What files does authconfig modify on RHEL?

Question

I am trying to allow RHEL to use login accounts that are created on the system, but use the passwords from Active Directory. I have seen someone use:

authconfig \
--enablekrb5 \
--krb5realm=KDCRealm.NET \
--krb5kdc=kcldap.net \
--krb5adminserver=kcldap.net \
--enablekrb5kdcdns \
--enablekrb5realmdns \
--update

although, I'm not sure how or what that command does, or what files it modifies.

Answer 1

The answer from slm is very good, but I was interested in exactly which files are going to be modified. This can be found in /usr/share/authconfig/authinfo.py. The below excerpt is from CentOS6:

SYSCONFDIR = "/etc"
PASSWORD_AUTH_PAM_SERVICE_AC = "password-auth-ac"
FINGERPRINT_AUTH_PAM_SERVICE_AC = "fingerprint-auth-ac"
SMARTCARD_AUTH_PAM_SERVICE_AC = "smartcard-auth-ac"

all_configs = [
        FileBackup("hesiod.conf", SYSCONFDIR+"/hesiod.conf"),
        FileBackup("yp.conf", SYSCONFDIR+"/yp.conf"),
        FileBackup("ldap.conf", SYSCONFDIR+"/ldap.conf"),
        FileBackup("nss_ldap.conf", SYSCONFDIR+"/nss_ldap.conf"),
        FileBackup("pam_ldap.conf", SYSCONFDIR+"/pam_ldap.conf"),
        FileBackup("nslcd.conf", SYSCONFDIR+"/nslcd.conf"),
        FileBackup("openldap.conf", SYSCONFDIR+"/openldap/ldap.conf"),
        FileBackup("krb5.conf", SYSCONFDIR+"/krb5.conf"),
        FileBackup("krb.conf", SYSCONFDIR+"/krb.conf"),
        FileBackup("pam_pkcs11.conf", SYSCONFDIR+"/pam_pkcs11/pam_pkcs11.conf"),
        FileBackup("smb.conf", SYSCONFDIR+"/samba/smb.conf"),
        FileBackup("nsswitch.conf", SYSCONFDIR+"/nsswitch.conf"),
        CacheBackup("cacheenabled.conf", ""),
        FileBackup("system-auth-ac", SYSCONFDIR+"/pam.d/"+AUTH_PAM_SERVICE_AC),
        FileBackup("password-auth-ac", SYSCONFDIR+"/pam.d/"+PASSWORD_AUTH_PAM_SERVICE_AC),
        FileBackup("fingerprint-auth-ac", SYSCONFDIR+"/pam.d/"+FINGERPRINT_AUTH_PAM_SERVICE_AC),
        FileBackup("smartcard-auth-ac", SYSCONFDIR+"/pam.d/"+SMARTCARD_AUTH_PAM_SERVICE_AC),
        FileBackup("authconfig", SYSCONFDIR+"/sysconfig/authconfig"),
        FileBackup("network", SYSCONFDIR+"/sysconfig/network"),
        FileBackup("libuser.conf", SYSCONFDIR+"/libuser.conf"),
        FileBackup("login.defs", SYSCONFDIR+"/login.defs"),
        FileBackup("sssd.conf", SYSCONFDIR+"/sssd/sssd.conf")]

The code also reveals that backups are being stored in here:

PATH_CONFIG_BACKUPS = "/var/lib/authconfig"

Answer 2

You can run authconfig-gtk to get an idea of the things authconfig can modify.

screenshots of GUI

                            

                            

In general most of the information in these tabs is manipulating information under the directory /etc/sysconfig. There are a number of files there that pertain to the configuration of a RedHat based distro such as Fedora, CentOS, or RHEL.

For example, there's a file called, ironically, authconfig which contains the choices from the dialogs in the screenshots above.

$ more /etc/sysconfig/authconfig
USEMKHOMEDIR=no
USEPAMACCESS=no
CACHECREDENTIALS=yes
USESSSDAUTH=no
USESHADOW=yes
USEWINBIND=no
USEDB=no
FORCELEGACY=no
USEFPRINTD=no
FORCESMARTCARD=no
PASSWDALGORITHM=sha512
USELDAPAUTH=no
USEPASSWDQC=no
USELOCAUTHORIZE=yes
USECRACKLIB=yes
USEWINBINDAUTH=no
USESMARTCARD=no
USELDAP=no
USENIS=no
USEKERBEROS=no
USESYSNETAUTH=no
USESSSD=no
USEHESIOD=no