Access-Control-Allow-Origin Multiple Origin Domains?

Is there a way to allow multiple cross-domains using the Access-Control-Allow-Origin header?

I'm aware of the *, but it is too open. I really want to allow just a couple domains.

As an example, something like this:

Access-Control-Allow-Origin: http://domain1.com, http://domain2.com

I have tried the above code but it doesn't seem to work in Firefox.

Is it possible to specify multiple domains or am I stuck with just one?

Answers

For Nginx users to allow CORS for multiple domains. To match a list of domain and subdomain this regex make it ease to work with fonts:

location ~* \.(?:ttf|ttc|otf|eot|woff|woff2)$ {
   if ( $http_origin ~* (https?://(.+\.)?(domain1|domain2|domain3)\.(?:me|co|com)$) ) {
      add_header "Access-Control-Allow-Origin" "$http_origin";
   }
}

This will only echo "Access-Control-Allow-Origin" headers that matches with the given list of domains.

Slightly tighter CORS config for nginx

# based on https://gist.github.com/4165271/
#
# Slightly tighter CORS config for nginx
#
# A modification of https://gist.github.com/1064640/ to include a white-list of URLs
#
# Despite the W3C guidance suggesting that a list of origins can be passed as part of
# Access-Control-Allow-Origin headers, several browsers (well, at least Firefox)
# don't seem to play nicely with this.
#
# To avoid the use of 'Access-Control-Allow-Origin: *', use a simple-ish whitelisting
# method to control access instead.
#
# NB: This relies on the use of the 'Origin' HTTP Header.

location / {

    if ($http_origin ~* (^https?://([^/]+\.)*(domainone|domaintwo)\.com$)) {
        set $cors "true";
    }

    # Nginx doesn't support nested If statements. This is where things get slightly nasty.
    # Determine the HTTP request method used
    if ($request_method = 'OPTIONS') {
        set $cors "${cors}options";
    }
    if ($request_method = 'GET') {
        set $cors "${cors}get";
    }
    if ($request_method = 'POST') {
        set $cors "${cors}post";
    }

    if ($cors = "true") {
        # Catch all incase there's a request method we're not dealing with properly
        add_header 'Access-Control-Allow-Origin' "$http_origin";
    }

    if ($cors = "trueget") {
        add_header 'Access-Control-Allow-Origin' "$http_origin";
        add_header 'Access-Control-Allow-Credentials' 'true';
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
        add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
    }

    if ($cors = "trueoptions") {
        add_header 'Access-Control-Allow-Origin' "$http_origin";

        #
        # Om nom nom cookies
        #
        add_header 'Access-Control-Allow-Credentials' 'true';
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';

        #
        # Custom headers and headers various browsers *should* be OK with but aren't
        #
        add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';

        #
        # Tell client that this pre-flight info is valid for 20 days
        #
        add_header 'Access-Control-Max-Age' 1728000;
        add_header 'Content-Type' 'text/plain charset=UTF-8';
        add_header 'Content-Length' 0;
        return 204;
    }

    if ($cors = "truepost") {
        add_header 'Access-Control-Allow-Origin' "$http_origin";
        add_header 'Access-Control-Allow-Credentials' 'true';
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
        add_header 'Access-Control-Allow-Headers' 'DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
    }

}