3/28/2020, 10:36HEADmaster

1 files changed, 341 insertions, 0 deletions

diff --git a/includes/vendor/maxmind-db/reader/src/MaxMind/Db/Reader/Decoder.php b/includes/vendor/maxmind-db/reader/src/MaxMind/Db/Reader/Decoder.php
new file mode 100644
index 0000000..a71b3de
--- /dev/null
+++ b/includes/vendor/maxmind-db/reader/src/MaxMind/Db/Reader/Decoder.php
@@ -0,0 +1,341 @@
+<?php
+
+namespace MaxMind\Db\Reader;
+
+// @codingStandardsIgnoreLine
+// We subtract 1 from the log to protect against precision loss.
+\define(__NAMESPACE__ . '\_MM_MAX_INT_BYTES', (log(PHP_INT_MAX, 2) - 1) / 8);
+
+class Decoder
+{
+    private $fileStream;
+    private $pointerBase;
+    private $pointerBaseByteSize;
+    // This is only used for unit testing
+    private $pointerTestHack;
+    private $switchByteOrder;
+
+    const _EXTENDED = 0;
+    const _POINTER = 1;
+    const _UTF8_STRING = 2;
+    const _DOUBLE = 3;
+    const _BYTES = 4;
+    const _UINT16 = 5;
+    const _UINT32 = 6;
+    const _MAP = 7;
+    const _INT32 = 8;
+    const _UINT64 = 9;
+    const _UINT128 = 10;
+    const _ARRAY = 11;
+    const _CONTAINER = 12;
+    const _END_MARKER = 13;
+    const _BOOLEAN = 14;
+    const _FLOAT = 15;
+
+    public function __construct(
+        $fileStream,
+        $pointerBase = 0,
+        $pointerTestHack = false
+    ) {
+        $this->fileStream = $fileStream;
+        $this->pointerBase = $pointerBase;
+
+        $this->pointerBaseByteSize = $pointerBase > 0 ? log($pointerBase, 2) / 8 : 0;
+        $this->pointerTestHack = $pointerTestHack;
+
+        $this->switchByteOrder = $this->isPlatformLittleEndian();
+    }
+
+    public function decode($offset)
+    {
+        list(, $ctrlByte) = unpack(
+            'C',
+            Util::read($this->fileStream, $offset, 1)
+        );
+        ++$offset;
+
+        $type = $ctrlByte >> 5;
+
+        // Pointers are a special case, we don't read the next $size bytes, we
+        // use the size to determine the length of the pointer and then follow
+        // it.
+        if ($type === self::_POINTER) {
+            list($pointer, $offset) = $this->decodePointer($ctrlByte, $offset);
+
+            // for unit testing
+            if ($this->pointerTestHack) {
+                return [$pointer];
+            }
+
+            list($result) = $this->decode($pointer);
+
+            return [$result, $offset];
+        }
+
+        if ($type === self::_EXTENDED) {
+            list(, $nextByte) = unpack(
+                'C',
+                Util::read($this->fileStream, $offset, 1)
+            );
+
+            $type = $nextByte + 7;
+
+            if ($type < 8) {
+                throw new InvalidDatabaseException(
+                    'Something went horribly wrong in the decoder. An extended type '
+                    . 'resolved to a type number < 8 ('
+                    . $type
+                    . ')'
+                );
+            }
+
+            ++$offset;
+        }
+
+        list($size, $offset) = $this->sizeFromCtrlByte($ctrlByte, $offset);
+
+        return $this->decodeByType($type, $offset, $size);
+    }
+
+    private function decodeByType($type, $offset, $size)
+    {
+        switch ($type) {
+            case self::_MAP:
+                return $this->decodeMap($size, $offset);
+            case self::_ARRAY:
+                return $this->decodeArray($size, $offset);
+            case self::_BOOLEAN:
+                return [$this->decodeBoolean($size), $offset];
+        }
+
+        $newOffset = $offset + $size;
+        $bytes = Util::read($this->fileStream, $offset, $size);
+        switch ($type) {
+            case self::_BYTES:
+            case self::_UTF8_STRING:
+                return [$bytes, $newOffset];
+            case self::_DOUBLE:
+                $this->verifySize(8, $size);
+
+                return [$this->decodeDouble($bytes), $newOffset];
+            case self::_FLOAT:
+                $this->verifySize(4, $size);
+
+                return [$this->decodeFloat($bytes), $newOffset];
+            case self::_INT32:
+                return [$this->decodeInt32($bytes, $size), $newOffset];
+            case self::_UINT16:
+            case self::_UINT32:
+            case self::_UINT64:
+            case self::_UINT128:
+                return [$this->decodeUint($bytes, $size), $newOffset];
+            default:
+                throw new InvalidDatabaseException(
+                    'Unknown or unexpected type: ' . $type
+                );
+        }
+    }
+
+    private function verifySize($expected, $actual)
+    {
+        if ($expected !== $actual) {
+            throw new InvalidDatabaseException(
+                "The MaxMind DB file's data section contains bad data (unknown data type or corrupt data)"
+            );
+        }
+    }
+
+    private function decodeArray($size, $offset)
+    {
+        $array = [];
+
+        for ($i = 0; $i < $size; ++$i) {
+            list($value, $offset) = $this->decode($offset);
+            array_push($array, $value);
+        }
+
+        return [$array, $offset];
+    }
+
+    private function decodeBoolean($size)
+    {
+        return $size === 0 ? false : true;
+    }
+
+    private function decodeDouble($bits)
+    {
+        // This assumes IEEE 754 doubles, but most (all?) modern platforms
+        // use them.
+        //
+        // We are not using the "E" format as that was only added in
+        // 7.0.15 and 7.1.1. As such, we must switch byte order on
+        // little endian machines.
+        list(, $double) = unpack('d', $this->maybeSwitchByteOrder($bits));
+
+        return $double;
+    }
+
+    private function decodeFloat($bits)
+    {
+        // This assumes IEEE 754 floats, but most (all?) modern platforms
+        // use them.
+        //
+        // We are not using the "G" format as that was only added in
+        // 7.0.15 and 7.1.1. As such, we must switch byte order on
+        // little endian machines.
+        list(, $float) = unpack('f', $this->maybeSwitchByteOrder($bits));
+
+        return $float;
+    }
+
+    private function decodeInt32($bytes, $size)
+    {
+        switch ($size) {
+            case 0:
+                return 0;
+            case 1:
+            case 2:
+            case 3:
+                $bytes = str_pad($bytes, 4, "\x00", STR_PAD_LEFT);
+                break;
+            case 4:
+                break;
+            default:
+                throw new InvalidDatabaseException(
+                    "The MaxMind DB file's data section contains bad data (unknown data type or corrupt data)"
+                );
+        }
+
+        list(, $int) = unpack('l', $this->maybeSwitchByteOrder($bytes));
+
+        return $int;
+    }
+
+    private function decodeMap($size, $offset)
+    {
+        $map = [];
+
+        for ($i = 0; $i < $size; ++$i) {
+            list($key, $offset) = $this->decode($offset);
+            list($value, $offset) = $this->decode($offset);
+            $map[$key] = $value;
+        }
+
+        return [$map, $offset];
+    }
+
+    private function decodePointer($ctrlByte, $offset)
+    {
+        $pointerSize = (($ctrlByte >> 3) & 0x3) + 1;
+
+        $buffer = Util::read($this->fileStream, $offset, $pointerSize);
+        $offset = $offset + $pointerSize;
+
+        switch ($pointerSize) {
+            case 1:
+                $packed = (pack('C', $ctrlByte & 0x7)) . $buffer;
+                list(, $pointer) = unpack('n', $packed);
+                $pointer += $this->pointerBase;
+                break;
+            case 2:
+                $packed = "\x00" . (pack('C', $ctrlByte & 0x7)) . $buffer;
+                list(, $pointer) = unpack('N', $packed);
+                $pointer += $this->pointerBase + 2048;
+                break;
+            case 3:
+                $packed = (pack('C', $ctrlByte & 0x7)) . $buffer;
+
+                // It is safe to use 'N' here, even on 32 bit machines as the
+                // first bit is 0.
+                list(, $pointer) = unpack('N', $packed);
+                $pointer += $this->pointerBase + 526336;
+                break;
+            case 4:
+                // We cannot use unpack here as we might overflow on 32 bit
+                // machines
+                $pointerOffset = $this->decodeUint($buffer, $pointerSize);
+
+                $byteLength = $pointerSize + $this->pointerBaseByteSize;
+
+                if ($byteLength <= _MM_MAX_INT_BYTES) {
+                    $pointer = $pointerOffset + $this->pointerBase;
+                } elseif (\extension_loaded('gmp')) {
+                    $pointer = gmp_strval(gmp_add($pointerOffset, $this->pointerBase));
+                } elseif (\extension_loaded('bcmath')) {
+                    $pointer = bcadd($pointerOffset, $this->pointerBase);
+                } else {
+                    throw new \RuntimeException(
+                        'The gmp or bcmath extension must be installed to read this database.'
+                    );
+                }
+        }
+
+        return [$pointer, $offset];
+    }
+
+    private function decodeUint($bytes, $byteLength)
+    {
+        if ($byteLength === 0) {
+            return 0;
+        }
+
+        $integer = 0;
+
+        for ($i = 0; $i < $byteLength; ++$i) {
+            $part = \ord($bytes[$i]);
+
+            // We only use gmp or bcmath if the final value is too big
+            if ($byteLength <= _MM_MAX_INT_BYTES) {
+                $integer = ($integer << 8) + $part;
+            } elseif (\extension_loaded('gmp')) {
+                $integer = gmp_strval(gmp_add(gmp_mul($integer, 256), $part));
+            } elseif (\extension_loaded('bcmath')) {
+                $integer = bcadd(bcmul($integer, 256), $part);
+            } else {
+                throw new \RuntimeException(
+                    'The gmp or bcmath extension must be installed to read this database.'
+                );
+            }
+        }
+
+        return $integer;
+    }
+
+    private function sizeFromCtrlByte($ctrlByte, $offset)
+    {
+        $size = $ctrlByte & 0x1f;
+
+        if ($size < 29) {
+            return [$size, $offset];
+        }
+
+        $bytesToRead = $size - 28;
+        $bytes = Util::read($this->fileStream, $offset, $bytesToRead);
+
+        if ($size === 29) {
+            $size = 29 + \ord($bytes);
+        } elseif ($size === 30) {
+            list(, $adjust) = unpack('n', $bytes);
+            $size = 285 + $adjust;
+        } elseif ($size > 30) {
+            list(, $adjust) = unpack('N', "\x00" . $bytes);
+            $size = ($adjust & (0x0FFFFFFF >> (32 - (8 * $bytesToRead))))
+                + 65821;
+        }
+
+        return [$size, $offset + $bytesToRead];
+    }
+
+    private function maybeSwitchByteOrder($bytes)
+    {
+        return $this->switchByteOrder ? strrev($bytes) : $bytes;
+    }
+
+    private function isPlatformLittleEndian()
+    {
+        $testint = 0x00FF;
+        $packed = pack('S', $testint);
+
+        return $testint === current(unpack('v', $packed));
+    }
+}