I am in the progress of migrating an old banner system to a new one and in doing so I want to rewrite the old banner system's URL's to the new one. I load my banners via an AJAX request, and therefore I require the Access-Control-Allow-Origin to be set to *.

I have the following VirtualHost configuration:

<VirtualHost *:80>
    ServerAdmin [email protected]
    ServerName banner.studenten.net

    # we want to allow XMLHTTPRequests
    Header set Access-Control-Allow-Origin "*"

    RewriteEngine on
    RewriteMap bannersOldToNew txt:/home/user/banner.studenten.net/banner-studenten-net-to-ads-all4students-nl-map

    # check whether a zoneid exists in the query string
    RewriteCond %{QUERY_STRING} ^(.*)zoneid=([1-9][0-9]*)(.*)
    # make sure the requested banner has been mapped
    RewriteCond ${bannersOldToNew:%2|NOTFOUND} !=NOTFOUND
    # rewrite to ads.all4students.nl
    RewriteRule ^/ads/.* http://ads.all4students.nl/delivery/ajs.php?%1zoneid=${bannersOldToNew:%2}%3 [R]
    # else 404 or something

    ErrorLog ${APACHE_LOG_DIR}/banner.studenten.net-error.log

    # Possible values include: debug, info, notice, warn, error, crit,
    # alert, emerg.
    LogLevel warn

    CustomLog ${APACHE_LOG_DIR}/banner.studenten.net-access.log combined

</VirtualHost>

My map file, /home/user/banner.studenten.net/banner-studenten-net-to-ads-all4students-nl-map, contains something like:

# oldId newId
140 11
141 12
142 13

Based on the above configuration I was expecting the following:

GET /ads/ajs.php?zoneid=140 HTTP/1.1
Host: banner.studenten.net

HTTP/1.1 302 Found
...
Access-Control-Allow-Origin: *
Location: http://ads.all4students.nl/delivery/ajs.php?zoneid=11

But instead I get the following:

GET /ads/ajs.php?zoneid=140 HTTP/1.1
Host: banner.studenten.net

HTTP/1.1 302 Found
...
Location: http://ads.all4students.nl/delivery/ajs.php?zoneid=11

Note the missing Access-Control-Allow-Origin header, this means the XMLHttpRequest is denied and the banner is not displayed. Any suggestions on how to fix this in Apache?