Check out this link:

https://help-2020r2.acumatica.com/Wiki/ShowWiki.aspx?pageid=c11d8fd2-9718-4ac9-a52b-928887db7651

you can add the Certificate via the SM200530 Encryption Certificates screen.

Once done you can use the added certificate(s) in your SFTP file sync.

Hi Eudes,

You need to set this up from the Encryption Certificates (SM.20.05.30) page. The key needs to be uploaded as a file attachment, in .pfx format. Documentation on this screen can be found here

If anyone form the Acumatica team is reading this -- there’s no documentation at all on SFTP with SSH Key in the product, and other users have asked the same thing before. See comments section of this post by @smarenich on his blog.

Hi Gabriel,

Thank you for the guidance. I want to tell you what I got so far from the tests. 

Test 1) I had the .ppk file and read somewhere in the communities that I could just rename the extension from .ppk to .pfx . The synchronisation raised the following error:  “public key is invalid” .
I guess this is not the right way to convert a ppk to pfx. If you know how, please let me know.

Test 2) I then loaded the .ppk file to the Encryption Certificates. The synchronization raised the following error: “Invalid private key file”.
The file was tested with other SSH toll and worked fine. 

Any ideas on how to go from here ? 

Many thanks 

@eudescoelho29 both formats are not the same. I think you will need to go from PPK to PEM, and then from PEM to PFX.

Step 1:Using PuTTY: Convert a .ppk private key (Putty) to a base64/pem private key for OpenSSH or OpenSSL

Step 2: Using openssl commandline:

openssl pkcs12 -inkey bob_key.pem -in bob_cert.cert -export -out bob_pfx.pfx

Just adding this link here which describes the difference between a .cert and .pfx file:

https://security.stackexchange.com/questions/29425/difference-between-pfx-and-cert-certificates

I have the same issue.  Trying your suggestion @Gabriel Michaud , but what are you using for `bob_cert.cert`? I have a .ppk, .pem (or .key), and a .pub.

.cert should be for an actual certificate...but what cert?