I am using Postal PIN Code API for getting Post Office(s) details search by Postal PIN Code in angular 5 application. Below is the url of the external API :
http://postalpincode.in/api/pincode/{**PINCODE}**
I am issuing a GET request from the application but it is giving me below error :
No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:4200' is therefore not allowed access
Although this request is working perfectly fine from browser and postman. I understand that we need to configure our server with cross-domain policies for accepting cross-domain request but this is an external API and I don't have control over it. How can I resolve this issue?
Thanks in Advance !!
Best: CORS header (requires server changes) CORS (Cross-Origin Resource Sharing) is a way for the server to say “I will accept your request, even though you came from a different origin.” This requires cooperation from the server – so if you can’t modify the server (e.g. if you’re using an external API), this approach won’t work.
Modify the server to add the header Access-Control-Allow-Origin: * to enable cross-origin requests from anywhere (or specify a domain instead of *). This should solve your problem.
2nd choice: Proxy Server If you can’t modify the server, you can run your own proxy. And this proxy can return the Access-Control-Allow-Origin header if it’s not at the Same Origin as your page.
Instead of sending API requests to some remote server, you’ll make requests to your proxy, which will forward them to the remote server.
Here are a few proxy options.
Ref: https://daveceddia.com/access-control-allow-origin-cors-errors-in-angular/
Related
I am attempting to configure Swagger Authentication on my resource server, so that I can authenticate against my authorization server.
I have the resource and authorization servers separated. They are both starting up on my localhost with different ports.
Resource Server on port 8083
Authorization Server on port 8081
Whenever I attempt to "Authorize", there is a CORS issues.
I forked a project from another website to use as my testing grounds. Below is the forked project.
https://github.com/cbriarnold/oauth2-spring-boot-2.0.2
To test, once both the authorization server and resource server are started, do the following:
Go to http://localhost:8083/swagger-ui.html
Click on "Authorize" button
Click on "Authorize" button in dialog
If you have the developer tools open, you will see that there is the CORS error
Access to fetch at 'http://localhost:8081/oauth/token/' from origin 'http://localhost:8083' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: Redirect is not allowed for a preflight request.
The http status code associated with the above CORS error was 302.
So, I modify the source to try to permitAll (I know this is undesired from a security perspective, but I am just trying to figure out what is going on). I will receive the same CORS error, but with the https status code of 403. Code is found on the following branch.
https://github.com/cbriarnold/oauth2-spring-boot-2.0.2/tree/permitAll
Any suggestions?
I think you need to add #CrossOrigin(/*your hitting server*/) on your controllers
it's a chrome security check to see if your are permitted to talk with that server or not it sends an option request at first and if you're permitted it send your original request which is accessing swagger
if you want to make sure if that is a cross origin problem or not try to send that request via postman because postman send your request direct without option request at first
I am trying to access NIFI rest api of another server from my machine using ajax like below,
url:"https://serverip:port/nifi-api/",
{Authorization : 'Bearer ' + 'access token here'}
Getting Response to preflight request doesn't pass access control
check: No 'Access-Control-Allow-Origin' header is present on the
requested resource error.
Apache NiFi's API is designed to be invoked by a variety of clients, but in this case I think you are encountering a security precaution put in place by CORS (Cross-Origin Resource Sharing).
If a piece of code on server A (your non-NiFi machine) makes an AJAX request to a different origin (your NiFi instance), and the HTTP method is not GET (and some other minor restrictions), server A will first send a "preflight" request, which is HTTP OPTIONS, to the remote instance to determine what requests are valid. A server can reply to this with the header Access-Control-Allow-Origin: *, which is a wildcard value denoting it accepts requests from any origin. However, if you want to send credentials along with the request, the originating hostname must be explicitly listed in the response (Access-Control-Allow-Origin: https://serverA.com).
Because NiFi uses an embedded Jetty server to host the API, you may have to explicitly add a CrossOriginFilter as described here.
I'm creating a web appliacation that will run on a server that I can not manage nor modify in any case.
Within that application, I need to exceute a AJAX call to a different server.
This will always be blocked by the 'Same Origin Policy'.
Where server01.test.net is the webserver and mail.test.net is the second server.
Is there a way to enable CORS by any means in the client side, as I'm not able to add the 'Access-Control-Allow-Origin "*"' on the server. Or any other workaournd?
Thanks
CORS is an option with the SERVER. In no way client can by themselves enable CORS.
If client would have been allowed to do that, the whole purpose of CORS would be defeated.
If the server you are calling does not support CORS, you will not be able to make the request to the third-party server using AJAX.
You will have to resort to setting up a pass-through AJAX route in your application. The client (browser) makes a request to your AJAX route which proxies the call to the third-party server and returns the result. Because the third-party request is happening on the server rather than the browser, Same Origin Policy doesn't apply.
This approach means there will be an additional request that wouldn't be necessary if you could use CORS, but there really isn't another option.
Am working in Mobile App develoment using HTML5 + Phonegap. Currently am working a mobile App using XMLRPC and its working fine. (Android and iOS)
I need to work the same application as a website in browsers. (using HTML5).
But when am trying to Run my application on website i am getting this error :
XMLHttpRequest cannot load 'Client' URL'. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost <http://localhost/>' is therefore not allowed access.
When am search experts says that use JSONP. But using same XMLRPC method can i work it ?
For example ;
For a Login purposes am using ;
$.xmlrpc({
url: 'http://clienturl/xmlrpc/common',
methodName: 'login',
params: [Database_name','user_name','Password'],
success: function(response, status, jqXHR) {
alert('success'); },
error: OnError
});
Its working fine as a Mobile Application.
But gets Access-Control-Allow-Origin cross domain issue when i am trying to run as a Website.
How can i fix this ?
By default the SOP (same origin policy) allows cross-origin requests, but it prevents receiving the responses of those requests. The Access-Control-Allow-Origin in your error message is a CORS (cross-origin resource sharing) header. It tells the browser that you allow reading the responses of a domain (your XMLRPC server's domain) by sending requests from another domain (your XMLRPC client's domain). So you have to send back CORS allow headers from your server if you want to call it with AJAX.
note: CORS won't work in old browsers.
Possible solutions:
If you call http://clienturl/xmlrpc/common from http://localhost then the
response.header('Access-Control-Allow-Origin', "*")
is one not so secure solution according to this: Origin http://localhost is not allowed by Access-Control-Allow-Origin
But you can always add another hostname (e.g. http://client.xml.rpc) for your client, for example by windows you can modify the hosts file and add a binding using the IIS server.
I don't recommend this solution, because it is a security risk with the allow credentials header.
Another more secure options is to make a list of allowed hosts, check from which host you got the actual request, and send back the proper header:
if (allowedHosts.contains(request.host))
if (request.host== "http://localhost")
response.header('Access-Control-Allow-Origin', "null");
else
response.header('Access-Control-Allow-Origin', request.host);
else
response.header('Access-Control-Allow-Origin', server.host);
This is the proper solution with multiple hosts, because if you allow credentials for *, then everybody will be able to read and write the session of a logged in user.
By http://localhost and file:/// IRIs you have to use the null origin. I am unsure about other protocols, I guess in the current browsers you have to use null origin by them as well.
I've a server named, foo.com where my application is running and accessing a service available on a different domain bar.foo.com.
With the simple XHR request to bar.foo.com/getUsers, I'm getting an error saying, No 'Access-Control-Allow-Origin' header is present. I do not want to use JSONP as a fallback to cross-domain issue.
Is there any easy fix I can do on server level to enable cross subdomain requests while XHRing?
It appears that I need to set allow-cross-domain headers on server when a response is returned as suggested by #Blender above.
Or I can use xdomain library which uses PostMessage API to enable cors. With this I can even read iframe's content served by different domain.