You can generate an xml output of all the products you can download with a certain subscription, and this will contain the URLs with tokens:
curl -H “Authorization: Token token=” https://scc.suse.com/connect/subscriptions/products
where is the “Registration code” for you subscription that you can find in the SCC web portal. You will find URLs like
https://updates.suse.com/SUSE/Updates/SLE-SERVER/12-SP1/x86_64/update/?…
and the part after the ? is the token.
Btw, mirroring can be done with the tool “yup” by Marcus Meissner, look at the opensuse build service. yup12 is not fully up-to-date at the moment, missing link for SLED 12. It uses other URLs for fetching the tokens but those cannot be guessed, they contain a number that you just need to know…