sftp-server set Permissions for all files

Question

I have an sftp-server and need to set all files' permissions to 775 which upload from client.How can I do that? Just found the umask set,but it is not fit for me as client may upload file with 664 permissions.

Answer 1

And how can I set to make all files to 775 whatever the client upload?

You cannot.

Resulting permission = Default permission AND (NOT umask)

With file:

default permission = 666 = 110 110 110
umask                    = whatever
resulting permission     = xx0 xx0 xx0

In summary, you cannot create an executable file using umask.