Debug PKI middleware

If you receive an Invalid OpenStack Identity Credentials message when you talk to an OpenStack service, it might be caused by the changeover from UUID tokens to PKI tokens in the Grizzly release. Learn how to troubleshoot this error.

The PKI-based token validation scheme relies on certificates from the Identity Service that are fetched through HTTP and stored in a local directory. The location for this directory is specified by the signing_dir configuration option. In your services configuration file, look for a section like this:

[keystone_authtoken]
signing_dir = /var/cache/glance/api
auth_uri = http://127.0.0.1:5000/
auth_host = 127.0.0.1
auth_port = 35357
auth_protocol = http
admin_tenant_name = service
admin_user = glance

If your service lacks this stanza, the keystoneclient/middleware/auth_token.py file specifies the defaults. If no value is specified for this directory, it defaults to a secure temporary directory. Initialization code for the service checks that the directory exists and is writable. If it does not exist, the code tries to create it. If this fails, the service fails to start. However, it often succeeds but problems occur later.

The first thing to check is that the signing_dir does, in fact, exist. If it does, check for the presence of the certificate files inside there:

$ ls -la /var/cache/glance/api/

total 24
drwx------. 2 ayoung root 4096 Jul 22 10:58 .
drwxr-xr-x. 4 root root 4096 Nov 7 2012 ..
-rw-r-----. 1 ayoung ayoung 1424 Jul 22 10:58 cacert.pem
-rw-r-----. 1 ayoung ayoung 15 Jul 22 10:58 revoked.pem
-rw-r-----. 1 ayoung ayoung 4518 Jul 22 10:58 signing_cert.pem

This directory contains two certificates and the token revocation list. If these files are not present, your service cannot fetch them from the Identity Service. To troubleshoot, try to talk to the Identity Service to make sure it is serving out the files, as follows:

$ curl http://localhost:35357/v2.0/certificates/signing

This command fetches the signing certificate:

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 1 (0x1)
    Signature Algorithm: sha1WithRSAEncryption
        Issuer: C=US, ST=Unset, L=Unset, O=Unset, CN=www.example.com
        Validity
            Not Before: Jul 22 14:57:31 2013 GMT
            Not After : Jul 20 14:57:31 2023 GMT
        Subject: C=US, ST=Unset, O=Unset, CN=www.example.com

Note the expiration dates of the certificate:

Not Before: Jul 22 14:57:31 2013 GMT
Not After : Jul 20 14:57:31 2023 GMT

The token revocation list is updated once a minute, but the certificates are not. One possible problem is that the certificates are the wrong files or garbage. You can remove these files and run another command against your server: They are fetched on demand.

The Identity Service log should show the access of the certificate files. You might have to turn up your logging levels. Set debug = True and verbose = True in your Identity Service configuration file and restart the Identity Service server.

(keystone.common.wsgi): 2013-07-24 12:18:11,461 DEBUG wsgi __call__
arg_dict: {}
(access): 2013-07-24 12:18:11,462 INFO core __call__ 127.0.0.1 - - [24/Jul/2013:16:18:11 +0000]
"GET http://localhost:35357/v2.0/certificates/signing HTTP/1.0" 200 4518

If the files do not appear in your directory after this, it is likely one of the following issues:

SELinux troubles often occur when you use Fedora/RHEL-based packages and you choose configuration options that do not match the standard policy. Run the setenforce permissive command. If that makes a difference, you should relabel the directory. If you are using a sub-directory of the /var/cache/ directory, run the following command:

# restorecon /var/cache/

If you are not using a /var/cache sub-directory, you should. Modify the signing_dir configuration option for your service and restart.

Set back to setenforce enforcing to confirm that your changes solve the problem.

If your certificates are fetched on demand, the PKI validation is working properly. Most likely, the token from the Identity Service is not valid for the operation you are attempting to perform, and your user needs a different role for the operation.