Python - Paramiko - incompatible ssh server

Question

I have an error on a script I have wrote since few months, it worked very good with a raspberry pi, but now with an orange pi I have this:

>>> import paramiko
>>> transport = paramiko.Transport("192.168.2.2", 22)
>>> transport.connect(username = "orangepi", password = "my_pass")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/dist-packages/paramiko/transport.py", line 978, in connect
    self.start_client()
  File "/usr/lib/python2.7/dist-packages/paramiko/transport.py", line 406, in start_client
    raise e
paramiko.ssh_exception.SSHException: Incompatible ssh server (no acceptable macs)

I can connect in console with ssh without problem.

Somebody has an idea ?

Solution 1

You should check if any of those MACs algorithms are available on your SSH server (sshd_config, key: MACs) :

• HMAC-SHA1
• HMAC-MD5
• HMAC-SHA1-96
• HMAC-MD5-96.

They are needed in order for Paramiko to connect to your SSH server.

Solution 2

On your remote server, edit /etc/ssh/sshd_config and add a MACs line or append to the existing one, with one or more of hmac-sha1,hmac-md5,hmac-sha1-96,hmac-md5-96 (values are comma-separated), for example:

MACs hmac-sha1

Now restart sshd: sudo systemctl restart ssh.

Comments

[Raito]

It seems like that you don't have a common MAC algorithm between Paramiko and your SSH server implementation. Paramiko supports HMAC-SHA1, HMAC-MD5, HMAC-SHA1-96, HMAC-MD5-96.

[Raito]

It may be solved by adding MACs [email protected] [others MAC algorithm] to your sshd_config on your Raspberry Pi, I think.

[Gert van den Berg]

Note that this is a security risk (tiny though), most of the other MACs are based on more secure hashes.