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stricter CSP policy

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This commit is contained in:
Ralf Becker 2020-01-28 17:14:38 +01:00
parent 9e80de5de7
commit d8289ef29d
4 changed files with 59 additions and 38 deletions
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4
api/src/Framework/Login.php
View File

@ -46,7 +46,9 @@ class Login
*/
function screen($extra_vars, $change_passwd=null)
{
Api\Header\ContentSecurityPolicy::add('frame-src', array()); // array() no external frame-sources
// set a more limiting CSP for our login page
Api\Header\ContentSecurityPolicy::add('frame-src', 'none');
Api\Header\ContentSecurityPolicy::add('media-src', 'none');
//error_log(__METHOD__."() this->template=$this->framework->template, this->template_dir=$this->framework->template_dir, get_class(this)=".get_class($this));
try {

13
api/src/Header/Content.php
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@ -73,8 +73,8 @@ class Content
$length += 5;
}
}
// mitigate risk of html downloads by using CSP or force download for IE
if (!$force_download && in_array($mime, array('text/html', 'application/xhtml+xml')))
// mitigate risk of html (or SVG) downloads by using CSP or force download for IE
if (!$force_download && in_array($mime, ['text/html', 'application/xhtml+xml', 'image/svg+xml']))
{
// use CSP only for current user-agents/versions I was able to positivly test
if (UserAgent::type() == 'chrome' && UserAgent::version() >= 24 ||
@ -83,11 +83,8 @@ class Content
UserAgent::type() == 'safari' && !UserAgent::mobile() && UserAgent::version() >= 536 || // OS X
UserAgent::type() == 'safari' && UserAgent::mobile() && UserAgent::version() >= 9537) // iOS 7
{
$csp = "script-src 'none'"; // forbid to execute any javascript
header("Content-Security-Policy: $csp");
header("X-Webkit-CSP: $csp"); // Chrome: <= 24, Safari incl. iOS
//header("X-Content-Security-Policy: $csp"); // FF <= 22
//error_log(__METHOD__."('$options[path]') ".UserAgent::type().'/'.UserAgent::version().(UserAgent::mobile()?'/mobile':'').": using Content-Security-Policy: $csp");
// forbid to execute any javascript (to be precise anything but images and styles)
ContentSecurityPolicy::header("image-src 'self' data: https:; style-src 'self' 'unsafe-inline' https:; default-src 'none'");
}
else // everything else get's a Content-dispostion: attachment, to be on save side
{
@ -95,7 +92,7 @@ class Content
$force_download = true;
}
}
// always tell browser to do not sniffing / use our content-type
// always tell browser to do no sniffing / use our content-type
header('X-Content-Type-Options: nosniff');
if ($no_content_type)

78
api/src/Header/ContentSecurityPolicy.php
View File

@ -20,20 +20,28 @@ use EGroupware\Api;
class ContentSecurityPolicy
{
/**
* Additional attributes or urls for CSP beside always added "self"
* Additional attributes or urls for CSP beside always added 'self' for everything not 'none'
*
* - "script-src 'self' 'unsafe-eval'" allows only self and eval, but forbids inline scripts, onchange, etc
* - "connect-src 'self'" allows ajax requests only to self
* - "style-src 'self' 'unsafe-inline'" allows only self and inline style, which we need
* - "frame-src 'self' manual.egroupware.org" allows frame and iframe content only for self or manual.egroupware.org
* - "manifest-src 'self'"
* - "media-src 'self' data:"
* - "img-src 'self' data: https:"
* - "default-src 'none'" disallows all not explicitly set sources
*
* @var array
*/
private static $sources = array(
'script-src' => array("'unsafe-eval'"),
'style-src' => array("'unsafe-inline'"),
private static $sources = array( // our dhtmlxcommon version (not the current) uses eval,
'script-src' => array("'unsafe-eval'"), // sidebox javascript links, et2_widget_date / jQueryUI datepicker, maybe more
'style-src' => array("'unsafe-inline'"), // eTemplate styles and custom framework colors
'connect-src' => null, // NOT array(), to allow setting no default connect-src!
'frame-src' => null, // NOT array(), to allow setting no default frame-src!
'manifest-src'=> ["'self'"],
'media-src' => ["data:"],
'img-src' => ["data:", "https:"],
'default-src' => ["'none'"], // disallows all not explicit set sources!
);
/**
@ -41,9 +49,8 @@ class ContentSecurityPolicy
*
* Calling this method with an empty array for frame-src, sets no defaults but "'self'"!
*
* @param string|array $set =array() URL (incl. protocol!)
* @param string $source valid CSP source types like 'script-src', 'style-src', 'connect-src', 'frame-src', ...
* @param string|array $attrs 'unsafe-eval' and/or 'unsafe-inline' (without quotes!) or URL (incl. protocol!)
* @param string|array $attrs 'unsafe-eval', 'unsafe-inline' (without quotes!), full URLs or protocols (incl. colon!)
*/
public static function add($source, $attrs)
{
@ -53,12 +60,14 @@ class ContentSecurityPolicy
if (in_array($source, ['frame-src', 'connect-src']) && !isset($attrs))
{
$attrs = [];
// no permssion / user-run-rights check for connect-src
if (($app_additional = Api\Hooks::process('csp-'.$source, [], $source === 'connect-src')))
// for regular (non login) pages, call hook allowing apps to add additional frame- and connect-src
if (basename($_SERVER['PHP_SELF']) !== 'login.php' &&
// no permission / user-run-rights check for connect-src
($app_additional = Api\Hooks::process('csp-'.$source, [], $source === 'connect-src')))
{
foreach($app_additional as $addtional)
foreach($app_additional as $app => $additional)
{
if ($addtional) $attrs = array_unique(array_merge($attrs, $addtional));
if ($additional) $attrs = array_unique(array_merge($attrs, $additional));
}
}
}
@ -81,13 +90,11 @@ class ContentSecurityPolicy
/**
* Set Content-Security-Policy attributes for script-src: 'unsafe-eval' and/or 'unsafe-inline'
*
* Using CK-Editor currently requires both to be set :(
*
* Old pre-et2 apps might need to call Api\Headers::script_src_attrs(array('unsafe-eval','unsafe-inline'))
*
* EGroupware itself currently still requires 'unsafe-eval'!
*
* @param string|array $set =array() 'unsafe-eval' and/or 'unsafe-inline' (without quotes!) or URL (incl. protocol!)
* @param string|array $set 'unsafe-eval', 'unsafe-inline' (without quotes!), full URLs or protocols (incl. colon!)
*/
public static function add_script_src($set=null)
{
@ -99,7 +106,7 @@ class ContentSecurityPolicy
*
* EGroupware itself currently still requires 'unsafe-inline'!
*
* @param string|array $set =array() 'unsafe-inline' (without quotes!) and/or URL (incl. protocol!)
* @param string|array $set 'unsafe-eval', 'unsafe-inline' (without quotes!), full URLs or protocols (incl. colon!)
*/
public static function add_style_src($set=null)
{
@ -109,7 +116,7 @@ class ContentSecurityPolicy
/**
* Set Content-Security-Policy attributes for connect-src:
*
* @param string|array $set =array() URL (incl. protocol!)
* @param string|array $set 'unsafe-eval', 'unsafe-inline' (without quotes!), full URLs or protocols (incl. colon!)
*/
public static function add_connect_src($set=null)
{
@ -121,8 +128,7 @@ class ContentSecurityPolicy
*
* Calling this method with an empty array sets no frame-src, but "'self'"!
*
* @param string|array $set =array() URL (incl. protocol!)
* @return string with attributes eg. "'unsafe-inline'"
* @param string|array $set 'unsafe-eval', 'unsafe-inline' (without quotes!), full URLs or protocols (incl. colon!)
*/
public static function add_frame_src($set=null)
{
@ -136,27 +142,43 @@ class ContentSecurityPolicy
*/
public static function send()
{
self::add('connect-src', null); // set defaults for connect-src (no run rights checked)
self::add('frame-src', null); // set defaults for frame-src
self::add('connect-src', null); // set defaults for connect-src (no run rights checked)
self::add('frame-src', null); // set defaults for frame-src
// force default-src 'none'
self::$sources['default-src'] = ["'none'"];
$policies = array();
foreach(self::$sources as $source => $urls)
{
$policies[] = "$source 'self' ".implode(' ', $urls);
foreach (self::$sources as $source => $urls) {
// for 'none' remove source, as we use "default-src 'none'"
if (in_array("'none'", $urls)) {
if ($source !== 'default-src') continue;
}
// automatic add 'self', if not 'none'
elseif (!in_array("'self'", $urls)) {
array_unshift($urls, "'self'");
}
$policies[] = "$source " . implode(' ', $urls);
}
$csp = implode('; ', $policies);
//$csp = "default-src * 'unsafe-eval' 'unsafe-inline'"; // allow everything
self::header(implode('; ', $policies));
}
/**
* Send a CSP header with given policy
*
* @param {string} $csp
*/
public static function header($csp)
{
$user_agent = UserAgent::type();
$version = UserAgent::version();
// recommendaton ist to not send regular AND deprecated headers together, as they can cause unexpected behavior
if ($user_agent == 'chrome' && $version < 25 || $user_agent == 'safari' && $version < 7)
// recommendation is to not send regular AND deprecated headers together, as they can cause unexpected behavior
if ($user_agent === 'chrome' && $version < 25 || $user_agent === 'safari' && $version < 7)
{
header("X-Webkit-CSP: $csp"); // Chrome: <= 24, Safari incl. iOS
}
elseif ($user_agent == 'firefox' && $version < 23 || $user_agent == 'msie') // Edge is reported as 'edge'!
elseif ($user_agent === 'firefox' && $version < 23 || $user_agent === 'msie') // Edge is reported as 'edge'!
{
header("X-Content-Security-Policy: $csp");
}

2
api/src/Html/HtmLawed.php
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@ -90,7 +90,7 @@ class HtmLawed
// tidy eats away even some wanted whitespace, so we switch it off;
// we used it for its compacting and beautifying capabilities, which resulted in better html for further processing
'tidy'=>0,
'elements' => "* -script -meta",
'elements' => "* -script -meta -object",
'deny_attribute' => 'on*',
'schemes'=>'href: file, ftp, http, https, mailto, tel, phone; src: cid, data, file, ftp, http, https; *:file, http, https',
'hook_tag' =>"hl_my_tag_transform",