How do I authenticate with LDAP via the command line?

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"

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"

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)'

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>

• 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:
  

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