Is it possible to limit the types and size of files uploaded to the sftp server?

Question

linux

At the moment there is a server on Ubuntu, it uses an sftp server to exchange files between the user (he uploads) and the program (it parses and uses). So that the user does not overfill, and in the name of security, is it possible to limit the types of uploaded files (or at least extensions) and their sizes? Superficial googling threw up only MySecureShell, but somehow it is a bit scary with the documentation IMHO. Maybe something can be solved with built-in Linux tools?

Answer 1

sftpd is a bit different from what you need.
You are using the standard one.
But if you take ProFTPd as a basis, then out of the box there is an option to use sftp. Those. what you need according to TK.
Just disable ftp itself in the config and leave only sftp.
Well, quotas, limits and other permissions / prohibitions in the config will be written with a bang.
And in the standard one, there is no such thing at all.