I'm struggling with this error, I use apache2 and set a Header :
Header set X-Frame-Options: "ALLOW-FROM ip"
Header set X-Frame-Options: "ALLOW-FROM domain-name"
but I get this error in the dev tools :
Invalid 'X-Frame-Options' header encountered when loading 'https://wewatch.ml/': 'ALLOW-FROM ip' is not a recognized directive. The header will be ignored
ALLOW-FROM is not recognized by most browsers. You should set Content-Security-Policy header with the value "frame-ancestors domain-name;" instead. If you set this, all browsers that understand it will ignore X-Frame-Options. Until IE11 was removed recently I would set both headers as IE11 didn't understand Content-Security-Policy, but would recognize ALLOW-FROM.
Related
I created an API endpoint using Google Cloud Functions and am trying to call it from a JS fetch function.
I am running into errors that I am pretty sure are related to either CORS or the output format, but I'm not really sure what is going on. A few other SO questions are similar, and helped me realize I needed to remove the mode: "no-cors". Most mention enabling CORS on the BE, so I added response.headers.set('Access-Control-Allow-Origin', '*') - which I learned of in this article - to ensure CORS would be enabled... But I still get the "Failed to fetch" error.
The Full Errors (reproducible in the live demo linked below) are:
Uncaught Error: Cannot add node 1 because a node with that id is
already in the Store. (This one is probably unrelated?)
Access to fetch at
'https://us-central1-stargazr-ncc-2893.cloudfunctions.net/nearest_csc?lat=37.75&lon=-122.5'
from origin 'https://o2gxx.csb.app' has been blocked by CORS policy:
Request header field access-control-allow-origin is not allowed by
Access-Control-Allow-Headers in preflight response.
GET
https://us-central1-stargazr-ncc-2893.cloudfunctions.net/nearest_csc?lat=37.75&lon=-122.5 net::ERR_FAILED
Uncaught (in promise) TypeError: Failed to fetch
See Code Snippets below, please note where I used <---- *** Message *** to denote parts of the code that have recently changed, giving me one of those two errors.
Front End Code:
function getCSC() {
let lat = 37.75;
let lng = -122.5;
fetch(
`https://us-central1-stargazr-ncc-2893.cloudfunctions.net/nearest_csc?lat=${lat}&lon=${lng}`,
{
method: "GET",
// mode: "no-cors", <---- **Uncommenting this predictably gets rid of CORS error but returns a Opaque object which seems to have no data**
headers: {
// Accept: "application/json", <---- **Originally BE returned stringified json. Not sure if I should be returning it as something else or if this is still needed**
Origin: "https://lget3.csb.app",
"Access-Control-Allow-Origin": "*"
}
}
)
.then(response => {
console.log(response);
console.log(response.json());
});
}
Back End Code:
import json
import math
import os
import flask
def nearest_csc(request):
"""
args: request object w/ args for lat/lon
returns: String, either with json representation of nearest site information or an error message
"""
lat = request.args.get('lat', type = float)
lon = request.args.get('lon', type = float)
# Get list of all csc site locations
with open(file_path, 'r') as f:
data = json.load(f)
nearby_csc = []
# Removed from snippet for clarity:
# populate nearby_csc (list) with sites (dictionaries) as elems
# Determine which site is the closest, assigned to var 'closest_site'
# Grab site url and return site data if within 100 km
if dist_km < 100:
closest_site['dist_km'] = dist_km
// return json.dumps(closest_site) <--- **Original return statement. Added 4 lines below in an attempt to get CORS set up, but did not seem to work**
response = flask.jsonify(closest_site)
response.headers.set('Access-Control-Allow-Origin', '*')
response.headers.set('Access-Control-Allow-Methods', 'GET, POST')
return response
return "No sites found within 100 km"
Fuller context for code snippets above:
Here is a Code Sandbox Demo of the above.
Here is the full BE code on GitHub, minus the most recent attempt at adding CORS.
The API endpoint.
I'm also wondering if it's possible that CodeSandbox does CORS in a weird way, but have had the same issue running it on localhost:3000, and of course in prod would have this on my own personal domain.
The Error would appear to be CORS-related ( 'https://o2gxx.csb.app' has been blocked by CORS policy: Request header field access-control-allow-origin is not allowed by Access-Control-Allow-Headers in preflight response.) but I thought adding response.headers.set('Access-Control-Allow-Origin', '*') would solve that. Do I need to change something else on the BE? On the FE?
TLDR;
I am getting the Errors "Failed to fetch" and "field access-control-allow-origin is not allowed by Access-Control-Allow-Headers" even after attempts to enable CORS on backend and add headers to FE. See the links above for live demo of code.
Drop the part of your frontend code that adds a Access-Control-Allow-Origin header.
Never add Access-Control-Allow-Origin as a request header in your frontend code.
The only effect that’ll ever have is a negative one: it’ll cause browsers to do CORS preflight OPTIONS requests even in cases when the actual (GET, POST, etc.) request from your frontend code would otherwise not trigger a preflight. And then the preflight will fail with this message:
Request header field Access-Control-Allow-Origin is not allowed by Access-Control-Allow-Headers in preflight response
…that is, it’ll fail with that unless the server the request is being made to has been configured to send an Access-Control-Allow-Headers: Access-Control-Allow-Origin response header.
But you never want Access-Control-Allow-Origin in the Access-Control-Allow-Headers response-header value. If that ends up making things work, you’re actually just fixing the wrong problem. Because the real fix is: never set Access-Control-Allow-Origin as a request header.
Intuitively, it may seem logical to look at it as “I’ve set Access-Control-Allow-Origin both in the request and in the response, so that should be better than just having it in the response” — but it’s actually worse than only setting it in the response (for the reasons described above).
So the bottom line: Access-Control-Allow-Origin is solely a response header, not a request header. You only ever want to set it in server-side response code, not frontend JavaScript code.
The code in the question was also trying to add an Origin header. You also never want to try to set that header in your frontend JavaScript code.
Unlike the case with the Access-Control-Allow-Origin header, Origin is actually a request header — but it’s a special header that’s controlled completely by browsers, and browsers won’t ever allow your frontend JavaScript code to set it. So don’t ever try to.
<LocationMatch "\.(?i:pps)$">
ForceType application/vnd.ms-powerpoint
Header set Content-Disposition attachment
</LocationMatch>
ForceType application/vnd.openxmlformats–officedocument.presentationml.slideshow
Header set Content-Disposition attachment
Not sure which direction you are wanting these applied, and I'm not an apache user, but the header actions are simple. Pick your request/response event, match the appropriate string and the header actions are:
HTTP::header replace Content-Type application/vnd.ms-powerpoint
HTTP::header insert Content-Disposition attachment
I am developing a webapp with static files on one server and api on another. The front end is developed using angular and backend using laravel.
For CSRF-TOKEN fetching during the first load, within angular run block I have this code
if(!$cookies.get('XSRF-TOKEN')){
$http.get(API+'/csrf_token').success(function(d){
$cookies.put('XSRF-TOKEN',d.XSRF_TOKEN);
//$cookies.put('laravel-session',d.LARAVEL_ID);
//$http.defaults.headers.common.X-CSRF-TOKEN = 'Basic YmVlcDpib29w';
//$http.defaults.headers.post['X-CSRF-TOKEN']=$cookies.get('XSRF-TOKEN');
$http.defaults.headers.post['X-CSRF-TOKEN']=d.XSRF_TOKEN;
});
The other way I have tried to get the same was using this way.
Also set $httpProvider.defaults.withCredentials = true; so that cookies be sent along with requests.
The route /csrf_token setup as
Route::get("/csrf_token", function(){
//return \Response::json("asd",200)->withCookie(cookie("XSRF-TOKEN",csrf_token()));
return csrf_token(); //\Crypt::encrypt(csrf_token())
});
All the ajax POST requests throw TokenMismatchException in VerifyCsrfToken.php line 67:.
Next I have sent the csrf_token parameter as _token attached with the post parameters, still the same problem.
Tried all the above, returning encrypted token from /csrf_token, but still same problem.
Repeated all the steps clearing the config:cache and composer dumpautoload in api server, but still same problem.
Reviewed config file ,some values -
'driver' => env('SESSION_DRIVER', 'file'),
'encrypt' => false,
'files' => storage_path('framework/sessions'),
'secure' => false,
(These values seem to be okay)
Next reviewed Virtual config file for CORS configuration (inside directory tag)
Header set Access-Control-Allow-Origin "www.mydomain.com" #real domain not posted
Header set Access-Control-Allow-Credentials 'true'
Header always set Access-Control-Max-Age "2000"
Header set Access-Control-Allow-Headers 'X-CSRF-TOKEN'
Header always set Access-Control-Allow-Headers "X-Requested-With, Content-Type, Origin, Authorization, Accept, Client-Security-Token, Accept-Encoding"
Header always set Access-Control-Allow-Methods "POST, GET, OPTIONS, DELETE, PUT"
Options Indexes FollowSymLinks Includes ExecCGI
AllowOverride All
Require local
Wasted hours googling.(frustrated). Need help.
NB: I couldn't find any more tutorial/answers similar to token mismatch problem netiher on stackoverflow nor on any other website that I havn't tried. Thanks.
I'm trying to get a JSON file from instagram, and I got an error when I make an $http.get :
insta.ctrl :
insta.controler 'instaCtrl' ($scope, $http), ->
$http.get('http://api.instagram.com/publicapi/oembed/?url=http://instagr.am/p/fA9uwTtkSN/')
.success(data), ->
#done !
.error(e), ->
#nah !
my apache2's conf
Header always set Access-Control-Allow-Origin "*"
Header always set Access-Control-Allow-Headers "X-Requested-With, Content-Type, Origin, Authorization, Accept, Client-Security-Token, Accept-Encoding"
Header always set Access-Control-Allow-Methods "POST, GET, OPTIONS, DELETE, PUT"
Error message on chrome :
XMLHttpRequest cannot load #url_of_intagram_api_here. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin '' is therefore not allowed access.
It work when I disable the internet security in chrome.
Any ideas?
Apparently Instagram API doesn't implement CORS. However they provide JSONP interface for data retrieving. So what you can do is to use jsonp method:
$http.jsonp('http://api.instagram.com/publicapi/oembed/?url=http://instagr.am/p/fA9uwTtkSN/&callback=JSON_CALLBACK').success(function(data) {
$scope.data = data;
});
Note callback=JSON_CALLBACK GET parameter you need to send.
Demo: http://plnkr.co/edit/OG1sT7A9OM1hWBqCvSmC?p=preview
I am using tcpdf with Cakephp. The PDFs are downloaded good in Linux but when it comes to Mac for Opera and Safari it add .html ectension to it.
I also noticed that even if it downloads as PDF document in FireFox and Google Chrome, the Pop-up to save as reads it as "HTML document" but save as PDF. PLease help me with this.
Try to modify headers, like:
header("Content-Description: File Transfer");
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename($file_name));
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header("Cache-Control: private", false); // required for certain browsers
header('Pragma: public');
header('Content-Length: ' . filesize($file_name));
Hope it works. :)
It seems like Mac and Safari are more strict when it comes to mime types, and always obeys the content type set in your scripts. So if the Content type is being set to text/html, Safari will expect it to be a HTML document and add the html extension. Firefox and Chrome are using this content-type header to present the file type (HTML document), but does not change the filename so it saves as a PDF.
As you are using CakePHP, it's a good idea to use the built in file response in your Controller:
$this->response->file($path,array('download' => true, 'name' => $filename));
return $this->response;
This will correctly set the headers you need for most files. See here for docs: http://book.cakephp.org/2.0/en/controllers/request-response.html#sending-files
Be warned, CakePHP might not know the mimetype of some files, and will default to text/html. Then you'll get the same problem in Safari. It's a good idea to test and if you see this happening, set the mime types yourself (BEFORE setting the file):
$ext = pathinfo($filename, PATHINFO_EXTENSION);
switch ($ext) {
case 'dotx':
$this->response->type('application/vnd.openxmlformats-officedocument.wordprocessingml.template');
break;
}
$this->response->file($path,array('download' => true, 'name' => $filename));
return $this->response;
I found by adding
$this->response->type('application/pdf');
to the view file and by updating to the latest version of the TCPDF vendor files it resolved the same issue for us (as well as other display issues).
In your controller simply add this
$this->response->header(array('Content-type: application/pdf'));
$this->response->type('pdf');
By adding this same issue is solved to me.