Package krb5-libs

The non-admin shared libraries used by Kerberos 5

http://web.mit.edu/kerberos/www/

Kerberos is a network authentication system. The krb5-libs package
contains the shared libraries needed by Kerberos 5. If you are using
Kerberos, you need to install this package.

File Formats (Section 5)
k5identity
The .k5identity file, which resides in a user's home directory, contains a list of rules for selecting a client principals based on the server being accessed...
k5login
The .k5login file, which resides in a user's home directory, contains a list of the Kerberos principals. Anyone with valid tickets for a principal in the file...
krb5.conf
The krb5.conf file is set up in the style of a Windows INI file. Sections are headed by the section name, in square brackets.