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<?php
/**
* @see https://github.com/zendframework/zend-http for the canonical source repository
* @copyright Copyright (c) 2005-2017 Zend Technologies USA Inc. (http://www.zend.com)
* @license https://github.com/zendframework/zend-http/blob/master/LICENSE.md New BSD License
*/
namespace Zend\Http\Header;
/**
* Content Security Policy 1.0 Header
*
* @link http://www.w3.org/TR/CSP/
*/
class ContentSecurityPolicy implements HeaderInterface
{
/**
* Valid directive names
*
* @var array
*/
protected $validDirectiveNames = [
// As per http://www.w3.org/TR/CSP/#directives
'default-src',
'script-src',
'object-src',
'style-src',
'img-src',
'media-src',
'frame-src',
'font-src',
'connect-src',
'sandbox',
'report-uri',
];
/**
* The directives defined for this policy
*
* @var array
*/
protected $directives = [];
/**
* Get the list of defined directives
*
* @return array
*/
public function getDirectives()
{
return $this->directives;
}
/**
* Sets the directive to consist of the source list
*
* Reverses http://www.w3.org/TR/CSP/#parsing-1
*
* @param string $name The directive name.
* @param array $sources The source list.
* @return self
* @throws Exception\InvalidArgumentException If the name is not a valid directive name.
*/
public function setDirective($name, array $sources)
{
if (! in_array($name, $this->validDirectiveNames, true)) {
throw new Exception\InvalidArgumentException(sprintf(
'%s expects a valid directive name; received "%s"',
__METHOD__,
(string) $name
));
}
if (empty($sources)) {
if ('report-uri' === $name) {
if (isset($this->directives[$name])) {
unset($this->directives[$name]);
}
return $this;
}
$this->directives[$name] = "'none'";
return $this;
}
array_walk($sources, [__NAMESPACE__ . '\HeaderValue', 'assertValid']);
$this->directives[$name] = implode(' ', $sources);
return $this;
}
/**
* Create Content Security Policy header from a given header line
*
* @param string $headerLine The header line to parse.
* @return self
* @throws Exception\InvalidArgumentException If the name field in the given header line does not match.
*/
public static function fromString($headerLine)
{
$header = new static();
$headerName = $header->getFieldName();
list($name, $value) = GenericHeader::splitHeaderLine($headerLine);
// Ensure the proper header name
if (strcasecmp($name, $headerName) != 0) {
throw new Exception\InvalidArgumentException(sprintf(
'Invalid header line for %s string: "%s"',
$headerName,
$name
));
}
// As per http://www.w3.org/TR/CSP/#parsing
$tokens = explode(';', $value);
foreach ($tokens as $token) {
$token = trim($token);
if ($token) {
list($directiveName, $directiveValue) = explode(' ', $token, 2);
if (! isset($header->directives[$directiveName])) {
$header->setDirective($directiveName, [$directiveValue]);
}
}
}
return $header;
}
/**
* Get the header name
*
* @return string
*/
public function getFieldName()
{
return 'Content-Security-Policy';
}
/**
* Get the header value
*
* @return string
*/
public function getFieldValue()
{
$directives = [];
foreach ($this->directives as $name => $value) {
$directives[] = sprintf('%s %s;', $name, $value);
}
return implode(' ', $directives);
}
/**
* Return the header as a string
*
* @return string
*/
public function toString()
{
return sprintf('%s: %s', $this->getFieldName(), $this->getFieldValue());
}
}