Re: SSH tunnel key exchange methods

Hi Dave

On Mon, Nov 30, 2015 at 10:41 AM, Akshay Joshi <akshay.joshi@enterprisedb.com> wrote:

Hi Dave

On Fri, Nov 27, 2015 at 3:01 PM, Dave Page <dpage@pgadmin.org> wrote:

On Fri, Nov 27, 2015 at 9:23 AM, Sven <svoop_6cedifwf9e@delirium.ch> wrote:
>> The key exchange methods offered when opening an SSH tunnel are all
>> SHA1 and therefore too weak:
>>
>> [sshd] fatal: Unable to negotiate with xxx.xxx.xxx.xxx: no matching
>> key exchange method found. Their offer:
>> diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1,
>> diffie-hellman-group1-sha1 [preauth]
>
> Any news on this? If there's no easy way to add safer kexes, I suggest
> you disable the SSH feature altogether. SHA1 is dead and IMO nobody
> should trust a connection established with SHA1 kexes in order to talk
> to databases.

Akshay, you know that code best of all. How do we enable safer kexes?

   Today I'll look into it on priority and update accordingly.

 

       I have found that "diffie-hellman-group-exchange-sha256" support has been added to the libssh2 code on September 24, it's not released yet. Please check https://github.com/libssh2/libssh2/pull/48 . Today I have tried to update the libssh2, but facing some compilation issues which needs to be fixed. I am working on it and then check do we need to change our logic or libssh2 will automatically used  "diffie-hellman-group-exchange-sha256".

 

--
Dave Page
Blog: http://pgsnake.blogspot.com
Twitter: @pgsnake

EnterpriseDB UK: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

--

Akshay Joshi

Principal Software Engineer 

Phone: +91 20-3058-9517
Mobile: +91 976-788-8246

--

Akshay Joshi

Principal Software Engineer 

Phone: +91 20-3058-9517
Mobile: +91 976-788-8246