Rules Conditions

As explained in the previous chapter, Security Policies are a set of rules that are evaluated at runtime to answer simple questions and return an "Allow" or "Deny" response.

Comparators

Conditions are evaluated against various metadata (see next sections) using one of the following comparator:

Comparator Description Value Example
Boolean Value Evaluates value as a boolean (as Golang would with strconv.ParseBool) true, false
String Matches Compares with value using a regular expression. Empty value always evaluates to false. localhost|127.0.01
String does not Match Opposite of String Matches (empty values always evaluate to true) (?i)\.txt$
String equals Strict string equality value
Glob Matcher Special Glob comparison only usable with FullPath field. See specific section below. (ip)/path/to/folder/**
Date Period Start/end dates in ISO8601 Format 2018-02-01T00:00+0100/2018-04-01T00:00+0100
Date after Start date in ISO8601 Format 2018-02-01T00:00+0100
Office Hours Multiple recurring periods Monday-Friday/09:00/18:30
CIDR Condition Network addresses comparisons 192.168.0.1/16

Glob Matcher

The Glob Matcher comparator is a specific manager performing "glob-like" comparison against files/folders paths. As such it's probably only useful in association with the FullPath field.

The expected pattern supports some specific flags and wildchars using the following format ([flags])/path/to/folder/[wildchars]:

  • Flags:
    • i : for case-insensitive comparison
    • p : The p flag refers to 'parents'. It means that it applies similarly to all segments of the path
  • Wildchars:
    • * : applies to all children first-level
    • ** : applies to all children recursively

Using these flags, you can for example provide a Read access to a specific folder and write access to everything below, by combining two rules:

  • (ip)datasource/path/to/folder => [RW] : open access to the folder and all its parents
  • (i)datasource/path/to/folder/** => [RW] : allow creating any resource below this folder

Request Metadata

Every request sent to the server via Cells APIs carries a set of metadata that can be used in Conditions to restrict or authorize particular accesses.

Metadata Description
Server Host Hostname to which the user has connected. This is can be used in conjunction with cells "Sites" that allow Cells to bind on different network addresses, and grant an access depending on the Site accessed.
HTTP Method GET, PUT, POST, DELETE, etc.
Request URI If you specifically want to deny access to a certain API endpoint
HTTP Protocol HTTP vs. HTTPS
User-Agent User-Agent header sent by Http client. Can be useful to prevent connection with Cells specific tools like Cells Client or Cells Sync, or with a specific Browser.
Content-Type Content-Type header of the incoming request. Can be used to disable sync client access by excluding "application/json+grpc" requests.
Cookies String Cookie header sent by browser
Time Server time when request is performed.

Nodes Metadata

Many Cells REST API requests carry information about a specific "node", which is a file or folder, located in one of the authorized workspace. This node may or may not exist at the time of the request.

Typically, an upload request will "PUT" an object to "/workspace/path/to/file.ext" that does not exist yet. On the other hand, a listing or stat request will generally point to an existing file that can expose its own advanced metadata.

Metadata Description
Basename The basename of the node is the last segment of its path (e.g. file.ext)
Full Path Full path of the node inside the datasources global tree (.e.g pydiods1/path/to/file.ext)
Node Type Whether it's a file (LEAF) or folder (COLLECTION).
Extension Extension attached to file name
Filesize Size in bytes, either from existing file, or from the Content-Length header for upload queries.
Modification Time Timestamp of the last modification date for an existing file.
Custom Metadata... Any other metadata that can be generated by Cells or by users (see below).

Using Custom Metadata can be typically used to evaluate a condition against user-defined tags. For example, you can define a policy that hides any file tagged with a specific value (like "confidential"), or on the opposite only show files that are tagged with a specific value (like "scanned-for-viruses")

Below are some condition examples:

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