Re: latest openssh can not connect to older server

[Sharuzzaman Ahmat Raslan <sharuzzaman@gmail.com>]

Hi.

New OpenSSH client will not connect to server that use SHA1.

Please refer to this: https://www.openssh.com/legacy.html

You should configure your old server to use more modern cipher

Thank you

On Sun, 19 Apr 2020, 8:13 pm David Balažic via Cygwin, <cygwin@cygwin.com>
wrote:

> Hi!
>
> I tried to backup some files from my server with scp and failed:
>
> $ scp  -v  root@the.server:/root/a.file  .
> Executing: program /usr/bin/ssh host the.server, user root, command
> scp -v -f /root/a.file
> OpenSSH_8.2p1, OpenSSL 1.1.1f  31 Mar 2020
> debug1: Connecting to the.server [192.168.1.11] port 22.
> debug1: Connection established.
> debug1: identity file /home/stein/.ssh/id_rsa type -1
> debug1: identity file /home/stein/.ssh/id_rsa-cert type -1
> debug1: identity file /home/stein/.ssh/id_dsa type -1
> debug1: identity file /home/stein/.ssh/id_dsa-cert type -1
> debug1: identity file /home/stein/.ssh/id_ecdsa type -1
> debug1: identity file /home/stein/.ssh/id_ecdsa-cert type -1
> debug1: identity file /home/stein/.ssh/id_ecdsa_sk type -1
> debug1: identity file /home/stein/.ssh/id_ecdsa_sk-cert type -1
> debug1: identity file /home/stein/.ssh/id_ed25519 type -1
> debug1: identity file /home/stein/.ssh/id_ed25519-cert type -1
> debug1: identity file /home/stein/.ssh/id_ed25519_sk type -1
> debug1: identity file /home/stein/.ssh/id_ed25519_sk-cert type -1
> debug1: identity file /home/stein/.ssh/id_xmss type -1
> debug1: identity file /home/stein/.ssh/id_xmss-cert type -1
> debug1: Local version string SSH-2.0-OpenSSH_8.2
> debug1: Remote protocol version 2.0, remote software version
> dropbear_2011.54
> debug1: no match: dropbear_2011.54
> debug1: Authenticating to the.server:22 as 'root'
> debug1: SSH2_MSG_KEXINIT sent
> debug1: SSH2_MSG_KEXINIT received
> debug1: kex: algorithm: (no match)
> Unable to negotiate with 192.168.1.11 port 22: no matching key
> exchange method found. Their offer:
> diffie-hellman-group1-sha1,diffie-hellman-group14-sha1
>
>
> I tried OpenSSH_8.0p1-2 which is still available in the cygwin
> setup-x86_64.exe wizard and that version works fine.
> (the version above is 8.2.p1-1 in the setup wizard)
>
> Regards,
> David
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