Re: SSH Key exchange (Kex error)

[Andreas Schneider <asn@xxxxxxxxxxxxxx>]

On Thursday, 1 February 2024 11:00:24 CET Bhautik Radadiya wrote:
> Hi,

Hi,

> We added that log verbose option but not able to see session logs, but
> 
> This exception in image might help you to understand issue.
>  We are getting it even after adding that set option line which i mentioned
> earlier.

I've just tested it with ssh-client from the examples directory and set the 
diffie-hellman-group14-sha1 kex. Works just fine with libssh 0.9.8:

[2024/02/01 11:12:21.580708, 2] ssh_kex_select_methods:  Negotiated diffie-
hellman-group14-sha1,ssh-ed25519,aes256-gcm@xxxxxxxxxxx,aes256-
gcm@xxxxxxxxxxx,aead-gcm,aead-gcm,none,none
 

	Andreas


> Thanks
> Bhautik
> 
> On Thu, Feb 1, 2024, 2:47 PM Jakub Jelen <jjelen@xxxxxxxxxx> wrote:
> > Please, provide debug log from the libssh session:
> > 
> > int verbosity = 4;
> > ssh_options_set(session, SSH_OPTIONS_LOG_VERBOSITY, &verbosity);
> > 
> > The OpenSSH command you used adds this option to some list, while the
> > libssh operation limits the kex algorithms to this single algorithm.
> > The verbose log as mentioned above will show you what the server
> > supports.
> > 
> > Jakub
> > 
> > On Wed, Jan 31, 2024 at 1:26 PM Bhautik Radadiya
> > 
> > <radadiyabhautik55@xxxxxxxxx> wrote:
> > > Yes, we tried through manual ssh command like below, and we are into the
> > 
> > devide.
> > 
> > > ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 Device_ip -p Port
> > > 
> > > Not sure what's stopping us through libssh.
> > > 
> > > Thanks
> > > Bhautik
> > > 
> > > On Wed, Jan 31, 2024, 5:38 PM Andreas Schneider <asn@xxxxxxxxxxxxxx>
> > 
> > wrote:
> > >> On Wednesday, 31 January 2024 11:31:53 CET Bhautik Radadiya wrote:
> > >> > Hi,
> > >> 
> > >> Hi,
> > >> 
> > >> > Hope you all are well!
> > >> > I am facing this (kex error : no match for method kex algos) issue in
> > 
> > my
> > 
> > >> > application while trying to connect to device.
> > >> > I am using libssh 0.9.5.
> > >> > I added this below line in my sshlib file but not working it.
> > >> > 
> > >> > ssh_option_set (my_session, SSH_OPTIO NS_KEY_EXCHANGE,
> > >> > "diffie-hellman-group14-sha1");
> > >> > 
> > >> > Can you please help me with this? Or Can you please provide some
> > 
> > guidance.
> > 
> > >> > It will be great help.
> > >> 
> > >> are you sure that the device supports this kex?
> > >> 
> > >> Did you enable verbose logging and check what the server returns?
> > >> 
> > >> 
> > >> Best regards
> > >> 
> > >>         Andreas
> > >> 
> > >> --
> > >> Andreas Schneider                 asn@xxxxxxxxxxxxxx
> > >> GPG-ID:     8DFF53E18F2ABC8D8F3C92237EE0FC4DCC014E3D


-- 
Andreas Schneider                 asn@xxxxxxxxxxxxxx
GPG-ID:     8DFF53E18F2ABC8D8F3C92237EE0FC4DCC014E3D