[Buildroot] Suggestion: increase username buffer size in busybox login

[Buildroot] Suggestion: increase username buffer size in busybox login

[Dmitry Golubovsky]

Hi,

Would anybody object to increase the size of the username buffer that
busybox login has:

loginutils/login.c, line 37

enum {
	TIMEOUT = 60,
	EMPTY_USERNAME_COUNT = 10,
	USERNAME_SIZE = 32,
	TTYNAME_SIZE = 32,
};

I would like to submit a patch to increase USERNAME_SIZE to 256.

My rationale is (disclaimer: mainly influenced by my own
buildroot-based project): now that we have PAM in place, more
interesting login schemes are possible such as authentication against
some remote host/domain which asks for usernames like user at host or
user at domain (or domain\user).

Where did the size 32 come from?

Or would it be better to raise this with busybox developers?

Thanks.

-- 
Dmitry Golubovsky

Anywhere on the Web

[Buildroot] Suggestion: increase username buffer size in busybox login

[Yann E. MORIN]

Dmitry, All,

On Tuesday 14 August 2012 15:47:50 Dmitry Golubovsky wrote:
> Would anybody object to increase the size of the username buffer that
> busybox login has:
> 
> loginutils/login.c, line 37
> 
> enum {
> 	TIMEOUT = 60,
> 	EMPTY_USERNAME_COUNT = 10,
> 	USERNAME_SIZE = 32,
> 	TTYNAME_SIZE = 32,
> };
> 
> I would like to submit a patch to increase USERNAME_SIZE to 256.
> 
> My rationale is (disclaimer: mainly influenced by my own
> buildroot-based project): now that we have PAM in place, more
> interesting login schemes are possible such as authentication against
> some remote host/domain which asks for usernames like user at host or
> user at domain (or domain\user).
> 
> Where did the size 32 come from?
> 
> Or would it be better to raise this with busybox developers?

Yep, probably. If there's a hard-reason for 32, they are the guys that
will know for sure, and if the change is accepted, they are the guys
that can apply it ;-)
    busybox at busybox.net

Regards,
Yann E. MORIN.

-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
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[Buildroot] Suggestion: increase username buffer size in busybox login

[Dmitry Golubovsky]

Hi,

On Tue, Aug 14, 2012 at 1:07 PM, Yann E. MORIN <yann.morin.1998@free.fr> wrote:

>> Or would it be better to raise this with busybox developers?
>
> Yep, probably. If there's a hard-reason for 32, they are the guys that
> will know for sure, and if the change is accepted, they are the guys
> that can apply it ;-)
>     busybox at busybox.net

Well, the busybox developers stick with the original Unix spec
limiting username length at 32 chars:

http://lists.busybox.net/pipermail/busybox/2012-August/078256.html

So I am repeating my question: is anybody among Buildroot users also
interested in such patching of busybox: in case longer usernames (like
firstname.lastname at host.example.org) are desired, increase the
username buffer in login.c to 256 characters?

Thanks.

-- 
Dmitry Golubovsky

Anywhere on the Web

[Buildroot] Suggestion: increase username buffer size in busybox login

[Thomas Petazzoni]

Le Tue, 14 Aug 2012 23:18:16 -0400,
Dmitry Golubovsky <golubovsky@gmail.com> a ?crit :

> Well, the busybox developers stick with the original Unix spec
> limiting username length at 32 chars:
> 
> http://lists.busybox.net/pipermail/busybox/2012-August/078256.html
> 
> So I am repeating my question: is anybody among Buildroot users also
> interested in such patching of busybox: in case longer usernames (like
> firstname.lastname at host.example.org) are desired, increase the
> username buffer in login.c to 256 characters?

This should not be implemented in Buildroot, as we don't want to keep
such "feature" patches on our packages. Make a patch to Busybox that
turns this into a configurable value, so that by default the length of
32 characters is used, but a Busybox configuration option allows to
extend that. Then, Buildroot users interested by this feature can
create a custom Busybox configuration.

Thanks!

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] Suggestion: increase username buffer size in busybox login

[Dmitry Golubovsky]

Hi,

On Fri, Aug 17, 2012 at 8:30 AM, Thomas Petazzoni
<thomas.petazzoni@free-electrons.com> wrote:

> This should not be implemented in Buildroot, as we don't want to keep
> such "feature" patches on our packages. Make a patch to Busybox that
> turns this into a configurable value, so that by default the length of
> 32 characters is used, but a Busybox configuration option allows to
> extend that. Then, Buildroot users interested by this feature can
> create a custom Busybox configuration.

Busybox developers increased this length to 64 for now ;) It is in the
daily snapshot and eventually will propagate to Buildroot (or can even
be enabled now by selecting daily snapshot).

Maybe this will be sufficient.

Thanks.

-- 
Dmitry Golubovsky

Anywhere on the Web

[Buildroot] Suggestion: increase username buffer size in busybox login

[Thomas Petazzoni]

Le Fri, 17 Aug 2012 08:46:32 -0400,
Dmitry Golubovsky <golubovsky@gmail.com> a ?crit :

> Busybox developers increased this length to 64 for now ;) It is in the
> daily snapshot and eventually will propagate to Buildroot (or can even
> be enabled now by selecting daily snapshot).
> 
> Maybe this will be sufficient.

If the change has been accepted upstream in Busybox, then we can
include a patch in Buildroot until a new version of Busybox gets
released, if that makes things easier/nicer for you.

Best regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] Suggestion: increase username buffer size in busybox login

[Dmitry Golubovsky]

Hi,

On Fri, Aug 17, 2012 at 9:17 AM, Thomas Petazzoni
<thomas.petazzoni@free-electrons.com> wrote:
> Le Fri, 17 Aug 2012 08:46:32 -0400,
> Dmitry Golubovsky <golubovsky@gmail.com> a ?crit :

> If the change has been accepted upstream in Busybox, then we can
> include a patch in Buildroot until a new version of Busybox gets
> released, if that makes things easier/nicer for you.

I believe it should be sufficient to just select a daily snapshot of
Busybox - no patches needed. Or it will appear in 1_20_3 - not sure
what their release cycle is.

I am already using Busybox daily snapshot in my project's config. But
for now I am more focused on linux-pam and systemd...

Thanks.

-- 
Dmitry Golubovsky

Anywhere on the Web