I had configured an ftp server in Centos 7, in which I used the vsftp package and in the vsftpd.conf file I used a command called deny_file in which I only indicated the file extensions that I would not allow to be uploaded to the server, however I saw that the ftp server was not safe and I wanted to put it secure with SSH, that is with SFTP, but despite having the deny_file in the vsftpd.conf it does not block the files by extension and I really want to know if any of you knows a way to do it
please help me,the other question is not explained clearly and I do not understand it.