The goal: to make an OpenLDAP server to authenticate using Kerberos V via GSSAPI
Setup: several virtual machines running on freshly installed/updated Debian Squeeze
A master KDC server
kdc.example.com
A LDAP server, running OpenLDAP
ldap.example.com
The problem:
tom@ldap:~$ ldapsearch -b 'dc=example,dc=com' SASL/GSSAPI authentication started ldap_sasl_interactive_bind_s: Other (e.g., implementation specific) error (80) additional info: SASL(-1): generic failure: GSSAPI Error: Unspecified GSS failure. Minor code may provide more information (Key table entry not found)
One might suggest to add that keytab entry, but:
ktutil: rkt /etc/ldap/ldap.keytab ktutil: list slot KVNO Principal ---- ---- --------------------------------------------------------------------- 1 2 ldap/ldap.example.com@EXAMPLE.COM 2 2 ldap/ldap.example.com@EXAMPLE.COM 3 2 ldap/ldap.example.com@EXAMPLE.COM 4 2 ldap/ldap.example.com@EXAMPLE.COM
So, the entry as suggested by the OpenLDAP manual is there allright. Deleting and re-creating both service principal and the keytab on ldap.example.com didn't help, I get the same error. And before I make the keytab file readable by openldap, I get "Permission denied" error instead of the one in the subject. Which implies that the right keytab file is being accessed, as set in /etc/default/slapd.
I have my doubts about the following part of slapd config:
root@ldap:~# cat /etc/ldap/slapd.d/cn=config.ldif | grep -v "^#" dn: cn=config objectClass: olcGlobal cn: config olcArgsFile: /var/run/slapd/slapd.args olcLogLevel: 256 olcPidFile: /var/run/slapd/slapd.pid olcToolThreads: 1 structuralObjectClass: olcGlobal entryUUID: d6737f5c-d321-1030-9dbe-27d2a7751e11 olcSaslHost: kdc.example.com olcSaslRealm: EXAMPLE.COM olcSaslSecProps: noplain,noactive,noanonymous,minssf=56 olcAuthzRegexp: {0}"uid=([^/]*),cn=EXAMPLE.COM,cn=GSSAPI,cn=auth" "uid=$1,ou=People,dc=example,dc=com" olcAuthzRegexp: {1}"uid=host/([^/]*).example.com,cn=example.com,cn=gssapi,cn=auth" "cn=$1,ou=hosts,dc=example,dc=com"
A HOWTO at https://help.ubuntu.com/community/OpenLDAPServer#Kerberos_Authentication mentiones:
Also, it is frequently necessary to map the Distinguished Name (DN) of an authorized Kerberos client to an existing entry in the DIT.
I fail to understand where in the tree this should be defined, what schema should be used, etc. After hours of googling, it's official: I'm stuck! Please, help.
Other things checked: Kerberos as such works fine (I can ssh without using a password to any machine in this setup). That means there should be no DNS-related problems.
ldapsearch -b 'dc=example,dc=com' -x
works OK.
SASL/GSSAPI has been tested using
sasl-sample-server -m GSSAPI -s ldap
and
sasl-sample-client -s ldap -n ldap.example.com -u tom
without errors:
root@ldap:~# sasl-sample-server -m GSSAPI -s ldap Forcing use of mechanism GSSAPI Sending list of 1 mechanism(s) S: R1NTQVBJ Waiting for client mechanism... C: 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 'GSSAPI' Sending response... S: YIGZBgkqhkiG9xIBAgICAG+BiTCBhqADAgEFoQMCAQ+iejB4oAMCARKicQRvkxggi9pW+yJ1ExbTwLDclqw/VQ98aPq8mt39hkO6PPfcO2cB+t6vJ01xRKBrT9D2qF2XK0SWD4PQNb5UFbH4RM/bKAxDuCfZ1MHKgIWTLu4bK7VGZTbYydcckU2d910jIdvkkHhaRqUEM4cqp/cR Waiting for client reply... C: got '' Sending response... S: BQQF/wAMAAAAAAAAMBOWqQcACAAlCodrXW66ZObsEd4= Waiting for client reply... C: BQQE/wAMAAAAAAAAFUYbXQQACAB0b20VynB4uGH/iIzoRhw=got '?' Negotiation complete Username: tom Realm: (NULL) SSF: 56 sending encrypted message 'srv message 1' S: AAAASgUEB/8AAAAAAAAAADATlqrqrBW0NRfPMXMdMz+zqY32YakrHqFps3o/vO6yDeyPSaSqprrhI+t7owk7iOsbrZ/idJRxCBm8Wazx Waiting for encrypted message... C: AAAATQUEBv8AAAAAAAAAABVGG17WC1+/kIV9xTMUdq6Y4qYmmTahHVCjidgGchTOOOrBLEwA9IqiTCdRFPVbK1EgJ34P/vxMQpV1v4WZpcztgot '' recieved decoded message 'client message 1'
root@ldap:~# sasl-sample-client -s ldap -n ldap.example.com -u tom service=ldap Waiting for mechanism list from server... S: R1NTQVBJrecieved 6 byte message Choosing best mechanism from: GSSAPI returning OK: tom Using mechanism GSSAPI Preparing initial. Sending initial response... C: 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 Waiting for server reply... S: YIGZBgkqhkiG9xIBAgICAG+BiTCBhqADAgEFoQMCAQ+iejB4oAMCARKicQRvkxggi9pW+yJ1ExbTwLDclqw/VQ98aPq8mt39hkO6PPfcO2cB+t6vJ01xRKBrT9D2qF2XK0SWD4PQNb5UFbH4RM/bKAxDuCfZ1MHKgIWTLu4bK7VGZTbYydcckU2d910jIdvkkHhaRqUEM4cqp/cRrecieved 156 byte message C: Waiting for server reply... S: BQQF/wAMAAAAAAAAMBOWqQcACAAlCodrXW66ZObsEd4=recieved 32 byte message Sending response... C: BQQE/wAMAAAAAAAAFUYbXQQACAB0b20VynB4uGH/iIzoRhw= Negotiation complete Username: tom SSF: 56 Waiting for encoded message... S: AAAASgUEB/8AAAAAAAAAADATlqrqrBW0NRfPMXMdMz+zqY32YakrHqFps3o/vO6yDeyPSaSqprrhI+t7owk7iOsbrZ/idJRxCBm8Wazxrecieved 78 byte message recieved decoded message 'srv message 1' sending encrypted message 'client message 1' C: AAAATQUEBv8AAAAAAAAAABVGG17WC1+/kIV9xTMUdq6Y4qYmmTahHVCjidgGchTOOOrBLEwA9IqiTCdRFPVbK1EgJ34P/vxMQpV1v4WZpczt