I have a CloudFront distribution that blocks the font download in Chrome (desktop version) with the fallowing error:
Font from origin 'https://....cloudfront.net' has been blocked from
loading by Cross-Origin Resource Sharing policy: No
'Access-Control-Allow-Origin' header is present on the requested
resource. Origin 'https://example.com' is therefore not allowed
access.
Where should I set this Access-Control-Allow-Origin header?
I tried adding the header in the "Origin" section of the could distribution but it does not produce any effect.
EDIT #1:
Nginx configuration on origin has the fallowing directive:
location ~ \.(eot|ttf|woff|woff2)$ {
add_header Access-Control-Allow-Origin *;
}
which on this test curl -I https://example.com/skin/frontend/smartwave/default/megamenu/css/fonts/fontawesome-webfont.woff
Retuns the fallowing response:
HTTP/1.1 200 OK
Server: nginx
Date: Tue, 02 Feb 2016 17:53:39 GMT
Content-Type: application/font-woff
Content-Length: 44432
Last-Modified: Wed, 13 May 2015 15:58:11 GMT
Connection: keep-alive
ETag: "55537493-ad90"
Pragma: public
Cache-Control: max-age=31536000, public, must-revalidate, proxy-revalidate
Accept-Ranges: bytes
From what I see here this header Access-Control-Allow-Origin is missing.
Also I whitelisted the header on CloudFront so that it will not block it:
That was hard to trace as the rules for headers were set in 2 different locations and not in one.
Fixing the correct header for the correct type of file did the job, but you have to consider the fact that in some locations trying to overwrite the NGINX rules does not work. It will only consider the first rule.
A comprehensive description of headers can be found here https://stackoverflow.com/a/10636765/1168944
Related
Given these request headers:
Host: api.example.org
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:41.0) Gecko/20100101 Firefox/41.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
DNT: 1
Origin: https://web.example.org
Access-Control-Request-Method: GET
Access-Control-Request-Headers: authorization
Connection: keep-alive
Pragma: no-cache
Cache-Control: no-cache
And these response headers:
Connection: keep-alive
Content-Length: 0
Content-Type: text/plain; charset=utf-8
Date: Tue, 13 Oct 2015 10:57:34 GMT
Server: nginx/1.8.0
access-control-allow-headers: Authorization, Content-Type
access-control-allow-methods: PUT, DELETE, PATCH
access-control-allow-origin: *
This works even though only the Authorization and Content-Type headers are explicitly allowed. Why didn't I have to allow other headers that my browser sends? (like DNT for example)
Update: this MDN page contains an overview of simple headers (default CORS-safelisted request headers):
A simple header (or CORS-safelisted request header) is one of the
following HTTP headers:
Accept
Accept-Language
Content-Language
Content-Type with a MIME type of its parsed value (ignoring parameters) of either application/x-www-form-urlencoded, multipart/form-data, or text/plain.
Or one of these client hint headers:
DPR
Downlink
Save-Data
Viewport-Width
Width
Without seeing your code to generate the headers, or on which system you are serving from, i.e. nginx or apache, the best I can do is refer you to http://client.cors-api.appspot.com/client which will allow you to test your CORS requests. Also, you should look at http://enable-cors.org/server.html for your specific setup. For instance on nginx, you could have something like this
add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
There is a set of normal headers, and then the set of headers that you have to explicitly call out. see http://www.html5rocks.com/en/tutorials/cors/#toc-adding-cors-support-to-the-server about setting it up on a server.
The Access-Control-Allow-Headers is attached by backend, you cannot control that header on client side.Access-Control-Allow-Headers should be returned in response object.
So to include other headers into Access-Control-Allow-Headers header in response object - you have to configure your web server or update backend application which serves requests to attach desired value of Access-Control-Allow-Headers to each request.
To allow any headers in your client requests server should add Access-Control-Allow-Origin: * header to each response.
There are a lot of articles and info of how you can setup CORS to work in the way you want. For example that one - Enabling CORS
i am using Apache as backend server and nginx as frontend server. I need to make PDF files downloadable (at this moment they are opening in a browser window).
Here's a link:
link
Here's what i have tried so far in my .htaccess file:
<FilesMatch "\.(pdf)$">
ForceType application/octet-stream
Header set Content-Disposition attachment
</FilesMatch>
Didn't work, just opens the file in a browser.
AddType application/force-download pdf
Didn't work.
AddType application/octet-stream .pdf
Didn't work.
UPDATE
Tried: wget --server-response -O /dev/null http://domain.com/files/teltomat.pdf
And got response:
HTTP request sent, awaiting response...
HTTP/1.1 200 OK
Server: nginx
Date: Wed, 24 Sep 2014 17:40:54 GMT
Content-Type: application/pdf
Content-Length: 3116445
Last-Modified: Wed, 24 Sep 2014 13:28:07 GMT
Connection: keep-alive
Keep-Alive: timeout=60
ETag: "5422c6e7-2f8d9d"
Expires: Thu, 31 Dec 2037 23:55:55 GMT
Cache-Control: max-age=315360000
Accept-Ranges: bytes
Length: 3116445 (3,0M) [application/pdf]
Saving to: ‘/dev/null’
You could try the HTML5 solution of adding a "download" instead of "target":
link
As it looks like the server's end is doing the right thing (by making the disposition "attachment") but maybe the browser is deciding on its own that it can handle PDF's inline and opens a new window instead.
I have setup apache2 with django and mod_wsgi in Debian Wheezy. I enabled mod_mem_cache with this configuration:
<IfModule mod_mem_cache.c>
CacheEnable mem /
MCacheSize 400000
MCacheMaxObjectCount 100
MCacheMinObjectSize 1
MCacheMaxObjectSize 500000
CacheIgnoreNoLastMod On
CacheIgnoreHeaders Set-Cookie
</IfModule>
based on the fact that MCacheMaxStreamingBuffer is the smaller of 100000 or MCacheMaxObjectSize as stated in the docs.
When I try hitting a page with size 3.3KB I get these response headers in firebug:
Connection Keep-Alive
Content-Encoding gzip
Content-Type text/html; charset=utf-8
Date Wed, 27 Aug 2014 14:47:39 GMT
Keep-Alive timeout=5, max=100
Server Apache/2.2.22 (Debian)
Transfer-Encoding chunked
Vary Cookie,Accept-Encoding
and the page isn't served from cache. In the page source there is however the correct header 'Cache-Control: max-age=300,must-revalidate' but doesn't show up in firebug.
In apache log I only see correctly:
[info] mem_cache: Cached url: https://83.212.**.**/?
With another test page that I created outside of django that doesn't have chunked encoding as a header, caching works fine. Why is the page not served from cache? Has anyone seen something similar?
I'm using LAMP (Linux, Apache, MySQL, PHP) server.
Currently the server sends the response with next Headers list. I want to eliminate Keep-Alive entry for security reasons, to have Headers list without it. Is it possible to prevent sending the Keep-Alive entry in the Headers list?
Current Response Headers:
Cache-Control private, no-cache, no-store, must-revalidate, post-check=0, pre-check=0
Connection Keep-Alive
Content-Encoding gzip
Content-Type text/html; charset=UTF-8
Date Thu, 13 Mar 2014 01:43:49 GMT
Expires Thu, 13 Mar 2014 01:43:49 GMT
Keep-Alive timeout=5, max=200
Last-Modified Thu, 13 Mar 2014 01:43:49 GMT
Pragma no-cache
Server Apache
Transfer-Encoding chunked
Vary Accept-Encoding
X-DNS-Prefetch-Control off
X-Frame-Options sameorigin
Response Headers I Would Like Instead:
Cache-Control private, no-cache, no-store, must-revalidate, post-check=0, pre-check=0
Connection Keep-Alive
Content-Encoding gzip
Content-Type text/html; charset=UTF-8
Date Thu, 13 Mar 2014 01:43:49 GMT
Expires Thu, 13 Mar 2014 01:43:49 GMT
Last-Modified Thu, 13 Mar 2014 01:43:49 GMT
Pragma no-cache
Server Apache
Transfer-Encoding chunked
Vary Accept-Encoding
X-DNS-Prefetch-Control off
X-Frame-Options sameorigin
Is it possible to prevent sending the Keep-Alive entry in the Headers list?
To my knowledge, no. The whole purpose of the Keep-Alive header is to communicate the need for a persistent connection to the client. So getting rid of the headers gets rid of the main form of communication between the client & the server.
That said, you might be able to get it unset by using unset in your Apache config or .htaccess as explained here. I emphasize might since I have had header directives not behave as expected in some versions of Apache. But assuming good faith, first be sure the headers module is enabled. In Ubuntu 12.04 you would do this:
sudo a2enmod headers
And then add this to your Apache config or .htaccess:
<IfModule mod_headers.c>
Header unset Keep-Alive
</IfModule>
Now restart Apache:
sudo service apache2 restart
More details on the header directive are here.
There are a few ways to this in apache:
Server-wide using the KeepAlive directive ( KeepAlive ). However you can not have this in per-directory configuration files, so setting KeepAlive Off will turn off keep alive for the entire server.
Using SetEnv or SetEnvIf with mod_env, and set the nokeepalive environmental variable. This will turn off keepalive for the location where the environmental is set, or the rule that is matched by SetEnvIf (depending with you use). e.g.
can be in HTACCESS
SetEnv nokeepalive 1
Using mod_rewrite to again set the environmental for a specific rule, e.g.
RewriteRule some-file.html - [E=nokeepalive:1]
Using PHP (or any other server site language) and sending the header Connection: close. This will cause Apache to omit the Keep-Alive header, since the connection is no longer keepalive. e.g.
php
header('Connection: close');
Use mod_headers to set the connection header to close again, e.g.
Header set Connection "close"
I personally have not tested the last one, but it should work.
KeepAlive behavior (availability and timeouts) is directly configurable:
http://httpd.apache.org/docs/2.4/mod/core.html#keepalive
Changing this is primarily an aspect of performance rather than security, but you're free to test the implications in your own environment.
I am starting to learn about http correctly.
I am working in lamp stack.
On the command line i am requesting a local page which will be served with apache to see the headers that are returned.
curl -i local.testsite
The page i am requesting has no content and i am not setting any headers but there are already a lot of headers sent in the response such as:
HTTP/1.1 200 OK
Date: Thu, 17 Jan 2013 20:28:52 GMT
Server: Apache/2.2.22 (Ubuntu)
X-Powered-By: PHP/5.3.10-1ubuntu3.4
Vary: Accept-Encoding
Content-Length: 0
Content-Type: text/html
So if i am not setting these, does apache set these automatically?
Yes Apache is setting those by default. By the way, if you only care about the headers, you should use
curl -I local.testsite
-I returns the headers only (HTTP HEAD request), such that even if you had content on the page you would only get the header.
Some are set by PHP:
The X-Powered-By header is set by the expose_php INI setting.
The Content-Type header is set by the default_mimetype INI setting.
The others are set by Apache:
The Server header is set by the ServerSignature directive.
The Vary: Accept-Encoding header is usually sent when mod_deflate is enabled.
Date and Content-Length are not configurable as they are part of the HTTP spec. Date is included as a MUST (except under some conditions) and Content-Length as a SHOULD.
See also How to remove date header from apache? and How to disable the Content-Length response header with Apache?.