[securemail] Bump phpseclib dependency to version 3.0.19

securemail/vendor/paragonie/constant_time_encoding/src/Hex.php

@@ -0,0 +1,146 @@
+<?php
+declare(strict_types=1);
+namespace ParagonIE\ConstantTime;
+
+use RangeException;
+use TypeError;
+
+/**
+ *  Copyright (c) 2016 - 2022 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 $binString (raw binary)
+     * @return string
+     * @throws TypeError
+     */
+    public static function encode(string $binString): string
+    {
+        $hex = '';
+        $len = Binary::safeStrlen($binString);
+        for ($i = 0; $i < $len; ++$i) {
+            /** @var array<int, int> $chunk */
+            $chunk = \unpack('C', $binString[$i]);
+            $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 $binString (raw binary)
+     * @return string
+     * @throws TypeError
+     */
+    public static function encodeUpper(string $binString): string
+    {
+        $hex = '';
+        $len = Binary::safeStrlen($binString);
+
+        for ($i = 0; $i < $len; ++$i) {
+            /** @var array<int, int> $chunk */
+            $chunk = \unpack('C', $binString[$i]);
+            $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 $encodedString
+     * @param bool $strictPadding
+     * @return string (raw binary)
+     * @throws RangeException
+     */
+    public static function decode(
+        string $encodedString,
+        bool $strictPadding = false
+    ): string {
+        $hex_pos = 0;
+        $bin = '';
+        $c_acc = 0;
+        $hex_len = Binary::safeStrlen($encodedString);
+        $state = 0;
+        if (($hex_len & 1) !== 0) {
+            if ($strictPadding) {
+                throw new RangeException(
+                    'Expected an even number of hexadecimal characters'
+                );
+            } else {
+                $encodedString = '0' . $encodedString;
+                ++$hex_len;
+            }
+        }
+
+        /** @var array<int, int> $chunk */
+        $chunk = \unpack('C*', $encodedString);
+        while ($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(
+                    'Expected hexadecimal character'
+                );
+            }
+            $c_val = ($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;
+    }
+}