Tag Archives: Security

Troubleshooting FreeIPA: pki-tomcatd fails to start

When performing the upgrade of FreeIPA, you may encounter an issue with pki-tomcatd failing to start. At first this issue looks related to the upgrade, but often reveals a latent problem and gets detected only because the upgrade triggers a restart of pki-tomcatd.

So how to troubleshoot this type of issue?

 

Upgrade logs

The upgrade is using /var/log/ipaupgrade.log and may contain a lot of useful information. In this specific case, I could see:

[...] DEBUG The ipa-server-upgrade command failed,
exception: ScriptError: CA did not start in 300.0s
[...] ERROR CA did not start in 300.0s
[...] ERROR The ipa-server-upgrade command failed. See
/var/log/ipaupgrade.log for more information

 

CA debug logs

The first step is to understand why pki-tomcatd refuses to start. This process is launched inside Tomcat and corresponds to the CA component of FreeIPA. It is logging into /var/log/pki/pki-tomcat/ca/debug:

[...][localhost-startStop-2]: ============================================
[...][localhost-startStop-2]: ===== DEBUG SUBSYSTEM INITIALIZED =======
[...][localhost-startStop-2]: ============================================
[...][localhost-startStop-2]: CMSEngine: restart at autoShutdown? false
[...][localhost-startStop-2]: CMSEngine: autoShutdown crumb file path? /var/lib/pki/pki-tomcat/logs/autoShutdown.crumb
[...][localhost-startStop-2]: CMSEngine: about to look for cert for auto-shutdown support:auditSigningCert cert-pki-ca
[...][localhost-startStop-2]: CMSEngine: found cert:auditSigningCert cert-pki-ca
[...][localhost-startStop-2]: CMSEngine: done init id=debug
[...][localhost-startStop-2]: CMSEngine: initialized debug
[...][localhost-startStop-2]: CMSEngine: initSubsystem id=log
[...][localhost-startStop-2]: CMSEngine: ready to init id=log
[...][localhost-startStop-2]: Creating RollingLogFile(/var/lib/pki/pki-tomcat/logs/ca/signedAudit/ca_audit)
[...][localhost-startStop-2]: Creating RollingLogFile(/var/lib/pki/pki-tomcat/logs/ca/system)
[...][localhost-startStop-2]: Creating RollingLogFile(/var/lib/pki/pki-tomcat/logs/ca/transactions)
[...][localhost-startStop-2]: CMSEngine: restart at autoShutdown? false
[...][localhost-startStop-2]: CMSEngine: autoShutdown crumb file path? /var/lib/pki/pki-tomcat/logs/autoShutdown.crumb
[...][localhost-startStop-2]: CMSEngine: about to look for cert for auto-shutdown support:auditSigningCert cert-pki-ca
[...][localhost-startStop-2]: CMSEngine: found cert:auditSigningCert cert-pki-ca
[...][localhost-startStop-2]: CMSEngine: done init id=log
[...][localhost-startStop-2]: CMSEngine: initialized log
[...][localhost-startStop-2]: CMSEngine: initSubsystem id=jss
[...][localhost-startStop-2]: CMSEngine: ready to init id=jss
[...][localhost-startStop-2]: CMSEngine: restart at autoShutdown? false
[...][localhost-startStop-2]: CMSEngine: autoShutdown crumb file path? /var/lib/pki/pki-tomcat/logs/autoShutdown.crumb
[...][localhost-startStop-2]: CMSEngine: about to look for cert for auto-shutdown support:auditSigningCert cert-pki-ca
[...][localhost-startStop-2]: CMSEngine: found cert:auditSigningCert cert-pki-ca
[...][localhost-startStop-2]: CMSEngine: done init id=jss
[...][localhost-startStop-2]: CMSEngine: initialized jss
[...][localhost-startStop-2]: CMSEngine: initSubsystem id=dbs
[...][localhost-startStop-2]: CMSEngine: ready to init id=dbs
[...][localhost-startStop-2]: DBSubsystem: init() mEnableSerialMgmt=true
[...][localhost-startStop-2]: Creating LdapBoundConnFactor(DBSubsystem)
[...][localhost-startStop-2]: LdapBoundConnFactory: init
[...][localhost-startStop-2]: LdapBoundConnFactory:doCloning true
[...][localhost-startStop-2]: LdapAuthInfo: init()
[...][localhost-startStop-2]: LdapAuthInfo: init begins
[...][localhost-startStop-2]: LdapAuthInfo: init ends
[...][localhost-startStop-2]: init: before makeConnection errorIfDown is true
[...][localhost-startStop-2]: makeConnection: errorIfDown true
[...][localhost-startStop-2]: TCP Keep-Alive: true
[...][localhost-startStop-2]: SSLClientCertificateSelectionCB: Setting desired cert nickname to: subsystemCert cert-pki-ca
[...][localhost-startStop-2]: LdapJssSSLSocket: set client auth cert nickname subsystemCert cert-pki-ca
[...][localhost-startStop-2]: SSL handshake happened
Could not connect to LDAP server host ipaserver.ipadomain.com port 636 Error netscape.ldap.LDAPException: Authentication failed (49)
 at com.netscape.cmscore.ldapconn.LdapBoundConnFactory.makeConnection(LdapBoundConnFactory.java:205)
 at com.netscape.cmscore.ldapconn.LdapBoundConnFactory.init(LdapBoundConnFactory.java:166)
 at com.netscape.cmscore.ldapconn.LdapBoundConnFactory.init(LdapBoundConnFactory.java:130)
 at com.netscape.cmscore.dbs.DBSubsystem.init(DBSubsystem.java:654)
 at com.netscape.cmscore.apps.CMSEngine.initSubsystem(CMSEngine.java:1172)
 at com.netscape.cmscore.apps.CMSEngine.initSubsystems(CMSEngine.java:1078)
 at com.netscape.cmscore.apps.CMSEngine.init(CMSEngine.java:570)
 at com.netscape.certsrv.apps.CMS.init(CMS.java:188)
 at com.netscape.certsrv.apps.CMS.start(CMS.java:1621)
 at com.netscape.cms.servlet.base.CMSStartServlet.init(CMSStartServlet.java:114)
 at javax.servlet.GenericServlet.init(GenericServlet.java:158)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.lang.reflect.Method.invoke(Method.java:498)
 at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:288)
 at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:285)
 at java.security.AccessController.doPrivileged(Native Method)
 at javax.security.auth.Subject.doAsPrivileged(Subject.java:549)
 at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:320)
 at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:175)
 at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:124)
 at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1270)
 at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1195)
 at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1085)
 at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5318)
 at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5610)
 at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
 at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:899)
 at org.apache.catalina.core.ContainerBase.access$000(ContainerBase.java:133)
 at org.apache.catalina.core.ContainerBase$PrivilegedAddChild.run(ContainerBase.java:156)

The exception shows that LDAP authentication failed with return code 49: invalid credentials.

 

Communication between pki-tomcatd and the LDAP server

We can see that pki-tomcatd is trying to open a LDAP connection through SSL but fails to authenticate. Within FreeIPA, pki-tomcat is storing data in the 389-ds LDAP server and needs to communicate through LDAP with this server.

The configuration of this communication channel can be read in /etc/pki/pki-tomcat/ca/CS.cfg:

internaldb.ldapauth.authtype=SslClientAuth
internaldb.ldapauth.bindDN=cn=Directory Manager
internaldb.ldapauth.bindPWPrompt=internaldb
internaldb.ldapauth.clientCertNickname=subsystemCert cert-pki-ca
internaldb.ldapconn.host=ipaserver.ipadomain.com
internaldb.ldapconn.port=636
internaldb.ldapconn.secureConn

The connection is using port 636 (SSL port) with SSL Client authentication (authtype=SslClientAuth). This means that pki-tomcatd provides a user certificate to the LDAP server, and the LDAP server maps a user to this certificate in order to authenticate the communications.

Note: Authtype can either be SslClientAuth or BasicAuth (authentication with username and password).

In this case, the SSL client authentication is done with the certificate named ‘subsystemCert cert-pki-ca‘ that is stored in /etc/pki/pki-tomcat/alias. So what could be causing the authentication to fail? We need to check that the certificate is available in /etc/pki/pki-tomcat/alias and that pki-tomcat is able to use the associated private key, and that the LDAP server is able to map this certificate to a user.

 

Check the subsystemCert cert-pki-ca

The first step consists in making sure that this certificate is present in /etc/pki/pki-tomcat/alias:

$ sudo certutil -L -d /etc/pki/pki-tomcat/alias -n 'subsystemCert cert-pki-ca'
Certificate:
 Data:
 Version: 3 (0x2)
...

 

Then make sure that the private key can be read using the password found in /var/lib/pki/pki-tomcat/conf/password.conf (with the tag internal=…)

$ sudo grep internal /var/lib/pki/pki-tomcat/conf/password.conf | cut -d= -f2 > /tmp/pwdfile.txt
$ sudo certutil -K -d /etc/pki/pki-tomcat/alias -f /tmp/pwdfile.txt -n 'subsystemCert cert-pki-ca'
certutil: Checking token "NSS Certificate DB" in slot "NSS User Private Key and Certificate Services"
< 0> rsa 86a7fe00cc2a01ad085f35d4ed3e84e7b82ab4f5 subsystemCert cert-pki-ca

At this point we know that pki-tomcat is able to access the certificate and the private key. So the issue is likely to be on the LDAP server side.

 

LDAP server configuration

The LDAP configuration describes how a certificate can be mapped to a user in /etc/dirsrv/slapd-IPADOMAIN-COM/certmap.conf:

$ sudo cat /etc/dirsrv/slapd-IPADOMAIN-COM/certmap.conf 
[...]
certmap default default
[...]
default:DNComps
default:FilterComps uid
certmap ipaca CN=Certificate Authority,O=IPADOMAIN.COM
ipaca:CmapLdapAttr seeAlso
ipaca:verifycert on

This means that when the LDAP server receives an authentication request with a certificate issued by the CA CN=Certificate Authority,O=IPADOMAIN.COM, it will look for users that contain a seeAlso attribute equal to the subject of the certificate, and the user entry must contain the certificate in the usercertificate attribute (verifycert: on).

With a default config, the ‘subsystemCert cert-pki-ca‘ is mapped to the user uid=pkidbuser,ou=people,o=ipaca. So let’s compare the user entry and the certificate:

$ ldapsearch -LLL -D 'cn=directory manager' -W -b uid=pkidbuser,ou=people,o=ipaca userCertificate description seeAlso
Enter LDAP Password: 
dn: uid=pkidbuser,ou=people,o=ipaca
userCertificate:: MIID...uwab3
description: 2;4;CN=Certificate Authority,O=IPADOMAIN.COM;CN=CA Subsystem,O=IPADOMAIN.COM
seeAlso: CN=CA Subsystem,O=IPADOMAIN.COM


$ sudo certutil -L -d /etc/pki/pki-tomcat/alias -n 'subsystemCert cert-pki-ca' -a
-----BEGIN CERTIFICATE-----
MIID...e5QAR
-----END CERTIFICATE-----

The certificate in the userCertificate attribute is different from the one in the NSS database! This can also be seen by comparing the serial number with the value from the ldap entry (in description: 2;<serial>;<issuer>;<subject>):

$ sudo certutil -L -d /etc/pki/pki-tomcat/alias -n 'subsystemCert cert-pki-ca' | grep Serial
 Serial Number: 1341718541 (0x4ff9000d

This explains why pki-tomcat could not authenticate to the LDAP server. The fix consists in updating the LDAP entry with the right certificate (and do not forget to update the description attribute with the right serial number!)

But we still do not know the root cause for the inconsistency between the NSS database /etc/pki/pki-tomcat/alias and the user entry for uid=pkidbuser. This could be described in another blog post (for the impatients, the automatic renewal of the certificate failed to update the LDAP server entry…)

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Troubleshooting: mapping between a SmartCard certificate and an IdM user

Authentication with a SmartCard may fail when the SmartCard certificate is not linked to any IdM user, or to a user different from the one specified on the console.

In order to find which user is associated to a given SmartCard certificate, you can run the following command:

ipaclient$ ipa certmap-match cert.pem
--------------
1 user matched
--------------
 Domain: IPADOMAIN.COM
 User logins: demosc1
----------------------------
Number of entries returned 1
----------------------------

If the result is not what you were expecting, you need first to check how certificates are mapped to users.

By default, a certificate is associated to a user when the user entry contains the full certificate in its usercertificate attribute. But this behavior can be modified by defining certificate mapping rules:

ipaclient$ ipa certmaprule-find
-------------------------------------------
1 Certificate Identity Mapping Rule matched
-------------------------------------------
 Rule name: rulesmartcard
 Mapping rule: (ipacertmapdata=X509:<I>{issuer_dn}<S>{subject_dn})
 Matching rule: <ISSUER>CN=Smart Card CA,O=EXAMPLE.ORG
 Enabled: FALSE
----------------------------
Number of entries returned 1
----------------------------

 

Mapping with full certificate content

When the mapping is based on the full certificate content, you can check if the user entry contains the certificate:

root@ipaclient$ ipa user-show demosc1
 User login: demosc1
[...]
Certificate: MIIC...

If it is not the case, associate the certificate with the user entry using:

ipaclient$ CERT=`cat cert.pem | tail -n +2 | head -n -1 | tr -d '\r\n'`
ipaclient$ ipa user-add-cert demosc1 --certificate $CERT

Once this is done, you may need to clear sssd cache to force SSSD to reload the entries before retrying ipa certmap-match:

ipaclient$ sudo sss_cache -E

 

Flexible mapping with certificate identity mapping rule

When the mapping is based on certificate mapping rules, the same tool ipa certmap-match can be used to check which user entry is associated to a certificate. When the result is not what you expect, you can enable sssd domain logs by adding the following in /etc/sssd/sssd.conf on IdM master:

[domain/ipadomain.com]
...
debug_level = 9

then restart sssd with

root@ipaserver$ systemctl restart sssd

The logs will be located in /var/log/sssd/sssd_ipadomain.log.

 

Check that the certificate identity mapping rules are properly loaded

When sssd is restarted, it reads the mapping rules and should print the following in /var/log/sssd/sssd_ipadomain.log:

[sssd[be[ipadomain.com]]] [sss_certmap_init] (0x0040): sss_certmap initialized.
[sssd[be[ipadomain.com]]] [ipa_certmap_parse_results] (0x4000): Trying to add rule [rulesmartcard][-1][<ISSUER>CN=Smart Card CA,O=EXAMPLE.ORG][(ipacertmapdata=X509:<I>{issuer_dn!nss_x500}<S>{subject_dn!nss_x500})].

If the rule has an invalid syntax, you will see instead:

[sssd[be[ipadomain.com]]] [sss_certmap_init] (0x0040): sss_certmap initialized.
[sssd[be[ipadomain.com]]] [ipa_certmap_parse_results] (0x4000): Trying to add rule [rulesmartcard][-1][<ISSUER>CN=Smart Card CA,O=EXAMPLE.ORG][(ipacertmapdata=X509:<I>{issuer_dn!x509}<S>{subject_dn})].
[sssd[be[ipadomain.com]]] [parse_template] (0x0040): Parse template invalid.
[sssd[be[ipadomain.com]]] [parse_ldap_mapping_rule] (0x0040): Failed to add template.
[sssd[be[ipadomain.com]]] [parse_mapping_rule] (0x0040): Failed to parse LDAP mapping rule.
[sssd[be[ipadomain.com]]] [ipa_certmap_parse_results] (0x0020): sss_certmap_add_rule failed for rule [rulesmartcard], skipping. Please check for typos and if rule syntax is supported.
[sssd[be[ipadomain.com]]] [ipa_subdomains_certmap_done] (0x0040): Unable to parse certmap results [22]: Invalid argument
[sssd[be[ipadomain.com]]] [ipa_subdomains_refresh_certmap_done] (0x0020): Failed to read certificate mapping rules [22]: Invalid argument

The log shows that the rule named rulesmartcard is invalid. Check the rule (see man page for sss-certmap for the supported syntax) and fix if needed:

ipaclient$ ipa certmaprule-show rulesmartcard
 Rule name: rulesmartcard
 Mapping rule: (ipacertmapdata=X509:<I>{issuer_dn!x509}<S>{subject_dn})
 Matching rule: <ISSUER>CN=Smart Card CA,O=EXAMPLE.ORG
 Enabled: TRUE
ipaclient$ ipa certmaprule-mod rulesmartcard --maprule '(ipacertmapdata=X509:<I>{issuer_dn}<S>{subject_dn})'

 

Check that the matching rule corresponds to the certificate

When SSSD tries to associate the certificate to a user, it starts by finding which rule can be applied based on the matching rule (for instance rulesmartcard applies to all certificates issued by CN=Smart Card CA,O=EXAMPLE.ORG because its matching rule is <ISSUER>CN=Smart Card CA,O=EXAMPLE.ORG).

If no matching rule applies to the certificate, SSSD will not be able to associate the certificate with a user, and will display the following in /var/log/sssd/sssd_ipadomain.log:

[sssd[be[ipadomain.com]]] [sss_cert_derb64_to_ldap_filter] (0x0040): Certificate does not match matching-rules.

In this case, you need to create or modify an identity mapping rule, so that the match rule applies to your certificate. See sss-certmap man page for the supported syntax of the –matchrule option of ipa certmaprule-add command.

Check that the expected certificate identity mapping rule is used

When SSSD tries to find the user associated to the certificate, you will see the following logs in /var/log/sssd/sssd_ipadomain.log:

[sssd[be[ipadomain.com]]] [dp_get_account_info_handler] (0x0200): Got request for [0x14][BE_REQ_BY_CERT][cert=MII..]
...
[sssd[be[ipadomain.com]]] [sdap_search_user_next_base] (0x0400): Searching for users with base [cn=accounts,dc=ipadomain,dc=com]
[sssd[be[ipadomain.com]]] [sdap_print_server] (0x2000): Searching 10.34.58.20:389
[sssd[be[ipadomain.com]]] [sdap_get_generic_ext_step] (0x0400): calling ldap_search_ext with [(&(ipacertmapdata=X509:<I>O=EXAMPLE.ORG,CN=Smart Card CA<S>CN=test,O=EXAMPLE.ORG)(objectclass=posixAccount)(uid=*)(&(uidNumber=*)(!(uidNumber=0))))][cn=accounts,dc=ipadomain,dc=com].
...
[sssd[be[ipadomain.com]]] [sdap_search_user_process] (0x0400): Search for users, returned 0 results.

The logs show the LDAP search performed by SSSD: IP address of the LDAP server, base and search filter. Carefully review this information and compare with what you would expect.

Check that the mapping rule defines a valid search filter

If the rule cannot be transformed to a valid search filter, you will see in /var/log/sssd/sssd_ipadomain.log:

[sssd[be[ipadomain.com]]] [sdap_get_generic_ext_step] (0x0400): calling ldap_search_ext with [(&(ipacertmapdata=X509:<I>O=EXAMPLE.ORG,CN=Smart Card CA<S>CN=test,O=EXAMPLE.ORG(objectclass=posixAccount)(uid=*)(&(uidNumber=*)(!(uidNumber=0))))][cn=accounts,dc=ipadomain,dc=com].
[...]
[sssd[be[ipadomain.com]]] [sdap_get_generic_ext_step] (0x0080): ldap_search_ext failed: Bad search filter

If it is the case, you need to fix the certmap rule using

ipaclient$ ipa certmaprule-mod rulesmartcard –maprule …

 

 

Troubleshooting: authentication to the system console or Gnome Desktop Manager of an IdM host with a SmartCard

IdM allows to authenticate to an IdM enrolled-host by providing a SmartCard certificate instead of a username/password. The below steps are based on system console authentication but the process is similar when using Gnome desktop  login authentication.

When the authentication fails, the issue usually comes from a wrong configuration of the IdM system for SmartCard, or of PKINIT.

 

Configuration of the IdM host for SmartCard authentication

If the console does not even prompt for the SmartCard PIN, chances are high that the system was not properly configured for SmartCard authentication.

SSSD configuration for smart card

Check that /etc/sssd.conf contains

[pam]
pam_cert_auth = True

If you need to update the file, do not forget to restart sssd with

root@ipaclient$ systemctl restart sssd

 

SmartCard CA must be trusted

Check that the SmartCard CA is trusted in the /etc/pki/nssdb database:

root@ipaclient$ certutil -L -d /etc/pki/nssdb/

Certificate Nickname Trust Attributes     SSL,S/MIME,JAR/XPI

SmartCardCA                               CT,C,C

If the CA is not present, add it using:

root@ipaclient$ certutil -A -d /etc/pki/nssdb -n SmartCardCA -t CT,C,C -i ca.pem

 

IdM host PKCS#11 module

Check that the IdM host is properly configured for Smart Cards. The opensc package must be installed, the the SmartCard daemon must be running, and the PKCS#11 module must be loaded

root@ipaclient$ dnf install opensc
root@ipaclient$ systemctl start pcscd.service pcscd.socket
root@ipaclient$ modutil -dbdir /etc/pki/nssdb -add "OpenSC" -libfile /usr/lib64/opensc-pkcs11.so

 

Configuration for PKINIT

If the console prompts for the SmartCard PIN but displays

ipaclient login: demosc1
Pin for PIV Card:
Login incorrect

it is possible that the authentication fails trying to acquire a Kerberos ticket with PKINIT. In this case, login with username/password to the IdM host and try to manually perform kinit in order to get more information:

root@ipaclient$ kinit -X X509_user_identity='PKCS11:opensc-pkcs11.so' demosc1

 

If  the command outputs the following:

kinit: Pre-authentication failed: Failed to verify own certificate (depth 1): self signed certificate in certificate chain while getting initial credentials

then check the content of /etc/krb5.conf on the IdM host. The realms section must contain a configuration for ipadomain with pkinit_anchors:

[realms]
 IPADOMAIN.COM = {
 pkinit_anchors = FILE:/var/lib/ipa-client/pki/kdc-ca-bundle.pem
 pkinit_pool = FILE:/var/lib/ipa-client/pki/ca-bundle.pem

}

The file defined in pkinit_anchors must exist, be readable and contain the certificate of the CA which signed the SmartCard certificate. If it is not the case, run the following commands on any IPA server:

root@ipaserver$ ipa-cacert-manage install -n SmartCardCA -t CT,C,C -p $DM_PWD ca.pem
root@ipaserver$ ipa-certupdate

And run the ipa-certupdate command on all IdM hosts in order to download the certificate.

If the kinit command output the following:

kinit: Certificate mismatch while getting initial credentials

check that the SmartCard certificate is associated to the username provided in the console (see mapping between a SmartCard certificate and an IdM user).

Troubleshooting: ssh to an IdM host with a SmartCard

IdM allows to perform ssh from a non-enrolled host into an IdM enrolled host, using Smart Card authentication instead of ssh authorized keys. The ssh command would be the following to log as demosc1 into the host ipaclient.ipadomain.com:

localuser@localhost$ ssh -I /usr/lib64/opensc-pkcs11.so -l demosc1 ipaclient.ipadomain.com
Enter PIN for 'PIV_II (PIV Card Holder pin)':

The -I option specifies a PKCS#11 shared library, and -l the username on the remote host.

 

Configuration of the local host

First check that the local host is properly configured for Smart Cards. The opensc package must be installed, and the the SmartCard daemon must be running.

localuser@localhost$ sudo dnf install opensc
localuser@localhost$ sudo systemctl start pcscd.service pcscd.socket

 

Configuration of the remote (IdM) host

When IdM is properly configured, ssh will prompt for the SmartCard PIN and authenticate the user. If there is an issue with the certificate, ssh will revert to another authentication type (private keys or username/password).

In this case, enable debug logs for ssh authentication on IdM host. Edit /etc/sssd/sssd.conf and add the following line in [ssh] section:

[ssh]
debug_level = 9

then restart sssd using

root@ipaclient$ systemctl restart sssd

The logs will be located on the IdM host in /var/log/sssd/sssd_ssh.log.

 

The Smart Card CA is not trusted by SSSD

If you see the following in /var/log/sssd/sssd_ssh.log:

[sssd[ssh]] [cert_to_ssh_key] (0x0020): CERT_VerifyCertificateNow failed [-8179].
[sssd[ssh]] [get_valid_certs_keys] (0x0040): cert_to_ssh_key failed, ignoring.

then it means that the CA that signed the Smart Card certificate is not trusted. The trusted certs are stored in /etc/pki/nssdb and can be found using:

root@ipaclient$ certutil -L -d /etc/pki/nssdb

Certificate Nickname Trust Attributes     SSL,S/MIME,JAR/XPI

SmartCardCA                               CT,C,C

 

If the CA cert is missing, add it using

root@ipaclient$ certutil -A -d /etc/pki/nssdb -n SmartCardCA -t CT,C,C -i ca.pem

 

The user is not an IdM user

If the ssh operation does not log any line in /var/log/sssd/sssd_ssh.log, it probably means that the supplied user name is not a user defined in IdM. You can check with:

root@ipaclient$ ipa user-find demosc1
---------------
0 users matched
---------------
----------------------------
Number of entries returned 0
----------------------------

Check that you provided the right user name, or define an IdM user and associate the SmartCard certificate with this user.

 

The certificate is not mapped to the IdM user

If you see the following in /var/log/sssd/sssd_ssh.log:

Found 1 entries in domain ipadomain.com

but the authentication fails, check that the SmartCard certificate is associated to the provided username (refer to mapping between a SmartCard certificate and an IdM user)

FreeIPA: troubleshooting SmartCard authentication

RHEL 7.4 beta is now available, delivering a new version of IPA which contains the support for Smart Card authentication. This feature allows to use a certificate contained in a SmartCard in order to login to IdM WebUI, to ssh to an IdM-enrolled host, or to login to the console or Gnome Desktop Manager of an IdM-enrolled host.

This feature is really powerful but may also seem difficult to troubleshoot. I will explain where to look for additional information when authentication fails, and how to fix the most common issues.

The information is split into posts specific to each authentication method:

 

 

Use an alternate identity for EUS configuration

During EUS setup, the administrator needs to provide a user DN and password to authenticate to the directory server (for instance during the dbca step, or while using eusm or Enterprise Manager).

 

In some companies, the database and the LDAP server are managed by different teams and the LDAP administrator credentials cannot be provided to the database administrator. In this case, it is possible to administer EUS using an alternate identity, i.e not cn=directory manager. The requirements for this alternate identity are the following:

  • the user must be a member of the group cn=OracleContextAdmins,cn=Groups,cn=OracleContext,<base DN>
  • the user must have the password-reset privilege

 

Here is an example of configuration steps: create a input.ldif file with the following content

$ cat input.ldif
dn: cn=eusadmin,cn=oraclecontext
changetype: add
objectclass: inetorgperson
cn: eusadmin
sn: eusadmin
uid: eusadmin
userpassword: password

dn: cn=eusadmin,,cn=oraclecontext
changetype: modify
add: ds-privilege-name
ds-privilege-name: password-reset

dn: cn=OracleContextAdmin,cn=groups,cn=OracleContext,dc=example,dc=com
changetype: modify
add: uniquemember
uniquemember: cn=eusadmin,cn=oraclecontext

And perform

$ $ORACLE_HOME/bin/ldapmodify -h localhost -p 1389 -D "cn=directory manager" -w password -f input.ldif

Note 1: this EUS admin user can be stored in your preferred location inside the DIT, but NOT BELOW cn=oraclecontext,<base DN>. For instance, cn=eusadmin,ou=people,dc=example,dc=com is valid, but cn=eusadmin,cn=oraclecontext,dc=example,dc=com is NOT valid.

Note 2: the EUS admin user does not have to be named eususer.

Note 3: if OUD is installed as a proxy server, then the EUS admin user must be stored locally inside OUD proxy, and for instance cn=eususer,cn=oraclecontext would be a valid location.

How to configure EUS + SSL authentication with OUD

During an EUS authentication, there are 2 communication channels: one between the sql client and the database, and another one between the database and the LDAP server. In a previous post, I explained that the database-to-OUD communication can be authenticated either through user/password or SSL.

EUS_auth

The sql client-to-database connection also supports multiple authentication methods:

  • user/password
  • SSL
  • Kerberos (described in this post)

In this post, I will explain how to configure SSL authentication. Note that SSL authentication is usually used in conjunction with DB-to-OUD SSL authentication. This post assumes that DB-to-OUD SSL authentication has already been set up as described there and that the database already has a wallet containing the DB certificate.

Using sqlplus, it is possible to connect to the DB using a client certificate instead of username/password. In order to do this, the DB must be configured with an SSL listener, and the sqlplus client must be configured to use a client certificate.

  1. Configure the database to allow SSL authentication:
    The file sqlnet.ora located in $ORACLE_HOME/network/admin must be modified to look like the following:

    NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)
      
    ADR_BASE = <$ORACLE_BASE>
    
    #ADDED FOR SSL 
    SQLNET.AUTHENTICATION_SERVICES= (TCPS, BEQ)
    SSL_CLIENT_AUTHENTICATION = TRUE
    WALLET_LOCATION = 
      (SOURCE =
        (METHOD = FILE)
        (METHOD_DATA =
          (DIRECTORY = <$ORACLE_BASE>/admin/<$ORACLE_SID>/wallet)
        )
      )
  2. Configure a SSL listener on the database:
    The listeners are defined in the configuration file listener.ora, located in $ORACLE_HOME/network/admin. The content of this file defines the port and protocol used by the listener, and the location of the wallet that will store the database certificate.

    LISTENER =
      (DESCRIPTION_LIST =
        (DESCRIPTION =
          (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
          (ADDRESS = (PROTOCOL = TCP)(HOST = <hostname>)(PORT = 1521))
    #ADDED FOR SSL
          (ADDRESS = (PROTOCOL = TCPS)(HOST = <hostname>)(PORT = 1575))
        )
      )
    
    ADR_BASE_LISTENER = <$ORACLE_BASE>
    
    #ADDED FOR SSL
    WALLET_LOCATION = (SOURCE=
      (METHOD = FILE)
        (METHOD_DATA =
          (DIRECTORY=<$ORACLE_BASE>/admin/<$ORACLE_SID>/wallet)
        )
      )
    
  3. Restart the listener:
    the modification of listeners.ora requires to restart the database listener with the following commands

    $ $ORACLE_HOME/bin/lsnrctl stop
    $ $ORACLE_HOME/bin/lsnrctl start
  4. Configure the sql client to use SSL authentication:

    The sql client reads its configuration from sqlnet.ora and tnsnames.ora. By default, those files are located in the same location as the DB configuration files ($ORACLE_HOME/network/admin), which can cause issues because the client and the server use a different wallet. In order to avoid configuration issues, it is recommended to have separate configuration files. To do this, the environment variable TNS_ADMIN is used to configure the path containing the client configuration files:

    $ setenv TNS_ADMIN /path/to/files
    

    or

    $ export TNS_ADMIN=/path/to/files
    

    Then the file tnsnames.ora will define how to reach the database using SSL:

    $ cat /path/to/files/tnsnames.ora 
    ORCL11G =
      (DESCRIPTION =
        (ADDRESS = (PROTOCOL = TCPS)(HOST = <hostname>)(PORT = 1575))
        (CONNECT_DATA =
          (SERVER = DEDICATED)
          (SERVICE_NAME = orcl11g)
        )
      )
    

    And finally the file sqlnet.ora defines the SSL configuration (wallet location…):

    $ cat sqlnet.ora 
    NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)
    SQLNET.AUTHENTICATION_SERVICES = (TCPS,BEQ)
    SSL_CLIENT_AUTHENTICATION = TRUE 
    WALLET_LOCATION =
      (SOURCE =
        (METHOD = FILE)
        (METHOD_DATA =
          (DIRECTORY = /path/to/client/wallet)
        )
      )
  5. Create the client wallet and the client certificate:
    The client wallet will store the client certificate as well as the certificates trusted by the client (i.e. the server certificate).
    The client certificate must contain a DN that corresponds to a LDAP entry on OUD server. The following commands create a client wallet, then add a self-signed certificate to the wallet for the user cn=Joe, and finally export the self-signed certificate to a file.

    $ orapki wallet create -wallet /path/to/client/wallet -pwd <password> -auto_login
    
    $ orapki wallet add -wallet /path/to/client/wallet -dn cn=Joe,ou=users,dc=example,dc=com -keysize 1024 -self_signed -validity 365 -pwd <password>
    
    $ orapki wallet export -wallet /path/to/client/wallet -dn cn=Joe,ou=users,dc=example,dc=com -cert joe-cert.txt
    

  6. Add the client certificate to the DB wallet:
    the database must trust the client certificate in order to accept SSL connections. As the above steps created a self-signed user certificate, the client certificate has to be imported as a trusted cert in the DB wallet.

    $ orapki wallet add -wallet <PathToDBWallet> -cert joe-cert.txt -trusted_cert -pwd <password>
    
  7. Add the DB certificate to the client wallet:
    the client must trust the DB certificate. If the DB certificate is a self-signed certificate, this means that the DB cert must be added to the client wallet.

    $ orapki wallet add -wallet /path/to/client/wallet -cert db-cert.txt -trusted_cert -pwd <password>
  8. Allow EUS to accept SSL connections between the client and the database:

     log in to Enterprise Manager: https://<hostname>:1158/em

    In the “Server” tab, select “Enterprise User Security” in the “Security” section, then “Manage Enterprise Domain” and click on “Configure”. In the “Configuration” tab, select the authentication methods that you want to allow between the client and the DB: Password, SSL, Kerberos.

  9. Test the SSL connection between the client and the database:

    The following command reads the sql configuration files, extracts the path to the client wallet, then connects to the DB using the certificate found in the client wallet:

    $ export TNS_ADMIN=/path/to/files
    $ sqlplus /@orcl11g
    
    SQL*Plus: Release 11.2.0.2.0 Production on Wed Mar 28 11:18:57 2012
    
    Copyright (c) 1982, 2010, Oracle.  All rights reserved.
    
    
    Connected to:
    Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
    With the Partitioning, OLAP, Data Mining and Real Application Testing options
    
    SQL>

Once authenticated with the client certificate, the enterprise user will be mapped to a schema exactly as a user/password authenticated user. EUS will also find the groups for the LDAP user and grant the corresponding roles to the EUS user.