diff --git a/extlib/ParagonIE/ConstantTime/Base32.php b/extlib/ParagonIE/ConstantTime/Base32.php
new file mode 100644
index 0000000000..a65c1c7343
--- /dev/null
+++ b/extlib/ParagonIE/ConstantTime/Base32.php
@@ -0,0 +1,396 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+/**
+ *  Copyright (c) 2016 Paragon Initiative Enterprises.
+ *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+/**
+ * Class Base32
+ * [A-Z][2-7]
+ *
+ * @package ParagonIE\ConstantTime
+ */
+abstract class Base32 implements EncoderInterface
+{
+    /**
+     * Decode a Base32-encoded string into raw binary
+     *
+     * @param string $src
+     * @return string
+     */
+    public static function decode(string $src, bool $strictPadding = false): string
+    {
+        return static::doDecode($src, false, $strictPadding);
+    }
+
+    /**
+     * Decode an uppercase Base32-encoded string into raw binary
+     *
+     * @param string $src
+     * @return string
+     */
+    public static function decodeUpper(string $src, bool $strictPadding = false): string
+    {
+        return static::doDecode($src, true, $strictPadding);
+    }
+
+    /**
+     * Encode into Base32 (RFC 4648)
+     *
+     * @param string $src
+     * @return string
+     */
+    public static function encode(string $src): string
+    {
+        return static::doEncode($src, false);
+    }
+
+    /**
+     * Encode into uppercase Base32 (RFC 4648)
+     *
+     * @param string $src
+     * @return string
+     */
+    public static function encodeUpper(string $src): string
+    {
+        return static::doEncode($src, true);
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 5-bit integers
+     * into 8-bit integers.
+     *
+     * @param int $src
+     * @return int
+     */
+    protected static function decode5Bits(int $src): int
+    {
+        $ret = -1;
+
+        // if ($src > 96 && $src < 123) $ret += $src - 97 + 1; // -64
+        $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 96);
+
+        // if ($src > 0x31 && $src < 0x38) $ret += $src - 24 + 1; // -23
+        $ret += (((0x31 - $src) & ($src - 0x38)) >> 8) & ($src - 23);
+
+        return $ret;
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 5-bit integers
+     * into 8-bit integers.
+     *
+     * Uppercase variant.
+     *
+     * @param int $src
+     * @return int
+     */
+    protected static function decode5BitsUpper(int $src): int
+    {
+        $ret = -1;
+
+        // if ($src > 64 && $src < 91) $ret += $src - 65 + 1; // -64
+        $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 64);
+
+        // if ($src > 0x31 && $src < 0x38) $ret += $src - 24 + 1; // -23
+        $ret += (((0x31 - $src) & ($src - 0x38)) >> 8) & ($src - 23);
+
+        return $ret;
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
+     * into 5-bit integers.
+     *
+     * @param $src
+     * @return string
+     */
+    protected static function encode5Bits(int $src): string
+    {
+        $diff = 0x61;
+
+        // if ($src > 25) $ret -= 72;
+        $diff -= ((25 - $src) >> 8) & 73;
+
+        return \pack('C', $src + $diff);
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
+     * into 5-bit integers.
+     *
+     * Uppercase variant.
+     *
+     * @param $src
+     * @return string
+     */
+    protected static function encode5BitsUpper(int $src): string
+    {
+        $diff = 0x41;
+
+        // if ($src > 25) $ret -= 40;
+        $diff -= ((25 - $src) >> 8) & 41;
+
+        return \pack('C', $src + $diff);
+    }
+
+
+    /**
+     * Base32 decoding
+     *
+     * @param string $src
+     * @param bool $upper
+     * @param bool $strictPadding
+     * @return string
+     */
+    protected static function doDecode(string $src, bool $upper = false, bool $strictPadding = false): string
+    {
+        // We do this to reduce code duplication:
+        $method = $upper
+            ? 'decode5BitsUpper'
+            : 'decode5Bits';
+
+        // Remove padding
+        $srcLen = Binary::safeStrlen($src);
+        if ($srcLen === 0) {
+            return '';
+        }
+        if ($strictPadding) {
+            if (($srcLen & 7) === 0) {
+                for ($j = 0; $j < 7; ++$j) {
+                    if ($src[$srcLen - 1] === '=') {
+                        $srcLen--;
+                    } else {
+                        break;
+                    }
+                }
+            }
+            if (($srcLen & 7) === 1) {
+                throw new \RangeException(
+                    'Incorrect padding'
+                );
+            }
+        } else {
+            $src = \rtrim($src, '=');
+            $srcLen = Binary::safeStrlen($src);
+        }
+
+        $err = 0;
+        $dest = '';
+        // Main loop (no padding):
+        for ($i = 0; $i + 8 <= $srcLen; $i += 8) {
+            $chunk = \unpack('C*', Binary::safeSubstr($src, $i, 8));
+            $c0 = static::$method($chunk[1]);
+            $c1 = static::$method($chunk[2]);
+            $c2 = static::$method($chunk[3]);
+            $c3 = static::$method($chunk[4]);
+            $c4 = static::$method($chunk[5]);
+            $c5 = static::$method($chunk[6]);
+            $c6 = static::$method($chunk[7]);
+            $c7 = static::$method($chunk[8]);
+
+            $dest .= \pack(
+                'CCCCC',
+                (($c0 << 3) | ($c1 >> 2)             ) & 0xff,
+                (($c1 << 6) | ($c2 << 1) | ($c3 >> 4)) & 0xff,
+                (($c3 << 4) | ($c4 >> 1)             ) & 0xff,
+                (($c4 << 7) | ($c5 << 2) | ($c6 >> 3)) & 0xff,
+                (($c6 << 5) | ($c7     )             ) & 0xff
+            );
+            $err |= ($c0 | $c1 | $c2 | $c3 | $c4 | $c5 | $c6 | $c7) >> 8;
+        }
+        // The last chunk, which may have padding:
+        if ($i < $srcLen) {
+            $chunk = \unpack('C*', Binary::safeSubstr($src, $i, $srcLen - $i));
+            $c0 = static::$method($chunk[1]);
+
+            if ($i + 6 < $srcLen) {
+                $c1 = static::$method($chunk[2]);
+                $c2 = static::$method($chunk[3]);
+                $c3 = static::$method($chunk[4]);
+                $c4 = static::$method($chunk[5]);
+                $c5 = static::$method($chunk[6]);
+                $c6 = static::$method($chunk[7]);
+
+                $dest .= \pack(
+                    'CCCC',
+                    (($c0 << 3) | ($c1 >> 2)             ) & 0xff,
+                    (($c1 << 6) | ($c2 << 1) | ($c3 >> 4)) & 0xff,
+                    (($c3 << 4) | ($c4 >> 1)             ) & 0xff,
+                    (($c4 << 7) | ($c5 << 2) | ($c6 >> 3)) & 0xff
+                );
+                $err |= ($c0 | $c1 | $c2 | $c3 | $c4 | $c5 | $c6) >> 8;
+            } elseif ($i + 5 < $srcLen) {
+                $c1 = static::$method($chunk[2]);
+                $c2 = static::$method($chunk[3]);
+                $c3 = static::$method($chunk[4]);
+                $c4 = static::$method($chunk[5]);
+                $c5 = static::$method($chunk[6]);
+
+                $dest .= \pack(
+                    'CCCC',
+                    (($c0 << 3) | ($c1 >> 2)             ) & 0xff,
+                    (($c1 << 6) | ($c2 << 1) | ($c3 >> 4)) & 0xff,
+                    (($c3 << 4) | ($c4 >> 1)             ) & 0xff,
+                    (($c4 << 7) | ($c5 << 2)             ) & 0xff
+                );
+                $err |= ($c0 | $c1 | $c2 | $c3 | $c4 | $c5) >> 8;
+            } elseif ($i + 4 < $srcLen) {
+                $c1 = static::$method($chunk[2]);
+                $c2 = static::$method($chunk[3]);
+                $c3 = static::$method($chunk[4]);
+                $c4 = static::$method($chunk[5]);
+
+                $dest .= \pack(
+                    'CCC',
+                    (($c0 << 3) | ($c1 >> 2)             ) & 0xff,
+                    (($c1 << 6) | ($c2 << 1) | ($c3 >> 4)) & 0xff,
+                    (($c3 << 4) | ($c4 >> 1)             ) & 0xff
+                );
+                $err |= ($c0 | $c1 | $c2 | $c3 | $c4) >> 8;
+            } elseif ($i + 3 < $srcLen) {
+                $c1 = static::$method($chunk[2]);
+                $c2 = static::$method($chunk[3]);
+                $c3 = static::$method($chunk[4]);
+
+                $dest .= \pack(
+                    'CC',
+                    (($c0 << 3) | ($c1 >> 2)             ) & 0xff,
+                    (($c1 << 6) | ($c2 << 1) | ($c3 >> 4)) & 0xff
+                );
+                $err |= ($c0 | $c1 | $c2 | $c3) >> 8;
+            } elseif ($i + 2 < $srcLen) {
+                $c1 = static::$method($chunk[2]);
+                $c2 = static::$method($chunk[3]);
+
+                $dest .= \pack(
+                    'CC',
+                    (($c0 << 3) | ($c1 >> 2)             ) & 0xff,
+                    (($c1 << 6) | ($c2 << 1)             ) & 0xff
+                );
+                $err |= ($c0 | $c1 | $c2) >> 8;
+            } elseif ($i + 1 < $srcLen) {
+                $c1 = static::$method($chunk[2]);
+
+                $dest .= \pack(
+                    'C',
+                    (($c0 << 3) | ($c1 >> 2)             ) & 0xff
+                );
+                $err |= ($c0 | $c1) >> 8;
+            } else {
+                $dest .= \pack(
+                    'C',
+                    (($c0 << 3)                          ) & 0xff
+                );
+                $err |= ($c0) >> 8;
+            }
+        }
+        if ($err !== 0) {
+            throw new \RangeException(
+                'Base32::doDecode() only expects characters in the correct base32 alphabet'
+            );
+        }
+        return $dest;
+    }
+
+    /**
+     * Base32 Decoding
+     *
+     * @param string $src
+     * @param bool $upper
+     * @return string
+     */
+    protected static function doEncode(string $src, bool $upper = false): string
+    {
+        // We do this to reduce code duplication:
+        $method = $upper
+            ? 'encode5BitsUpper'
+            : 'encode5Bits';
+        
+        $dest = '';
+        $srcLen = Binary::safeStrlen($src);
+
+        // Main loop (no padding):
+        for ($i = 0; $i + 5 <= $srcLen; $i += 5) {
+            $chunk = \unpack('C*', Binary::safeSubstr($src, $i, 5));
+            $b0 = $chunk[1];
+            $b1 = $chunk[2];
+            $b2 = $chunk[3];
+            $b3 = $chunk[4];
+            $b4 = $chunk[5];
+            $dest .=
+                static::$method(              ($b0 >> 3)  & 31) .
+                static::$method((($b0 << 2) | ($b1 >> 6)) & 31) .
+                static::$method((($b1 >> 1)             ) & 31) .
+                static::$method((($b1 << 4) | ($b2 >> 4)) & 31) .
+                static::$method((($b2 << 1) | ($b3 >> 7)) & 31) .
+                static::$method((($b3 >> 2)             ) & 31) .
+                static::$method((($b3 << 3) | ($b4 >> 5)) & 31) .
+                static::$method(  $b4                     & 31);
+        }
+        // The last chunk, which may have padding:
+        if ($i < $srcLen) {
+            $chunk = \unpack('C*', Binary::safeSubstr($src, $i, $srcLen - $i));
+            $b0 = $chunk[1];
+            if ($i + 3 < $srcLen) {
+                $b1 = $chunk[2];
+                $b2 = $chunk[3];
+                $b3 = $chunk[4];
+                $dest .=
+                    static::$method(              ($b0 >> 3)  & 31) .
+                    static::$method((($b0 << 2) | ($b1 >> 6)) & 31) .
+                    static::$method((($b1 >> 1)             ) & 31) .
+                    static::$method((($b1 << 4) | ($b2 >> 4)) & 31) .
+                    static::$method((($b2 << 1) | ($b3 >> 7)) & 31) .
+                    static::$method((($b3 >> 2)             ) & 31) .
+                    static::$method((($b3 << 3)             ) & 31) .
+                    '=';
+            } elseif ($i + 2 < $srcLen) {
+                $b1 = $chunk[2];
+                $b2 = $chunk[3];
+                $dest .=
+                    static::$method(              ($b0 >> 3)  & 31) .
+                    static::$method((($b0 << 2) | ($b1 >> 6)) & 31) .
+                    static::$method((($b1 >> 1)             ) & 31) .
+                    static::$method((($b1 << 4) | ($b2 >> 4)) & 31) .
+                    static::$method((($b2 << 1)             ) & 31) .
+                    '===';
+            } elseif ($i + 1 < $srcLen) {
+                $b1 = $chunk[2];
+                $dest .=
+                    static::$method(              ($b0 >> 3)  & 31) .
+                    static::$method((($b0 << 2) | ($b1 >> 6)) & 31) .
+                    static::$method((($b1 >> 1)             ) & 31) .
+                    static::$method((($b1 << 4)             ) & 31) .
+                    '====';
+            } else {
+                $dest .=
+                    static::$method(              ($b0 >> 3)  & 31) .
+                    static::$method( ($b0 << 2)               & 31) .
+                    '======';
+            }
+        }
+        return $dest;
+    }
+}
diff --git a/extlib/ParagonIE/ConstantTime/Base32Hex.php b/extlib/ParagonIE/ConstantTime/Base32Hex.php
new file mode 100644
index 0000000000..5aff0a6b3a
--- /dev/null
+++ b/extlib/ParagonIE/ConstantTime/Base32Hex.php
@@ -0,0 +1,111 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+/**
+ *  Copyright (c) 2016 Paragon Initiative Enterprises.
+ *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+/**
+ * Class Base32Hex
+ * [0-9][A-V]
+ *
+ * @package ParagonIE\ConstantTime
+ */
+abstract class Base32Hex extends Base32
+{
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 5-bit integers
+     * into 8-bit integers.
+     *
+     * @param int $src
+     * @return int
+     */
+    protected static function decode5Bits(int $src): int
+    {
+        $ret = -1;
+
+        // if ($src > 0x30 && $src < 0x3a) ret += $src - 0x2e + 1; // -47
+        $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src - 47);
+
+        // if ($src > 0x60 && $src < 0x77) ret += $src - 0x61 + 10 + 1; // -86
+        $ret += (((0x60 - $src) & ($src - 0x77)) >> 8) & ($src - 86);
+
+        return $ret;
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 5-bit integers
+     * into 8-bit integers.
+     *
+     * @param int $src
+     * @return int
+     */
+    protected static function decode5BitsUpper(int $src): int
+    {
+        $ret = -1;
+
+        // if ($src > 0x30 && $src < 0x3a) ret += $src - 0x2e + 1; // -47
+        $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src - 47);
+
+        // if ($src > 0x40 && $src < 0x57) ret += $src - 0x41 + 10 + 1; // -54
+        $ret += (((0x40 - $src) & ($src - 0x57)) >> 8) & ($src - 54);
+
+        return $ret;
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
+     * into 5-bit integers.
+     *
+     * @param int $src
+     * @return string
+     */
+    protected static function encode5Bits(int $src): string
+    {
+        $src += 0x30;
+
+        // if ($src > 0x39) $src += 0x61 - 0x3a; // 39
+        $src += ((0x39 - $src) >> 8) & 39;
+
+        return \pack('C', $src);
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
+     * into 5-bit integers.
+     *
+     * Uppercase variant.
+     *
+     * @param int $src
+     * @return string
+     */
+    protected static function encode5BitsUpper(int $src): string
+    {
+        $src += 0x30;
+
+        // if ($src > 0x39) $src += 0x41 - 0x3a; // 7
+        $src += ((0x39 - $src) >> 8) & 7;
+
+        return \pack('C', $src);
+    }
+}
\ No newline at end of file
diff --git a/extlib/ParagonIE/ConstantTime/Base64.php b/extlib/ParagonIE/ConstantTime/Base64.php
new file mode 100644
index 0000000000..df801cc8ec
--- /dev/null
+++ b/extlib/ParagonIE/ConstantTime/Base64.php
@@ -0,0 +1,229 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+/**
+ *  Copyright (c) 2016 Paragon Initiative Enterprises.
+ *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+/**
+ * Class Base64
+ * [A-Z][a-z][0-9]+/
+ *
+ * @package ParagonIE\ConstantTime
+ */
+abstract class Base64 implements EncoderInterface
+{
+    /**
+     * Encode into Base64
+     *
+     * Base64 character set "[A-Z][a-z][0-9]+/"
+     *
+     * @param string $src
+     * @return string
+     */
+    public static function encode(string $src): string
+    {
+        $dest = '';
+        $srcLen = Binary::safeStrlen($src);
+        // Main loop (no padding):
+        for ($i = 0; $i + 3 <= $srcLen; $i += 3) {
+            $chunk = \unpack('C*', Binary::safeSubstr($src, $i, 3));
+            $b0 = $chunk[1];
+            $b1 = $chunk[2];
+            $b2 = $chunk[3];
+
+            $dest .=
+                static::encode6Bits(               $b0 >> 2       ) .
+                static::encode6Bits((($b0 << 4) | ($b1 >> 4)) & 63) .
+                static::encode6Bits((($b1 << 2) | ($b2 >> 6)) & 63) .
+                static::encode6Bits(  $b2                     & 63);
+        }
+        // The last chunk, which may have padding:
+        if ($i < $srcLen) {
+            $chunk = \unpack('C*', Binary::safeSubstr($src, $i, $srcLen - $i));
+            $b0 = $chunk[1];
+            if ($i + 1 < $srcLen) {
+                $b1 = $chunk[2];
+                $dest .=
+                    static::encode6Bits(               $b0 >> 2       ) .
+                    static::encode6Bits((($b0 << 4) | ($b1 >> 4)) & 63) .
+                    static::encode6Bits( ($b1 << 2)               & 63) . '=';
+            } else {
+                $dest .=
+                    static::encode6Bits( $b0 >> 2) .
+                    static::encode6Bits(($b0 << 4) & 63) . '==';
+            }
+        }
+        return $dest;
+    }
+
+    /**
+     * decode from base64 into binary
+     *
+     * Base64 character set "./[A-Z][a-z][0-9]"
+     *
+     * @param string $src
+     * @param bool $strictPadding
+     * @return string|bool
+     * @throws \RangeException
+     */
+    public static function decode(string $src, bool $strictPadding = false): string
+    {
+        // Remove padding
+        $srcLen = Binary::safeStrlen($src);
+        if ($srcLen === 0) {
+            return '';
+        }
+
+        if ($strictPadding) {
+            if (($srcLen & 3) === 0) {
+                if ($src[$srcLen - 1] === '=') {
+                    $srcLen--;
+                    if ($src[$srcLen - 1] === '=') {
+                        $srcLen--;
+                    }
+                }
+            }
+            if (($srcLen & 3) === 1) {
+                throw new \RangeException(
+                    'Incorrect padding'
+                );
+            }
+            if ($src[$srcLen - 1] === '=') {
+                throw new \RangeException(
+                    'Incorrect padding'
+                );
+            }
+        } else {
+            $src = \rtrim($src, '=');
+            $srcLen = Binary::safeStrlen($src);
+        }
+
+        $err = 0;
+        $dest = '';
+        // Main loop (no padding):
+        for ($i = 0; $i + 4 <= $srcLen; $i += 4) {
+            $chunk = \unpack('C*', Binary::safeSubstr($src, $i, 4));
+            $c0 = static::decode6Bits($chunk[1]);
+            $c1 = static::decode6Bits($chunk[2]);
+            $c2 = static::decode6Bits($chunk[3]);
+            $c3 = static::decode6Bits($chunk[4]);
+
+            $dest .= \pack(
+                'CCC',
+                ((($c0 << 2) | ($c1 >> 4)) & 0xff),
+                ((($c1 << 4) | ($c2 >> 2)) & 0xff),
+                ((($c2 << 6) |  $c3      ) & 0xff)
+            );
+            $err |= ($c0 | $c1 | $c2 | $c3) >> 8;
+        }
+        // The last chunk, which may have padding:
+        if ($i < $srcLen) {
+            $chunk = \unpack('C*', Binary::safeSubstr($src, $i, $srcLen - $i));
+            $c0 = static::decode6Bits($chunk[1]);
+
+            if ($i + 2 < $srcLen) {
+                $c1 = static::decode6Bits($chunk[2]);
+                $c2 = static::decode6Bits($chunk[3]);
+                $dest .= \pack(
+                    'CC',
+                    ((($c0 << 2) | ($c1 >> 4)) & 0xff),
+                    ((($c1 << 4) | ($c2 >> 2)) & 0xff)
+                );
+                $err |= ($c0 | $c1 | $c2) >> 8;
+            } elseif ($i + 1 < $srcLen) {
+                $c1 = static::decode6Bits($chunk[2]);
+                $dest .= \pack(
+                    'C',
+                    ((($c0 << 2) | ($c1 >> 4)) & 0xff)
+                );
+                $err |= ($c0 | $c1) >> 8;
+            } elseif ($i < $srcLen && $strictPadding) {
+                $err |= 1;
+            }
+        }
+        if ($err !== 0) {
+            return false;
+        }
+        return $dest;
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 6-bit integers
+     * into 8-bit integers.
+     *
+     * Base64 character set:
+     * [A-Z]      [a-z]      [0-9]      +     /
+     * 0x41-0x5a, 0x61-0x7a, 0x30-0x39, 0x2b, 0x2f
+     *
+     * @param int $src
+     * @return int
+     */
+    protected static function decode6Bits(int $src): int
+    {
+        $ret = -1;
+
+        // if ($src > 0x40 && $src < 0x5b) $ret += $src - 0x41 + 1; // -64
+        $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 64);
+
+        // if ($src > 0x60 && $src < 0x7b) $ret += $src - 0x61 + 26 + 1; // -70
+        $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 70);
+
+        // if ($src > 0x2f && $src < 0x3a) $ret += $src - 0x30 + 52 + 1; // 5
+        $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src + 5);
+
+        // if ($src == 0x2b) $ret += 62 + 1;
+        $ret += (((0x2a - $src) & ($src - 0x2c)) >> 8) & 63;
+
+        // if ($src == 0x2f) ret += 63 + 1;
+        $ret += (((0x2e - $src) & ($src - 0x30)) >> 8) & 64;
+
+        return $ret;
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
+     * into 6-bit integers.
+     *
+     * @param int $src
+     * @return string
+     */
+    protected static function encode6Bits(int $src): string
+    {
+        $diff = 0x41;
+
+        // if ($src > 25) $diff += 0x61 - 0x41 - 26; // 6
+        $diff += ((25 - $src) >> 8) & 6;
+
+        // if ($src > 51) $diff += 0x30 - 0x61 - 26; // -75
+        $diff -= ((51 - $src) >> 8) & 75;
+
+        // if ($src > 61) $diff += 0x2b - 0x30 - 10; // -15
+        $diff -= ((61 - $src) >> 8) & 15;
+
+        // if ($src > 62) $diff += 0x2f - 0x2b - 1; // 3
+        $diff += ((62 - $src) >> 8) & 3;
+
+        return \pack('C', $src + $diff);
+    }
+}
diff --git a/extlib/ParagonIE/ConstantTime/Base64DotSlash.php b/extlib/ParagonIE/ConstantTime/Base64DotSlash.php
new file mode 100644
index 0000000000..7f975139b1
--- /dev/null
+++ b/extlib/ParagonIE/ConstantTime/Base64DotSlash.php
@@ -0,0 +1,88 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+/**
+ *  Copyright (c) 2016 Paragon Initiative Enterprises.
+ *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+/**
+ * Class Base64DotSlash
+ * ./[A-Z][a-z][0-9]
+ *
+ * @package ParagonIE\ConstantTime
+ */
+abstract class Base64DotSlash extends Base64
+{
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 6-bit integers
+     * into 8-bit integers.
+     *
+     * Base64 character set:
+     * ./         [A-Z]      [a-z]     [0-9]
+     * 0x2e-0x2f, 0x41-0x5a, 0x61-0x7a, 0x30-0x39
+     *
+     * @param int $src
+     * @return int
+     */
+    protected static function decode6Bits(int $src): int
+    {
+        $ret = -1;
+
+        // if ($src > 0x2d && $src < 0x30) ret += $src - 0x2e + 1; // -45
+        $ret += (((0x2d - $src) & ($src - 0x30)) >> 8) & ($src - 45);
+
+        // if ($src > 0x40 && $src < 0x5b) ret += $src - 0x41 + 2 + 1; // -62
+        $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 62);
+
+        // if ($src > 0x60 && $src < 0x7b) ret += $src - 0x61 + 28 + 1; // -68
+        $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 68);
+
+        // if ($src > 0x2f && $src < 0x3a) ret += $src - 0x30 + 54 + 1; // 7
+        $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src + 7);
+
+        return $ret;
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
+     * into 6-bit integers.
+     *
+     * @param int $src
+     * @return string
+     */
+    protected static function encode6Bits(int $src): string
+    {
+        $src += 0x2e;
+
+        // if ($src > 0x2f) $src += 0x41 - 0x30; // 17
+        $src += ((0x2f - $src) >> 8) & 17;
+
+        // if ($src > 0x5a) $src += 0x61 - 0x5b; // 6
+        $src += ((0x5a - $src) >> 8) & 6;
+
+        // if ($src > 0x7a) $src += 0x30 - 0x7b; // -75
+        $src -= ((0x7a - $src) >> 8) & 75;
+
+        return \pack('C', $src);
+    }
+}
diff --git a/extlib/ParagonIE/ConstantTime/Base64DotSlashOrdered.php b/extlib/ParagonIE/ConstantTime/Base64DotSlashOrdered.php
new file mode 100644
index 0000000000..3fb4209e68
--- /dev/null
+++ b/extlib/ParagonIE/ConstantTime/Base64DotSlashOrdered.php
@@ -0,0 +1,82 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+/**
+ *  Copyright (c) 2016 Paragon Initiative Enterprises.
+ *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+/**
+ * Class Base64DotSlashOrdered
+ * ./[0-9][A-Z][a-z]
+ *
+ * @package ParagonIE\ConstantTime
+ */
+abstract class Base64DotSlashOrdered extends Base64
+{
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 6-bit integers
+     * into 8-bit integers.
+     *
+     * Base64 character set:
+     * [.-9]      [A-Z]      [a-z]
+     * 0x2e-0x39, 0x41-0x5a, 0x61-0x7a
+     *
+     * @param int $src
+     * @return int
+     */
+    protected static function decode6Bits(int $src): int
+    {
+        $ret = -1;
+
+        // if ($src > 0x2d && $src < 0x3a) ret += $src - 0x2e + 1; // -45
+        $ret += (((0x2d - $src) & ($src - 0x3a)) >> 8) & ($src - 45);
+
+        // if ($src > 0x40 && $src < 0x5b) ret += $src - 0x41 + 12 + 1; // -52
+        $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 52);
+
+        // if ($src > 0x60 && $src < 0x7b) ret += $src - 0x61 + 38 + 1; // -58
+        $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 58);
+
+        return $ret;
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
+     * into 6-bit integers.
+     *
+     * @param int $src
+     * @return string
+     */
+    protected static function encode6Bits(int $src): string
+    {
+        $src += 0x2e;
+
+        // if ($src > 0x39) $src += 0x41 - 0x3a; // 7
+        $src += ((0x39 - $src) >> 8) & 7;
+
+        // if ($src > 0x5a) $src += 0x61 - 0x5b; // 6
+        $src += ((0x5a - $src) >> 8) & 6;
+
+        return \pack('C', $src);
+    }
+}
diff --git a/extlib/ParagonIE/ConstantTime/Base64UrlSafe.php b/extlib/ParagonIE/ConstantTime/Base64UrlSafe.php
new file mode 100644
index 0000000000..f250095d18
--- /dev/null
+++ b/extlib/ParagonIE/ConstantTime/Base64UrlSafe.php
@@ -0,0 +1,95 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+/**
+ *  Copyright (c) 2016 Paragon Initiative Enterprises.
+ *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+/**
+ * Class Base64DotSlash
+ * ./[A-Z][a-z][0-9]
+ *
+ * @package ParagonIE\ConstantTime
+ */
+abstract class Base64UrlSafe extends Base64
+{
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 6-bit integers
+     * into 8-bit integers.
+     *
+     * Base64 character set:
+     * [A-Z]      [a-z]      [0-9]      -     _
+     * 0x41-0x5a, 0x61-0x7a, 0x30-0x39, 0x2d, 0x5f
+     *
+     * @param int $src
+     * @return int
+     */
+    protected static function decode6Bits(int $src): int
+    {
+        $ret = -1;
+
+        // if ($src > 0x40 && $src < 0x5b) $ret += $src - 0x41 + 1; // -64
+        $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 64);
+
+        // if ($src > 0x60 && $src < 0x7b) $ret += $src - 0x61 + 26 + 1; // -70
+        $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 70);
+
+        // if ($src > 0x2f && $src < 0x3a) $ret += $src - 0x30 + 52 + 1; // 5
+        $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src + 5);
+
+        // if ($src == 0x2c) $ret += 62 + 1;
+        $ret += (((0x2c - $src) & ($src - 0x2e)) >> 8) & 63;
+
+        // if ($src == 0x5f) ret += 63 + 1;
+        $ret += (((0x5e - $src) & ($src - 0x60)) >> 8) & 64;
+
+        return $ret;
+    }
+
+    /**
+     * Uses bitwise operators instead of table-lookups to turn 8-bit integers
+     * into 6-bit integers.
+     *
+     * @param int $src
+     * @return string
+     */
+    protected static function encode6Bits(int $src): string
+    {
+        $diff = 0x41;
+
+        // if ($src > 25) $diff += 0x61 - 0x41 - 26; // 6
+        $diff += ((25 - $src) >> 8) & 6;
+
+        // if ($src > 51) $diff += 0x30 - 0x61 - 26; // -75
+        $diff -= ((51 - $src) >> 8) & 75;
+
+        // if ($src > 61) $diff += 0x2d - 0x30 - 10; // -13
+        $diff -= ((61 - $src) >> 8) & 13;
+
+        // if ($src > 62) $diff += 0x5f - 0x2b - 1; // 3
+        $diff += ((62 - $src) >> 8) & 49;
+
+        return \pack('C', $src + $diff);
+    }
+}
diff --git a/extlib/ParagonIE/ConstantTime/Binary.php b/extlib/ParagonIE/ConstantTime/Binary.php
new file mode 100644
index 0000000000..1028e66eda
--- /dev/null
+++ b/extlib/ParagonIE/ConstantTime/Binary.php
@@ -0,0 +1,98 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+/**
+ *  Copyright (c) 2016 Paragon Initiative Enterprises.
+ *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+/**
+ * Class Binary
+ *
+ * Binary string operators that don't choke on
+ * mbstring.func_overload
+ *
+ * @package ParagonIE\ConstantTime
+ */
+abstract class Binary
+{
+    /**
+     * Safe string length
+     *
+     * @ref mbstring.func_overload
+     *
+     * @param string $str
+     * @return int
+     */
+    public static function safeStrlen(string $str): int
+    {
+        if (\function_exists('mb_strlen')) {
+            return \mb_strlen($str, '8bit');
+        } else {
+            return \strlen($str);
+        }
+    }
+
+    /**
+     * Safe substring
+     *
+     * @ref mbstring.func_overload
+     *
+     * @staticvar boolean $exists
+     * @param string $str
+     * @param int $start
+     * @param int $length
+     * @return string
+     * @throws \TypeError
+     */
+    public static function safeSubstr(
+        string $str,
+        int $start = 0,
+        $length = null
+    ): string {
+        if (\function_exists('mb_substr')) {
+            // mb_substr($str, 0, NULL, '8bit') returns an empty string on PHP
+            // 5.3, so we have to find the length ourselves.
+            if ($length === null) {
+                if ($start >= 0) {
+                    $length = self::safeStrlen($str) - $start;
+                } else {
+                    $length = -$start;
+                }
+            }
+            // $length calculation above might result in a 0-length string
+            if ($length === 0) {
+                return '';
+            }
+            return \mb_substr($str, $start, $length, '8bit');
+        }
+        if ($length === 0) {
+            return '';
+        }
+        // Unlike mb_substr(), substr() doesn't accept NULL for length
+        if ($length !== null) {
+            return \substr($str, $start, $length);
+        } else {
+            return \substr($str, $start);
+        }
+    }
+}
\ No newline at end of file
diff --git a/extlib/ParagonIE/ConstantTime/EncoderInterface.php b/extlib/ParagonIE/ConstantTime/EncoderInterface.php
new file mode 100644
index 0000000000..ca699168d2
--- /dev/null
+++ b/extlib/ParagonIE/ConstantTime/EncoderInterface.php
@@ -0,0 +1,52 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+/**
+ *  Copyright (c) 2016 Paragon Initiative Enterprises.
+ *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+/**
+ * Interface EncoderInterface
+ * @package ParagonIE\ConstantTime
+ */
+interface EncoderInterface
+{
+    /**
+     * Convert a binary string into a hexadecimal string without cache-timing
+     * leaks
+     *
+     * @param string $binString (raw binary)
+     * @return string
+     */
+    public static function encode(string $binString): string;
+
+    /**
+     * Convert a binary string into a hexadecimal string without cache-timing
+     * leaks
+     *
+     * @param string $encodedString
+     * @param bool $strictPadding Error on invalid padding
+     * @return string (raw binary)
+     */
+    public static function decode(string $encodedString, bool $strictPadding = false): string;
+}
diff --git a/extlib/ParagonIE/ConstantTime/Encoding.php b/extlib/ParagonIE/ConstantTime/Encoding.php
new file mode 100644
index 0000000000..8ea8aec498
--- /dev/null
+++ b/extlib/ParagonIE/ConstantTime/Encoding.php
@@ -0,0 +1,245 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+/**
+ *  Copyright (c) 2016 Paragon Initiative Enterprises.
+ *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+/**
+ * Class Encoding
+ * @package ParagonIE\ConstantTime
+ */
+abstract class Encoding
+{
+    /**
+     * RFC 4648 Base32 encoding
+     *
+     * @param $str
+     * @return string
+     */
+    public static function base32Encode(string $str): string
+    {
+        return Base32::encode($str);
+    }
+
+    /**
+     * RFC 4648 Base32 encoding
+     *
+     * @param $str
+     * @return string
+     */
+    public static function base32EncodeUpper(string $str): string
+    {
+        return Base32::encodeUpper($str);
+    }
+
+    /**
+     * RFC 4648 Base32 decoding
+     *
+     * @param $str
+     * @return string
+     */
+    public static function base32Decode(string $str): string
+    {
+        return Base32::decode($str);
+    }
+
+    /**
+     * RFC 4648 Base32 decoding
+     *
+     * @param $str
+     * @return string
+     */
+    public static function base32DecodeUpper(string $str): string
+    {
+        return Base32::decodeUpper($str);
+    }
+
+    /**
+     * RFC 4648 Base32 encoding
+     *
+     * @param $str
+     * @return string
+     */
+    public static function base32HexEncode(string $str): string
+    {
+        return Base32Hex::encode($str);
+    }
+
+
+    /**
+     * RFC 4648 Base32 encoding
+     *
+     * @param $str
+     * @return string
+     */
+    public static function base32HexEncodeUpper(string $str): string
+    {
+        return Base32Hex::encodeUpper($str);
+    }
+
+    /**
+     * RFC 4648 Base32 decoding
+     *
+     * @param $str
+     * @return string
+     */
+    public static function base32HexDecode(string $str): string
+    {
+        return Base32Hex::decode($str);
+    }
+
+    /**
+     * RFC 4648 Base32 decoding
+     *
+     * @param $str
+     * @return string
+     */
+    public static function base32HexDecodeUpper(string $str): string
+    {
+        return Base32Hex::decodeUpper($str);
+    }
+
+    /**
+     * RFC 4648 Base64 encoding
+     *
+     * @param $str
+     * @return string
+     */
+    public static function base64Encode(string $str): string
+    {
+        return Base64::encode($str);
+    }
+
+    /**
+     * RFC 4648 Base32 decoding
+     *
+     * @param $str
+     * @return string
+     */
+    public static function base64Decode(string $str): string
+    {
+        return Base64::decode($str);
+    }
+
+    /**
+     * Encode into Base64
+     *
+     * Base64 character set "./[A-Z][a-z][0-9]"
+     * @param $src
+     * @return string
+     */
+    public static function base64EncodeDotSlash(string $str): string
+    {
+        return Base64DotSlash::encode($str);
+    }
+
+    /**
+     * Decode from base64 to raw binary
+     *
+     * Base64 character set "./[A-Z][a-z][0-9]"
+     *
+     * @param $src
+     * @return bool|string
+     * @throws \RangeException
+     */
+    public static function base64DecodeDotSlash(string $str): string
+    {
+        return Base64DotSlash::decode($str);
+    }
+
+    /**
+     * Encode into Base64
+     *
+     * Base64 character set "[.-9][A-Z][a-z]" or "./[0-9][A-Z][a-z]"
+     * @param $src
+     * @return string
+     */
+    public static function base64EncodeDotSlashOrdered(string $str): string
+    {
+        return Base64DotSlashOrdered::encode($str);
+    }
+
+    /**
+     * Decode from base64 to raw binary
+     *
+     * Base64 character set "[.-9][A-Z][a-z]" or "./[0-9][A-Z][a-z]"
+     *
+     * @param $src
+     * @return bool|string
+     * @throws \RangeException
+     */
+    public static function base64DecodeDotSlashOrdered(string $str): string
+    {
+        return Base64DotSlashOrdered::decode($str);
+    }
+
+    /**
+     * Convert a binary string into a hexadecimal string without cache-timing
+     * leaks
+     *
+     * @param string $bin_string (raw binary)
+     * @return string
+     */
+    public static function hexEncode(string $bin_string): string
+    {
+        return Hex::encode($bin_string);
+    }
+
+    /**
+     * Convert a hexadecimal string into a binary string without cache-timing
+     * leaks
+     *
+     * @param string $hex_string
+     * @return string (raw binary)
+     * @throws \RangeException
+     */
+    public static function hexDecode(string $hex_string): string
+    {
+        return Hex::decode($hex_string);
+    }
+
+    /**
+     * Convert a binary string into a hexadecimal string without cache-timing
+     * leaks
+     *
+     * @param string $bin_string (raw binary)
+     * @return string
+     */
+    public static function hexEncodeUpper(string $bin_string): string
+    {
+        return Hex::encodeUpper($bin_string);
+    }
+
+    /**
+     * Convert a binary string into a hexadecimal string without cache-timing
+     * leaks
+     *
+     * @param string $bin_string (raw binary)
+     * @return string
+     */
+    public static function hexDecodeUpper(string $bin_string): string
+    {
+        return Hex::decode($bin_string);
+    }
+}
diff --git a/extlib/ParagonIE/ConstantTime/Hex.php b/extlib/ParagonIE/ConstantTime/Hex.php
new file mode 100644
index 0000000000..1d10937fe3
--- /dev/null
+++ b/extlib/ParagonIE/ConstantTime/Hex.php
@@ -0,0 +1,132 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+/**
+ *  Copyright (c) 2016 Paragon Initiative Enterprises.
+ *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+/**
+ * Class Hex
+ * @package ParagonIE\ConstantTime
+ */
+abstract class Hex implements EncoderInterface
+{
+    /**
+     * Convert a binary string into a hexadecimal string without cache-timing
+     * leaks
+     *
+     * @param string $bin_string (raw binary)
+     * @return string
+     */
+    public static function encode(string $bin_string): string
+    {
+        $hex = '';
+        $len = Binary::safeStrlen($bin_string);
+        for ($i = 0; $i < $len; ++$i) {
+            $chunk = \unpack('C', Binary::safeSubstr($bin_string, $i, 2));
+            $c = $chunk[1] & 0xf;
+            $b = $chunk[1] >> 4;
+            $hex .= pack(
+                'CC',
+                (87 + $b + ((($b - 10) >> 8) & ~38)),
+                (87 + $c + ((($c - 10) >> 8) & ~38))
+            );
+        }
+        return $hex;
+    }
+
+    /**
+     * Convert a binary string into a hexadecimal string without cache-timing
+     * leaks, returning uppercase letters (as per RFC 4648)
+     *
+     * @param string $bin_string (raw binary)
+     * @return string
+     */
+    public static function encodeUpper(string $bin_string): string
+    {
+        $hex = '';
+        $len = Binary::safeStrlen($bin_string);
+        for ($i = 0; $i < $len; ++$i) {
+            $chunk = \unpack('C', Binary::safeSubstr($bin_string, $i, 2));
+            $c = $chunk[1] & 0xf;
+            $b = $chunk[1] >> 4;
+            $hex .= pack(
+                'CC',
+                (55 + $b + ((($b - 10) >> 8) & ~6)),
+                (55 + $c + ((($c - 10) >> 8) & ~6))
+            );
+        }
+        return $hex;
+    }
+
+    /**
+     * Convert a hexadecimal string into a binary string without cache-timing
+     * leaks
+     *
+     * @param string $hex_string
+     * @param bool $strictPadding
+     * @return string (raw binary)
+     * @throws \RangeException
+     */
+    public static function decode(string $hexString, bool $strictPadding = false): string
+    {
+        $hex_pos = 0;
+        $bin = '';
+        $c_acc = 0;
+        $hex_len = Binary::safeStrlen($hexString);
+        $state = 0;
+        if (($hex_len & 1) !== 0) {
+            if ($strictPadding) {
+                throw new \RangeException(
+                    'Expected an even number of hexadecimal characters'
+                );
+            } else {
+                $hexString = '0' . $hexString;
+                ++$hex_len;
+            }
+        }
+
+        $chunk = \unpack('C*', $hexString);
+        while ($hex_pos < $hex_len) {
+            ++$hex_pos;
+            $c = $chunk[$hex_pos];
+            $c_num = $c ^ 48;
+            $c_num0 = ($c_num - 10) >> 8;
+            $c_alpha = ($c & ~32) - 55;
+            $c_alpha0 = (($c_alpha - 10) ^ ($c_alpha - 16)) >> 8;
+            if (($c_num0 | $c_alpha0) === 0) {
+                throw new \RangeException(
+                    'hexEncode() only expects hexadecimal characters'
+                );
+            }
+            $c_val = ($c_num0 & $c_num) | ($c_alpha & $c_alpha0);
+            if ($state === 0) {
+                $c_acc = $c_val * 16;
+            } else {
+                $bin .= \pack('C', $c_acc | $c_val);
+            }
+            $state ^= 1;
+        }
+        return $bin;
+    }
+}
diff --git a/extlib/ParagonIE/ConstantTime/RFC4648.php b/extlib/ParagonIE/ConstantTime/RFC4648.php
new file mode 100644
index 0000000000..63b2ee69f5
--- /dev/null
+++ b/extlib/ParagonIE/ConstantTime/RFC4648.php
@@ -0,0 +1,166 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+/**
+ *  Copyright (c) 2016 Paragon Initiative Enterprises.
+ *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+/**
+ * Class RFC4648
+ *
+ * This class conforms strictly to the RFC
+ *
+ * @package ParagonIE\ConstantTime
+ */
+abstract class RFC4648
+{
+    /**
+     * RFC 4648 Base64 encoding
+     *
+     * "foo" -> "Zm9v"
+     *
+     * @param string $str
+     * @return string
+     */
+    public function base64Encode(string $str): string
+    {
+        return Base64::encode($str);
+    }
+
+    /**
+     * RFC 4648 Base64 decoding
+     *
+     * "Zm9v" -> "foo"
+     *
+     * @param string $str
+     * @return string
+     */
+    public function base64Decode(string $str): string
+    {
+        return Base64::decode($str, true);
+    }
+
+    /**
+     * RFC 4648 Base64 (URL Safe) encoding
+     *
+     * "foo" -> "Zm9v"
+     *
+     * @param string $str
+     * @return string
+     */
+    public function base64UrlSafeEncode(string $str): string
+    {
+        return Base64UrlSafe::encode($str);
+    }
+
+    /**
+     * RFC 4648 Base64 (URL Safe) decoding
+     *
+     * "Zm9v" -> "foo"
+     *
+     * @param string $str
+     * @return string
+     */
+    public function base64UrlSafeDecode(string $str): string
+    {
+        return Base64UrlSafe::decode($str, true);
+    }
+
+    /**
+     * RFC 4648 Base32 encoding
+     *
+     * "foo" -> "MZXW6==="
+     *
+     * @param string $str
+     * @return string
+     */
+    public function base32Encode(string $str): string
+    {
+        return Base32::encodeUpper($str);
+    }
+
+    /**
+     * RFC 4648 Base32 encoding
+     *
+     * "MZXW6===" -> "foo"
+     *
+     * @param string $str
+     * @return string
+     */
+    public function base32Decode(string $str): string
+    {
+        return Base32::decodeUpper($str, true);
+    }
+
+    /**
+     * RFC 4648 Base32-Hex encoding
+     *
+     * "foo" -> "CPNMU==="
+     *
+     * @param string $str
+     * @return string
+     */
+    public function base32HexEncode(string $str): string
+    {
+        return Base32::encodeUpper($str);
+    }
+
+    /**
+     * RFC 4648 Base32-Hex decoding
+     *
+     * "CPNMU===" -> "foo"
+     *
+     * @param string $str
+     * @return string
+     */
+    public function base32HexDecode(string $str): string
+    {
+        return Base32::decodeUpper($str, true);
+    }
+
+    /**
+     * RFC 4648 Base16 decoding
+     *
+     * "foo" -> "666F6F"
+     *
+     * @param string $str
+     * @return string
+     */
+    public function base16Encode(string $str): string
+    {
+        return Hex::encodeUpper($str);
+    }
+
+    /**
+     * RFC 4648 Base16 decoding
+     *
+     * "666F6F" -> "foo"
+     *
+     * @param string $str
+     * @return string
+     */
+    public function base16Decode(string $str): string
+    {
+        return Hex::decode($str, true);
+    }
+}
\ No newline at end of file
diff --git a/extlib/ParagonIE/LICENSE.txt b/extlib/ParagonIE/LICENSE.txt
new file mode 100644
index 0000000000..06302425a3
--- /dev/null
+++ b/extlib/ParagonIE/LICENSE.txt
@@ -0,0 +1,48 @@
+The MIT License (MIT)
+
+Copyright (c) 2016 Paragon Initiative Enterprises
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+------------------------------------------------------------------------------
+This library was based on the work of Steve "Sc00bz" Thomas.
+------------------------------------------------------------------------------
+
+The MIT License (MIT)
+
+Copyright (c) 2014 Steve Thomas
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+