7

I can successfully connect and search to an Active Directory domain controller using ldapsearch. I am using the -x option, to specify a username/password authentication (password being specified by -W and username by -D).

I currently need to dump directory from a MIT-kerberos domain. Kerberos is the only protocol available for authentication. I can retrieve a kerberos TGT ticket with kinit. I am using these command lines:

ldapsearch  -Y SASL -b "REALM.INC" -H ldap://kerberos_IP_address
-> ldap_sasl_interactive_bind_s: Unknown authentication method (-6)
  additional info: SASL(-4): no mechanism available: No worthy mechs found

ldapsearch -o "mech=GSSAPI" ...
-> Invalid general option name: mech

How can I authenticate with kerberos using ldapsearch?

Many thanks for your help&replies

1
  • What happened when you do ldapsearch -H ldap://kerberos_IP_address -U administrator -s base -b "CN=Users,DC=domain,DC=com" -Y GSSAPI -s sub "(cn=*)" ? Does klist show valid tickets in cache ?
    – Abey
    Apr 20, 2017 at 16:21

3 Answers 3

8

You may be missing the libsasl2-modules-gssapi-mit package.

Without:

# ldapsearch -H ldap://dc1 -Y GSSAPI -b 'DC=ad-test,DC=vx'
ldap_sasl_interactive_bind_s: Unknown authentication method (-6)
    additional info: SASL(-4): no mechanism available: No worthy mechs found

Install:

# apt install libsasl2-modules-gssapi-mit

With:

# ldapsearch -H ldap://dc1 -Y GSSAPI -b 'DC=ad-test,DC=vx'
SASL/GSSAPI authentication started
SASL username: Administrator@AD-TEST.VX
SASL SSF: 256
SASL data security layer installed.
...

SASL is enabled by default, and will auto-detect a compatible mechanism, so specifying -Y GSSAPI isn't even necessary:

# ldapsearch -H ldap://dc1 -b 'DC=ad-test,DC=vx'
SASL/GSSAPI authentication started
SASL username: Administrator@AD-TEST.VX
SASL SSF: 256
SASL data security layer installed.
...
1

depending on your ldapsearch & OS version, you can try to first authenticate to kerberos using kinit and "cache" your ticket, use it in a kerberos env variable, and then let ldapsearch use this variable, with something like this :

kinit -c /tmp/<yourlogin>.cc.tmp <yourlogin>
export KRB5CCNAME=/tmp/<yourlogin>.cc.tmp
ldapsearch -Tx -h <host> -p <port> -Y GSSAPI -b "dc=example,dc=com" cn=*
2
  • -T means something different to debian / OpenLDAP than it does to Solaris.
    – 84104
    Apr 20, 2017 at 22:27
  • my commands run perfectly on a Linux RHEL 6.x, didn't try on debian tho, but it should work anyway assuming that the variable is set and the -Y is passed i suppose, thanks for the info btw
    – olivierg
    Apr 20, 2017 at 22:35
1

-Y is used to specify the SASL mechanism, which will probably be GSSAPI, though could be GSS-SPNEGO. Also, base dn must be in dn syntax (i.e., dc=example,dc=com), not domain syntax (example.com).

$ ldapsearch -x -b '' -s base supportedSASLMechanisms -H ldap://192.0.2.1/
dn:
supportedSASLMechanisms: GSSAPI

$ ldapsearch -Y GSSAPI -b dc=example,dc=com -H ldap://192.0.2.1/

$ ldapsearch -x -b '' -s base supportedSASLMechanisms -H ldap://192.0.2.2/
dn:
supportedSASLMechanisms: GSS-SPNEGO
supportedSASLMechanisms: GSSAPI
0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.