Error authenticating squid with Active Directory and Kerberos

Question

I'm trying to integrate squid 3.5.19 with AD/Kerberos (Windows 2008 R2), but I get always TCP_DENIED:HIER_NONE

These are the errors in /var/log/squid/cache.log

2016/07/28 10:26:01.583 kid1| 29,4| UserRequest.cc(290) authenticate: No Proxy-Auth header and no working alternative. Requesting auth header.
2016/07/28 10:26:01.584 kid1| 29,9| UserRequest.cc(487) addReplyAuthHeader: headertype:46 authuser:NULL
2016/07/28 10:26:01.584 kid1| 29,9| Config.cc(188) fixHeader: Sending type:46 header: 'Negotiate'
2016/07/28 10:26:01.625 kid1| 29,9| UserRequest.cc(328) authenticate: header Negotiate TlRMTVNTUAABAAAAl4II4gAAAAAAAAAAAAAAAAAAAAAKAFopAAAADw==.
2016/07/28 10:26:01.625 kid1| 29,9| UserRequest.cc(332) authenticate: This is a new checklist test on:local=192.168.50.22:3128 remote=192.168.50.47:56015 FD 16 flags=1
2016/07/28 10:26:01.625 kid1| 29,4| UserRequest.cc(350) authenticate: No connection authentication type
2016/07/28 10:26:01.625 kid1| 29,9| Config.cc(36) CreateAuthUser: header = 'Negotiate TlRMTVNTUAABAAAAl4II4gAAAAAAAAAAAAAAAAAAAAAKAFopAAAADw=='
2016/07/28 10:26:01.625 kid1| 29,5| User.cc(39) User: Initialised auth_user '0x2857400'.
2016/07/28 10:26:01.625 kid1| 29,5| UserRequest.cc(95) UserRequest: initialised request 0x28576b0
2016/07/28 10:26:01.625 kid1| 29,9| Config.cc(267) decode: decode Negotiate authentication
2016/07/28 10:26:01.625 kid1| 29,9| UserRequest.cc(53) valid: Validating Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.625 kid1| 29,5| UserRequest.cc(73) valid: Validated. Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.625 kid1| 29,9| UserRequest.cc(53) valid: Validating Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.625 kid1| 29,5| UserRequest.cc(73) valid: Validated. Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.625 kid1| 29,9| UserRequest.cc(63) authenticated: user not fully authenticated.
2016/07/28 10:26:01.625 kid1| 29,9| UserRequest.cc(225) authenticate: auth state negotiate none. Received blob: 'Negotiate TlRMTVNTUAABAAAAl4II4gAAAAAAAAAAAAAAAAAAAAAKAFopAAAADw=='
2016/07/28 10:26:01.625 kid1| 29,9| UserRequest.cc(53) valid: Validating Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.625 kid1| 29,5| UserRequest.cc(73) valid: Validated. Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.625 kid1| 29,9| UserRequest.cc(63) authenticated: user not fully authenticated.
2016/07/28 10:26:01.625 kid1| 29,9| UserRequest.cc(53) valid: Validating Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.625 kid1| 29,5| UserRequest.cc(73) valid: Validated. Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.625 kid1| 29,9| UserRequest.cc(46) start: 0x28576b0
2016/07/28 10:26:01.625 kid1| 29,8| UserRequest.cc(134) startHelperLookup: credentials state is '2'
negotiate_kerberos_auth.cc(610): pid=11509 :2016/07/28 10:26:01| negotiate_kerberos_auth: DEBUG: Got 'YR TlRMTVNTUAABAAAAl4II4gAAAAAAAAAAAAAAAAAAAAAKAFopAAAADw==' from squid (length: 59).
negotiate_kerberos_auth.cc(663): pid=11509 :2016/07/28 10:26:01| negotiate_kerberos_auth: DEBUG: Decode 'TlRMTVNTUAABAAAAl4II4gAAAAAAAAAAAAAAAAAAAAAKAFopAAAADw==' (decoded length: 40).
negotiate_kerberos_auth.cc(673): pid=11509 :2016/07/28 10:26:01| negotiate_kerberos_auth: WARNING: received type 1 NTLM token
2016/07/28 10:26:01.626 kid1| 29,8| UserRequest.cc(266) HandleReply: helper: '0x2860438/0x2860438' sent us reply={result=BH, notes={message: received type 1 NTLM token; }}
2016/07/28 10:26:01.626 kid1| 29,6| UserRequest.cc(175) releaseAuthServer: releasing Negotiate auth server '0x2860438'
2016/07/28 10:26:01.626 kid1| ERROR: Negotiate Authentication validating user. Result: {result=BH, notes={message: received type 1 NTLM token; }}
2016/07/28 10:26:01.626 kid1| 29,9| UserRequest.cc(53) valid: Validating Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.626 kid1| 29,5| UserRequest.cc(73) valid: Validated. Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.626 kid1| 29,9| UserRequest.cc(53) valid: Validating Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.626 kid1| 29,5| UserRequest.cc(73) valid: Validated. Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.626 kid1| 29,9| UserRequest.cc(63) authenticated: user not fully authenticated.
2016/07/28 10:26:01.626 kid1| 29,9| UserRequest.cc(328) authenticate: header Negotiate TlRMTVNTUAABAAAAl4II4gAAAAAAAAAAAAAAAAAAAAAKAFopAAAADw==.
2016/07/28 10:26:01.626 kid1| 29,9| UserRequest.cc(53) valid: Validating Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.626 kid1| 29,5| UserRequest.cc(73) valid: Validated. Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.626 kid1| 29,9| UserRequest.cc(63) authenticated: user not fully authenticated.
2016/07/28 10:26:01.626 kid1| 29,9| UserRequest.cc(256) authenticate: auth state negotiate failed. Negotiate TlRMTVNTUAABAAAAl4II4gAAAAAAAAAAAAAAAAAAAAAKAFopAAAADw==
2016/07/28 10:26:01.626 kid1| 29,9| UserRequest.cc(53) valid: Validating Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.626 kid1| 29,5| UserRequest.cc(73) valid: Validated. Auth::UserRequest '0x28576b0'.
2016/07/28 10:26:01.626 kid1| 29,9| UserRequest.cc(63) authenticated: user not fully authenticated.
2016/07/28 10:26:01.626 kid1| 29,9| UserRequest.cc(487) addReplyAuthHeader: headertype:46 authuser:NULL
2016/07/28 10:26:01.626 kid1| 29,9| Config.cc(188) fixHeader: Sending type:46 header: 'Negotiate'
2016/07/28 10:26:01.732 kid1| 29,9| UserRequest.cc(487) addReplyAuthHeader: headertype:46 authuser:NULL
2016/07/28 10:26:01.732 kid1| 29,9| Config.cc(188) fixHeader: Sending type:46 header: 'Negotiate'
2016/07/28 10:26:01.913 kid1| 29,9| UserRequest.cc(487) addReplyAuthHeader: headertype:46 authuser:NULL
2016/07/28 10:26:01.913 kid1| 29,9| Config.cc(188) fixHeader: Sending type:46 header: 'Negotiate'
2016/07/28 10:26:01.956 kid1| 29,9| UserRequest.cc(487) addReplyAuthHeader: headertype:46 authuser:NULL
2016/07/28 10:26:01.956 kid1| 29,9| Config.cc(188) fixHeader: Sending type:46 header: 'Negotiate'
2016/07/28 10:26:01.980 kid1| 29,9| UserRequest.cc(487) addReplyAuthHeader: headertype:46 authuser:NULL
2016/07/28 10:26:01.980 kid1| 29,9| Config.cc(188) fixHeader: Sending type:46 header: 'Negotiate'
2016/07/28 10:26:01.993 kid1| 29,9| UserRequest.cc(487) addReplyAuthHeader: headertype:46 authuser:NULL
2016/07/28 10:26:01.993 kid1| 29,9| Config.cc(188) fixHeader: Sending type:46 header: 'Negotiate'
2016/07/28 10:26:02.004 kid1| 29,9| UserRequest.cc(487) addReplyAuthHeader: headertype:46 authuser:NULL
2016/07/28 10:26:02.004 kid1| 29,9| Config.cc(188) fixHeader: Sending type:46 header: 'Negotiate'
2016/07/28 10:26:09.555 kid1| 29,6| UserRequest.cc(179) releaseAuthServer: No Negotiate auth server to release.
2016/07/28 10:26:09.556 kid1| 29,6| UserRequest.cc(179) releaseAuthServer: No Negotiate auth server to release.
2016/07/28 10:26:09.556 kid1| 29,5| UserRequest.cc(101) ~UserRequest: freeing request 0x28576b0
2016/07/28 10:26:09.556 kid1| 29,5| User.cc(21) ~User: doing nothing to clear Negotiate scheme data for '0x2857400'
2016/07/28 10:26:09.556 kid1| 29,5| User.cc(127) ~User: Freeing auth_user '0x2857400'.
2016/07/28 10:26:09.559 kid1| 29,6| UserRequest.cc(179) releaseAuthServer: No Negotiate auth server to release.
2016/07/28 10:26:09.559 kid1| 29,6| UserRequest.cc(179) releaseAuthServer: No Negotiate auth server to release.
2016/07/28 10:26:09.559 kid1| 29,5| UserRequest.cc(101) ~UserRequest: freeing request 0x286f4d0
2016/07/28 10:26:09.559 kid1| 29,5| User.cc(21) ~User: doing nothing to clear Negotiate scheme data for '0x286f2a0'
2016/07/28 10:26:09.559 kid1| 29,5| User.cc(127) ~User: Freeing auth_user '0x286f2a0'.
2016/07/28 10:26:09.563 kid1| 29,6| UserRequest.cc(179) releaseAuthServer: No Negotiate auth server to release.
2016/07/28 10:26:09.563 kid1| 29,6| UserRequest.cc(179) releaseAuthServer: No Negotiate auth server to release.
2016/07/28 10:26:09.563 kid1| 29,5| UserRequest.cc(101) ~UserRequest: freeing request 0x2857ab0
2016/07/28 10:26:09.563 kid1| 29,5| User.cc(21) ~User: doing nothing to clear Negotiate scheme data for '0x241e990'
2016/07/28 10:26:09.563 kid1| 29,5| User.cc(127) ~User: Freeing auth_user '0x241e990'.

I've created the keytab on Windows using ktpass:

ktpass /princ host/[email protected] /mapuser [email protected] /crypto rc4-hmac-nt /pass * /ptype KRB5_NT_PRINCIPAL /out C:\Soporte\winkrb5.keytab

and then copied to squid, and I see the following thing:

 klist -kt /etc/squid/HTTP.keytab
Keytab name: FILE:/etc/squid/HTTP.keytab
KVNO Timestamp           Principal
---- ------------------- ------------------------------------------------------
   3 12/31/1969 21:00:00 HTTP/[email protected]

I wonder if the wrong timestamp has to do with the problem

Kerberos and relevant squid config files are as follows:

[logging] default = FILE:/var/log/krb5libs.log kdc = FILE:/var/log/krb5kdc.log admin_server = FILE:/var/log/kadmind.log

[libdefaults]
 dns_lookup_realm = false
 ticket_lifetime = 24h
 renew_lifetime = 7d
 forwardable = true
 rdns = false
 default_realm = EXAMPLE.LOCAL
 default_ccache_name = KEYRING:persistent:%{uid}

; for Windows 2008 with AES
    default_tgs_enctypes = aes256-cts-hmac-sha1-96 rc4-hmac des-cbc-crc des-cbc-md5
    default_tkt_enctypes = aes256-cts-hmac-sha1-96 rc4-hmac des-cbc-crc des-cbc-md5
    permitted_enctypes = aes256-cts-hmac-sha1-96 rc4-hmac des-cbc-crc des-cbc-md5

squid.conf:

auth_param negotiate program /usr/lib64/squid/negotiate_kerberos_auth -d  -s HTTP/[email protected]
auth_param negotiate children 10
auth_param negotiate keep_alive on
acl kerb_auth proxy_auth REQUIRED

Is the keytab timestamp the cause of errors? Am I doing something wrong?

Solution 1

The 'negotiate_kerberos_auth: WARNING: received type 1 NTLM token' in log means your browser supplied the Negotiate/NTLM token instead of Negotiate/Kerberos that your negotiate_kerberos_auth is able to handle.

You will need to have NTLM authenticator for Negotiate authentication scheme configured too. One way is to install and configure Samba as indicated on http://wiki.squid-cache.org/ConfigExamples/Authenticate/WindowsActiveDirectory#NTLM or use the redirection of NTLM credentials to LDAP server as indicated on http://docs.diladele.com/administrator_guide_4_6/active_directory/install_prerequisites_for_ntlm_authentication.html

If your machine is within domain and user is a domain user then most probably you have configured your proxy as IP address and Kerberos requires proxy to be set as FQDN in browser. For troubleshooting steps see http://docs.diladele.com/administrator_guide_4_6/active_directory/troubleshooting.html.

Solution 2

Well, finally thanks @Rafael I've found the solution:

Replace:

auth_param negotiate program /usr/lib64/squid/negotiate_kerberos_auth -d  -s HTTP/[email protected]

by:

auth_param negotiate program /usr/lib64/squid/negotiate_wrapper_auth -d --ntlm /usr/bin/ntlm_auth --diagnostics --helper-protocol=squid-2.5-ntlmssp --domain=EXAMPLE --kerberos /usr/lib64/squid/negotiate_kerberos_auth -d -s GSS_C_NO_NAME

Also, I've started smb and winbind services

Comments

[Admin]

What about the browser? Does it support Kerberos auth and is it configured to do so?

[Admin]

I tested with Internet Explorer, AFAIK theroretically it suppors out of the box. Also with Firefox, with network.negotiate-auth.trusted-uris using .example.local. Anyone of them work.

[sebelk]

I login from Windows 7 and joined to domain. I'd want to use kerberos. I'm tried with both Internet Explorer and Firefox with proxy set as FQDN.

[sebelk]

Is mandatory to use NTLM authenticator too besides kerberos?

[Grigory Sergeev]

Why not mark Rafael's answer as such then? :)