Here you have some links of interest:
syslog-ng
SSL
OpenSSL: The Open Source toolkit for SSL/TLS
SSL Certificates HOWTO
Kerberos
The Moron's Guide to Kerberos, Version 1.2.2
Designing an Authentication System: a Dialogue in Four Scenes
Kerberos: The Network Authentication Protocol
Heimdal
Kerberos Papers and Documentation
OpenLDAP
OpenLDAP.org
OpenLDAP Admin Guide
Cyrus SASL
SASL: Simple Authentication and Security Layer
Cyrus SASL Library
PAM
Linux-PAM
The Linux-PAM System Administrators' Guide
pam_krb5 project
nss_ldap
Other Kerberos/LDAP HOWTOs
LDAP Linux HOWTO
LDAP Implementation HOWTO
OpenLDAP, OpenSSL, SASL and KerberosV HOWTO
The Heimdal, Samba and LDAP howto
Replacing NIS with Kerberos and LDAP HOWTO