Bug 2002 - plain text password failure with passwords longer than 8 chars
Summary: plain text password failure with passwords longer than 8 chars
Alias: None
Product: Samba 3.0
Classification: Unclassified
Component: User/Group Accounts (show other bugs)
Version: 3.0.7
Hardware: All Linux
: P3 normal
Target Milestone: 3.0.26
Assignee: Samba Bugzilla Account
QA Contact: Samba QA Contact
Depends on:
Reported: 2004-11-08 05:40 UTC by Lars Müller
Modified: 2020-07-12 16:23 UTC (History)
1 user (show)

See Also:

Fix (621 bytes, text/plain)
2007-01-30 19:01 UTC, Jan Engelhardt
no flags Details

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Description Lars Müller 2004-11-08 05:40:33 UTC
This bug was created by Jan Engelhardt <jengelh@linux01.gwdg.de> at the SuSE
bugzilla.  As I don't care about plain passwords I feed it to Samba.org.

The original report from Jan:

The smbd refuses a (plaintext) password whose 9'th, 10'th, etc. characters are

(Now read reproduction)

In [samba-3.0.4-1.14, or any minor updates]
samba-3.0.4/source/auth/pass_check.c, around line 446 in function
string_combinations2() near:


the following is happening (upon initial entrance to the function):
s = "nohohzuiW"
offset = 0
fn = ... <I don't care>
N = 9
PASSWORD_LENGTH is #defined to be 8 (found out by gdb)
Thus, len is set to 8 -- and thus only the first eight characters are probed for
upper-/lowercase, 9'th, 10'th and so on always stay lower case.

A workaround is to remove the offending three lines, though that might impact
speed, as the Samba developers tell us in include/includes.h:948 near

/* what is the longest significant password available on your system?  
 Knowing this speeds up password searches a lot */

Guess what... 8 chars was for DES, but MD5 and Blowfish support more. I did not
want to raise PASSWORD_LENGTH because in fact PASSWORD_LENGTH is (IMO) useless
-- the string length is anyway calculated in string_combinations2(), and if
PASSWORD_LENGTH is greater than the length of my password (it must be, otherwise
MD5/BF don't work), there is no use in the call to [using the macro] MIN().

How to reproduce:
Add a new user to the Shadow subsystem (i.e. /etc/passwd, /etc/shadow), giving
him a password like "nohohzuiW".
In smb.conf, encrypt passwords = no, update encrypted = no, min password length = 8
The client machine should preferably be Windows 95/98/98SE.

And I really mean Windows, because that's the only one sending plaintext
password in all-uppercase. smbclient works fine with this password.
Comment 1 Lars Müller 2005-04-27 08:50:14 UTC
Jan: Please retest with the current Samba version.  This bug might be fixed with
svn checkin 5290 to fix bug #2323.

You find current, 3.0.14a packages for SuSE Linux products at

ftp://ftp.SuSE.com/pub/projects/samba/ or

*** This bug has been marked as a duplicate of 2323 ***
Comment 2 Jan Engelhardt 2005-04-27 11:36:35 UTC
svn #5290 (said fix) is already in 3.0.13-1(suse.i586.rpm).

As for 3.0.14a, do you have a source tree, or a diff from 3.0.13-1 to said
3.0.14a? Thanks.
Comment 3 Lars Müller 2005-04-27 11:49:24 UTC
All packages are using the Samba.org 3.0.14a tar ball.  And Samba.org also
provides diffs from the previous to the next version.

See http://download.Samba.org/samba/ftp/patch-3.0.13-3.0.14a.diffs.gz

But I might have missunderstood you.
Comment 4 Jan Engelhardt 2005-04-27 12:27:44 UTC
>All packages are using the Samba.org 3.0.14a tar ball.  And Samba.org also
provides diffs from the previous to the next version.

If the samba-3.0.13-1.i586.rpm from SUSE 9.3 is a 3.0.14a, then:
- svn #5290 is already applied
- password authentication still fails

I doubt that it has to be addressed in sesssetup.c, because it's an auth issue
of strings_compare2() <auth/pass_check.c>.
Comment 5 Lars Müller 2005-04-27 13:45:42 UTC
The Samba version inside the SuSE RPMs named 3.0.13 is a Samba.org 3.0.13. 
Nothing else.  My comment #3 was with regard to the packages available at
ftp.SuSE.com or download.Samba.org atm.

Bug #2323 was fixed with Samba 3.0.11.  Therfore I expect this bug will stay in

But please test it and reopen this bug if it still exits with 3.0.14a. 
Unfortunately I don't have a Windows 9x at my home test network.
Comment 6 Jan Engelhardt 2005-04-29 08:21:21 UTC
Can you provide a diff -u between suse's 3.0.13-1 and your 3.0.14a? (Don't want
to download 14+ megs, slow link) Thanks.
Comment 7 Jan Engelhardt 2005-05-11 05:43:10 UTC
Please reopen. The bug persists in 3.0.14A.
Comment 8 Gerald (Jerry) Carter (dead mail address) 2005-05-11 06:06:56 UTC
this actually was not a duplicate of bug 2323.  Reopening and assigning to myself.
Comment 9 Jan Engelhardt 2006-05-30 03:51:37 UTC
Comment 10 Jan Engelhardt 2007-01-30 19:01:10 UTC
Created attachment 2262 [details]

Please consider inclusion.
Comment 11 Björn Jacke 2020-07-12 16:23:39 UTC
this doesn't seem to be a problem any more. however due to missing test in bug 9705 we unfortunately have non-working plaintext auth since a long time. But anyway I'll close this one here as fixed now.