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fix($sanitize): Use same whitelist mechanism as $compile does.
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`$sanitize` now uses the same mechanism as `$compile` to validate uris.
By this, the validation in `$sanitize` is more general and can be
configured in the same way as the one in `$compile`.

Changes
- Creates the new private service `$$sanitizeUri`.
- Moves related specs from `compileSpec.js` into `sanitizeUriSpec.js`.
- Refactors the `linky` filter to be less dependent on `$sanitize`
  internal functions.

Fixes #3748.
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tbosch committed Nov 26, 2013
1 parent 68ceb17 commit 3335234
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Showing 9 changed files with 550 additions and 339 deletions.
1 change: 1 addition & 0 deletions angularFiles.js
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,7 @@ angularFiles = {
'src/ng/parse.js',
'src/ng/q.js',
'src/ng/rootScope.js',
'src/ng/sanitizeUri.js',
'src/ng/sce.js',
'src/ng/sniffer.js',
'src/ng/timeout.js',
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5 changes: 5 additions & 0 deletions src/AngularPublic.js
Original file line number Diff line number Diff line change
Expand Up @@ -65,6 +65,7 @@
$ParseProvider,
$RootScopeProvider,
$QProvider,
$$SanitizeUriProvider,
$SceProvider,
$SceDelegateProvider,
$SnifferProvider,
Expand Down Expand Up @@ -136,6 +137,10 @@ function publishExternalAPI(angular){

angularModule('ng', ['ngLocale'], ['$provide',
function ngModule($provide) {
// $$sanitizeUriProvider needs to be before $compileProvider as it is used by it.
$provide.provider({
$$sanitizeUri: $$SanitizeUriProvider
});
$provide.provider('$compile', $CompileProvider).
directive({
a: htmlAnchorDirective,
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34 changes: 12 additions & 22 deletions src/ng/compile.js
Original file line number Diff line number Diff line change
Expand Up @@ -493,14 +493,12 @@ var $compileMinErr = minErr('$compile');
*
* @description
*/
$CompileProvider.$inject = ['$provide'];
function $CompileProvider($provide) {
$CompileProvider.$inject = ['$provide', '$$sanitizeUriProvider'];
function $CompileProvider($provide, $$sanitizeUriProvider) {
var hasDirectives = {},
Suffix = 'Directive',
COMMENT_DIRECTIVE_REGEXP = /^\s*directive\:\s*([\d\w\-_]+)\s+(.*)$/,
CLASS_DIRECTIVE_REGEXP = /(([\d\w\-_]+)(?:\:([^;]+))?;?)/,
aHrefSanitizationWhitelist = /^\s*(https?|ftp|mailto|tel|file):/,
imgSrcSanitizationWhitelist = /^\s*(https?|ftp|file):|data:image\//;
CLASS_DIRECTIVE_REGEXP = /(([\d\w\-_]+)(?:\:([^;]+))?;?)/;

// Ref: http://developers.whatwg.org/webappapis.html#event-handler-idl-attributes
// The assumption is that future DOM event attribute names will begin with
Expand Down Expand Up @@ -584,10 +582,11 @@ function $CompileProvider($provide) {
*/
this.aHrefSanitizationWhitelist = function(regexp) {
if (isDefined(regexp)) {
aHrefSanitizationWhitelist = regexp;
$$sanitizeUriProvider.aHrefSanitizationWhitelist(regexp);
return this;
} else {
return $$sanitizeUriProvider.aHrefSanitizationWhitelist();
}
return aHrefSanitizationWhitelist;
};


Expand All @@ -614,18 +613,18 @@ function $CompileProvider($provide) {
*/
this.imgSrcSanitizationWhitelist = function(regexp) {
if (isDefined(regexp)) {
imgSrcSanitizationWhitelist = regexp;
$$sanitizeUriProvider.imgSrcSanitizationWhitelist(regexp);
return this;
} else {
return $$sanitizeUriProvider.imgSrcSanitizationWhitelist();
}
return imgSrcSanitizationWhitelist;
};


this.$get = [
'$injector', '$interpolate', '$exceptionHandler', '$http', '$templateCache', '$parse',
'$controller', '$rootScope', '$document', '$sce', '$animate',
'$controller', '$rootScope', '$document', '$sce', '$animate', '$$sanitizeUri',
function($injector, $interpolate, $exceptionHandler, $http, $templateCache, $parse,
$controller, $rootScope, $document, $sce, $animate) {
$controller, $rootScope, $document, $sce, $animate, $$sanitizeUri) {

var Attributes = function(element, attr) {
this.$$element = element;
Expand Down Expand Up @@ -730,16 +729,7 @@ function $CompileProvider($provide) {
// sanitize a[href] and img[src] values
if ((nodeName === 'A' && key === 'href') ||
(nodeName === 'IMG' && key === 'src')) {
// NOTE: urlResolve() doesn't support IE < 8 so we don't sanitize for that case.
if (!msie || msie >= 8 ) {
normalizedVal = urlResolve(value).href;
if (normalizedVal !== '') {
if ((key === 'href' && !normalizedVal.match(aHrefSanitizationWhitelist)) ||
(key === 'src' && !normalizedVal.match(imgSrcSanitizationWhitelist))) {
this[key] = value = 'unsafe:' + normalizedVal;
}
}
}
this[key] = value = $$sanitizeUri(value, key === 'src');
}

if (writeAttr !== false) {
Expand Down
74 changes: 74 additions & 0 deletions src/ng/sanitizeUri.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,74 @@
'use strict';

/**
* @description
* Private service to sanitize uris for links and images. Used by $compile and $sanitize.
*/
function $$SanitizeUriProvider() {
var aHrefSanitizationWhitelist = /^\s*(https?|ftp|mailto|tel|file):/,
imgSrcSanitizationWhitelist = /^\s*(https?|ftp|file):|data:image\//;

/**
* @description
* Retrieves or overrides the default regular expression that is used for whitelisting of safe
* urls during a[href] sanitization.
*
* The sanitization is a security measure aimed at prevent XSS attacks via html links.
*
* Any url about to be assigned to a[href] via data-binding is first normalized and turned into
* an absolute url. Afterwards, the url is matched against the `aHrefSanitizationWhitelist`
* regular expression. If a match is found, the original url is written into the dom. Otherwise,
* the absolute url is prefixed with `'unsafe:'` string and only then is it written into the DOM.
*
* @param {RegExp=} regexp New regexp to whitelist urls with.
* @returns {RegExp|ng.$compileProvider} Current RegExp if called without value or self for
* chaining otherwise.
*/
this.aHrefSanitizationWhitelist = function(regexp) {
if (isDefined(regexp)) {
aHrefSanitizationWhitelist = regexp;
return this;
}
return aHrefSanitizationWhitelist;
};


/**
* @description
* Retrieves or overrides the default regular expression that is used for whitelisting of safe
* urls during img[src] sanitization.
*
* The sanitization is a security measure aimed at prevent XSS attacks via html links.
*
* Any url about to be assigned to img[src] via data-binding is first normalized and turned into
* an absolute url. Afterwards, the url is matched against the `imgSrcSanitizationWhitelist`
* regular expression. If a match is found, the original url is written into the dom. Otherwise,
* the absolute url is prefixed with `'unsafe:'` string and only then is it written into the DOM.
*
* @param {RegExp=} regexp New regexp to whitelist urls with.
* @returns {RegExp|ng.$compileProvider} Current RegExp if called without value or self for
* chaining otherwise.
*/
this.imgSrcSanitizationWhitelist = function(regexp) {
if (isDefined(regexp)) {
imgSrcSanitizationWhitelist = regexp;
return this;
}
return imgSrcSanitizationWhitelist;
};

this.$get = function() {
return function sanitizeUri(uri, isImage) {
var regex = isImage ? imgSrcSanitizationWhitelist : aHrefSanitizationWhitelist;
var normalizedVal;
// NOTE: urlResolve() doesn't support IE < 8 so we don't sanitize for that case.
if (!msie || msie >= 8 ) {
normalizedVal = urlResolve(uri).href;
if (normalizedVal !== '' && !normalizedVal.match(regex)) {
return 'unsafe:'+normalizedVal;
}
}
return uri;
};
};
}
44 changes: 28 additions & 16 deletions src/ngSanitize/filter/linky.js
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
'use strict';

/* global htmlSanitizeWriter: false */
/* global sanitizeText: false */

/**
* @ngdoc filter
Expand Down Expand Up @@ -100,7 +100,7 @@
</doc:scenario>
</doc:example>
*/
angular.module('ngSanitize').filter('linky', function() {
angular.module('ngSanitize').filter('linky', ['$sanitize', function($sanitize) {
var LINKY_URL_REGEXP =
/((ftp|https?):\/\/|(mailto:)?[A-Za-z0-9._%+-]+@)\S*[^\s.;,(){}<>]/,
MAILTO_REGEXP = /^mailto:/;
Expand All @@ -110,28 +110,40 @@ angular.module('ngSanitize').filter('linky', function() {
var match;
var raw = text;
var html = [];
// TODO(vojta): use $sanitize instead
var writer = htmlSanitizeWriter(html);
var url;
var i;
var properties = {};
if (angular.isDefined(target)) {
properties.target = target;
}
while ((match = raw.match(LINKY_URL_REGEXP))) {
// We can not end in these as they are sometimes found at the end of the sentence
url = match[0];
// if we did not match ftp/http/mailto then assume mailto
if (match[2] == match[3]) url = 'mailto:' + url;
i = match.index;
writer.chars(raw.substr(0, i));
properties.href = url;
writer.start('a', properties);
writer.chars(match[0].replace(MAILTO_REGEXP, ''));
writer.end('a');
addText(raw.substr(0, i));
addLink(url, match[0].replace(MAILTO_REGEXP, ''));
raw = raw.substring(i + match[0].length);
}
writer.chars(raw);
return html.join('');
addText(raw);
return $sanitize(html.join(''));

function addText(text) {
if (!text) {
return;
}
html.push(sanitizeText(text));
}

function addLink(url, text) {
html.push('<a ');
if (angular.isDefined(target)) {
html.push('target="');
html.push(target);
html.push('" ');
}
html.push('href="');
html.push(url);
html.push('">');
addText(text);
html.push('</a>');
}
};
});
}]);
46 changes: 36 additions & 10 deletions src/ngSanitize/sanitize.js
Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,8 @@ var $sanitizeMinErr = angular.$$minErr('$sanitize');
* it into the returned string, however, since our parser is more strict than a typical browser
* parser, it's possible that some obscure input, which would be recognized as valid HTML by a
* browser, won't make it through the sanitizer.
* The whitelist is configured using the functions `aHrefSanitizationWhitelist` and
* `imgSrcSanitizationWhitelist` of {@link ng.$compileProvider `$compileProvider`}.
*
* @param {string} html Html input.
* @returns {string} Sanitized html.
Expand Down Expand Up @@ -128,11 +130,24 @@ var $sanitizeMinErr = angular.$$minErr('$sanitize');
</doc:scenario>
</doc:example>
*/
var $sanitize = function(html) {
function $SanitizeProvider() {
this.$get = ['$$sanitizeUri', function($$sanitizeUri) {
return function(html) {
var buf = [];
htmlParser(html, htmlSanitizeWriter(buf, function(uri, isImage) {
return !/^unsafe/.test($$sanitizeUri(uri, isImage));
}));
return buf.join('');
};
}];
}

function sanitizeText(chars) {
var buf = [];
htmlParser(html, htmlSanitizeWriter(buf));
return buf.join('');
};
var writer = htmlSanitizeWriter(buf, angular.noop);
writer.chars(chars);
return buf.join('');
}


// Regular Expressions for parsing tags and attributes
Expand All @@ -145,7 +160,6 @@ var START_TAG_REGEXP =
COMMENT_REGEXP = /<!--(.*?)-->/g,
DOCTYPE_REGEXP = /<!DOCTYPE([^>]*?)>/i,
CDATA_REGEXP = /<!\[CDATA\[(.*?)]]>/g,
URI_REGEXP = /^((ftp|https?):\/\/|mailto:|tel:|#)/i,
// Match everything outside of normal chars and " (quote character)
NON_ALPHANUMERIC_REGEXP = /([^\#-~| |!])/g;

Expand Down Expand Up @@ -353,8 +367,18 @@ function htmlParser( html, handler ) {
*/
var hiddenPre=document.createElement("pre");
function decodeEntities(value) {
hiddenPre.innerHTML=value.replace(/</g,"&lt;");
return hiddenPre.innerText || hiddenPre.textContent || '';
if (!value) {
return '';
}
// Note: IE8 does not preserve spaces at the start/end of innerHTML
var spaceRe = /^(\s*)([\s\S]*?)(\s*)$/;
var parts = spaceRe.exec(value);
parts[0] = '';
if (parts[2]) {
hiddenPre.innerHTML=parts[2].replace(/</g,"&lt;");
parts[2] = hiddenPre.innerText || hiddenPre.textContent;
}
return parts.join('');
}

/**
Expand Down Expand Up @@ -384,7 +408,7 @@ function encodeEntities(value) {
* comment: function(text) {}
* }
*/
function htmlSanitizeWriter(buf){
function htmlSanitizeWriter(buf, uriValidator){
var ignore = false;
var out = angular.bind(buf, buf.push);
return {
Expand All @@ -398,7 +422,9 @@ function htmlSanitizeWriter(buf){
out(tag);
angular.forEach(attrs, function(value, key){
var lkey=angular.lowercase(key);
if (validAttrs[lkey]===true && (uriAttrs[lkey]!==true || value.match(URI_REGEXP))) {
var isImage = (tag === 'img' && lkey === 'src') || (lkey === 'background');
if (validAttrs[lkey] === true &&
(uriAttrs[lkey] !== true || uriValidator(value, isImage))) {
out(' ');
out(key);
out('="');
Expand Down Expand Up @@ -430,4 +456,4 @@ function htmlSanitizeWriter(buf){


// define ngSanitize module and register $sanitize service
angular.module('ngSanitize', []).value('$sanitize', $sanitize);
angular.module('ngSanitize', []).provider('$sanitize', $SanitizeProvider);
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1 comment on commit 3335234

@petebacondarwin
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@tbosch - the first character of the subject should be lower case, and there should be no full stop at the end:

fix($sanitize): Uuse same whitelist mechanism as $compile does

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