Issues

Exception raised on client:

ssh: Unknown exception: q must be exactly 160, 224, or 256 bits long
ssh: Traceback (most recent call last):
ssh:   File "/usr/lib/python3/dist-packages/paramiko/transport.py", line 2109, in run
ssh:     handler(self.auth_handler, m)
ssh:   File "/usr/lib/python3/dist-packages/paramiko/auth_handler.py", line 298, in _parse_service_accept
ssh:     sig = self.private_key.sign_ssh_data(blob)
ssh:   File "/usr/lib/python3/dist-packages/paramiko/dsskey.py", line 108, in sign_ssh_data
ssh:     key = dsa.DSAPrivateNumbers(
ssh:   File "/usr/lib/python3/dist-packages/cryptography/hazmat/primitives/asymmetric/dsa.py", line 250, in private_key
ssh:     return backend.load_dsa_private_numbers(self)
ssh:   File "/usr/lib/python3/dist-packages/cryptography/hazmat/backends/openssl/backend.py", line 853, in load_dsa_private_numbers
ssh:     dsa._check_dsa_private_numbers(numbers)
ssh:   File "/usr/lib/python3/dist-packages/cryptography/hazmat/primitives/asymmetric/dsa.py", line 147, in _check_dsa_private_numbers
ssh:     _check_dsa_parameters(parameters)
ssh:   File "/usr/lib/python3/dist-packages/cryptography/hazmat/primitives/asymmetric/dsa.py", line 139, in _check_dsa_parameters
ssh:     raise ValueError("q must be exactly 160, 224, or 256 bits long")
ssh: ValueError: q must be exactly 160, 224, or 256 bits long
ssh: 
BackendException: ssh connection to niziak-backup@192.168.179.90:22 failed: q must be exactly 160, 224, or 256 bits long

Client is Debian 11 (paramiko version 2.7.2) Remote side was upgraded to Debian 12 (paramiko version 2.12.0)

Upgrading paramiko on client helps:

python3 -m pip install -U paramiko

ssh: Exception: Invalid packet blocking
ssh: Traceback (most recent call last):
ssh:   File "/usr/lib/python3/dist-packages/paramiko/transport.py", line 2055, in run
ssh:     ptype, m = self.packetizer.read_message()
ssh:                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ssh:   File "/usr/lib/python3/dist-packages/paramiko/packet.py", line 493, in read_message
ssh:     raise SSHException("Invalid packet blocking")
ssh: paramiko.ssh_exception.SSHException: Invalid packet blocking
ssh: 
Attempt of put Nr. 1 failed. EOFError: 
Attempt of put Nr. 2 failed. OSError: Socket is closed
Attempt of put Nr. 3 failed. OSError: Socket is closed
Attempt of put Nr. 4 failed. OSError: Socket is closed
Giving up after 5 attempts. OSError: Socket is closed
Attempt of put Nr. 1 failed. OSError: Socket is closed
Attempt of put Nr. 2 failed. OSError: Socket is closed

Not known reason or solution. SSH connection on remote side gently disconnects.

Workaround: Bump duplicity version on client side (from 0.8.22 to 1.2.2)

--- Start running command BKP at 02:17:02.067 ---
BackendException: ssh connection to mybackup@192.168.64.251:22 failed: not a valid RSA private key file
02:17:02.740 Task 'BKP' failed with exit code '23'.
--- Finished state FAILED 'code 23' at 02:17:02.740 - Runtime 00:00:00.673 ---

Reason: paramiko doesn't accept OpenSSH key format Solution: ssh-keygen -p -m PEM -f ~/.ssh/id_rsa