ssh: no common algorithm for host key

System info

OS

Windows (Windows Server 2022 Datacenter)

redpanda-connect version

4.89.1

Description

I wanted to update my old benthos version to the latest redpanda-connect but it seems there is an issue when connecting via SSH.
My input config:

input:
  label: <redacted>
  sftp:
    address: <redacted>
    credentials:
      username: <redacted>
      password: <redacted>
      host_public_key: <redacted>
    paths: [/*/*.xml]
    codec: all-bytes
    watcher:
      enabled: true
      minimum_age: 1m
      poll_interval: 10m
      cache: ftpcache_nats

For the host_public_key I used the result of ssh-keyscan -p 22 <redacted>.
But my processing log shows:

time="2026-04-27T10:29:06Z" level=error msg="Failed to connect to sftp: connecting to SFTP server: ssh: handshake failed: ssh: no common algorithm for host key; we offered: [ssh-rsa], peer offered: [rsa-sha2-512 rsa-sha2-256]" @service=benthos label=cedris_ftp path=root.input

Additional information

I can connect to the SFTP server via WinSCP just fine.

Start by reproducing the SFTP connection from the provided configuration on Windows, then trace the SSH handshake algorithm negotiation that reports the offered host-key algorithms. Compare the configured host_public_key and the server's rsa-sha2-512/rsa-sha2-256 offers. Done means the connection succeeds without weakening host-key verification.