1 files changed, 182 insertions, 0 deletions
diff --git a/wp-includes/Requests/src/Ssl.php b/wp-includes/Requests/src/Ssl.php
new file mode 100644
index 0000000..99da11d
--- /dev/null
+++ b/wp-includes/Requests/src/Ssl.php
@@ -0,0 +1,182 @@
+<?php
+/**
+ * SSL utilities for Requests
+ *
+ * @package Requests\Utilities
+ */
+
+namespace WpOrg\Requests;
+
+use WpOrg\Requests\Exception\InvalidArgument;
+use WpOrg\Requests\Utility\InputValidator;
+
+/**
+ * SSL utilities for Requests
+ *
+ * Collection of utilities for working with and verifying SSL certificates.
+ *
+ * @package Requests\Utilities
+ */
+final class Ssl {
+	/**
+	 * Verify the certificate against common name and subject alternative names
+	 *
+	 * Unfortunately, PHP doesn't check the certificate against the alternative
+	 * names, leading things like 'https://www.github.com/' to be invalid.
+	 *
+	 * @link https://tools.ietf.org/html/rfc2818#section-3.1 RFC2818, Section 3.1
+	 *
+	 * @param string|Stringable $host Host name to verify against
+	 * @param array $cert Certificate data from openssl_x509_parse()
+	 * @return bool
+	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $host argument is not a string or a stringable object.
+	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $cert argument is not an array or array accessible.
+	 */
+	public static function verify_certificate($host, $cert) {
+		if (InputValidator::is_string_or_stringable($host) === false) {
+			throw InvalidArgument::create(1, '$host', 'string|Stringable', gettype($host));
+		}
+
+		if (InputValidator::has_array_access($cert) === false) {
+			throw InvalidArgument::create(2, '$cert', 'array|ArrayAccess', gettype($cert));
+		}
+
+		$has_dns_alt = false;
+
+		// Check the subjectAltName
+		if (!empty($cert['extensions']['subjectAltName'])) {
+			$altnames = explode(',', $cert['extensions']['subjectAltName']);
+			foreach ($altnames as $altname) {
+				$altname = trim($altname);
+				if (strpos($altname, 'DNS:') !== 0) {
+					continue;
+				}
+
+				$has_dns_alt = true;
+
+				// Strip the 'DNS:' prefix and trim whitespace
+				$altname = trim(substr($altname, 4));
+
+				// Check for a match
+				if (self::match_domain($host, $altname) === true) {
+					return true;
+				}
+			}
+
+			if ($has_dns_alt === true) {
+				return false;
+			}
+		}
+
+		// Fall back to checking the common name if we didn't get any dNSName
+		// alt names, as per RFC2818
+		if (!empty($cert['subject']['CN'])) {
+			// Check for a match
+			return (self::match_domain($host, $cert['subject']['CN']) === true);
+		}
+
+		return false;
+	}
+
+	/**
+	 * Verify that a reference name is valid
+	 *
+	 * Verifies a dNSName for HTTPS usage, (almost) as per Firefox's rules:
+	 * - Wildcards can only occur in a name with more than 3 components
+	 * - Wildcards can only occur as the last character in the first
+	 *   component
+	 * - Wildcards may be preceded by additional characters
+	 *
+	 * We modify these rules to be a bit stricter and only allow the wildcard
+	 * character to be the full first component; that is, with the exclusion of
+	 * the third rule.
+	 *
+	 * @param string|Stringable $reference Reference dNSName
+	 * @return boolean Is the name valid?
+	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed argument is not a string or a stringable object.
+	 */
+	public static function verify_reference_name($reference) {
+		if (InputValidator::is_string_or_stringable($reference) === false) {
+			throw InvalidArgument::create(1, '$reference', 'string|Stringable', gettype($reference));
+		}
+
+		if ($reference === '') {
+			return false;
+		}
+
+		if (preg_match('`\s`', $reference) > 0) {
+			// Whitespace detected. This can never be a dNSName.
+			return false;
+		}
+
+		$parts = explode('.', $reference);
+		if ($parts !== array_filter($parts)) {
+			// DNSName cannot contain two dots next to each other.
+			return false;
+		}
+
+		// Check the first part of the name
+		$first = array_shift($parts);
+
+		if (strpos($first, '*') !== false) {
+			// Check that the wildcard is the full part
+			if ($first !== '*') {
+				return false;
+			}
+
+			// Check that we have at least 3 components (including first)
+			if (count($parts) < 2) {
+				return false;
+			}
+		}
+
+		// Check the remaining parts
+		foreach ($parts as $part) {
+			if (strpos($part, '*') !== false) {
+				return false;
+			}
+		}
+
+		// Nothing found, verified!
+		return true;
+	}
+
+	/**
+	 * Match a hostname against a dNSName reference
+	 *
+	 * @param string|Stringable $host Requested host
+	 * @param string|Stringable $reference dNSName to match against
+	 * @return boolean Does the domain match?
+	 * @throws \WpOrg\Requests\Exception\InvalidArgument When either of the passed arguments is not a string or a stringable object.
+	 */
+	public static function match_domain($host, $reference) {
+		if (InputValidator::is_string_or_stringable($host) === false) {
+			throw InvalidArgument::create(1, '$host', 'string|Stringable', gettype($host));
+		}
+
+		// Check if the reference is blocklisted first
+		if (self::verify_reference_name($reference) !== true) {
+			return false;
+		}
+
+		// Check for a direct match
+		if ((string) $host === (string) $reference) {
+			return true;
+		}
+
+		// Calculate the valid wildcard match if the host is not an IP address
+		// Also validates that the host has 3 parts or more, as per Firefox's ruleset,
+		// as a wildcard reference is only allowed with 3 parts or more, so the
+		// comparison will never match if host doesn't contain 3 parts or more as well.
+		if (ip2long($host) === false) {
+			$parts    = explode('.', $host);
+			$parts[0] = '*';
+			$wildcard = implode('.', $parts);
+			if ($wildcard === (string) $reference) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+}