ICloud/Apple ID authentication mistery

Question

Short question is.
Why does the AFP connection to my Mac-Lion bypass the password when connecting from another Mac signed in iCloud?
Here are some details.
1. The Mac-Lion is off-cloud and I reset the keychain many times.
2. I am connecting from the account "xyz" on the other Mac, which is signed in the same iCloud account that the old Mac used to be signed in.
3. It connects to the account "xyz" on Mac-Lion , bypassing the login / password prompt.
4. If I sign off iCloud on the other Mac, I do get the prompt asking to which account on Mac-Lion I want to connect and to enter the password.
5. If I sign on again, it bypasses the password again.
6. This is the only thing that the console tells me: 3/23/15 9:53:25.917 PM Firewall: Allow AppleFileServer connecting from 192.168.1.110:61427 to port 548 proto=6
No amount of brute force search/grep helped. There seems to be no trace of my Apple ID on Mac-Lion, at least not in the searchable files.
Yet, there must a permission buried somewhere on Mac-Lion that grant access to the incoming connections from my Apple ID. Where can that be and how can I reset it? 
Thank you,

Answer 1

If your device is signed into an old ID that is an earlier version of the ID you want to sign in with, do the following:
If you are using iMessage and FaceTime, make sure you are signed into these services with your current ID.  If they are signed into the old ID, go to Settings>Messages>Send & Receive and Settings>FaceTime, tap the ID, sign out, then sign back in with your current ID.
Then temporarily recreate the old ID by going to https://appleid.apple.com, click Manage my Apple ID and sign in with your current iCloud ID.  Click edit next to the primary email account, change it back to your old email address and save the change.  (You should not have to verify the old email account so it doesn’t matter if you no longer have access to it.)  Now go to Settings>iCloud, turn off Find My iDevice and enter your current password when prompted (even though it prompts you for the password for your old ID).  Then save any photo stream photos that you wish to keep to your camera roll (unless you are using iCloud Photo Library).  When finished go to Settings>iCloud, tap Sign Out (or Delete Account if you are not running iOS 8) and choose Delete from My iDevice when prompted (your iCloud data will still be in iCloud).  Next, go back to https://appleid.apple.com and change your primary email address back to the way it was.  Now you can go to Settings>iCloud and sign back in with your current iCloud ID and password (your data will download back to your device).