Because you have a very simple CORS policy (Allow all requests from XXX domain), you don’t need to make it so complicated. Try doing the following first (A very basic implementation of CORS). If you haven’t already, install the CORS nuget package. Install-Package Microsoft.AspNetCore.Cors In the ConfigureServices method of your startup.cs, add the CORS services. … Read more
Try adding the following middleware to your NodeJS/Express app (I have added some comments for your convenience): // Add headers before the routes are defined app.use(function (req, res, next) { // Website you wish to allow to connect res.setHeader(‘Access-Control-Allow-Origin’, ‘http://localhost:8888’); // Request methods you wish to allow res.setHeader(‘Access-Control-Allow-Methods’, ‘GET, POST, OPTIONS, PUT, PATCH, DELETE’); // … Read more
I wrote an article on this issue a while back, Cross Domain AJAX. The easiest way to handle this if you have control of the responding server is to add a response header for: Access-Control-Allow-Origin: * This will allow cross-domain Ajax. In PHP, you’ll want to modify the response like so: <?php header(‘Access-Control-Allow-Origin: *’); ?> … Read more
mode: ‘no-cors’ won’t magically make things work. In fact it makes things worse, because one effect it has is to tell browsers, “Block my frontend JavaScript code from seeing contents of the response body and headers under all circumstances.” Of course you never want that. What happens with cross-origin requests from frontend JavaScript is that … Read more
When you start playing around with custom request headers you will get a CORS preflight. This is a request that uses the HTTP OPTIONS verb and includes several headers, one of which being Access-Control-Request-Headers listing the headers the client wants to include in the request. You need to reply to that CORS preflight with the … Read more
Here’s how you can debug CORS requests using curl. Sending a regular CORS request using cUrl: curl -H “Origin: http://example.com” –verbose \ https://www.googleapis.com/discovery/v1/apis?fields= The -H “Origin: http://example.com” flag is the third party domain making the request. Substitute in whatever your domain is. The –verbose flag prints out the entire response so you can see the … Read more
The CORS spec is all-or-nothing. It only supports *, null or the exact protocol + domain + port: http://www.w3.org/TR/cors/#access-control-allow-origin-response-header Your server will need to validate the origin header using the regex, and then you can echo the origin value in the Access-Control-Allow-Origin response header.
Both attributes have been added to Bootstrap CDN to implement Subresource Integrity. Subresource Integrity defines a mechanism by which user agents may verify that a fetched resource has been delivered without unexpected manipulation Reference Integrity attribute is to allow the browser to check the file source to ensure that the code is never loaded if … Read more
This is a part of security, you cannot do that. If you want to allow credentials then your Access-Control-Allow-Origin must not use *. You will have to specify the exact protocol + domain + port. For reference see these questions : Access-Control-Allow-Origin wildcard subdomains, ports and protocols Cross Origin Resource Sharing with Credentials Besides * … Read more
I spent some time being confused as to the purpose of the preflight request but I think I’ve got it now. The key insight is that preflight requests are not a security thing. Rather, they’re a not-changing-the-rules thing. Preflight requests have nothing to do with security, and they have no bearing on applications that are … Read more