# central usermanagement
-...using ldap and kerberos
+...using ldap and kerberos
# motivation
-warum:
+warum:
-* skaliert
-* sicherheit
-* komfort (single sign on)
-warum nicht:
+* skaliert
+* sicherheit
+* komfort (single sign on)
+warum nicht:
-* fehlerquelle komplexitaet
-* gefahr single point of failure / break in
--> infrastruktur!
+* fehlerquelle komplexitaet
+* gefahr single point of failure / break in
+-> infrastruktur!
# theorie
-recommended reading:
+recommended reading:
-* [[http://www.openinput.com/auth-howto/index.html|http://www.openinput.com/auth-howto/index.html]]
-* [[http://www.pdc.kth.se/heimdal/|http://www.pdc.kth.se/heimdal/]]
-* [[http://www.openldap.org/doc/admin23/|http://www.openldap.org/doc/admin23/]]
-architektur:
+* [[http://www.openinput.com/auth-howto/index.html|http://www.openinput.com/auth-howto/index.html]]
+* [[http://www.pdc.kth.se/heimdal/|http://www.pdc.kth.se/heimdal/]]
+* [[http://www.openldap.org/doc/admin23/|http://www.openldap.org/doc/admin23/]]
+architektur:
-* trusted third party, der KDC. hat gemeinsames secret mit allen hosts/services/usern. "principals". generiert auf anfrage ticket mit zeit, ip, und welcher user zu welchem service.
-design decisions:
+* trusted third party, der KDC. hat gemeinsames secret mit allen hosts/services/usern. "principals". generiert auf anfrage ticket mit zeit, ip, und welcher user zu welchem service.
+design decisions:
-* keine passwoerter im ldap, alles via kerberos, rueckwaertskompatibilitaet via pam_krb, nicht sasl oder pam_ldap.
-* kerberos datenbank im ldap, keine seperate replikation noetig (nur mit heimdal).
-* eigene ldap range fuer uid/groupid, root und systemuser bleiben lokal falls das netzwerk spinnt.
+* keine passwoerter im ldap, alles via kerberos, rueckwaertskompatibilitaet via pam_krb, nicht sasl oder pam_ldap.
+* kerberos datenbank im ldap, keine seperate replikation noetig (nur mit heimdal).
+* eigene ldap range fuer uid/groupid, root und systemuser bleiben lokal falls das netzwerk spinnt.
# required software
-zutaten am server:
+zutaten am server:
-* heimdal kerberos (ldap), alternativen: mit, shishi
-* openldap, alternativ: mysql, postgresql
-* wohlgepflegtes dns und reverse-dns
-* schwer empfohlen: replikation und redundanz
+* heimdal kerberos (ldap), alternativen: mit, shishi
+* openldap, alternativ: mysql, postgresql
+* wohlgepflegtes dns und reverse-dns
+* schwer empfohlen: replikation und redundanz
[[!format txt """
sudo aptitude install slapd heimdal-kdc
"""]]
-zutaten am host:
+zutaten am host:
-* libnss-ldap
-* pam-krb5
-* sasl mit gssapi provider
-* richtige zeit, zb. openntpd (kann aber nicht stratum faken fuer windows)
-* kerberized client/serversoftware (zb. openssh, apache2)
+* libnss-ldap
+* pam-krb5
+* sasl mit gssapi provider
+* richtige zeit, zb. openntpd (kann aber nicht stratum faken fuer windows)
+* kerberized client/serversoftware (zb. openssh, apache2)
[[!format txt """
sudo aptitude install libnss-ldap libpam-krb5 libsasl2-gssapi-mit heimdal-clients
# vorbereitung: domain name service
-config im dns (da gibts uebrigens auch welche mit ldap/sql backend ;):
+config im dns (da gibts uebrigens auch welche mit ldap/sql backend ;):
-aka "srv records rock! - for kerberos but not for ldap :("
+aka "srv records rock! - for kerberos but not for ldap :("
-config file /etc/krb5.conf auf allen hosts ident!
+config file /etc/krb5.conf auf allen hosts ident!
-was ist ein "canonical hostname"?
+was ist ein "canonical hostname"?
-zonefile mm-karton.com (snippet):
+zonefile mm-karton.com (snippet):
[[!format txt """
$ORIGIN mm-karton.com.
kerberos A 10.128.0.24
_ldap._tcp SRV 10 1 88 ldap
_ldap._tcp SRV 20 1 88 ldap-1
"""]]
-zonefile mm-karton.net (snippet), afaik heimdal specific:
+zonefile mm-karton.net (snippet), afaik heimdal specific:
[[!format txt """
_kerberos TXT "MM-KARTON.COM"
"""]]
# config am server
-/etc/ldap/slapd.conf
+/etc/ldap/slapd.conf
[[!format txt """
by dn="cn=lefant@mm-karton.com,dc=mm-karton,dc=com" write
by dn="cn=ldap/srv-vie-27.vie.mm-karton.com@mm-karton.com,ou=kdc,dc=mm-karton,dc=com" read
"""]]
-/etc/default/slapd
+/etc/default/slapd
[[!format txt """
# Default location of the slapd.conf file
SLAPD_CONF=
# will try to figure it out from $SLAPD_CONF (/etc/ldap/slapd.conf)
SLAPD_PIDFILE=
-# Configure if the slurpd daemon should be started. Possible values:
+# Configure if the slurpd daemon should be started. Possible values:
# - yes: Always start slurpd
# - no: Never start slurpd
# - auto: Start slurpd if a replica option is found in slapd.conf (default)
[ -L /var/run/ldapi ] || ln -s /var/run/slapd/ldapi /var/run/ldapi
"""]]
-/etc/heimdal-kdc/kadmin.acl
+/etc/heimdal-kdc/kadmin.acl
[[!format txt """
lefant/admin@MM-KARTON.COM all
"""]]
-/etc/heimdal-kdc/kdc.conf
+/etc/heimdal-kdc/kdc.conf
[[!format txt """
[kdc]
database = {
# config am host
-/etc/libnss-ldap.conf
+/etc/libnss-ldap.conf
[[!format txt """
BASE dc=mm-karton, dc=com
URI ldap://ldap.mm-karton.com/,ldap://ldap-1.mm-karton.com/
nss_reconnect_maxconntries 3
nss_initgroups_ignoreusers arpwatch,asterisk,backup,bin,bind,clamav,cricket,daemon,Debian-exim,debianmirror,dovecot,fetchmail,ftp,games,gnats,identd,irc,list,lp,mail,man,messagebus,mysql,nagios,news,nobody,ntp,ntpd,nut,openvpn,pdns,proftpd,proxy,puppet,root,smmsp,smmta,smsd,snmp,snort,sshd,statd,sync,sys,uucp,www-data,zope
"""]]
-/etc/nsswitch.conf
+/etc/nsswitch.conf
[[!format txt """
passwd: files ldap
group: files ldap
netgroup: nis
"""]]
-/etc/krb5.conf
+/etc/krb5.conf
[[!format txt """
[libdefaults]
default_realm = MM-KARTON.COM
auth_to_local = DEFAULT
}
"""]]
-/etc/pam.d/common-account
+/etc/pam.d/common-account
[[!format txt """
account required pam_access.so
account sufficient pam_krb5.so forwardable realm=MMK.MMDOM.NET minimum_uid=20000
account sufficient pam_krb5.so forwardable realm=MM-KARTON.COM minimum_uid=20000
account required pam_unix.so
"""]]
-/etc/pam.d/common-auth
+/etc/pam.d/common-auth
[[!format txt """
auth optional pam_group.so
auth sufficient pam_krb5.so forwardable realm=MMK.MMDOM.NET minimum_uid=20000 try_first_pass
auth sufficient pam_krb5.so forwardable realm=MM-KARTON.COM minimum_uid=20000 try_first_pass
auth required pam_unix.so try_first_pass
"""]]
-/etc/pam.d/common-session
+/etc/pam.d/common-session
[[!format txt """
session required pam_mkhomedir.so umask=0022 skel=/etc/mmskel
session sufficient pam_krb5.so forwardable realm=MMK.MMDOM.NET minimum_uid=20000
session sufficient pam_krb5.so forwardable realm=MM-KARTON.COM minimum_uid=20000
session required pam_unix.so
"""]]
-restrict logins to certain users:
+restrict logins to certain users:
-/etc/security/access.conf
+/etc/security/access.conf
[[!format txt """
# first, to avoid delays when network is still unavailable
+:ALL:LOCAL
# deny everything else
-:ALL:ALL
"""]]
-/etc/adduser.conf (snippet)
+/etc/adduser.conf (snippet)
[[!format txt """
# FIRST_[GU]ID to LAST_[GU]ID inclusive is the range of UIDs of dynamically
# allocated user accounts/groups.
FIRST_UID=1000
LAST_UID=19999
"""]]
-ldap client config (administration):
+ldap client config (administration):
-/etc/ldap/ldap.conf
+/etc/ldap/ldap.conf
[[!format txt """
BASE dc=mm-karton, dc=com
URI ldap://ldap.mm-karton.com/
ssl start_tls
tls_cacert /etc/ssl/certs/ca_crt.pem
"""]]
-ldapwhoami, ldapsearch
+ldapwhoami, ldapsearch
-sudo, nopasswd, weil solches haben wir ja nicht...
+sudo, nopasswd, weil solches haben wir ja nicht...
-/etc/sudoers
+/etc/sudoers
[[!format txt """
lefant ALL=(ALL) NOPASSWD:ALL
"""]]
# single sign on fuer applikationen (gssapi support, das grosse fragezeichen)
-/etc/ssh/sshd_config (snippet)
+/etc/ssh/sshd_config (snippet)
[[!format txt """
GSSAPIAuthentication yes
GSSAPIKeyExchange yes
"""]]
-/etc/ssh/ssh_config (snippet)
+/etc/ssh/ssh_config (snippet)
[[!format txt """
host *
GSSAPIAuthentication yes
GSSAPIDelegateCredentials yes
GSSAPITrustDns yes
"""]]
-firefox: out-of-the-box!
+firefox: out-of-the-box!
-apache: (apt-get install libapache2-mod-auth-kerb) config snippet
+apache: (apt-get install libapache2-mod-auth-kerb) config snippet
[[!format txt """
<Location />
AuthType Kerberos
# misc stuff
-* tcpdump
-* strace
-* $HOME/.k5login
\ No newline at end of file
+* tcpdump
+* strace
+* $HOME/.k5login
\ No newline at end of file