1 files changed, 1066 insertions, 0 deletions

diff --git a/vendor/paragonie/sodium_compat/src/Core32/Int64.php b/vendor/paragonie/sodium_compat/src/Core32/Int64.php
new file mode 100644
index 0000000..dd06a3f
--- /dev/null
+++ b/vendor/paragonie/sodium_compat/src/Core32/Int64.php
@@ -0,0 +1,1066 @@
+<?php
+
+/**
+ * Class ParagonIE_Sodium_Core32_Int64
+ *
+ * Encapsulates a 64-bit integer.
+ *
+ * These are immutable. It always returns a new instance.
+ */
+class ParagonIE_Sodium_Core32_Int64
+{
+    /**
+     * @var array<int, int> - four 16-bit integers
+     */
+    public $limbs = array(0, 0, 0, 0);
+
+    /**
+     * @var int
+     */
+    public $overflow = 0;
+
+    /**
+     * @var bool
+     */
+    public $unsignedInt = false;
+
+    /**
+     * ParagonIE_Sodium_Core32_Int64 constructor.
+     * @param array $array
+     * @param bool $unsignedInt
+     */
+    public function __construct($array = array(0, 0, 0, 0), $unsignedInt = false)
+    {
+        $this->limbs = array(
+            (int) $array[0],
+            (int) $array[1],
+            (int) $array[2],
+            (int) $array[3]
+        );
+        $this->overflow = 0;
+        $this->unsignedInt = $unsignedInt;
+    }
+
+    /**
+     * Adds two int64 objects
+     *
+     * @param ParagonIE_Sodium_Core32_Int64 $addend
+     * @return ParagonIE_Sodium_Core32_Int64
+     */
+    public function addInt64(ParagonIE_Sodium_Core32_Int64 $addend)
+    {
+        $i0 = $this->limbs[0];
+        $i1 = $this->limbs[1];
+        $i2 = $this->limbs[2];
+        $i3 = $this->limbs[3];
+        $j0 = $addend->limbs[0];
+        $j1 = $addend->limbs[1];
+        $j2 = $addend->limbs[2];
+        $j3 = $addend->limbs[3];
+
+        $r3 = $i3 + ($j3 & 0xffff);
+        $carry = $r3 >> 16;
+
+        $r2 = $i2 + ($j2 & 0xffff) + $carry;
+        $carry = $r2 >> 16;
+
+        $r1 = $i1 + ($j1 & 0xffff) + $carry;
+        $carry = $r1 >> 16;
+
+        $r0 = $i0 + ($j0 & 0xffff) + $carry;
+        $carry = $r0 >> 16;
+
+        $r0 &= 0xffff;
+        $r1 &= 0xffff;
+        $r2 &= 0xffff;
+        $r3 &= 0xffff;
+
+        $return = new ParagonIE_Sodium_Core32_Int64(
+            array($r0, $r1, $r2, $r3)
+        );
+        $return->overflow = $carry;
+        $return->unsignedInt = $this->unsignedInt;
+        return $return;
+    }
+
+    /**
+     * Adds a normal integer to an int64 object
+     *
+     * @param int $int
+     * @return ParagonIE_Sodium_Core32_Int64
+     * @throws SodiumException
+     * @throws TypeError
+     */
+    public function addInt($int)
+    {
+        ParagonIE_Sodium_Core32_Util::declareScalarType($int, 'int', 1);
+        /** @var int $int */
+        $int = (int) $int;
+
+        $i0 = $this->limbs[0];
+        $i1 = $this->limbs[1];
+        $i2 = $this->limbs[2];
+        $i3 = $this->limbs[3];
+
+        $r3 = $i3 + ($int & 0xffff);
+        $carry = $r3 >> 16;
+
+        $r2 = $i2 + (($int >> 16) & 0xffff) + $carry;
+        $carry = $r2 >> 16;
+
+        $r1 = $i1 + $carry;
+        $carry = $r1 >> 16;
+
+        $r0 = $i0 + $carry;
+        $carry = $r0 >> 16;
+
+        $r0 &= 0xffff;
+        $r1 &= 0xffff;
+        $r2 &= 0xffff;
+        $r3 &= 0xffff;
+        $return = new ParagonIE_Sodium_Core32_Int64(
+            array($r0, $r1, $r2, $r3)
+        );
+        $return->overflow = $carry;
+        $return->unsignedInt = $this->unsignedInt;
+        return $return;
+    }
+
+    /**
+     * @param int $b
+     * @return int
+     */
+    public function compareInt($b = 0)
+    {
+        $gt = 0;
+        $eq = 1;
+
+        $i = 4;
+        $j = 0;
+        while ($i > 0) {
+            --$i;
+            /** @var int $x1 */
+            $x1 = $this->limbs[$i];
+            /** @var int $x2 */
+            $x2 = ($b >> ($j << 4)) & 0xffff;
+            /** int */
+            $gt |= (($x2 - $x1) >> 8) & $eq;
+            /** int */
+            $eq &= (($x2 ^ $x1) - 1) >> 8;
+        }
+        return ($gt + $gt - $eq) + 1;
+    }
+
+    /**
+     * @param int $b
+     * @return bool
+     */
+    public function isGreaterThan($b = 0)
+    {
+        return $this->compareInt($b) > 0;
+    }
+
+    /**
+     * @param int $b
+     * @return bool
+     */
+    public function isLessThanInt($b = 0)
+    {
+        return $this->compareInt($b) < 0;
+    }
+
+    /**
+     * @param int $hi
+     * @param int $lo
+     * @return ParagonIE_Sodium_Core32_Int64
+     */
+    public function mask64($hi = 0, $lo = 0)
+    {
+        /** @var int $a */
+        $a = ($hi >> 16) & 0xffff;
+        /** @var int $b */
+        $b = ($hi) & 0xffff;
+        /** @var int $c */
+        $c = ($lo >> 16) & 0xffff;
+        /** @var int $d */
+        $d = ($lo & 0xffff);
+        return new ParagonIE_Sodium_Core32_Int64(
+            array(
+                $this->limbs[0] & $a,
+                $this->limbs[1] & $b,
+                $this->limbs[2] & $c,
+                $this->limbs[3] & $d
+            ),
+            $this->unsignedInt
+        );
+    }
+
+    /**
+     * @param int $int
+     * @param int $size
+     * @return ParagonIE_Sodium_Core32_Int64
+     * @throws SodiumException
+     * @throws TypeError
+     * @psalm-suppress MixedAssignment
+     */
+    public function mulInt($int = 0, $size = 0)
+    {
+        if (ParagonIE_Sodium_Compat::$fastMult) {
+            return $this->mulIntFast($int);
+        }
+        ParagonIE_Sodium_Core32_Util::declareScalarType($int, 'int', 1);
+        ParagonIE_Sodium_Core32_Util::declareScalarType($size, 'int', 2);
+        /** @var int $int */
+        $int = (int) $int;
+        /** @var int $size */
+        $size = (int) $size;
+
+        if (!$size) {
+            $size = 63;
+        }
+
+        $a = clone $this;
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->unsignedInt = $this->unsignedInt;
+
+        // Initialize:
+        $ret0 = 0;
+        $ret1 = 0;
+        $ret2 = 0;
+        $ret3 = 0;
+        $a0 = $a->limbs[0];
+        $a1 = $a->limbs[1];
+        $a2 = $a->limbs[2];
+        $a3 = $a->limbs[3];
+
+        /** @var int $size */
+        /** @var int $i */
+        for ($i = $size; $i >= 0; --$i) {
+            $mask = -($int & 1);
+            $x0 = $a0 & $mask;
+            $x1 = $a1 & $mask;
+            $x2 = $a2 & $mask;
+            $x3 = $a3 & $mask;
+
+            $ret3 += $x3;
+            $c = $ret3 >> 16;
+
+            $ret2 += $x2 + $c;
+            $c = $ret2 >> 16;
+
+            $ret1 += $x1 + $c;
+            $c = $ret1 >> 16;
+
+            $ret0 += $x0 + $c;
+
+            $ret0 &= 0xffff;
+            $ret1 &= 0xffff;
+            $ret2 &= 0xffff;
+            $ret3 &= 0xffff;
+
+            $a3 = $a3 << 1;
+            $x3 = $a3 >> 16;
+            $a2 = ($a2 << 1) | $x3;
+            $x2 = $a2 >> 16;
+            $a1 = ($a1 << 1) | $x2;
+            $x1 = $a1 >> 16;
+            $a0 = ($a0 << 1) | $x1;
+            $a0 &= 0xffff;
+            $a1 &= 0xffff;
+            $a2 &= 0xffff;
+            $a3 &= 0xffff;
+
+            $int >>= 1;
+        }
+        $return->limbs[0] = $ret0;
+        $return->limbs[1] = $ret1;
+        $return->limbs[2] = $ret2;
+        $return->limbs[3] = $ret3;
+        return $return;
+    }
+
+    /**
+     * @param ParagonIE_Sodium_Core32_Int64 $A
+     * @param ParagonIE_Sodium_Core32_Int64 $B
+     * @return array<int, ParagonIE_Sodium_Core32_Int64>
+     * @throws SodiumException
+     * @throws TypeError
+     * @psalm-suppress MixedInferredReturnType
+     */
+    public static function ctSelect(
+        ParagonIE_Sodium_Core32_Int64 $A,
+        ParagonIE_Sodium_Core32_Int64 $B
+    ) {
+        $a = clone $A;
+        $b = clone $B;
+        /** @var int $aNeg */
+        $aNeg = ($a->limbs[0] >> 15) & 1;
+        /** @var int $bNeg */
+        $bNeg = ($b->limbs[0] >> 15) & 1;
+        /** @var int $m */
+        $m = (-($aNeg & $bNeg)) | 1;
+        /** @var int $swap */
+        $swap = $bNeg & ~$aNeg;
+        /** @var int $d */
+        $d = -$swap;
+
+        /*
+        if ($bNeg && !$aNeg) {
+            $a = clone $int;
+            $b = clone $this;
+        } elseif($bNeg && $aNeg) {
+            $a = $this->mulInt(-1);
+            $b = $int->mulInt(-1);
+        }
+         */
+        $x = $a->xorInt64($b)->mask64($d, $d);
+        return array(
+            $a->xorInt64($x)->mulInt($m),
+            $b->xorInt64($x)->mulInt($m)
+        );
+    }
+
+    /**
+     * @param array<int, int> $a
+     * @param array<int, int> $b
+     * @param int $baseLog2
+     * @return array<int, int>
+     */
+    public function multiplyLong(array $a, array $b, $baseLog2 = 16)
+    {
+        $a_l = count($a);
+        $b_l = count($b);
+        /** @var array<int, int> $r */
+        $r = array_fill(0, $a_l + $b_l + 1, 0);
+        $base = 1 << $baseLog2;
+        for ($i = 0; $i < $a_l; ++$i) {
+            $a_i = $a[$i];
+            for ($j = 0; $j < $a_l; ++$j) {
+                $b_j = $b[$j];
+                $product = ($a_i * $b_j) + $r[$i + $j];
+                $carry = ($product >> $baseLog2 & 0xffff);
+                $r[$i + $j] = ($product - (int) ($carry * $base)) & 0xffff;
+                $r[$i + $j + 1] += $carry;
+            }
+        }
+        return array_slice($r, 0, 5);
+    }
+
+    /**
+     * @param int $int
+     * @return ParagonIE_Sodium_Core32_Int64
+     */
+    public function mulIntFast($int)
+    {
+        // Handle negative numbers
+        $aNeg = ($this->limbs[0] >> 15) & 1;
+        $bNeg = ($int >> 31) & 1;
+        $a = array_reverse($this->limbs);
+        $b = array(
+            $int & 0xffff,
+            ($int >> 16) & 0xffff,
+            -$bNeg & 0xffff,
+            -$bNeg & 0xffff
+        );
+        if ($aNeg) {
+            for ($i = 0; $i < 4; ++$i) {
+                $a[$i] = ($a[$i] ^ 0xffff) & 0xffff;
+            }
+            ++$a[0];
+        }
+        if ($bNeg) {
+            for ($i = 0; $i < 4; ++$i) {
+                $b[$i] = ($b[$i] ^ 0xffff) & 0xffff;
+            }
+            ++$b[0];
+        }
+        // Multiply
+        $res = $this->multiplyLong($a, $b);
+
+        // Re-apply negation to results
+        if ($aNeg !== $bNeg) {
+            for ($i = 0; $i < 4; ++$i) {
+                $res[$i] = (0xffff ^ $res[$i]) & 0xffff;
+            }
+            // Handle integer overflow
+            $c = 1;
+            for ($i = 0; $i < 4; ++$i) {
+                $res[$i] += $c;
+                $c = $res[$i] >> 16;
+                $res[$i] &= 0xffff;
+            }
+        }
+
+        // Return our values
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->limbs = array(
+            $res[3] & 0xffff,
+            $res[2] & 0xffff,
+            $res[1] & 0xffff,
+            $res[0] & 0xffff
+        );
+        if (count($res) > 4) {
+            $return->overflow = $res[4] & 0xffff;
+        }
+        $return->unsignedInt = $this->unsignedInt;
+        return $return;
+    }
+
+    /**
+     * @param ParagonIE_Sodium_Core32_Int64 $right
+     * @return ParagonIE_Sodium_Core32_Int64
+     */
+    public function mulInt64Fast(ParagonIE_Sodium_Core32_Int64 $right)
+    {
+        $aNeg = ($this->limbs[0] >> 15) & 1;
+        $bNeg = ($right->limbs[0] >> 15) & 1;
+
+        $a = array_reverse($this->limbs);
+        $b = array_reverse($right->limbs);
+        if ($aNeg) {
+            for ($i = 0; $i < 4; ++$i) {
+                $a[$i] = ($a[$i] ^ 0xffff) & 0xffff;
+            }
+            ++$a[0];
+        }
+        if ($bNeg) {
+            for ($i = 0; $i < 4; ++$i) {
+                $b[$i] = ($b[$i] ^ 0xffff) & 0xffff;
+            }
+            ++$b[0];
+        }
+        $res = $this->multiplyLong($a, $b);
+        if ($aNeg !== $bNeg) {
+            if ($aNeg !== $bNeg) {
+                for ($i = 0; $i < 4; ++$i) {
+                    $res[$i] = ($res[$i] ^ 0xffff) & 0xffff;
+                }
+                $c = 1;
+                for ($i = 0; $i < 4; ++$i) {
+                    $res[$i] += $c;
+                    $c = $res[$i] >> 16;
+                    $res[$i] &= 0xffff;
+                }
+            }
+        }
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->limbs = array(
+            $res[3] & 0xffff,
+            $res[2] & 0xffff,
+            $res[1] & 0xffff,
+            $res[0] & 0xffff
+        );
+        if (count($res) > 4) {
+            $return->overflow = $res[4];
+        }
+        return $return;
+    }
+
+    /**
+     * @param ParagonIE_Sodium_Core32_Int64 $int
+     * @param int $size
+     * @return ParagonIE_Sodium_Core32_Int64
+     * @throws SodiumException
+     * @throws TypeError
+     * @psalm-suppress MixedAssignment
+     */
+    public function mulInt64(ParagonIE_Sodium_Core32_Int64 $int, $size = 0)
+    {
+        if (ParagonIE_Sodium_Compat::$fastMult) {
+            return $this->mulInt64Fast($int);
+        }
+        ParagonIE_Sodium_Core32_Util::declareScalarType($size, 'int', 2);
+        if (!$size) {
+            $size = 63;
+        }
+        list($a, $b) = self::ctSelect($this, $int);
+
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->unsignedInt = $this->unsignedInt;
+
+        // Initialize:
+        $ret0 = 0;
+        $ret1 = 0;
+        $ret2 = 0;
+        $ret3 = 0;
+        $a0 = $a->limbs[0];
+        $a1 = $a->limbs[1];
+        $a2 = $a->limbs[2];
+        $a3 = $a->limbs[3];
+        $b0 = $b->limbs[0];
+        $b1 = $b->limbs[1];
+        $b2 = $b->limbs[2];
+        $b3 = $b->limbs[3];
+
+        /** @var int $size */
+        /** @var int $i */
+        for ($i = (int) $size; $i >= 0; --$i) {
+            $mask = -($b3 & 1);
+            $x0 = $a0 & $mask;
+            $x1 = $a1 & $mask;
+            $x2 = $a2 & $mask;
+            $x3 = $a3 & $mask;
+
+            $ret3 += $x3;
+            $c = $ret3 >> 16;
+
+            $ret2 += $x2 + $c;
+            $c = $ret2 >> 16;
+
+            $ret1 += $x1 + $c;
+            $c = $ret1 >> 16;
+
+            $ret0 += $x0 + $c;
+
+            $ret0 &= 0xffff;
+            $ret1 &= 0xffff;
+            $ret2 &= 0xffff;
+            $ret3 &= 0xffff;
+
+            $a3 = $a3 << 1;
+            $x3 = $a3 >> 16;
+            $a2 = ($a2 << 1) | $x3;
+            $x2 = $a2 >> 16;
+            $a1 = ($a1 << 1) | $x2;
+            $x1 = $a1 >> 16;
+            $a0 = ($a0 << 1) | $x1;
+            $a0 &= 0xffff;
+            $a1 &= 0xffff;
+            $a2 &= 0xffff;
+            $a3 &= 0xffff;
+
+            $x0 = ($b0 & 1) << 16;
+            $x1 = ($b1 & 1) << 16;
+            $x2 = ($b2 & 1) << 16;
+
+            $b0 = ($b0 >> 1);
+            $b1 = (($b1 | $x0) >> 1);
+            $b2 = (($b2 | $x1) >> 1);
+            $b3 = (($b3 | $x2) >> 1);
+
+            $b0 &= 0xffff;
+            $b1 &= 0xffff;
+            $b2 &= 0xffff;
+            $b3 &= 0xffff;
+
+        }
+        $return->limbs[0] = $ret0;
+        $return->limbs[1] = $ret1;
+        $return->limbs[2] = $ret2;
+        $return->limbs[3] = $ret3;
+
+        return $return;
+    }
+
+    /**
+     * OR this 64-bit integer with another.
+     *
+     * @param ParagonIE_Sodium_Core32_Int64 $b
+     * @return ParagonIE_Sodium_Core32_Int64
+     */
+    public function orInt64(ParagonIE_Sodium_Core32_Int64 $b)
+    {
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->unsignedInt = $this->unsignedInt;
+        $return->limbs = array(
+            (int) ($this->limbs[0] | $b->limbs[0]),
+            (int) ($this->limbs[1] | $b->limbs[1]),
+            (int) ($this->limbs[2] | $b->limbs[2]),
+            (int) ($this->limbs[3] | $b->limbs[3])
+        );
+        return $return;
+    }
+
+    /**
+     * @param int $c
+     * @return ParagonIE_Sodium_Core32_Int64
+     * @throws SodiumException
+     * @throws TypeError
+     * @psalm-suppress MixedArrayAccess
+     */
+    public function rotateLeft($c = 0)
+    {
+        ParagonIE_Sodium_Core32_Util::declareScalarType($c, 'int', 1);
+        /** @var int $c */
+        $c = (int) $c;
+
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->unsignedInt = $this->unsignedInt;
+        $c &= 63;
+        if ($c === 0) {
+            // NOP, but we want a copy.
+            $return->limbs = $this->limbs;
+        } else {
+            /** @var array<int, int> $limbs */
+            $limbs =& $return->limbs;
+
+            /** @var array<int, int> $myLimbs */
+            $myLimbs =& $this->limbs;
+
+            /** @var int $idx_shift */
+            $idx_shift = ($c >> 4) & 3;
+            /** @var int $sub_shift */
+            $sub_shift = $c & 15;
+
+            for ($i = 3; $i >= 0; --$i) {
+                /** @var int $j */
+                $j = ($i + $idx_shift) & 3;
+                /** @var int $k */
+                $k = ($i + $idx_shift + 1) & 3;
+                $limbs[$i] = (int) (
+                    (
+                        ((int) ($myLimbs[$j]) << $sub_shift)
+                            |
+                        ((int) ($myLimbs[$k]) >> (16 - $sub_shift))
+                    ) & 0xffff
+                );
+            }
+        }
+        return $return;
+    }
+
+    /**
+     * Rotate to the right
+     *
+     * @param int $c
+     * @return ParagonIE_Sodium_Core32_Int64
+     * @throws SodiumException
+     * @throws TypeError
+     * @psalm-suppress MixedArrayAccess
+     */
+    public function rotateRight($c = 0)
+    {
+        ParagonIE_Sodium_Core32_Util::declareScalarType($c, 'int', 1);
+        /** @var int $c */
+        $c = (int) $c;
+
+        /** @var ParagonIE_Sodium_Core32_Int64 $return */
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->unsignedInt = $this->unsignedInt;
+        $c &= 63;
+        /** @var int $c */
+        if ($c === 0) {
+            // NOP, but we want a copy.
+            $return->limbs = $this->limbs;
+        } else {
+            /** @var array<int, int> $limbs */
+            $limbs =& $return->limbs;
+
+            /** @var array<int, int> $myLimbs */
+            $myLimbs =& $this->limbs;
+
+            /** @var int $idx_shift */
+            $idx_shift = ($c >> 4) & 3;
+            /** @var int $sub_shift */
+            $sub_shift = $c & 15;
+
+            for ($i = 3; $i >= 0; --$i) {
+                /** @var int $j */
+                $j = ($i - $idx_shift) & 3;
+                /** @var int $k */
+                $k = ($i - $idx_shift - 1) & 3;
+                $limbs[$i] = (int) (
+                    (
+                        ((int) ($myLimbs[$j]) >> (int) ($sub_shift))
+                            |
+                        ((int) ($myLimbs[$k]) << (16 - (int) ($sub_shift)))
+                    ) & 0xffff
+                );
+            }
+        }
+        return $return;
+    }
+    /**
+     * @param int $c
+     * @return ParagonIE_Sodium_Core32_Int64
+     * @throws SodiumException
+     * @throws TypeError
+     */
+    public function shiftLeft($c = 0)
+    {
+        ParagonIE_Sodium_Core32_Util::declareScalarType($c, 'int', 1);
+        /** @var int $c */
+        $c = (int) $c;
+
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->unsignedInt = $this->unsignedInt;
+        $c &= 63;
+
+        if ($c >= 16) {
+            if ($c >= 48) {
+                $return->limbs = array(
+                    $this->limbs[3], 0, 0, 0
+                );
+            } elseif ($c >= 32) {
+                $return->limbs = array(
+                    $this->limbs[2], $this->limbs[3], 0, 0
+                );
+            } else {
+                $return->limbs = array(
+                    $this->limbs[1], $this->limbs[2], $this->limbs[3], 0
+                );
+            }
+            return $return->shiftLeft($c & 15);
+        }
+        if ($c === 0) {
+            $return->limbs = $this->limbs;
+        } elseif ($c < 0) {
+            /** @var int $c */
+            return $this->shiftRight(-$c);
+        } else {
+            if (!is_int($c)) {
+                throw new TypeError();
+            }
+            /** @var int $carry */
+            $carry = 0;
+            for ($i = 3; $i >= 0; --$i) {
+                /** @var int $tmp */
+                $tmp = ($this->limbs[$i] << $c) | ($carry & 0xffff);
+                $return->limbs[$i] = (int) ($tmp & 0xffff);
+                /** @var int $carry */
+                $carry = $tmp >> 16;
+            }
+        }
+        return $return;
+    }
+
+    /**
+     * @param int $c
+     * @return ParagonIE_Sodium_Core32_Int64
+     * @throws SodiumException
+     * @throws TypeError
+     */
+    public function shiftRight($c = 0)
+    {
+        ParagonIE_Sodium_Core32_Util::declareScalarType($c, 'int', 1);
+        $c = (int) $c;
+        /** @var int $c */
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->unsignedInt = $this->unsignedInt;
+        $c &= 63;
+
+        $negative = -(($this->limbs[0] >> 15) & 1);
+        if ($c >= 16) {
+            if ($c >= 48) {
+                $return->limbs = array(
+                    (int) ($negative & 0xffff),
+                    (int) ($negative & 0xffff),
+                    (int) ($negative & 0xffff),
+                    (int) $this->limbs[0]
+                );
+            } elseif ($c >= 32) {
+                $return->limbs = array(
+                    (int) ($negative & 0xffff),
+                    (int) ($negative & 0xffff),
+                    (int) $this->limbs[0],
+                    (int) $this->limbs[1]
+                );
+            } else {
+                $return->limbs = array(
+                    (int) ($negative & 0xffff),
+                    (int) $this->limbs[0],
+                    (int) $this->limbs[1],
+                    (int) $this->limbs[2]
+                );
+            }
+            return $return->shiftRight($c & 15);
+        }
+
+        if ($c === 0) {
+            $return->limbs = $this->limbs;
+        } elseif ($c < 0) {
+            return $this->shiftLeft(-$c);
+        } else {
+            if (!is_int($c)) {
+                throw new TypeError();
+            }
+            /** @var int $carryRight */
+            $carryRight = ($negative & 0xffff);
+            $mask = (int) (((1 << ($c + 1)) - 1) & 0xffff);
+            for ($i = 0; $i < 4; ++$i) {
+                $return->limbs[$i] = (int) (
+                    (($this->limbs[$i] >> $c) | ($carryRight << (16 - $c))) & 0xffff
+                );
+                $carryRight = (int) ($this->limbs[$i] & $mask);
+            }
+        }
+        return $return;
+    }
+
+
+    /**
+     * Subtract a normal integer from an int64 object.
+     *
+     * @param int $int
+     * @return ParagonIE_Sodium_Core32_Int64
+     * @throws SodiumException
+     * @throws TypeError
+     */
+    public function subInt($int)
+    {
+        ParagonIE_Sodium_Core32_Util::declareScalarType($int, 'int', 1);
+        $int = (int) $int;
+
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->unsignedInt = $this->unsignedInt;
+
+        /** @var int $carry */
+        $carry = 0;
+        for ($i = 3; $i >= 0; --$i) {
+            /** @var int $tmp */
+            $tmp = $this->limbs[$i] - (($int >> 16) & 0xffff) + $carry;
+            /** @var int $carry */
+            $carry = $tmp >> 16;
+            $return->limbs[$i] = (int) ($tmp & 0xffff);
+        }
+        return $return;
+    }
+
+    /**
+     * The difference between two Int64 objects.
+     *
+     * @param ParagonIE_Sodium_Core32_Int64 $b
+     * @return ParagonIE_Sodium_Core32_Int64
+     */
+    public function subInt64(ParagonIE_Sodium_Core32_Int64 $b)
+    {
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->unsignedInt = $this->unsignedInt;
+        /** @var int $carry */
+        $carry = 0;
+        for ($i = 3; $i >= 0; --$i) {
+            /** @var int $tmp */
+            $tmp = $this->limbs[$i] - $b->limbs[$i] + $carry;
+            /** @var int $carry */
+            $carry = ($tmp >> 16);
+            $return->limbs[$i] = (int) ($tmp & 0xffff);
+        }
+        return $return;
+    }
+
+    /**
+     * XOR this 64-bit integer with another.
+     *
+     * @param ParagonIE_Sodium_Core32_Int64 $b
+     * @return ParagonIE_Sodium_Core32_Int64
+     */
+    public function xorInt64(ParagonIE_Sodium_Core32_Int64 $b)
+    {
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->unsignedInt = $this->unsignedInt;
+        $return->limbs = array(
+            (int) ($this->limbs[0] ^ $b->limbs[0]),
+            (int) ($this->limbs[1] ^ $b->limbs[1]),
+            (int) ($this->limbs[2] ^ $b->limbs[2]),
+            (int) ($this->limbs[3] ^ $b->limbs[3])
+        );
+        return $return;
+    }
+
+    /**
+     * @param int $low
+     * @param int $high
+     * @return self
+     * @throws SodiumException
+     * @throws TypeError
+     */
+    public static function fromInts($low, $high)
+    {
+        ParagonIE_Sodium_Core32_Util::declareScalarType($low, 'int', 1);
+        ParagonIE_Sodium_Core32_Util::declareScalarType($high, 'int', 2);
+
+        $high = (int) $high;
+        $low = (int) $low;
+        return new ParagonIE_Sodium_Core32_Int64(
+            array(
+                (int) (($high >> 16) & 0xffff),
+                (int) ($high & 0xffff),
+                (int) (($low >> 16) & 0xffff),
+                (int) ($low & 0xffff)
+            )
+        );
+    }
+
+    /**
+     * @param int $low
+     * @return self
+     * @throws SodiumException
+     * @throws TypeError
+     */
+    public static function fromInt($low)
+    {
+        ParagonIE_Sodium_Core32_Util::declareScalarType($low, 'int', 1);
+        $low = (int) $low;
+
+        return new ParagonIE_Sodium_Core32_Int64(
+            array(
+                0,
+                0,
+                (int) (($low >> 16) & 0xffff),
+                (int) ($low & 0xffff)
+            )
+        );
+    }
+
+    /**
+     * @return int
+     */
+    public function toInt()
+    {
+        return (int) (
+            (($this->limbs[2] & 0xffff) << 16)
+                |
+            ($this->limbs[3] & 0xffff)
+        );
+    }
+
+    /**
+     * @param string $string
+     * @return self
+     * @throws SodiumException
+     * @throws TypeError
+     */
+    public static function fromString($string)
+    {
+        ParagonIE_Sodium_Core32_Util::declareScalarType($string, 'string', 1);
+        $string = (string) $string;
+        if (ParagonIE_Sodium_Core32_Util::strlen($string) !== 8) {
+            throw new RangeException(
+                'String must be 8 bytes; ' . ParagonIE_Sodium_Core32_Util::strlen($string) . ' given.'
+            );
+        }
+        $return = new ParagonIE_Sodium_Core32_Int64();
+
+        $return->limbs[0]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[0]) & 0xff) << 8);
+        $return->limbs[0] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[1]) & 0xff);
+        $return->limbs[1]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[2]) & 0xff) << 8);
+        $return->limbs[1] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[3]) & 0xff);
+        $return->limbs[2]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[4]) & 0xff) << 8);
+        $return->limbs[2] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[5]) & 0xff);
+        $return->limbs[3]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[6]) & 0xff) << 8);
+        $return->limbs[3] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[7]) & 0xff);
+        return $return;
+    }
+
+    /**
+     * @param string $string
+     * @return self
+     * @throws SodiumException
+     * @throws TypeError
+     */
+    public static function fromReverseString($string)
+    {
+        ParagonIE_Sodium_Core32_Util::declareScalarType($string, 'string', 1);
+        $string = (string) $string;
+        if (ParagonIE_Sodium_Core32_Util::strlen($string) !== 8) {
+            throw new RangeException(
+                'String must be 8 bytes; ' . ParagonIE_Sodium_Core32_Util::strlen($string) . ' given.'
+            );
+        }
+        $return = new ParagonIE_Sodium_Core32_Int64();
+
+        $return->limbs[0]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[7]) & 0xff) << 8);
+        $return->limbs[0] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[6]) & 0xff);
+        $return->limbs[1]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[5]) & 0xff) << 8);
+        $return->limbs[1] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[4]) & 0xff);
+        $return->limbs[2]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[3]) & 0xff) << 8);
+        $return->limbs[2] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[2]) & 0xff);
+        $return->limbs[3]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[1]) & 0xff) << 8);
+        $return->limbs[3] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[0]) & 0xff);
+        return $return;
+    }
+
+    /**
+     * @return array<int, int>
+     */
+    public function toArray()
+    {
+        return array(
+            (int) ((($this->limbs[0] & 0xffff) << 16) | ($this->limbs[1] & 0xffff)),
+            (int) ((($this->limbs[2] & 0xffff) << 16) | ($this->limbs[3] & 0xffff))
+        );
+    }
+
+    /**
+     * @return ParagonIE_Sodium_Core32_Int32
+     */
+    public function toInt32()
+    {
+        $return = new ParagonIE_Sodium_Core32_Int32();
+        $return->limbs[0] = (int) ($this->limbs[2]);
+        $return->limbs[1] = (int) ($this->limbs[3]);
+        $return->unsignedInt = $this->unsignedInt;
+        $return->overflow = (int) (ParagonIE_Sodium_Core32_Util::abs($this->limbs[1], 16) & 0xffff);
+        return $return;
+    }
+
+    /**
+     * @return ParagonIE_Sodium_Core32_Int64
+     */
+    public function toInt64()
+    {
+        $return = new ParagonIE_Sodium_Core32_Int64();
+        $return->limbs[0] = (int) ($this->limbs[0]);
+        $return->limbs[1] = (int) ($this->limbs[1]);
+        $return->limbs[2] = (int) ($this->limbs[2]);
+        $return->limbs[3] = (int) ($this->limbs[3]);
+        $return->unsignedInt = $this->unsignedInt;
+        $return->overflow = ParagonIE_Sodium_Core32_Util::abs($this->overflow);
+        return $return;
+    }
+
+    /**
+     * @param bool $bool
+     * @return self
+     */
+    public function setUnsignedInt($bool = false)
+    {
+        $this->unsignedInt = !empty($bool);
+        return $this;
+    }
+
+    /**
+     * @return string
+     * @throws TypeError
+     */
+    public function toString()
+    {
+        return ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[0] >> 8) & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[0] & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[1] >> 8) & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[1] & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[2] >> 8) & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[2] & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[3] >> 8) & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[3] & 0xff);
+    }
+
+    /**
+     * @return string
+     * @throws TypeError
+     */
+    public function toReverseString()
+    {
+        return ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[3] & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[3] >> 8) & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[2] & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[2] >> 8) & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[1] & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[1] >> 8) & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[0] & 0xff) .
+            ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[0] >> 8) & 0xff);
+    }
+
+    /**
+     * @return string
+     */
+    public function __toString()
+    {
+        try {
+            return $this->toString();
+        } catch (TypeError $ex) {
+            // PHP engine can't handle exceptions from __toString()
+            return '';
+        }
+    }
+}