Credential Data File Format
===========================

Every credential stored on the myproxy server has a credential file 
(with .creds extension) and a data file (with .data extension). The 
credential file stores the proxy while the data file stores other
information about the credential.

The credential filename has the format
<username>.creds or
<username>-<credname>.creds

and the data filename has the format
<username>.data or
<username>-<credname>.data

where, if <username> contains '/', then it's the MD5 digest of the
username instead, and '/' characters in <credname> are replaced with
'-' characters.

Unfortunately, <username> may contain '-' making it ambiguous as to
where <username> ends and <credname> starts, so USERNAME and NAME in
the data file must be used to disambiguate.

The format of a data file is as follows :

OWNER=<owner name>
LIFETIME=<credential lifetime>

The data file may also contain the following optional fields :

PASSPHRASE=<passphrase>
NAME=<credential name>
DESCRIPTION=<credential description>
RETRIEVERS=<retriever regex>
RENEWERS=<renewer regex>
USERNAME=<username>

Every data file ends with END_OPTIONS field that marks the end of the
data file.

