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Setup

Setup#

IPA Server Authentication with User Certificate or Smart Card Setup#

The ipa-experimental-x509-auth-plugin enables external authentication for the FreeIPA server web UI to log in using a certificate or smart card.

Warning: This plug-in is experimental. Do not use it in production environments.

Note: This plug-in does not verify if a certificate has been revoked. Configure the Apache web server to enable revocation checks.

The procedure has been tested with Red Hat Enterprise Linux 7.3 and FreeIPA 4.4.

Warning: Certificate-based authentication for Web UI was integrated into FreeIPA 4.5.0. The setup described below is not required anymore

FreeIPA Server Configuration#

  • Red Hat Enterprise Linux 7.3

  • FreeIPA 4.4.0 or newer

Installing the Web UI Plug-in#

To to download, install and configure the web UI plug-in, run on your FreeIPA server:

# cd /etc/yum.repos.d/
# curl -O ``\ ```https://copr.fedorainfracloud.org/coprs/g/freeipa/ipa-experimental-x509-auth-plugin/repo/epel-7/group_freeipa-ipa-experimental-x509-auth-plugin-epel-7.repo`` <https://copr.fedorainfracloud.org/coprs/g/freeipa/ipa-experimental-x509-auth-plugin/repo/epel-7/group_freeipa-ipa-experimental-x509-auth-plugin-epel-7.repo>`__

  • To install the plug-in:

# yum install -y ipa-experimental-x509-auth-plugin

After the package is installed in the /usr/share/ipa/ui/js/plugins/ FreeIPA plug-in directory, yum automatically enables the mod_lookup_identity module and configures the System Security Services Daemon (SSSD).

  • Set the OK-AS-DELEGATE flag to the web server’s Kerberos service principal:

# ipa service-mod --ok-to-auth-as-delegate=True HTTP/$(hostname)

This Kerberos flag enables the service to forward Kerberos tickets. Use this flag only with security-reviewed and trusted services.

Example Authentication Using a Certificate#

Smart cards use a digitally signed certificated, issued from a public key infrastructure (PKI) provider to authenticate a user. Authenticating using a soft token works like smart cards with user certificates. However, smart cards additionally require a hardware reader and a driver for the smart card. Follow your smart card provider’s documentation, how to generate the keys and how to add them to the smart card.

Authenticating to the Web UI Using a FreeIPA CA-signed Certificate#

To create a new account and authenticate to the web UI using a certificate issued by the FreeIPA certificate authority (CA):

  • Create a demo user account in FreeIPA with a certificate and store the private key in the ~/demo.key file.

    For details, see Using FreeIPA/Dogtag PKI to Issue User Certificates.

  • Verify that the certificate is displayed in the output of the ipa user-show command:

 # ipa user-show demo
 ...
 Certificate: MIIDjjCCAnagAwIBAgIBGTANBgkqhkiG.....

Alternatively, verify that the certificate is shown in the user's
account details in the web UI.

  • To download the certificate for the demo user to the ~/demo_cert.pem file, run:

# echo '-----BEGIN CERTIFICATE-----' > ~/demo_cert.pem
# ipa user-show demo | grep Certificate:\  | cut -d ' ' -f 4 | fold -64 >> ~/demo_cert.pem
# echo '-----END CERTIFICATE-----' >> ~/demo_cert.pem

  • Convert the certificate and private key to a PKCS #12-formated ~/demo_cert.pfx file:

# openssl pkcs12 -export -out ~/demo_cert.pfx -inkey ~/demo.key -in ~/demo_cert.pem

PKCS #12-formatted files are password protected and store private and public keys. Additionally, it can optionally include intermediate and root certificates. You can import these files to browsers and web servers, such as Apache Tomcat.

  • Import the ~/demo_cert.pfx file to your web browsers certificate store. For details, see your web browser’s documentation.

You are now able to authenticate to the web UI using the certificate.

Authenticating to the Web UI using a Certificate Signed by an External CA#

If you are running FreeIPA with certificates signed by an external certificate authority (CA), the certificates are usually stored in a local NSS database, such as ~/nssdb/.

To create a new account and authenticate to the web UI using a certificate issued by an external CA:

  • Create a new user account:

# ipa user-add demo --first=Demo --last=Demo

  • Assign the certificate from the ~/nssdb/ NSS database to the FreeIPA demo user account:

# ipa user-add-cert --certificate="$( certutil -L -d ~/nssdb/ -a -n alpha | grep -v '.---' )" demo

  • Export the certificate in PKCS #12 format from the ~/nssdb/ NSS database:

# pk12util -o demo_cert.pfx -n alpha -d ~/nssdb/

  • To verify external signed certificates, the Apache web server must use the CA certificate:

* To export the CA certificate from the ~/nssdb/ NSS database:

# certutil -L -d ~/nssdb/ -a -n cacert > ca_cert.pem

:* Import the CA certificate to the Apache web server’s certificate store:

# certutil -A -n ext_authCA -t CT,C,C  -d /etc/httpd/alias/ -a -i ca_cert.pem

  • Restart the web server service:

# systemctl restart httpd

  • Import the ~/demo_cert.pfx file to your web browsers certificate store. For details, see your web browser’s documentation.

You are now able to authenticate to the web UI using the certificate.

Verifying the Web UI Log-in Using the Command Line#

To verify the authentication to the web UI with certificates using the command line, run:

# curl --cert demo_cert.pem --key demo.key ``\ ```https://ipaserver/ipa/session/login_x509 <https://ipaserver/ipa/session/login_x509>`__`` -siv``

Developer NOTES#

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