If you're using our Send Generated Codes feature, the fields we POST to your keygen URL are documented here:
http://www.e-junkie.com/ej/help.keygen.htm
These submissions are intended to mimic the format of PayPal IPN, so any existing script that can receive PayPal IPN should be able to accept these with little or no modification, as long as they don't need to validate the IPN with PayPal (which would fail since we are not PayPal, and we validate the original IPN with PayPal in the first place) and can handle or ignore the extra fields we add to the base IPN data set.
Note that one of the extra fields we add is a 'handshake' variable, which the keygen script could use to verify a transmission is coming from our server. You would need to update the script's handshake reference if you ever change your E-junkie Login Email or Password.
Our server IPs may change from time to time, so it would be better to allow any connections from the base domain "e-junkie.com" rather than going by fixed IPs. You could do a DNS lookup for "e-junkie.com" and allow any IPs in that list, or have the script simply do a reverse-lookup on any IP contacting it to see if it resolves back to "e-junkie.com". If you're on a typical Linux/Apache-based Web server (as most are) and hosting the keygen script on your Web site's server, you can place the keygen script in its own subdirectory along with a plaintext file named ".htaccess" (note the leading "."), listing these directives in that file:
<limit GET>
satisfy any
order allow,deny
Allow from e-junkie.com
</limit>
<limit POST>
satisfy any
order allow,deny
Allow from e-junkie.com
</limit>
