2.3.5. Configuring Firefox to use Kerberos for SSO
You can configure Firefox to use Kerberos for Single Sign-on. In order for this functionality to work correctly, you need to configure your web browser to send your Kerberos credentials to the appropriate
KDC.The following section describes the configuration changes and other requirements to achieve this.
You now need to ensure that you have Kerberos tickets. In a command shell, type kinit
to retrieve Kerberos tickets. To display the list of available tickets, type klist
. The following shows an example output from these commands:
If you have followed the configuration steps above and Negotiate authentication is not working, you can turn on verbose logging of the authentication process. This could help you find the cause of the problem. To enable verbose logging, use the following procedure:
-
Close all instances of Firefox.
-
Open a command shell, and enter the following commands:
export NSPR_LOG_MODULES=negotiateauth:5
export NSPR_LOG_FILE=/tmp/moz.log
-
Restart Firefox
from that shell
, and visit the website you were unable to authenticate to earlier. Information will be logged to /tmp/moz.log
, and may give a clue to the problem. For example:
-1208550944[90039d0]: entering nsNegotiateAuth::GetNextToken()
-1208550944[90039d0]: gss_init_sec_context() failed: Miscellaneous failure
No credentials cache found
This indicates that you do not have Kerberos tickets, and need to run kinit
.
If you are able to run kinit
successfully from your machine but you are unable to authenticate, you might see something like this in the log file:
-1208994096[8d683d8]: entering nsAuthGSSAPI::GetNextToken()
-1208994096[8d683d8]: gss_init_sec_context() failed: Miscellaneous failure
Server not found in Kerberos database
This generally indicates a Kerberos configuration problem. Make sure that you have the correct entries in the [domain_realm] section of the /etc/krb5.conf
file. For example:
.example.com = EXAMPLE.COM
example.com = EXAMPLE.COM
If nothing appears in the log it is possible that you are behind a proxy, and that proxy is stripping off the HTTP headers required for Negotiate authentication. As a workaround, you can try to connect to the server using HTTPS instead, which allows the request to pass through unmodified. Then proceed to debug using the log file, as described above.