Re: SSH Key exchange (Kex error)

[Jakub Jelen <jjelen@xxxxxxxxxx>]

Hi,
if this is with the following option applied, it does not sounds like working:

ssh_option_set (my_session, SSH_OPTIONS_KEY_EXCHANGE,
"diffie-hellman-group14-sha1");

check if there is no other line in the code that would set the
highlighted kex options or if there is no configuration file that
would override this.

Jakub

On Thu, Feb 1, 2024 at 11:11 AM Bhautik Radadiya
<radadiyabhautik55@xxxxxxxxx> wrote:
>
> 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.
>
> 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
>> >>
>> >>
>>
>>