5.8. Authentication
5.8. Authentication ipa component, BZ# 894388 The Identity Management installer configures all integrated services to listen on all interfaces. The administrator has no means to instruct the Identity Management installer to listen only on chosen interfaces even though the installer requires a valid interface IP address as one installation parameter. To work around this problem, change service configuration after Identity Management installation. ipa component, BZ# 894378 Identity Management LDAP permission manipulation plugin validates subtree and filter permission specifiers as mutually exclusive even though it is a valid combination in the underlying LDAP Access Control Instruction (ACI). Permissions with filter and subtree specifiers can be neither created nor modified. This affects for example the Add Automount Keys permission which cannot be modified. ipa component, BZ# 817080 In some cases the certificates tracked by certmonger are not cleared when running the ipa-server-install --uninstall command. This will cause a subsequent re-installation to fail with an unexpected error. sssd component, BZ# 892604 The ssh_cache utility sets the DEBUG level after it processes the command-line parameters. If the command-line parameters cannot be processed, the utility prints DEBUG lines that are not supposed to be printed by default. To avoid this, correct parameters must be used. sssd component, BZ# 891647 It is possible to specify the enumerate=true value in the sssd.conf file to access all users in the system. However, using enumerate=true is not recommended in large environments as this can lead to high CPU consumption. As a result, operations like login or logout can be slowed down. ipa component, BZ# 888579 The Identity Management server processes Kerberos Password Expiration Time field as a 32-bit integer. If Maximum Lifetime of a user password in Identity Management Password Policy is set to a value causing the resulting Kerberos Password Expiration Time timestamp to exceed 32 bits and to overflow, the passwords that are being changed are configured with an expiration time that lies in the past and are always rejected. To ensure that new user passwords are valid and can be changed properly, do not set password Maximum Lifetime in Identity Management Password Policy to values that would cause the Kerberos Password Expiration Time timestamp to exceed 32 bits; that is, passwords that would expire after 2038-01-19. At the moment, recommended values for the Maximum Lifetime field are numbers lower than 9000 days. sssd component, BZ# 785877 When reconnecting to an LDAP server, SSSD does not check it was re-initialized during the downtime. If the server was re-initialized during the downtime and was filled with completely different data, SSSD does not update its database. As a consequence, the user can get invalid information from SSSD. To work around this problem: stop SSSD before reconnecting to the re-initialized server; clear the SSSD caches manually before reconnecting; start SSSD. krb5 component In environments where entropy is scarce, the kadmind tool can take longer to initialize after startup than it did in releases as it attempts to read data from the /dev/random file and seed its internal random number generator (RNG). Clients which attempt to connect to the kadmin service can time out and fail with a GSS-API or Kerberos error. After the service completely finishes initializing itself, it will process messages received from now-disconnected clients and can log clock-skew or decrypt-integrity-check-failed errors for those connections. To work around this problem, use a service such as rngd to seed the system RNG using hardware sources of entropy. ipa component, BZ# 887193 The Identity Management server in Red Hat Enterprise Linux 6.3 introduced a technical preview of SELinux user mapping feature, which enabled a mapping of SELinux users to users managed by the Identity Management based on custom rules. However, the default configured SELinux user ( guest_u:s0 ) used when no custom rule matches is too constraining. An Identity Management user authenticating to Red Hat Enterprise Linux 6.4 can be assigned the too constraining SELinux user in which case a login through graphical session would always fail. To work around this problem, change a too constraining default SELinux user in the Identity Management server from guest_u:s0 to a more relaxed value unconfined_u:s0-s0:c0.c1023 : An unconfined SELinux user will be now assigned to the Identity Management user by default, which will allow the user to successfully authenticate through graphical interface. ipa component, BZ# 761574 When attempting to view a host in the web UI, the following message can appear: Attempting to delete installed certificates through the web UI or command-line interface can fail with the same error message. To work around this problem, run the following command: ipa component, BZ# 877324 After upgrading to Red Hat Identity Manager 2.2, it is not possible to add SSH public keys in the web UI. However, SSH public keys can be added on the command line by running ipa user-mod <user> --sshpubkey . sssd component, BZ# 880150 Rules with sudoUser specified as +netgroup are always matched with the sssd sudoers plugin. sssd component When the ldap_sasl_authid is not configured in the sssd.conf file, SSSD terminates unexpectedly with a segmentation fault. To avoid this problem, ensure that the option is configured. ipa component When upgrading the ipa-server package using anaconda , the following error message is logged in the upgrade.log file: This problem does not occur when using yum . sssd component In the Identity Manager subdomain code, a User Principal Name (UPN) is by default built from the SAM Account Name and Active Directory trust users, that is user@DOMAIN . The UPN can be changed to differ from the UPN in Active Directory, however only the default format, user@DOMAIN , is supported. sssd component, BZ# 805921 Sometimes, group members may not be visible when running the getent group groupname command. This can be caused by an incorrect ldap_schema in the [domain/DOMAINNAME] section of the sssd.conf file. SSSD supports three LDAP schema types: RFC 2307, RFC 2307bis, and IPA. By default, SSSD uses the more common RFC 2307 schema. The difference between RFC 2307 and RFC 2307bis is the way which group membership is stored in the LDAP server. In an RFC 2307 server, group members are stored as the multi-valued memberuid attribute which contains the name of the users that are members. In an RFC2307bis server, group members are stored as the multi-valued attribute member (or sometimes uniqueMember) which contains the DN of the user or group that is a member of this group. RFC2307bis allows nested groups to be maintained as well. When encountering this problem: add ldap_schema = rfc2307bis in the sssd.conf file, detele the /var/lib/sss/db/cache_DOMAINNAME.ldb file, and restart SSSD . If the workaround does not work, add ldap_group_member = uniqueMember in the sssd.conf file, delete the cache file and restart SSSD. Identity Management component, BZ# 826973 When Identity Management is installed with its CA certificate signed by an external CA, the installation is processed in 2 stages. In the first stage, a CSR is generated to be signed by an external CA. The second stage of the installation then accepts a file with the new signed certificate for the Identity Management CA and a certificate of the external CA. During the second stage of the installation, a signed Identity Management CA certificate subject is validated. However, there is a bug in the certificate subject validation procedure and its default value ( O=USDREALM , where USDREALM is the realm of the new Identity Management installation) is never pulled. Consequently, the second stage of the installation process always fails unless the --subject option is specified. To work around this issue, add the following option for the second stage of the installation: --subject "O=USDREALM" where USDREALM is the realm of the new Identity Management installation. If a custom subject was used for the first stage of the installation, use its value instead. Using this work around, the certificate subject validation procedure succeeds and the installation continues as expected. Identity Management component, BZ# 822350 When a user is migrated from a remote LDAP, the user's entry in the Directory Server does not contain Kerberos credentials needed for a Kerberos login. When the user visits the password migration page, Kerberos credentials are generated for the user and logging in via Kerberos authentication works as expected. However, Identity Management does not generate the credentials correctly when the migrated password does not follow the password policy set on the Identity Management server. Consequently, when the password migration is done and a user tries to log in via Kerberos authentication, the user is prompted to change the password as it does not follow the password policy, but the password change is never successful and the user is not able to use Kerberos authentication. To work around this issue, an administrator can reset the password of a migrated user with the ipa passwd command. When reset, user's Kerberos credentials in the Directory Server are properly generated and the user is able to log in using Kerberos authentication. Identity Management component In the Identity Management webUI, deleting a DNS record may, under come circumstances, leave it visible on the page showing DNS records. This is only a display issue and does not affect functionality of DNS records in any way. Identity Management component, BZ# 790513 The ipa-client package does not install the policycoreutils package as its dependency, which may cause install/uninstall issues when using the ipa-client-install setup script. To work around this issue, install the policycoreutils package manually: Identity Management component, BZ# 813376 Updating the Identity Management LDAP configuration via the ipa-ldap-updater fails with a traceback error when executed by a non-root user due to the SASL EXTERNAL bind requiring root privileges. To work around this issue, run the aforementioned command as the root user. Identity Management component, BZ# 794882 With netgroups, when adding a host as a member that Identity Management does not have stored as a host already, that host is considered to be an external host. This host can be controlled with netgroups, but Identity Management has no knowledge of it. Currently, there is no way to use the netgroup-find option to search for external hosts. Also, note that when a host is added to a netgroup as an external host, rather than being added in Identity Management as an external host, that host is not automatically converted within the netgroup rule. Identity Management component, BZ# 786629 Because a permission does not provide write access to an entry, delegation does not work as expected. The 389 Directory Server ( 389-ds ) distinguishes access between entries and attributes. For example, an entry can be granted add or delete access, whereas an attribute can be granted read, search, and write access. To grant write access to an entry, the list of writable attributes needs to be provided. The filter , subtree , and other options are used to target those entries which are writable. Attributes define which part(s) of those entries are writable. As a result, the list of attributes will be writable to members of the permission. sssd component, BZ# 808063 The manpage entry for the ldap_disable_paging option in the sssd-ldap man page does not indicate that it accepts the boolean values True or False, and defaulting to False if it is not explicitly specified. Identity Management component, BZ# 812127 Identity Management relies on the LDAP schema to know what type of data to expect in a given attribute. If, in certain situations (such as replication), data that does not meet those expectations is inserted into an attribute, Identity Management will not be able to handle the entry, and LDAP tools have do be used to manually clean up that entry. Identity Management component, BZ# 812122 Identity Management sudo commands are not case sensitive. For example, executing the following commands will result in the latter one failing due to the case insensitivity: Identity Management component When an Identity Management server is installed with a custom hostname that is not resolvable, the ipa-server-install command should add a record to the static hostname lookup table in /etc/hosts and enable further configuration of Identity Management integrated services. However, a record is not added to /etc/hosts when an IP address is passed as an CLI option and not interactively. Consequently, Identity Management installation fails because integrated services that are being configured expect the Identity Management server hostname to be resolvable. To work around this issue, complete one of the following: Run the ipa-server-install without the --ip-address option and pass the IP address interactively. Add a record to /etc/hosts before the installation is started. The record should contain the Identity Management server IP address and its full hostname (the hosts(5) man page specifies the record format). As a result, the Identity Management server can be installed with a custom hostname that is not resolvable. sssd component Upgrading SSSD from the version provided in Red Hat Enterprise Linux 6.1 to the version shipped with Red Hat Enterprise Linux 6.2 may fail due to a bug in the dependent library libldb . This failure occurs when the SSSD cache contains internal entries whose distinguished name contains the \, character sequence. The most likely example of this is for an invalid memberUID entry to appear in an LDAP group of the form: memberUID is a multi-valued attribute and should not have multiple users in the same attribute. If the upgrade issue occurs, identifiable by the following debug log message: remove the /var/lib/sss/db/cache_<DOMAIN>.ldb file and restart SSSD. Warning Removing the /var/lib/sss/db/cache_<DOMAIN>.ldb file purges the cache of all entries (including cached credentials). sssd component, BZ# 751314 When a group contains certain incorrect multi-valued memberUID values, SSSD fails to sanitize the values properly. The memberUID value should only contain one username. As a result, SSSD creates incorrect users, using the broken memberUID values as their usernames. This, for example, causes problems during cache indexing. Identity Management component Two Identity Management servers, both with a CA (Certificate Authority) installed, use two replication replication agreements. One is for user, group, host, and other related data. Another replication agreement is established between the CA instances installed on the servers. If the CA replication agreement is broken, the Identity Management data is still shared between the two servers, however, because there is no replication agreement between the two CAs, issuing a certificate on one server will cause the other server to not recognize that certificate, and vice versa. Identity Management component The Identity Management ( ipa ) package cannot be build with a 6ComputeNode subscription. sssd component, BZ# 741264 Active Directory performs certain LDAP referral-chasing that is incompatible with the referral mechanism included in the openldap libraries. Notably, Active Directory sometimes attempts to return a referral on an LDAP bind attempt, which used to cause a hang, and is now denied by the openldap libraries. As a result, SSSD may suffer from performance issues and occasional failures resulting in missing information. To work around this issue, disable referral-chasing by setting the following parameter in the [domain/DOMAINNAME] section of the /etc/sssd/sssd.conf file:
kinit admin ipa config-mod --ipaselinuxusermapdefault=unconfined_u:s0-s0:c0.c1023 Certificate operation cannot be completed: Unable to communicate with CMS (Unauthorized) ~]# yum downgrade ipa-server libipa_hbac libipa_hbac-python ipa-python ipa-client ipa-admintools ipa-server-selinux /sbin/restorecon: lstat(/var/lib/pki-ca/publish*) failed: No such file or directory ~]# yum install policycoreutils ~]USD ipa sudocmd-add /usr/bin/X ... ~]USD ipa sudocmd-add /usr/bin/x ipa: ERROR: sudo command with name "/usr/bin/x" already exists memberUID: user1,user2 (Wed Nov 2 15:18:21 2011) [sssd] [ldb] (0): A transaction is still active in ldb context [0xaa0460] on /var/lib/sss/db/cache_<DOMAIN>.ldb ldap_referrals = false