I've got a local dev site running on http://mysite.local/
(it's a Django admin site with Grappelli installed, if that's any relevance).
The admin site opens a popup window for some operations (i.e. via showRelatedObjectLookupPopup())
Due to previous similar issues with same-origin-policy (in production, the admin site loads some URLs from a CDN domain, which can trigger it) we have a "normaliser" JS function that explicitly sets:
document.domain = "mysite.local";
Both in the parent and in the popup, on page load.
The popup contains a link with an onclick handler that triggers a JS function in the parent:
onclick="opener.dismissRelatedLookupPopup(window, '422'); return false;"
Clicking this link in Chrome or FF results in a similar browser error:
Permission denied to access property "dismissRelatedLookupPopup" on
cross-origin object
or
Blocked a frame with origin "http://mysite.local" from accessing a
cross-origin frame.
Both the popup and the opener URLs share the same protocol, domain and port.
This is only an issue on the local domain. On dev/uat/production sites, (i.e. dev.mysite.com), all of which have their domain set to the superdomain "mysite.com" by the above "normaliser" function, the popup can successfully call the JS function in the parent.
What's stopping it on the local domain? What have I missed?
It seems that switching the local domain, as per the original suggestion from #charlietfl, has indeed fixed the issue. It now runs locally as local.mysite.com instead of mysite.local, and the same-origin error has gone. I'm still unclear on what was triggering the error (was it because the the domain had only two parts as opposed to three? Was it something specific to domains ending in ".local"?) but in the unlikely event that anyone else trips up on this, that's what fixed it for me.
I have an iframe that contains a https:// login page, and I have some JavaScript that applies CSS styles to the iframe on the parent window - this parent window being http://. The protocols don't match, and although I know this is to do with the cross domain issue, I can't figure out how it is possible to set both iframe and parent window to use the same protocol without affecting security.
Any help would be appreciated, and code can be posted if required.
Thanks
Since it's different scheme , you can't access it directly.
But it all depends on what you want to do :
You can use : postMessage , hash period check , create cross proxy iframe which has access to parent.parent
You can also use window.name ( but this will reload the other page).
You should tell us what you ACTUALLY want to do ( after you access the page)
I am attempting to share data across subdomains using Safari. I would like to use an HTML5 database (specifically localStorage as my data is nothing but key-value pairs).
However, it seems as though data stored to example.com can not be accessed from sub.example.com (or vice versa). Is there any way to share a single database in this situation?
Update 2016
This library from Zendesk worked for me.
Sample:
Hub
// Config s.t. subdomains can get, but only the root domain can set and del
CrossStorageHub.init([
{origin: /\.example.com$/, allow: ['get']},
{origin: /:\/\/(www\.)?example.com$/, allow: ['get', 'set', 'del']}
]);
Note the $ for matching the end of the string. The regular expression in the above example will match origins such as valid.example.com, but not invalid.example.com.malicious.com.
Client
var storage = new CrossStorageClient('https://store.example.com/hub.html');
storage.onConnect().then(function() {
return storage.set('newKey', 'foobar');
}).then(function() {
return storage.get('existingKey', 'newKey');
}).then(function(res) {
console.log(res.length); // 2
}).catch(function(err) {
// Handle error
});
Check https://stackoverflow.com/a/39788742/5064633
There is simple way to use cross-domain anything, just create simple page that will be included as proxy iframe hosted on domain you try to access, send PostMessage to that iframe and inside iframe you do your LocalStorage database manipulation. Here is a link to article that do this with lcoalStorage. And here is demo that send message to different page in subdomain check the source code, it use iframe and PostMessage.
EDIT: New version of sysend.js library (used by above demo) use BroadcastChannel if browser support it, but still it require Iframe. Recent version also simplify using of Cross-Origin messages, you have html of the iframe in repo, that you can use (or you can use simple html file with single script tag with the lib) and in parent you just need to call one function sysend.proxy('https://example.com'); where example.com need to have proxy.html file (you can also use your own filename and different path).
Google Chrome blocks localStoage access from an iFrame in another domain by default,unless 3rd party cookie is enabled and so does Safari on iPhone...the only solution seems to be opening the parent domain on a different domain and then sending to to the Child via window.postMessage but looks ugly and shifty on phones...
Yes. This is how:
For sharing between subdomains of a given superdomain (e.g. foo.example.com vs bar.example.com vs example.com), there's a technique you can use in that situation. It can be applied to localStorage, IndexedDB, SharedWorker, BroadcastChannel, etc, all of which offer shared functionality between same-origin pages, but for some reason don't respect any modification to document.domain that would let them use the superdomain as their origin directly.
NOTE: This technique depends on setting document.domain to allow direct communication between iframes on different subdomains. That functionality has now been deprecated. (As of April 2021 it continues to work in all major browsers however. From Chrome v109 the feature will be disabled unless an Origin-Agent-Cluster: ?0 header is also sent.)
NOTE: Be aware that this technique removes the same-origin defences that block malicious script on a subdomain from affecting the main-domain window, or visa versa, potentially broadening the attack surface for XSS attacks. There are other security implications for shared hosting as well - see the MDN document.domain page for details.
(1) Pick one "main" domain to for the data to belong to: i.e. either https://foo.example.com or https://bar.example.com or https://example.com will hold your localStorage data. Let's say you pick https://example.com.
(2) Use localStorage normally for that chosen domain's pages.
(3) On all other https://*.example.com pages (the other domains), use JavaScript to set document.domain = "example.com"; (always the superdomain). Then also create a hidden <iframe>, and navigate it to some page on the chosen https://example.com domain (It doesn't matter what page, as long as you can insert a very little snippet of JavaScript on there. If you're creating the site, just make an empty page specifically for this purpose. If you're writing an extension or a Greasemonkey-style userscript and so don't have any control over pages on the example.com server, just pick the most lightweight page you can find and insert your script into it. Some kind of "not found" page would probably be fine).
(4) The script on the hidden iframe page need only (a) set document.domain = "example.com";, and (b) notify the parent window when this is done. After that, the parent window can access the iframe window and all its objects without restriction! So the minimal iframe page is something like:
<!doctype html>
<html>
<head>
<script>
document.domain = "example.com";
window.parent.iframeReady(); // function defined & called on parent window
</script>
</head>
<body></body>
</html>
If writing a userscript, you might not want to add externally-accessible functions such as iframeReady() to your unsafeWindow, so instead a better way to notify the main window userscript might be to use a custom event:
window.parent.dispatchEvent(new CustomEvent("iframeReady"));
Which you'd detect by adding a listener for the custom "iframeReady" event to your main page's window.
(NOTE: You need to set document.domain = example.com even if the iframe's domain is already example.com: Assigning a value to document.domain implicitly sets the origin's port to null, and both ports must match for the iframe and its parent to be considered same-origin. See the note here: https://developer.mozilla.org/en-US/docs/Web/Security/Same-origin_policy#Changing_origin)
(5) Once the hidden iframe has informed its parent window that it's ready, script in the parent window can just use iframe.contentWindow.localStorage, iframe.contentWindow.indexedDB, iframe.contentWindow.BroadcastChannel, iframe.contentWindow.SharedWorker instead of window.localStorage, window.indexedDB, etc. ...and all these objects will be scoped to the chosen https://example.com origin - so they'll have the this same shared origin for all of your pages!
The most awkward part of this technique is that you have to wait for the iframe to load before proceeding. So you can't just blithely start using localStorage in your DOMContentLoaded handler, for example. Also you might want to add some error handling to detect if the hidden iframe fails to load correctly.
Obviously, you should also make sure the hidden iframe is not removed or navigated during the lifetime of your page... OTOH I don't know what the result of that would be, but very likely bad things would happen.
And, a caveat: setting/changing document.domain can be blocked using the Feature-Policy header, in which case this technique will not be usable as described.
However, there is a significantly more-complicated generalization of this technique, that can't be blocked by Feature-Policy, and that also allows entirely unrelated domains to share data, communications, and shared workers (i.e. not just subdomains off a common superdomain). #jcubic already described it in their answer, namely:
The general idea is that, just as above, you create a hidden iframe to provide the correct origin for access; but instead of then just grabbing the iframe window's properties directly, you use script inside the iframe to do all of the work, and you communicate between the iframe and your main window only using postMessage() and addEventListener("message",...).
This works because postMessage() can be used even between different-origin Windows. But it's also significantly more complicated because you have to pass everything through some kind of messaging infrastructure that you create between the iframe and the main window, rather than just using the localStorage, IndexedDB, etc. APIs directly in your main window's code.
is it possible for javascript inside an iFrame to update the URL (hash) of the parent page (and retrieve it)
Does it have any permissions?
To further explain, I have no hosting for this domain, I can only set up an Iframe. I also cannot use a DNS config to get that page to display because of limitations of my hoster.
I also cannot transfer the domain to them to make that work because my clients wants to keep control of the domain.
Thank you for your help!
If the <iframe> page is within the same domain, probably yes. Otherwise you don't get access to the parent page due to cross-domain restrictions.
You can change the URL of the parent page though:
top.location.href = 'http://www.example.com';
due to security constraints you will not be able to access properties of the parent window IF the domain,port or protocol is different than the one in the iframe.
To be short, the answer is NO.
Your script works only inside the context of that iframe.
If you try for example,
var loc = document.location;
you will see what I mean.
One solution is that when you give the other side your iframe, you should add a script in witch you can do whatever you want, because it runs on their domain.
Maybe dynamically create the source of your iframe and stuff.
HI, i got a simple html page, localy with an iframe. the iframe includes a generated page which got a javascript function. i know want to call that function. of course, im getting "permission denied". so since im new to js and all that stuff i dont know if it's actually possible to do that. give me some hints for searching or a nice solution.
i do cal lthe func like: parent.myiframe.myfunc();
I guess the page in the iframe resides on another server / domain. Modern browser do not allow "cross site scripting", see: http://de.wikipedia.org/wiki/Cross-Site_Scripting
If possible, move the site in the iframe to the same server. An alternative (workaround) would be to proxy the page on the local server, so that that for the client it seems to be loaded from the same domain.
Edit: This is also called a "Same Origin Policy". You can only call java script functions in a document that is:
from the same domain (www.mydomain.com)
from the same subdomain (mail.mydomain.com <- no go!)
both use the same port (p.Ex.
accessing a http://... document from
a http*s*:// document won't work).
There might be another workaround if you have access to the iframe's source:
Change the iframe domain to the same as the outer frame's, by applying:
document.domain = "domain.com";
in the iframe source (see http://ajaxian.com/archives/how-to-make-xmlhttprequest-calls-to-another-server-in-your-domain for more information).
Also there is a Draft for "Cross-Origin Resource Sharing" (http://www.w3.org/TR/cors/) that is already partially implemented in several browser, see: http://www.webdavsystem.com/ajax/programming/cross_origin_requests