Initial documentation
[hcoop/zz_old/modwaklog.git] / README
3 mod_waklog is an Apache module that provides aklog-like semantics
4 for the web. mod_waklog will acquire (and store in the kernel) an
5 AFS credential when a connection is opened, use the credential for
6 the duration of the connection, and will remove the credential when
7 the connection is closed.
9 mod_waklog allows you to permit directories using AFS ACLs, and access
10 them via a web browser. An ACL of "umweb:servers rl" is required for
11 each mod_waklog-protected directory.
13 mod_waklog allows scripts to run as you. Programs which use AFS
14 credentials to authenticate themselves do so as you.
16 mod_waklog often is used with mod_cosign, and uses the cosign-provided
17 krbtgt to acquire an AFS credential; this extends single signon to AFS
18 via the web.
22 Apache processes a request in multiple phases.
24 mod_waklog runs at phase 0 to acquire credentials via a keytab, and
25 runs at phase 2 to remove the credentials.
27 mod_waklog runs at phase 7 to acquire credentials of whatever krbtgt
28 is referenced via KRB5CCNAME (e.g., set by mod_cosign).
30 mod_waklog runs at connection termination to remove the credentials
31 it acquired at phase 0 or phase 7.
33 Apache calls stat() between phase 1 and phase 2 to determine if it
34 has access to the directory; if it doesn't have read access at that
35 point, it won't try to read it again, even if later phases would
36 acquire credentials which would allow it to do so. mod_waklog
37 acquires an afs credential for a principal in the pts group
38 umweb:servers at phase 0, and removes this credential at phase 2;
39 directories permitted "umweb:servers rl" will allow the stat() call
40 to succeed.