PBIS Open AD authentication stops working on ubuntu with errors: "user accout has expired" and "is your account locked?"

Question

We have been using PowerBroker Identity Services Open to authenticate active directory users from ubuntu hosts successfully for six months.

Recently AD authentication stopped working on several workstations after users performed an apt-get upgrade of 200+ packages at once. Authentication attempts give the errors, "invalid password," "user account has expired," or "is your account locked?"

I have not been able to link the issue to a specific package upgrade but workstations build from scratch with the same package versions do not experience the issue. I have tried reinstalling PBIS and validated all the config files but I'm missing something.... I'm at a loss and would love any advice anyone has. I'd rather not have to rebuild another box the next time this happens!

Authentication Attempts

I first verified that the the AD user account was enabled, was not locked and had not expired. Local user authentication works fine through lightdm and ssh.

1. lightdm

   • valid credentials
     • error returned to user "Invalid password, please try again."
     • auth.log: nothing
     • syslog: nothing

   • incorrect password

     • error returned to user "Invalid password, please try again."

     • auth.log:

       lightdm: [lsass-pam] [module:pam_lsass]pam_sm_authenticate error [login:username][error code:40022]
       

     • syslog:

       lsass: [LwKrb5GetTgtImpl /builder/src-buildserver/Platform-8.0/src/linux/lwadvapi/threaded/krbtgt.c:276] KRB5 Error code: -1765328360 (Message: Preauthentication failed)
       lsass: [lsass] Failed to authenticate user (name = 'username') -> error = 40022, symbol = LW_ERROR_PASSWORD_MISMATCH, client pid = 17768
       

2. ssh

   • valid credentials

     • ssh disconnect with "Connection closed by IP_ADDRESS."

     • auth.log:

       sshd[18237]: error: PAM: User account has expired for DOMAIN\\USER from HOSTNAME
       sshd[18237]: error: Received disconnect from IP_ADDRESS: 13: Unable to authenticate [preauth]
       

     • syslog: nothing

   • incorrect password

     • ssh disconnect with "Connection closed by IP_ADDRESS."

     • auth.log:

       sshd[18276]: [lsass-pam] [module:pam_lsass]pam_sm_authenticate error [login:domain\username][error code:40022]
       sshd[18272]: error: PAM: Authentication failure for domain\\username from hostname
       

     • syslog

       lsass: [LwKrb5GetTgtImpl /builder/src-buildserver/Platform-8.0/src/linux/lwadvapi/threaded/krbtgt.c:276] KRB5 Error code: -1765328360 (Message: Preauthentication failed)
       lsass: [lsass] Failed to authenticate user (name = 'domain\username') -> error = 40022, symbol = LW_ERROR_PASSWORD_MISMATCH, client pid = 18276
       

3. Just trying some crazy local stuff (and no, the account is not locked in AD)

           root@hostname:~# su - domain\\username
           su: Authentication failure
           (Ignored)
           reenter password for pam_mount:
           DOMAIN\username@hostname:~$ sudo cat /etc/fstab
           [sudo] password for DOMAIN\username:
           sudo: account validation failure, is your account locked?
           DOMAIN\username@hostname:~$
   

Configuration

• Ubuntu 14.04
• PBIS Open 8.0.1.2029 (pbis-open-8.0.1.2029.linux.x86_64.deb.sh)

• /opt/pbis/bin/config --dump

  AllowDeleteTo ""  
  AllowReadTo ""  
  AllowWriteTo ""
  MaxDiskUsage 104857600
  MaxEventLifespan 90
  MaxNumEvents 100000
  DomainSeparator "\\"
  SpaceReplacement "^"
  EnableEventlog false
  Providers "ActiveDirectory"
  DisplayMotd false
  PAMLogLevel "error"
  UserNotAllowedError "Access denied"
  AssumeDefaultDomain true
  CreateHomeDir true
  CreateK5Login true
  SyncSystemTime true
  TrimUserMembership true
  LdapSignAndSeal false
  LogADNetworkConnectionEvents true
  NssEnumerationEnabled true
  NssGroupMembersQueryCacheOnly true
  NssUserMembershipQueryCacheOnly false
  RefreshUserCredentials true
  CacheEntryExpiry 14400
  DomainManagerCheckDomainOnlineInterval 300
  DomainManagerUnknownDomainCacheTimeout 3600
  MachinePasswordLifespan 2592000
  MemoryCacheSizeCap 0
  HomeDirPrefix "/home"
  HomeDirTemplate "%H/%D/%U"
  RemoteHomeDirTemplate ""
  HomeDirUmask "022"
  LoginShellTemplate "/bin/bash"
  SkeletonDirs "/etc/skel"
  UserDomainPrefix "DOMAIN.COM"
  DomainManagerIgnoreAllTrusts false
  DomainManagerIncludeTrustsList
  DomainManagerExcludeTrustsList
  RequireMembershipOf "DOMAIN\\DOMAIN-GROUP"
  Local_AcceptNTLMv1 true
  Local_HomeDirTemplate "%H/local/%D/%U"
  Local_HomeDirUmask "022"
  Local_LoginShellTemplate "/bin/sh"
  Local_SkeletonDirs "/etc/skel"
  UserMonitorCheckInterval 1800
  LsassAutostart true
  EventlogAutostart true
  

• /opt/pbis/bin/get-status

  LSA Server Status:
  
  Compiled daemon version: 8.0.1.2029
  Packaged product version: 8.0.2029.67662
  Uptime:        1 days 1 hours 4 minutes 26 seconds
  
  [Authentication provider: lsa-activedirectory-provider]
  
          Status:        Online
          Mode:          Un-provisioned
          Domain:        DOMAIN.COM
          Domain SID:    S-1-5-21-3537566271-1428921453-776812789
          Forest:        domain.com
          Site:          NYC
          Online check interval:  300 seconds
          [Trusted Domains: 1]
  
  
          [Domain: DOMAIN]
  
                  DNS Domain:       domain.com
                  Netbios name:     DOMAIN
                  Forest name:      domain.com
                  Trustee DNS name:
                  Client site name: NYC
                  Domain SID:       S-1-5-21-3537566271-1428921453-776812789
                  Domain GUID:      0b6b6d88-ea48-314a-8bad-a997a57bc1f4
                  Trust Flags:      [0x001d]
                                    [0x0001 - In forest]
                                    [0x0004 - Tree root]
                                    [0x0008 - Primary]
                                    [0x0010 - Native]
                  Trust type:       Up Level
                  Trust Attributes: [0x0000]
                  Trust Direction:  Primary Domain
                  Trust Mode:       In my forest Trust (MFT)
                  Domain flags:     [0x0001]
                                    [0x0001 - Primary]
  
                  [Domain Controller (DC) Information]
  
                          DC Name:              dc2.nyc.domain.com
                          DC Address:           10.x.x.50
                          DC Site:              NYC
                          DC Flags:             [0x0000f1fc]
                          DC Is PDC:            no
                          DC is time server:    yes
                          DC has writeable DS:  yes
                          DC is Global Catalog: yes
                          DC is running KDC:    yes
  
                  [Global Catalog (GC) Information]
  
                          GC Name:              dc1.nyc.domain.com
                          GC Address:           10.x.x.50
                          GC Site:              NYC
                          GC Flags:             [0x0000f3fd]
                          GC Is PDC:            yes
                          GC is time server:    yes
                          GC has writeable DS:  yes
                          GC is running KDC:    yes
  

• /opt/pbis/bin/find-objects --user USERNAME

  User object [1 of 1] (S-1-5-21-3537566271-1428921453-776812789-1107)
  ============
  Enabled: yes
  Distinguished name: CN=USERNAME,OU=User,OU=User Accounts,DC=domain,DC=com
  SAM account name: username
  NetBIOS domain name: DOMAIN
  UPN: [email protected]
  Display Name: First Last
  Alias: <null>
  UNIX name: DOMAIN\username
  GECOS: First LAst
  Shell: /bin/bash
  Home directory: /home/DOMAIN/username
  Windows home directory: \\domain.com\dfs\NYC\Users\username
  Local windows home directory:
  UID: 1023411283
  Primary group SID: S-1-5-21-3537566271-1428921453-776812789-513
  Primary GID: 1023410689
  Password expired: no
  Password never expires: yes
  Change password on next logon: no
  User can change password: yes
  Account disabled: no
  Account expired: no
  Account locked: no    
  

• /etc/pbis/pbis-krb5-ad.conf

  [libdefaults]
      default_tgs_enctypes = AES256-CTS AES128-CTS RC4-HMAC DES-CBC-MD5 DES-CBC-CRC
      default_tkt_enctypes = AES256-CTS AES128-CTS RC4-HMAC DES-CBC-MD5 DES-CBC-CRC
      preferred_enctypes = AES256-CTS AES128-CTS RC4-HMAC DES-CBC-MD5 DES-CBC-CRC
      dns_lookup_kdc = true
      pkinit_kdc_hostname = <DNS>
      pkinit_anchors = DIR:/var/lib/pbis/trusted_certs
      pkinit_cert_match = &&<EKU>msScLogin<PRINCIPAL>
      pkinit_eku_checking = kpServerAuth
      pkinit_win2k_require_binding = false
      pkinit_identities = PKCS11:/opt/pbis/lib/libpkcs11.so
  

• /etc/pam.d/common-session

  session [default=1]                     pam_permit.so
  session requisite                       pam_deny.so
  session required                        pam_permit.so
  session optional                        pam_umask.so
  session required                        pam_unix.so
  session optional                        pam_mount.so
  session [success=ok default=ignore]     pam_lsass.so
  session optional                        pam_systemd.so
  

• /etc/pam.d/common-auth

  auth    [success=2 default=ignore]      pam_unix.so nullok_secure
  auth    [success=1 default=ignore]      pam_lsass.so try_first_pass
  auth    requisite                       pam_deny.so
  auth    required                        pam_permit.so
  auth    optional                        pam_cap.so
  auth    optional                        pam_mount.so
  

• /opt/pbis/share/pbis.pam-auth-update

  Name: Likewise
  Default: yes
  Priority: 250
  Conflicts: winbind
  Auth-Type: Primary
  Auth:
          [success=end default=ignore]    pam_lsass.so try_first_pass
  Auth-Initial:
          [success=end default=ignore]    pam_lsass.so
  Account-Type: Primary
  Account:
          [success=ok new_authtok_reqd=ok default=ignore]         pam_lsass.so unknown_ok
          [success=end new_authtok_reqd=done default=ignore]      pam_lsass.so
  Session-Type: Additional
  Session:
          sufficient      pam_lsass.so
  Password-Type: Primary
  Password:
          [success=end default=ignore]    pam_lsass.so use_authtok try_first_pass
  Password-Initial:
          [success=end default=ignore]    pam_lsass.so
  

• /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf

  [SeatDefaults]
  user-session=ubuntu
  greeter-show-manual-login=true
  

• /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf

  [SeatDefaults]
  allow-guest=false
  greeter-show-remote-login=false
  greeter-show-manual-login=true
  greeter-session=unity-greeter
  

Solution 1

The key line is this:

sshd[18237]: error: PAM: User account has expired for DOMAIN\\USER from HOSTNAME

This indicates that a PAM module believes the account has expired. I'd focus less on auth/session and more on account, which is the facility focused on account properties not related to authentication. Your first task is to identify the module causing the problem. Once you know that, it should be much easier to identify why the module thinks the user should be blocked.

Review the applicable account modules one by one, and try adding the debug flag to individual entries to expand the logging output if you need more hints. If truly stumped and it wouldn't violate the security of a critical environment, you can also try commenting the account lines one at a time until you identify your culprit.

As for what changed, more than likely your PAM config was modified when these packages were installed. Chances are that the users in question were in this state all along, but the database associated with the misbehaving account module was being bypassed. (skipped, commented, not present at all, etc.)

Solution 2

FYI: domainjoin-cli configure --enable pam will re-add these lines after an upgrade as well. PBIS Open 8.x and higher properly deliver a /usr/share/pam-configs/pbis configuration so that this shouldn't happen in the future.

Additionally, PBIS logs more specific errors to the daemon facility of syslog, so you can view them in ubuntu in /var/log/syslog rather than /var/log/secure.

Solution 3

Thanks again to @Andrew B for helping me find the solution.

For the record, here is a copy of the correct /etc/pam.d/common-account configuration that FIXES my issue (the two pam_lsass.so lines were missing from the systems that were not working):

 account [success=3 new_authtok_reqd=done default=ignore]        pam_unix.so
 account [success=ok new_authtok_reqd=ok default=ignore]         pam_lsass.so unknown_ok
 account [success=1 new_authtok_reqd=done default=ignore]        pam_lsass.so
 account requisite                       pam_deny.so
 account required                        pam_permit.so

Comments

[Peter M]

I've been banking my head against a wall for weeks on this -- thank you very, very much @Andrew B! I compared /etc/pam.d/common-account on a working machine with the non working machine and both pam_lsass.so entries were missing. For the record, here are the two lines that were missing from common-account on the system: account [success=ok new_authtok_reqd=ok default=ignore] pam_lsass.so unknown_ok AND account [success=1 new_authtok_reqd=done default=ignore] pam_lsass.so

[Andrew B]

Ooof. Yeah, that pam_unix.so line was bad news. success=3 means "skip over the next 3 lines if successful", and without those next two lines you're skipping past the end of the file. Hard to interpret what happens next without seeing your full account stack, but you'd definitely be skipping past 1 line in another file or the end of the stack entirely.