Sodium_Core32_Int32 $a */32        /** @var ParagonIE_Sodium_Core32_Int32 $b */33        /** @var ParagonIE_Sodium_Core32_Int32 $c */34        /** @var ParagonIE_Sodium_Core32_Int32 $d */35 36        # a = PLUS(a,b); d = ROTATE(XOR(d,a),16);37        $a = $a->addInt32($b);38        $d = $d->xorInt32($a)->rotateLeft(16);39 40        # c = PLUS(c,d); b = ROTATE(XOR(b,c),12);41        $c = $c->addInt32($d);42        $b = $b->xorInt32($c)->rotateLeft(12);43 44        # a = PLUS(a,b); d = ROTATE(XOR(d,a), 8);45        $a = $a->addInt32($b);46        $d = $d->xorInt32($a)->rotateLeft(8);47 48        # c = PLUS(c,d); b = ROTATE(XOR(b,c), 7);49        $c = $c->addInt32($d);50        $b = $b->xorInt32($c)->rotateLeft(7);51 52        return array($a, $b, $c, $d);53    }