I need to give some customers access to my server(Azure VM) via either FTP or SQL (they want to retrieve files via FTP and want to connect to a special database), no remote desktop.
Currently I'm using Azure's P2S VPN for this (I gave them the client-installer and client certificate), is this good enough for this kind of purpose? should I keep other security concerns in mind? Thanks!
A Point-to-Site (P2S) configuration lets you create a secure connection from an individual client computer to a virtual network. VPN connection over SSTP (Secure Socket Tunneling Protocol). I find a similar qustion with you, you could refer to this link.
Based on my experience, it is very important for you to replace certificate regularly. Also, you need open suitable ports on Azure NSG and your VM firewall. More information about Azure NSG please refer to this link.