There are four distinct and separate layers of security to consider when using the File Storage service. Each layer has its own authorization entities and methods which are separate from the other layers.
Watch a video overview about security in File Storage.
The Oracle Cloud Infrastructure (OCI) policy layer uses policies to control what users can do within OCI, such as creating instances, a VCN and its security rules, mount targets, and file systems.
The Network security layer controls which instance IP Addresses or CIDR blocks can connect to a host file system. It uses VCN security list rules to allow or deny traffic to the mount target, and therefore access to any associated file system.
The NFS export option layer is a method of applying access control per-file system export based on source IP address that bridges the Network Security layer and the NFS v.3 Unix Security layer.
The NFS v.3 Unix security layer controls what users can do on the instance, such as installing applications, creating directories, mounting external file systems to a local mount point, and reading and writing files.
|This security layer...||Uses these...||To control actions like...|
|Oracle Cloud Infrastructure (OCI)||OCI Users and policies||Creating instances and VCNs. Creating, listing, and associating file systems and mount targets.|
|Network security||IP addresses, CIDR blocks, security lists||Connecting the client instance to the mount target.|
|NFS export options||File system exports, IP addresses, Unix users||Privileged source port connection, reading and writing files, and limiting root user access on a per-file system basis.|
|NFS v.3 Unix security||Unix users, file mode bits||Mounting file systems, reading and writing files.|
You create users and groups in Oracle Cloud Infrastructure. Then, you can use policies to specify which users and groups can create, access, or modify resources such as file systems, mount targets, and export options.
The network security layer allows you to use VCN security lists to block the appropriate ports from specific IP addresses and CIDR blocks and restrict host access. However, this is on an ‘all or nothing’ basis - the client either can or cannot access the mount target, and therefore all file systems associated with it. See Working with NFS Export Options to specify granular controls on a per-file system basis.
File Storage service supports the AUTH_UNIX style of authentication and permission checking for remote NFS client requests. When mounting file systems, we recommend that you use the
-nosuid option. This option disables set-user-identifier or set-group-identifier bits. Remote users are prevented from gaining higher privileges using a
setuid program. For more information, see Mounting File Systems.
Remember that users in UNIX aren’t the same as users in OCI - they’re not linked or associated in any way. The OCI policy layer doesn’t govern anything that happens inside the file system, the UNIX security layer does. Conversely, the UNIX security layer doesn’t govern creating file systems or mount targets in OCI.
NFS export options are a method of applying access control at the network security layer and the NFS v.3 Unix security layer. You can use NFS export options to limit access levels by IP addresses or CIDR blocks connecting to multiple file systems through exports of an associated mount target. Access can be restricted so that each client’s file system is inaccessible and invisible to the other, allowing for managed hosted environment security. Moreover, you can set permissions for read-only, read-write, or root-squash for your file systems. See Working with NFS Export Options for more information.