--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/Requests/IPv6.php	Mon Oct 14 17:39:30 2019 +0200
@@ -0,0 +1,190 @@
+<?php
+/**
+ * Class to validate and to work with IPv6 addresses
+ *
+ * @package Requests
+ * @subpackage Utilities
+ */
+
+/**
+ * Class to validate and to work with IPv6 addresses
+ *
+ * This was originally based on the PEAR class of the same name, but has been
+ * entirely rewritten.
+ *
+ * @package Requests
+ * @subpackage Utilities
+ */
+class Requests_IPv6 {
+	/**
+	 * Uncompresses an IPv6 address
+	 *
+	 * RFC 4291 allows you to compress consecutive zero pieces in an address to
+	 * '::'. This method expects a valid IPv6 address and expands the '::' to
+	 * the required number of zero pieces.
+	 *
+	 * Example:  FF01::101   ->  FF01:0:0:0:0:0:0:101
+	 *           ::1         ->  0:0:0:0:0:0:0:1
+	 *
+	 * @author Alexander Merz <alexander.merz@web.de>
+	 * @author elfrink at introweb dot nl
+	 * @author Josh Peck <jmp at joshpeck dot org>
+	 * @copyright 2003-2005 The PHP Group
+	 * @license http://www.opensource.org/licenses/bsd-license.php
+	 * @param string $ip An IPv6 address
+	 * @return string The uncompressed IPv6 address
+	 */
+	public static function uncompress($ip) {
+		if (substr_count($ip, '::') !== 1) {
+			return $ip;
+		}
+
+		list($ip1, $ip2) = explode('::', $ip);
+		$c1 = ($ip1 === '') ? -1 : substr_count($ip1, ':');
+		$c2 = ($ip2 === '') ? -1 : substr_count($ip2, ':');
+
+		if (strpos($ip2, '.') !== false) {
+			$c2++;
+		}
+		// ::
+		if ($c1 === -1 && $c2 === -1) {
+			$ip = '0:0:0:0:0:0:0:0';
+		}
+		// ::xxx
+		else if ($c1 === -1) {
+			$fill = str_repeat('0:', 7 - $c2);
+			$ip = str_replace('::', $fill, $ip);
+		}
+		// xxx::
+		else if ($c2 === -1) {
+			$fill = str_repeat(':0', 7 - $c1);
+			$ip = str_replace('::', $fill, $ip);
+		}
+		// xxx::xxx
+		else {
+			$fill = ':' . str_repeat('0:', 6 - $c2 - $c1);
+			$ip = str_replace('::', $fill, $ip);
+		}
+		return $ip;
+	}
+
+	/**
+	 * Compresses an IPv6 address
+	 *
+	 * RFC 4291 allows you to compress consecutive zero pieces in an address to
+	 * '::'. This method expects a valid IPv6 address and compresses consecutive
+	 * zero pieces to '::'.
+	 *
+	 * Example:  FF01:0:0:0:0:0:0:101   ->  FF01::101
+	 *           0:0:0:0:0:0:0:1        ->  ::1
+	 *
+	 * @see uncompress()
+	 * @param string $ip An IPv6 address
+	 * @return string The compressed IPv6 address
+	 */
+	public static function compress($ip) {
+		// Prepare the IP to be compressed
+		$ip = self::uncompress($ip);
+		$ip_parts = self::split_v6_v4($ip);
+
+		// Replace all leading zeros
+		$ip_parts[0] = preg_replace('/(^|:)0+([0-9])/', '\1\2', $ip_parts[0]);
+
+		// Find bunches of zeros
+		if (preg_match_all('/(?:^|:)(?:0(?::|$))+/', $ip_parts[0], $matches, PREG_OFFSET_CAPTURE)) {
+			$max = 0;
+			$pos = null;
+			foreach ($matches[0] as $match) {
+				if (strlen($match[0]) > $max) {
+					$max = strlen($match[0]);
+					$pos = $match[1];
+				}
+			}
+
+			$ip_parts[0] = substr_replace($ip_parts[0], '::', $pos, $max);
+		}
+
+		if ($ip_parts[1] !== '') {
+			return implode(':', $ip_parts);
+		}
+		else {
+			return $ip_parts[0];
+		}
+	}
+
+	/**
+	 * Splits an IPv6 address into the IPv6 and IPv4 representation parts
+	 *
+	 * RFC 4291 allows you to represent the last two parts of an IPv6 address
+	 * using the standard IPv4 representation
+	 *
+	 * Example:  0:0:0:0:0:0:13.1.68.3
+	 *           0:0:0:0:0:FFFF:129.144.52.38
+	 *
+	 * @param string $ip An IPv6 address
+	 * @return string[] [0] contains the IPv6 represented part, and [1] the IPv4 represented part
+	 */
+	protected static function split_v6_v4($ip) {
+		if (strpos($ip, '.') !== false) {
+			$pos = strrpos($ip, ':');
+			$ipv6_part = substr($ip, 0, $pos);
+			$ipv4_part = substr($ip, $pos + 1);
+			return array($ipv6_part, $ipv4_part);
+		}
+		else {
+			return array($ip, '');
+		}
+	}
+
+	/**
+	 * Checks an IPv6 address
+	 *
+	 * Checks if the given IP is a valid IPv6 address
+	 *
+	 * @param string $ip An IPv6 address
+	 * @return bool true if $ip is a valid IPv6 address
+	 */
+	public static function check_ipv6($ip) {
+		$ip = self::uncompress($ip);
+		list($ipv6, $ipv4) = self::split_v6_v4($ip);
+		$ipv6 = explode(':', $ipv6);
+		$ipv4 = explode('.', $ipv4);
+		if (count($ipv6) === 8 && count($ipv4) === 1 || count($ipv6) === 6 && count($ipv4) === 4) {
+			foreach ($ipv6 as $ipv6_part) {
+				// The section can't be empty
+				if ($ipv6_part === '') {
+					return false;
+				}
+
+				// Nor can it be over four characters
+				if (strlen($ipv6_part) > 4) {
+					return false;
+				}
+
+				// Remove leading zeros (this is safe because of the above)
+				$ipv6_part = ltrim($ipv6_part, '0');
+				if ($ipv6_part === '') {
+					$ipv6_part = '0';
+				}
+
+				// Check the value is valid
+				$value = hexdec($ipv6_part);
+				if (dechex($value) !== strtolower($ipv6_part) || $value < 0 || $value > 0xFFFF) {
+					return false;
+				}
+			}
+			if (count($ipv4) === 4) {
+				foreach ($ipv4 as $ipv4_part) {
+					$value = (int) $ipv4_part;
+					if ((string) $value !== $ipv4_part || $value < 0 || $value > 0xFF) {
+						return false;
+					}
+				}
+			}
+			return true;
+		}
+		else {
+			return false;
+		}
+	}
+}