Advice on Registration Approaches

[Alex Rice]

On Sunday, January 12, 2003, at 07:47  PM, Igor de Oliveira Couto wrote:
> I had a look at eSellerate after reading your post - it does sound 
> very interesting. How do you integrate their code into Rev stacks? 
> Does the SDK include a Rev-compatible external or plug-in? - probably 
> wishing for too much here...

You don't have to use their SDK. If you don't use it, you would use 
their web storefront instead of their integrated e-sellers. Also you 
would use your own serial # scheme instead of their dynamic serial # 
scheme.

However, it should be possible to create a Rev external from their SDK. 
Then we would have access to all the extra features in the SDK like 
checking for updates, downloading, instant registration, etc.

> Could you elaborate on that? What is a 'message digest'? - SHA / MD5? 
> This sounds interesting, too!...

There is a md5digest function built into Rev. Take a look at the docs 
for that.

You could use md5digest to obfuscate the actual key string, and just 
concentrate on creating license key strings that are not too easy to 
guess. I guess it's like a two-level obfuscation. Someone might guess 
that you are using MD5, but they wouldn't have a whole lot to go on for 
guessing the original strings.

This transcript returns a 32 character hex string which you could 
distribute to the public as a registration code:

put empty into tHash
get binaryDecode( "h*", md5digest("actxual license key"), tHash)
put tHash

Then at runtime, you could recreate the string "actxual license key" 
and compare the above with what the user entered for their license key. 
"actxual license key" could be created by an algorithm, constant 
strings, the user's name, or anything. What "actxual license key" 
really is depends on your creativity and whether you are generating the 
key at the time of purchase, or beforehand in a batch.

Alex Rice, Software Developer
Architectural Research Consultants, Inc.
alrice at ARCplanning.com
alrice at swcp.com