A.10.1 Is PuTTY a port of OpenSSH, or based on OpenSSH or OpenSSL?
No, it isn't. PuTTY is almost completely composed of code written from scratch for PuTTY. The only code we share with OpenSSH is the detector for SSH-1 CRC compensation attacks, written by CORE SDI S.A; we share no code at all with OpenSSL.