Extract SSH Key from Filezilla Client

Created 10 May 2017 15:52, updated 12 April 2019 10:40

I always forget this, so I'm documenting it here for myself. If you make SFTP connections from automated scripts or within a program, you really want to be supplying the SSH key.

On Windows, this can be extracted by doing the following:

  1. Open registry editor (regedit.exe)
  2. Go to HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\SshHostKeys
  3. All the keys are stored, with types, on the right hand side under the SshHostKeys folder. The Name of each entry contains the host.
  4. Delete the key for the host you're looking for, and reconnect using Filezilla. It should supply you with a challenge response with the key and value for future use. In code, you will use a combination of the Hostkey algorithm and the fingerprint. So, for this response from FileZilla:

    In code this would be referenced as:
    SshHostKeyFingerprint = "ecdsa-sha2-nistp384 384 b1:88:d6:eb:83:18:7e:80:77:9f:ef:xx:xx:xx:xx:xx"
  5. You may want to confirm this key with the owner of the source system!