Setup CrushFTP SFTP with ECDSA Support

This document shows how to properly configure ECDSA support for SFTP on a CrushFTP server. This is needed for VMware NSX-T backups to properly function.

1. Create ECDSA Key#

Steps to Create ECDSA Key files

1. Open Command Prompt as Administrator
2. Run Below commands to generate key files:

cd C:\Program Files\CrushFTP
ssh-keygen -A
ssh-keygen -t ecdsa -f ssh_host_ecdsa_key -N ""

Output:

Generating public/private ecdsa key pair.
Your identification has been saved in ssh_host_ecdsa_key.
Your public key has been saved in ssh_host_ecdsa_key.pub.
The key fingerprint is:
SHA256:uoSFybTIOdocoYO69ew/o58ULcKnvRCRJgDNThGYF14 contso\username@server-name
The key's randomart image is:

+---[ECDSA 256]---+
|+==oo.E          |
| .+o o           |
| oo *            |
|.o.X = .         |
|+ * O = S        |
|.= o O +         |
|o + + =          |
| o o +o+         |
|.  .=+*o         |
+----[SHA256]-----+

2. Modify CrushFTP SFTP Settings#

1. Login to CrushFTP HTTPS interface with admin
2. Click on > Admin > Preferences > and select the SFTP interface you wish to modify
3. Click on the SSH Tab, and edit the Server Host Key (DSA): ./ssh_host_ecdsa_key

4. Click on Save
5. Test the connection with Filezilla or WinSCP