Secure Remote Password (SRP)

https://en.wikipedia.org/wiki/Secure_Remote_Password_protocol

1. Client sends username

2. Server gets username and sends salt and B

3. Client gets salt and B, sends A (randomized number) and M1 (calculate with salt, B, A and password, S_Carol = (B − kg^x)^(a + ux))

4. Server verifies M1

ppk to pem

 From https://tecadmin.net/convert-ppk-to-pem-using-command/

1. sudo apt-get install putty-tools

2. puttygen server1.ppk -O private-openssh -o server1.pem

Convert to private-public key

https://www.tbs-certificates.co.uk/FAQ/en/putty-ppk-vers-openssl-openssh.html