PHPIndex

<?php

/**
 * Validates the HTML attribute style, otherwise known as CSS.
 * @note We don't implement the whole CSS specification, so it might be
 *       difficult to reuse this component in the context of validating
 *       actual stylesheet declarations.
 * @note If we were really serious about validating the CSS, we would
 *       tokenize the styles and then parse the tokens. Obviously, we
 *       are not doing that. Doing that could seriously harm performance,
 *       but would make these components a lot more viable for a CSS
 *       filtering solution.
 */
class HTMLPurifier_AttrDef_CSS extends HTMLPurifier_AttrDef
{

    /**
     * @param string $css
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool|string
     */
    public function validate($css, $config, $context)
    {
        $css = $this->parseCDATA($css);

        $definition = $config->getCSSDefinition();
        $allow_duplicates = $config->get("CSS.AllowDuplicates");


        // According to the CSS2.1 spec, the places where a
        // non-delimiting semicolon can appear are in strings
        // escape sequences.   So here is some dumb hack to
        // handle quotes.
        $len = strlen($css);
        $accum = "";
        $declarations = array();
        $quoted = false;
        for ($i = 0; $i < $len; $i++) {
            $c = strcspn($css, ";'\"", $i);
            $accum .= substr($css, $i, $c);
            $i += $c;
            if ($i == $len) break;
            $d = $css[$i];
            if ($quoted) {
                $accum .= $d;
                if ($d == $quoted) {
                    $quoted = false;
                }
            } else {
                if ($d == ";") {
                    $declarations[] = $accum;
                    $accum = "";
                } else {
                    $accum .= $d;
                    $quoted = $d;
                }
            }
        }
        if ($accum != "") $declarations[] = $accum;

        $propvalues = array();
        $new_declarations = '';

        /**
         * Name of the current CSS property being validated.
         */
        $property = false;
        $context->register('CurrentCSSProperty', $property);

        foreach ($declarations as $declaration) {
            if (!$declaration) {
                continue;
            }
            if (!strpos($declaration, ':')) {
                continue;
            }
            list($property, $value) = explode(':', $declaration, 2);
            $property = trim($property);
            $value = trim($value);
            $ok = false;
            do {
                if (isset($definition->info[$property])) {
                    $ok = true;
                    break;
                }
                if (ctype_lower($property)) {
                    break;
                }
                $property = strtolower($property);
                if (isset($definition->info[$property])) {
                    $ok = true;
                    break;
                }
            } while (0);
            if (!$ok) {
                continue;
            }
            // inefficient call, since the validator will do this again
            if (strtolower(trim($value)) !== 'inherit') {
                // inherit works for everything (but only on the base property)
                $result = $definition->info[$property]->validate(
                    $value,
                    $config,
                    $context
                );
            } else {
                $result = 'inherit';
            }
            if ($result === false) {
                continue;
            }
            if ($allow_duplicates) {
                $new_declarations .= "$property:$result;";
            } else {
                $propvalues[$property] = $result;
            }
        }

        $context->destroy('CurrentCSSProperty');

        // procedure does not write the new CSS simultaneously, so it's
        // slightly inefficient, but it's the only way of getting rid of
        // duplicates. Perhaps config to optimize it, but not now.

        foreach ($propvalues as $prop => $value) {
            $new_declarations .= "$prop:$value;";
        }

        return $new_declarations ? $new_declarations : false;

    }

}

// vim: et sw=4 sts=4

<?php

/**
 * Dummy AttrDef that mimics another AttrDef, BUT it generates clones
 * with make.
 */
class HTMLPurifier_AttrDef_Clone extends HTMLPurifier_AttrDef
{
    /**
     * What we're cloning.
     * @type HTMLPurifier_AttrDef
     */
    protected $clone;

    /**
     * @param HTMLPurifier_AttrDef $clone
     */
    public function __construct($clone)
    {
        $this->clone = $clone;
    }

    /**
     * @param string $v
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool|string
     */
    public function validate($v, $config, $context)
    {
        return $this->clone->validate($v, $config, $context);
    }

    /**
     * @param string $string
     * @return HTMLPurifier_AttrDef
     */
    public function make($string)
    {
        return clone $this->clone;
    }
}

// vim: et sw=4 sts=4

<?php

// Enum = Enumerated
/**
 * Validates a keyword against a list of valid values.
 * @warning The case-insensitive compare of this function uses PHP's
 *          built-in strtolower and ctype_lower functions, which may
 *          cause problems with international comparisons
 */
class HTMLPurifier_AttrDef_Enum extends HTMLPurifier_AttrDef
{

    /**
     * Lookup table of valid values.
     * @type array
     * @todo Make protected
     */
    public $valid_values = array();

    /**
     * Bool indicating whether or not enumeration is case sensitive.
     * @note In general this is always case insensitive.
     */
    protected $case_sensitive = false; // values according to W3C spec

    /**
     * @param array $valid_values List of valid values
     * @param bool $case_sensitive Whether or not case sensitive
     */
    public function __construct($valid_values = array(), $case_sensitive = false)
    {
        $this->valid_values = array_flip($valid_values);
        $this->case_sensitive = $case_sensitive;
    }

    /**
     * @param string $string
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool|string
     */
    public function validate($string, $config, $context)
    {
        $string = trim($string);
        if (!$this->case_sensitive) {
            // we may want to do full case-insensitive libraries
            $string = ctype_lower($string) ? $string : strtolower($string);
        }
        $result = isset($this->valid_values[$string]);

        return $result ? $string : false;
    }

    /**
     * @param string $string In form of comma-delimited list of case-insensitive
     *      valid values. Example: "foo,bar,baz". Prepend "s:" to make
     *      case sensitive
     * @return HTMLPurifier_AttrDef_Enum
     */
    public function make($string)
    {
        if (strlen($string) > 2 && $string[0] == 's' && $string[1] == ':') {
            $string = substr($string, 2);
            $sensitive = true;
        } else {
            $sensitive = false;
        }
        $values = explode(',', $string);
        return new HTMLPurifier_AttrDef_Enum($values, $sensitive);
    }
}

// vim: et sw=4 sts=4

<?php

/**
 * Validates an integer.
 * @note While this class was modeled off the CSS definition, no currently
 *       allowed CSS uses this type.  The properties that do are: widows,
 *       orphans, z-index, counter-increment, counter-reset.  Some of the
 *       HTML attributes, however, find use for a non-negative version of this.
 */
class HTMLPurifier_AttrDef_Integer extends HTMLPurifier_AttrDef
{

    /**
     * Whether or not negative values are allowed.
     * @type bool
     */
    protected $negative = true;

    /**
     * Whether or not zero is allowed.
     * @type bool
     */
    protected $zero = true;

    /**
     * Whether or not positive values are allowed.
     * @type bool
     */
    protected $positive = true;

    /**
     * @param $negative Bool indicating whether or not negative values are allowed
     * @param $zero Bool indicating whether or not zero is allowed
     * @param $positive Bool indicating whether or not positive values are allowed
     */
    public function __construct($negative = true, $zero = true, $positive = true)
    {
        $this->negative = $negative;
        $this->zero = $zero;
        $this->positive = $positive;
    }

    /**
     * @param string $integer
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool|string
     */
    public function validate($integer, $config, $context)
    {
        $integer = $this->parseCDATA($integer);
        if ($integer === '') {
            return false;
        }

        // we could possibly simply typecast it to integer, but there are
        // certain fringe cases that must not return an integer.

        // clip leading sign
        if ($this->negative && $integer[0] === '-') {
            $digits = substr($integer, 1);
            if ($digits === '0') {
                $integer = '0';
            } // rm minus sign for zero
        } elseif ($this->positive && $integer[0] === '+') {
            $digits = $integer = substr($integer, 1); // rm unnecessary plus
        } else {
            $digits = $integer;
        }

        // test if it's numeric
        if (!ctype_digit($digits)) {
            return false;
        }

        // perform scope tests
        if (!$this->zero && $integer == 0) {
            return false;
        }
        if (!$this->positive && $integer > 0) {
            return false;
        }
        if (!$this->negative && $integer < 0) {
            return false;
        }

        return $integer;
    }
}

// vim: et sw=4 sts=4

<?php

/**
 * Validates the HTML attribute lang, effectively a language code.
 * @note Built according to RFC 3066, which obsoleted RFC 1766
 */
class HTMLPurifier_AttrDef_Lang extends HTMLPurifier_AttrDef
{

    /**
     * @param string $string
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool|string
     */
    public function validate($string, $config, $context)
    {
        $string = trim($string);
        if (!$string) {
            return false;
        }

        $subtags = explode('-', $string);
        $num_subtags = count($subtags);

        if ($num_subtags == 0) { // sanity check
            return false;
        }

        // process primary subtag : $subtags[0]
        $length = strlen($subtags[0]);
        switch ($length) {
            case 0:
                return false;
            case 1:
                if (!($subtags[0] == 'x' || $subtags[0] == 'i')) {
                    return false;
                }
                break;
            case 2:
            case 3:
                if (!ctype_alpha($subtags[0])) {
                    return false;
                } elseif (!ctype_lower($subtags[0])) {
                    $subtags[0] = strtolower($subtags[0]);
                }
                break;
            default:
                return false;
        }

        $new_string = $subtags[0];
        if ($num_subtags == 1) {
            return $new_string;
        }

        // process second subtag : $subtags[1]
        $length = strlen($subtags[1]);
        if ($length == 0 || ($length == 1 && $subtags[1] != 'x') || $length > 8 || !ctype_alnum($subtags[1])) {
            return $new_string;
        }
        if (!ctype_lower($subtags[1])) {
            $subtags[1] = strtolower($subtags[1]);
        }

        $new_string .= '-' . $subtags[1];
        if ($num_subtags == 2) {
            return $new_string;
        }

        // process all other subtags, index 2 and up
        for ($i = 2; $i < $num_subtags; $i++) {
            $length = strlen($subtags[$i]);
            if ($length == 0 || $length > 8 || !ctype_alnum($subtags[$i])) {
                return $new_string;
            }
            if (!ctype_lower($subtags[$i])) {
                $subtags[$i] = strtolower($subtags[$i]);
            }
            $new_string .= '-' . $subtags[$i];
        }
        return $new_string;
    }
}

// vim: et sw=4 sts=4

<?php

/**
 * Decorator that, depending on a token, switches between two definitions.
 */
class HTMLPurifier_AttrDef_Switch
{

    /**
     * @type string
     */
    protected $tag;

    /**
     * @type HTMLPurifier_AttrDef
     */
    protected $withTag;

    /**
     * @type HTMLPurifier_AttrDef
     */
    protected $withoutTag;

    /**
     * @param string $tag Tag name to switch upon
     * @param HTMLPurifier_AttrDef $with_tag Call if token matches tag
     * @param HTMLPurifier_AttrDef $without_tag Call if token doesn't match, or there is no token
     */
    public function __construct($tag, $with_tag, $without_tag)
    {
        $this->tag = $tag;
        $this->withTag = $with_tag;
        $this->withoutTag = $without_tag;
    }

    /**
     * @param string $string
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool|string
     */
    public function validate($string, $config, $context)
    {
        $token = $context->get('CurrentToken', true);
        if (!$token || $token->name !== $this->tag) {
            return $this->withoutTag->validate($string, $config, $context);
        } else {
            return $this->withTag->validate($string, $config, $context);
        }
    }
}

// vim: et sw=4 sts=4

<?php

/**
 * Validates arbitrary text according to the HTML spec.
 */
class HTMLPurifier_AttrDef_Text extends HTMLPurifier_AttrDef
{

    /**
     * @param string $string
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool|string
     */
    public function validate($string, $config, $context)
    {
        return $this->parseCDATA($string);
    }
}

// vim: et sw=4 sts=4

<?php

/**
 * Validates a URI as defined by RFC 3986.
 * @note Scheme-specific mechanics deferred to HTMLPurifier_URIScheme
 */
class HTMLPurifier_AttrDef_URI extends HTMLPurifier_AttrDef
{

    /**
     * @type HTMLPurifier_URIParser
     */
    protected $parser;

    /**
     * @type bool
     */
    protected $embedsResource;

    /**
     * @param bool $embeds_resource Does the URI here result in an extra HTTP request?
     */
    public function __construct($embeds_resource = false)
    {
        $this->parser = new HTMLPurifier_URIParser();
        $this->embedsResource = (bool)$embeds_resource;
    }

    /**
     * @param string $string
     * @return HTMLPurifier_AttrDef_URI
     */
    public function make($string)
    {
        $embeds = ($string === 'embedded');
        return new HTMLPurifier_AttrDef_URI($embeds);
    }

    /**
     * @param string $uri
     * @param HTMLPurifier_Config $config
     * @param HTMLPurifier_Context $context
     * @return bool|string
     */
    public function validate($uri, $config, $context)
    {
        if ($config->get('URI.Disable')) {
            return false;
        }

        $uri = $this->parseCDATA($uri);

        // parse the URI
        $uri = $this->parser->parse($uri);
        if ($uri === false) {
            return false;
        }

        // add embedded flag to context for validators
        $context->register('EmbeddedURI', $this->embedsResource);

        $ok = false;
        do {

            // generic validation
            $result = $uri->validate($config, $context);
            if (!$result) {
                break;
            }

            // chained filtering
            $uri_def = $config->getDefinition('URI');
            $result = $uri_def->filter($uri, $config, $context);
            if (!$result) {
                break;
            }

            // scheme-specific validation
            $scheme_obj = $uri->getSchemeObj($config, $context);
            if (!$scheme_obj) {
                break;
            }
            if ($this->embedsResource && !$scheme_obj->browsable) {
                break;
            }
            $result = $scheme_obj->validate($uri, $config, $context);
            if (!$result) {
                break;
            }

            // Post chained filtering
            $result = $uri_def->postFilter($uri, $config, $context);
            if (!$result) {
                break;
            }

            // survived gauntlet
            $ok = true;

        } while (false);

        $context->destroy('EmbeddedURI');
        if (!$ok) {
            return false;
        }
        // back to string
        return $uri->toString();
    }
}

// vim: et sw=4 sts=4