54

The LDAP server is hosted on Solaris. The client is CentOS. OpenLDAP/NSLCD/SSH authentication via LDAP work fine, but I am not able to use the ldapsearch commands to debug LDAP issues.

[root@tst-01 ~]# ldapsearch
SASL/EXTERNAL authentication started
ldap_sasl_interactive_bind_s: Unknown authentication method (-6)
        additional info: SASL(-4): no mechanism available:
[root@tst-01 ~]# cat /etc/openldap/ldap.conf
TLS_CACERTDIR /etc/openldap/cacerts
URI ldap://ldap1.tst.domain.tld ldap://ldap2.tst.domain.tld
BASE dc=tst,dc=domain,dc=tld
[root@tst-01 ~]# ls -al /etc/openldap/cacerts
total 12
drwxr-xr-x. 2 root root 4096 Jun  6 10:31 .
drwxr-xr-x. 3 root root 4096 Jun 10 10:12 ..
-rw-r--r--. 1 root root  895 Jun  6 10:01 cacert.pem
lrwxrwxrwx. 1 root root   10 Jun  6 10:31 cf848aa4.0 -> cacert.pem
[root@tst-01 ~]#

I have tried authentication with a certificate via ldapsearch giving /etc/openldap/cacerts/cacert.pem as a parameter, but it didn't accept this certificate for authentication.

4 Answers 4

80

You may wish to turn off SASL and use simple authentication with the "-x" option. For example, a search to find a particular user

ldapsearch -x -D "uid=search-user,ou=People,dc=example,dc=com" \
           -W -H ldap://ldap.example.com -b "ou=People,dc=example,dc=com" \
           -s sub 'uid=test-user'

Will find "test-user" by

  • -D - Use bind user "search-user"
  • -W - Prompt for password
  • -H - URL of LDAP server. Non-SSL in this case; use "ldaps://" for SSL
  • -b - The search base
  • -s - Search scope - i.e. base for base of tree, one for on level down and sub for recursively searching down the tree (can take a while)
  • Finally the search filter as a non-option argument. In this case we will search for the uid of "test-user"
3
  • 2
    Fred has it right, except that you don't need to specify the search base or host if you are happy with the ones specified in /etc/openldap/ldap.conf i.e. the following should probably work: ldapsearch -x -D "<bind dn>" -W <query>
    – Jason Tan
    Commented Jun 11, 2013 at 18:26
  • How do we specify the user name for ldap login
    – myloginid
    Commented Sep 24, 2016 at 19:04
  • 4
    It depends what you mean by "user name". The bind DN (for authenticating to actually run the query) is given by the -D argument. The actual search, in this example for a user record, is given in the filter as the last argument. Commented Sep 25, 2016 at 5:12
8

Seems that I ask same question at: https://stackoverflow.com/questions/27571558/how-was-authentication-built-on-ldap

See http://thecarlhall.wordpress.com/2011/01/04/ldap-authentication-authorization-dissected-and-digested/ :

  • Get a connection to the LDAP server.
  • Bind as the application user.
  • Search for the DN (distinguished name) of the user to be authenticated.
  • Bind as user to be authenticated using DN from step 3.

That may be summarized as (experiment in command line):

$ ldapsearch -x -h ldap.company.com -s sub -b 'dc=europe,dc=com' "uid=XYZ"
....
dn: uid=XYZ,dc=sales,dc=europe,dc=com
...
$ ldapsearch -W -h ldap.company.com -D 'uid=XYZ,dc=sales,dc=europe,dc=com' \
    -s sub -b 'dc=europe,dc=com' "uid=XYZ"
5

Note, if you don't know your full bind DN, you can also just use your normal username or email with -U

ldapsearch -v -h contoso.com -U [email protected] -w 'MY_PASSWORD' -b 'DC=contoso,DC=com' '(objectClass=computer)'
5

We're using FreeIPA/IDM and I was able to authenticate against this using the following:

$ ldapsearch -h idm-01a.somednsdom.com \
    -D 'uid=<my username>,cn=users,cn=accounts,dc=somedcdom,dc=com' \
    -o ldif-wrap=no \
    -b 'cn=accounts,dc=somedcdom,dc=com' \
    -W uid=<my username>
Explanation
  • This will return all the details around the uid=<my username>
  • uid=<my username> is the filter (RFC 4515 compliant LDAP search filter)
  • The uid=<my username> is the query/filter to perform
  • o ldif-wrap=no disables wrapping of results
  • The -W forces ldapsearch to query for the password for the bind distinguished name uid=<my username>,cn=users,cn=accounts,dc=somedcdom,dc=com
  • When prompted for the password for this user the prompt will look like this:

    Enter LDAP Password:
    
Refereneces

For reference from the ldapsearch manpage & CLI help:

   -D binddn
          Use the Distinguished Name binddn to bind to the LDAP directory.  
          For SASL binds, the server is expected to ignore this value.

   -b searchbase
          Use searchbase as the starting point for the search instead of the 
          default.

   -W     Prompt for simple authentication.  This is used instead of specifying 
          the password on the command line.

  -o <opt>[=<optparam] general options
             nettimeout=<timeout> (in seconds, or "none" or "max")
             ldif-wrap=<width> (in columns, or "no" for no wrapping)

Full Example

$ ldapsearch -h idm-01a.somednsdom.com \
    -D 'uid=joeuser,cn=users,cn=accounts,dc=somedcdom,dc=com' \
    -o ldif-wrap=no \
    -b 'cn=accounts,dc=somedcdom,dc=com' \
    -W uid=joeuser

# extended LDIF
#
# LDAPv3
# base <cn=accounts,dc=somedcdom,dc=com> with scope subtree
# filter: uid=joeuser
# requesting: ALL
#

# joeuser, users, accounts, somedcdom.com
dn: uid=joeuser,cn=users,cn=accounts,dc=somedcdom,dc=com
memberOf: cn=ipausers,cn=groups,cn=accounts,dc=somedcdom,dc=com
memberOf: cn=sysadmin,cn=groups,cn=accounts,dc=somedcdom,dc=com
memberOf: ipaUniqueID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXXXXXX,cn=sudorules,cn=sudo,dc=somedcdom,dc=com
memberOf: cn=eng-systems,cn=groups,cn=accounts,dc=somedcdom,dc=com
memberOf: ipaUniqueID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXXXXXX,cn=hbac,dc=somedcdom,dc=com
memberOf: cn=admins,cn=groups,cn=accounts,dc=somedcdom,dc=com
memberOf: ipaUniqueID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXXXXXX,cn=sudorules,cn=sudo,dc=somedcdom,dc=com
memberOf: cn=User Administrator,cn=roles,cn=accounts,dc=somedcdom,dc=com
memberOf: cn=User Administrators,cn=privileges,cn=pbac,dc=somedcdom,dc=com
memberOf: cn=System: Add User to default group,cn=permissions,cn=pbac,dc=somedcdom,dc=com
...
...
krbLoginFailedCount: 0
krbLastFailedAuth: 20190320223946Z
loginShell: /bin/bash
krbExtraData:: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
krbPasswordExpiration: 20190829144625Z
krbLastPwdChange: 20190302144625Z
krbLastAdminUnlock: 20190111080021Z
ipaSshPubKey: ssh-rsa A....XXXXXXXXXXXX...jelByox0PM5Q== [email protected]
mepManagedEntry: cn=joeuser,cn=groups,cn=accounts,dc=somedcdom,dc=com
displayName: Joe User
uid: joeuser
krbCanonicalName: [email protected]
objectClass: top
objectClass: person
objectClass: organizationalperson
objectClass: inetorgperson
objectClass: inetuser
objectClass: posixaccount
objectClass: krbprincipalaux
objectClass: krbticketpolicyaux
objectClass: ipaobject
objectClass: ipasshuser
objectClass: ipaSshGroupOfPubKeys
objectClass: mepOriginEntry
initials: JU
gecos: Joe User
sn: Mingolelli
homeDirectory: /home/joeuser
mail: [email protected]
krbPrincipalName: [email protected]
givenName: Joe
cn: Joe User
ipaUniqueID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
uidNumber: 900000000
gidNumber: 900000000
krbPwdPolicyReference: cn=admins,cn=SOMEDCDOM.COM,cn=kerberos,dc=somedcdom,dc=com

# search result
search: 2
result: 0 Success

# numResponses: 2
# numEntries: 1

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