[OE-core] [PATCH 2/2] openssh: allow empty passwords if PAM allows it as well

[Koen Kooi]

Op 14 okt. 2013, om 10:25 heeft Richard Purdie <richard.purdie at linuxfoundation.org> het volgende geschreven:

> On Sun, 2013-10-13 at 17:30 +0200, Koen Kooi wrote:
>> Op 13 okt. 2013, om 15:39 heeft Richard Purdie <richard.purdie at linuxfoundation.org> het volgende geschreven:
>> 
>>> On Sun, 2013-10-13 at 12:01 +0200, Koen Kooi wrote:
>>>> Op 12 okt. 2013, om 10:37 heeft Richard Purdie <richard.purdie at linuxfoundation.org> het volgende geschreven:
>>>> 
>>>>> On Fri, 2013-10-11 at 15:37 +0200, Koen Kooi wrote:
>>>>>> Signed-off-by: Koen Kooi <koen at dominion.thruhere.net>
>>>>>> ---
>>>>>> meta/recipes-connectivity/openssh/openssh-6.2p2/sshd_config | 2 +-
>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>> 
>>>>>> diff --git a/meta/recipes-connectivity/openssh/openssh-6.2p2/sshd_config b/meta/recipes-connectivity/openssh/openssh-6.2p2/sshd_config
>>>>>> index 4f9b626..175e8f3 100644
>>>>>> --- a/meta/recipes-connectivity/openssh/openssh-6.2p2/sshd_config
>>>>>> +++ b/meta/recipes-connectivity/openssh/openssh-6.2p2/sshd_config
>>>>>> @@ -59,7 +59,7 @@ Protocol 2
>>>>>> 
>>>>>> # To disable tunneled clear text passwords, change to no here!
>>>>>> #PasswordAuthentication yes
>>>>>> -#PermitEmptyPasswords no
>>>>>> +PermitEmptyPasswords yes
>>>>>> 
>>>>>> # Change to no to disable s/key passwords
>>>>>> #ChallengeResponseAuthentication yes
>>>>> 
>>>>> I'm struggling to connect the "if PAM allows it as well" part of the
>>>>> shortlog to this change? How is this conditional on PAM?
>>>> 
>>>> If PAM disallows empty passwords this option doesn't do anything. The
>>>> PAM rules run before the openssh config options get applied.
>>> 
>>> What if PAM isn't being used?
>> 
>> I haven't tested that, but I suspect it will only allow empty passwords if you set it to 'yes'.
> 
> Let me put this a different way. I think this commit allows empty
> passwords for users both using PAM and those who are not.

Right

> I think the
> commit message needs to clearly say that as its a fairly serious
> security change for both cases.

Right again.

> I'm not actually sure this makes sense as a default and it may be better
> off being configurable, defaulting to off...

Allowing passwordless (well, null passwords to be exact) logins is the current default for both PAM and dropbear, openssh is the odd one out. I don't really care what the default should be, just that all 3 should use the same :)

So should I resubmit this patch with an amended commit message or rework it and change the defaults in PAM and dropbear as well?

regards,

Koen