Bug 2543 - Incorrect caching of server details when anonymous login succeeds
Incorrect caching of server details when anonymous login succeeds
Status: CLOSED FIXED
Product: Samba 3.0
Classification: Unclassified
Component: libsmbclient
3.0.9
x86 Linux
: P3 normal
: none
Assigned To: Derrell Lipman
Samba QA Contact
:
Depends on:
Blocks:
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Reported: 2005-03-24 01:46 UTC by Narayana Pattipati
Modified: 2005-08-24 10:28 UTC (History)
1 user (show)

See Also:


Attachments
patch to correct caching if session setup is done with anonymous login (1.53 KB, patch)
2005-03-24 02:37 UTC, Narayana Pattipati
no flags Details

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Description Narayana Pattipati 2005-03-24 01:46:35 UTC
In libsmbclient.c:smbc_server() function, while setting up session by sending
sesssetupX SMB, first, a username/password is tried. If session setup fails, say
because of wrong password, then anonymous login is tried.

        if (!cli_session_setup(&c, username,
                               password, strlen(password),
                               password, strlen(password),
                               workgroup) &&
            /* try an anonymous login if it failed */
            !cli_session_setup(&c, "", "", 1,"", 0, workgroup)) {
                cli_shutdown(&c);
                errno = EPERM;
                return NULL;
        }

If anonymous login succeeds, the server details for this connection is cached
later. 

        /* now add it to the cache (internal or external)  */
        /* Let the cache function set errno if it wants to */
        errno = 0;
        if (context->callbacks.add_cached_srv_fn(context, srv, server, share,
workgroup, username)) {
                int saved_errno = errno;
                DEBUG(3, (" Failed to add server to cache\n"));
                errno = saved_errno;
                if (errno == 0) {
                        errno = ENOMEM;
                }
                goto failed;
        }

You can observe that "username" is used while caching, even if session was setup
with anonymous login.

This causes troubles in smb client applications (like GNOME's gnome-vfs
smb-method program). When wrong password is supplied first time, session setup
fails and anonymous connection is tried. If anonymous connection succeeds, then
server is cached with the "username". But anonymous connection may fail to list
shares in a server, in the later part of code. So, authentication is requested
once again. This time even if correct password is supplied, the cached
server(with "username") is used, which will fail again.

Solution is to use anonymous id only if server session is setup with that id. 

Will submit a patch soon which should fix the issue.
Comment 1 Narayana Pattipati 2005-03-24 02:37:21 UTC
Created attachment 1111 [details]
patch to correct caching if session setup is done with anonymous login
Comment 2 Narayana Pattipati 2005-03-24 02:40:00 UTC
The attached patch checks if session setup was succeeded with regular login or
anonymous login and use the same user while caching the server.

Please review the patch.
Comment 3 Nate Nielsen 2005-03-30 09:41:36 UTC
3.0.11 and later contain some changes to this code which prevent automatic
anonymous logins. The patch will probably need to take those changes into account. 
Comment 4 Derrell Lipman 2005-03-31 14:18:55 UTC
Anonymous login username cached when reverting to anonymous login.

Note: There is also a reasonably new flag in context->flags which forces no
reversion to anonymous login.
Comment 5 Gerald (Jerry) Carter 2005-08-24 10:28:22 UTC
sorry for the same, cleaning up the database to prevent unecessary reopens of bugs.