comparison vendor/zendframework/zend-diactoros/src/HeaderSecurity.php @ 0:c75dbcec494b

Initial commit from drush-created site

+<?php
+/**
+ * Zend Framework (http://framework.zend.com/)
+ *
+ * @see       http://github.com/zendframework/zend-diactoros for the canonical source repository
+ * @copyright Copyright (c) 2015-2016 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   https://github.com/zendframework/zend-diactoros/blob/master/LICENSE.md New BSD License
+ */
+
+namespace Zend\Diactoros;
+
+use InvalidArgumentException;
+
+/**
+ * Provide security tools around HTTP headers to prevent common injection vectors.
+ *
+ * Code is largely lifted from the Zend\Http\Header\HeaderValue implementation in
+ * Zend Framework, released with the copyright and license below.
+ *
+ * @copyright Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   http://framework.zend.com/license/new-bsd New BSD License
+ */
+final class HeaderSecurity
+{
+    /**
+     * Private constructor; non-instantiable.
+     * @codeCoverageIgnore
+     */
+    private function __construct()
+    {
+    }
+
+    /**
+     * Filter a header value
+     *
+     * Ensures CRLF header injection vectors are filtered.
+     *
+     * Per RFC 7230, only VISIBLE ASCII characters, spaces, and horizontal
+     * tabs are allowed in values; header continuations MUST consist of
+     * a single CRLF sequence followed by a space or horizontal tab.
+     *
+     * This method filters any values not allowed from the string, and is
+     * lossy.
+     *
+     * @see http://en.wikipedia.org/wiki/HTTP_response_splitting
+     * @param string $value
+     * @return string
+     */
+    public static function filter($value)
+    {
+        $value  = (string) $value;
+        $length = strlen($value);
+        $string = '';
+        for ($i = 0; $i < $length; $i += 1) {
+            $ascii = ord($value[$i]);
+
+            // Detect continuation sequences
+            if ($ascii === 13) {
+                $lf = ord($value[$i + 1]);
+                $ws = ord($value[$i + 2]);
+                if ($lf === 10 && in_array($ws, [9, 32], true)) {
+                    $string .= $value[$i] . $value[$i + 1];
+                    $i += 1;
+                }
+
+                continue;
+            }
+
+            // Non-visible, non-whitespace characters
+            // 9 === horizontal tab
+            // 32-126, 128-254 === visible
+            // 127 === DEL
+            // 255 === null byte
+            if (($ascii < 32 && $ascii !== 9)
+                || $ascii === 127
+                || $ascii > 254
+            ) {
+                continue;
+            }
+
+            $string .= $value[$i];
+        }
+
+        return $string;
+    }
+
+    /**
+     * Validate a header value.
+     *
+     * Per RFC 7230, only VISIBLE ASCII characters, spaces, and horizontal
+     * tabs are allowed in values; header continuations MUST consist of
+     * a single CRLF sequence followed by a space or horizontal tab.
+     *
+     * @see http://en.wikipedia.org/wiki/HTTP_response_splitting
+     * @param string $value
+     * @return bool
+     */
+    public static function isValid($value)
+    {
+        $value  = (string) $value;
+
+        // Look for:
+        // \n not preceded by \r, OR
+        // \r not followed by \n, OR
+        // \r\n not followed by space or horizontal tab; these are all CRLF attacks
+        if (preg_match("#(?:(?:(?<!\r)\n)|(?:\r(?!\n))|(?:\r\n(?![ \t])))#", $value)) {
+            return false;
+        }
+
+        // Non-visible, non-whitespace characters
+        // 9 === horizontal tab
+        // 10 === line feed
+        // 13 === carriage return
+        // 32-126, 128-254 === visible
+        // 127 === DEL (disallowed)
+        // 255 === null byte (disallowed)
+        if (preg_match('/[^\x09\x0a\x0d\x20-\x7E\x80-\xFE]/', $value)) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Assert a header value is valid.
+     *
+     * @param string $value
+     * @throws InvalidArgumentException for invalid values
+     */
+    public static function assertValid($value)
+    {
+        if (! is_string($value) && ! is_numeric($value)) {
+            throw new InvalidArgumentException(sprintf(
+                'Invalid header value type; must be a string or numeric; received %s',
+                (is_object($value) ? get_class($value) : gettype($value))
+            ));
+        }
+        if (! self::isValid($value)) {
+            throw new InvalidArgumentException(sprintf(
+                '"%s" is not valid header value',
+                $value
+            ));
+        }
+    }
+
+    /**
+     * Assert whether or not a header name is valid.
+     *
+     * @see http://tools.ietf.org/html/rfc7230#section-3.2
+     * @param mixed $name
+     * @throws InvalidArgumentException
+     */
+    public static function assertValidName($name)
+    {
+        if (! is_string($name)) {
+            throw new InvalidArgumentException(sprintf(
+                'Invalid header name type; expected string; received %s',
+                (is_object($name) ? get_class($name) : gettype($name))
+            ));
+        }
+        if (! preg_match('/^[a-zA-Z0-9\'`#$%&*+.^_|~!-]+$/', $name)) {
+            throw new InvalidArgumentException(sprintf(
+                '"%s" is not valid header name',
+                $name
+            ));
+        }
+    }
+}