Permissions¶

As described in the concepts section, permissions can be set on any object.

Formalism¶

On each kind of object the set of permissions can be:

Permission	Description
read	Any listed principal can read the object.
write	Any listed principal can write the object, which further implies read, update, and delete.
create	Any listed principal can create a new child object.

In the case of a creation, since an object can have several kinds of children, the permission is prefixed by the type of child (for instance groups:create, collections:create).

The following table lists all permissions that can be associated to each kind of object.

Object	Associated permissions	Description
Configuration	`buckets:create`	Create new buckets.
Bucket	`read`	Read all objects in the bucket.
	`write`	Write + read on the bucket and all children objects.
	`collections:create`	Create new collections in the bucket.
	`groups:create`	Create new groups in the bucket.
Collection	`read`	Read all objects in the collection.
	`write`	Write and read all objects in the collection.
	`records:create`	Create new records in the collection.
Record	`read`	Read the record. record.
Record	`write`	Write and read the record.
Group	`read`	Read the group group.
Group	`write`	Write and read the group

Every modification of an object (including the creation of new objects) grant the write permission to their creator.

Note

There is no delete permission. Anyone with the write permission on an object can delete it.

Principals¶

During the authentication phase, a set of :term:`principal`s for the current authenticated user will be bound to to the request.

The main principal is considered the user ID and follows this formalism: {type}:{identifier} (e.g. for Firefox Account: fxa:32aa95a474c984d41d395e2d0b614aa2).

There are two special principals:

system.Authenticated: All authenticated users.
system.Everyone: Anyone (authenticated or anonymous). Using this principal is useful when a rule should apply to all users.

Note

A user can also be another application (in order to provide service to service authentication).

Get the current user ID¶

The currently authenticated user ID can be obtained on the root URL.

$ http GET http://localhost:8888/v1/ --auth user:pass
HTTP/1.1 200 OK
Access-Control-Expose-Headers: Backoff, Retry-After, Alert, Content-Length
Content-Length: 288
Content-Type: application/json; charset=UTF-8
Date: Thu, 16 Jul 2015 09:48:47 GMT
Server: waitress

{
    "documentation": "https://kinto.readthedocs.org/",
    "hello": "cloud storage",
    "settings": {
        "cliquet.batch_max_requests": 25
    },
    "url": "http://localhost:8888/v1/",
    "userid": "basicauth:631c2d625ee5726172cf67c6750de10a3e1a04bcd603bc9ad6d6b196fa8257a6",
    "version": "1.4.0"
}

In this case the user ID is: basicauth:631c2d625ee5726172cf67c6750de10a3e1a04bcd603bc9ad6d6b196fa8257a6

Note

If Alice wants to share objects with Bob, Bob will need to give Alice his user ID - this is an easy way to obtain that ID.

Retrieve permissions¶

GET /(object url)¶

Synopsis:	Retrieve the object data and permissions.

Requires authentication

Example request

$ http GET http://localhost:8888/v1/buckets/default --auth="bob:" --verbose

GET /v1/buckets/default HTTP/1.1
Accept: */*
Accept-Encoding: gzip, deflate
Authorization: Basic Ym9iOg==
Connection: keep-alive
Host: localhost:8888
User-Agent: HTTPie/0.9.2

Example response

HTTP/1.1 200 OK
Access-Control-Expose-Headers: Backoff, Retry-After, Alert, Content-Length, Last-Modified, ETag
Connection: keep-alive
Content-Length: 187
Content-Type: application/json; charset=UTF-8
Date: Thu, 20 Aug 2015 16:18:48 GMT
ETag: "1440087528171"
Last-Modified: Thu, 20 Aug 2015 16:18:48 GMT
Server: nginx/1.4.6 (Ubuntu)

{
    "data": {
        "id": "fec930f1-4e30-5b1c-2a63-0fafbe508d48",
        "last_modified": 1440087528171
    },
    "permissions": {
        "write": [
            "basicauth:206691a25679e4e1135f16aa77ebcf211c767393c4306cfffe6cc228ac0886b6"
        ]
    }
}

Add a permission¶

PATCH /(object url)¶

Synopsis:	Add principals or permissions to the object.

Requires authentication

Example request

$ echo '{"permissions": {"read": ["system.Authenticated"]}}' | \
  http PATCH https://kinto.dev.mozaws.net/v1/buckets/default/collections/tasks \
  --auth bob:

PATCH /v1/buckets/default/collections/tasks HTTP/1.1
Accept: application/json
Accept-Encoding: gzip, deflate
Authorization: Basic Ym9iOg==
Connection: keep-alive
Content-Length: 52
Content-Type: application/json; charset=utf-8
Host: kinto.dev.mozaws.net
User-Agent: HTTPie/0.8.0

{
    "permissions": {
        "read": [
            "system.Authenticated"
        ]
    }
}

Example response

HTTP/1.1 200 OK
Access-Control-Expose-Headers: Backoff, Retry-After, Alert, Content-Length
Connection: keep-alive
Content-Length: 188
Content-Type: application/json; charset=UTF-8
Date: Thu, 20 Aug 2015 16:43:51 GMT
ETag: "1440089003843"
Last-Modified: Thu, 20 Aug 2015 16:43:23 GMT
Server: nginx/1.4.6 (Ubuntu)

{
    "data": {
        "id": "tasks",
        "last_modified": 1440089003843
    },
    "permissions": {
        "read": [
            "system.Authenticated"
        ],
        "write": [
            "basicauth:206691a25679e4e1135f16aa77ebcf211c767393c4306cfffe6cc228ac0886b6"
        ]
    }
}

Replace or remove permissions¶

Note

The user ID that updates the permissions is always granted the write permission. This is in order to prevent accidental loss of ownership on an object.

PUT /(object url)¶

Synopsis:	Replace existing principals or permissions of the object.

Requires authentication

Example request

$ echo '{"permissions": {"write": ["groups:writers"]}}' | \
  http PUT https://kinto.dev.mozaws.net/v1/buckets/default/collections/tasks \
  --auth bob:

PUT /v1/buckets/default/collections/tasks HTTP/1.1
Accept: application/json
Accept-Encoding: gzip, deflate
Authorization: Basic Ym9iOg==
Connection: keep-alive
Content-Length: 57
Content-Type: application/json; charset=utf-8
Host: kinto.dev.mozaws.net
User-Agent: HTTPie/0.8.0

{
    "permissions": {
        "write": [
            "groups:writers"
        ]
    }
}

Example response

HTTP/1.1 200 OK
Access-Control-Expose-Headers: Backoff, Retry-After, Alert, Content-Length
Connection: keep-alive
Content-Length: 182
Content-Type: application/json; charset=UTF-8
Date: Thu, 20 Aug 2015 16:50:37 GMT
ETag: "1440089437221"
Last-Modified: Thu, 20 Aug 2015 16:50:37 GMT
Server: nginx/1.4.6 (Ubuntu)

{
    "data": {
        "id": "tasks",
        "last_modified": 1440089437221
    },
    "permissions": {
        "write": [
            "groups:writers"
        ],
        "write": [
            "basicauth:206691a25679e4e1135f16aa77ebcf211c767393c4306cfffe6cc228ac0886b6"
        ]
    }
}