I remember that BSDs original ftpd had a login password limitation with a wrong bytes allocation and a resulting RCE attack surface, which ultimately is still a

I remember that BSDs original ftpd had a login password limitation with a wrong bytes allocation and a resulting RCE attack surface, which ultimately is still a threat to outdated ProFTPd instances running on Windows. (see exploitdb, it's full of PoCs) I always asked myself: Why not simply use sshd and no login shell for the created user? Gives you legit transport encryption, blocking of keys/certs you wanna ban, and is the definition of battleproven software. I never understood plaintext auth via encrypted transportation layers. They simply don't make sense to me from a security standpoint, and the risks of a broken transport layer is just too damn high as you must have control of every OSI level to really be able to verify it and that's never the case.