In my previous blog on deploying the OpenID extension with OpenSSO, there is a step (step #3 for OpenSSO) in which you have to add the OpenID attribute you created to OpenSSO’s embedded OpenDS directory.
To be more explicit, a way to achieve this is to connect to you OpenSSO DS store and run the following ldif fragment:

dn: cn=schema
changetype: modify
add: attributeTypes
attributeTypes: ( 2.16.840.1.113730.3.1.9990 NAME ‘openid-attributes’ DESC ‘Persisted attributes (OpenID)’ SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 SINGLE-VALUE X-ORIGIN ‘
Attributes (OpenID)’ )
–
add: objectClasses
objectClasses: ( 2.16.840.1.113730.3.2.9999 NAME ‘openiduser’ DESC ‘Class to hold the OpenID related attributes’ SUP top AUXILIARY MAY ( uid $
openid-attributes ) X-ORIGIN ‘OpenID Attributes object class’ )
–

To connect to the OpenSSO embedded store, I recommend you use a tool (e.g. Apache Directory Studio). Feed it with the relevant information: hostname (i.e. opensso.example.com), port (usually 50389) and possibly your encryption method.

Of course, tune the ldif example above to the same name (here openid-attributes) you used in amUser.xml