Access Manager API for PubNub Python-Tornado SDK
Access Manager v2
This is the outdated Access Manager v2 API. For details about the latest version, see Access Manager v3.
Python version support
Python SDK versions 5.0.0 and higher no longer support Python v2.7 and the Twisted and Tornado frameworks. If you require support for any of these, use SDK version 4.8.1.
Note that PubNub will stop supporting versions of Python lower than 3.7 by the end of 2021.
PubNub Access Manager (PAM) v2 allows you to enforce secure controls for client access to resources within the PubNub network. With PAM, your servers can grant their clients access to individual PubNub resources for a limited duration, with the ability to extend access or add permissions for additional resources.
As soon as PAM is enabled, no publish/subscribe operations can be done without first explicitly providing an authorization token to the PubNub object. If an invalid token is provided, the requesting client will receive a Forbidden error.
For more information about PAM, refer to Managing Permissions with Access Manager.
Grant
Requires Access Manager add-on Requires that the Access Manager add-on is enabled for your key. See this page on enabling add-on features on your keys:
https://support.pubnub.com/hc/en-us/articles/360051974791-How-do-I-enable-add-on-features-for-my-keys-
The grant
method allows you to grant permissions for one or more resources to one or more authKeys
. You may need to make multiple grant calls with an authKey
so that you can specify explicit permissions for each channel
, channelGroup
and uuid
resources. For common permissions, you can normally use a single request.
Privileges specifically granted to an application's subscribe_key
always take precedence over privileges granted to channel
or auth_key
. Therefore an application that requires authentication at the user level should not grant access at either the Application or Channel levels. View the Grant Levels section for more details.
The grant request allows your server to securely grant access for your clients on the following resources within the platform. Each resource allows a limited set of permissions that control the operations that can be performed by the clients. For permissions and API operations mapping information, refer to Managing Permissions with Access Manager.
Resource | Permissions |
---|---|
channel | read , write , get , manage , update , join , delete |
uuid | get , update , delete |
channelGroup | read , manage |
Wildcard notation allows you to grant permissions to multiple channels at a time and later revoke these permissions in the same manner. You can only go one level deep using wildcards. In other words:
a.*
grants access on all channels that begin witha.
.*
ora.b.*
won't work this way. If you grant on*
ora.b.*
, the grant treats*
ora.b.*
as a channel name, not a wildcard.
Wildcard revokes
You can revoke permissions with wildcards from one level deep, like a.*
, only when you initially used wildcards to grant permissions to a.*
.
When a user attempts to access a PubNub resource, PAM will evaluate any existing rules using the following order of precedence before access to a channel is granted to the user:
- Application Level - PAM privileges are always evaluated first at the
Application
level. If eitherread
orwrite
attribute is set toTrue
for asubscribe_key
, PAM will immediately grant access for that attribute without proceeding to check permissions at eitherChannel
orUser
levels. If an attribute is set toFalse
at the Application level, PAM proceeds to evaluate the attribute at the next most granular level. - Channel Level - After first verifying an attribute at the Application level, PAM evaluates the attribute at the Channel level. If an attribute is set to
True
for a combination ofsubscribe_key
, andchannel
, PAM grants access for that attribute at theChannel
level without proceeding to check whether there may beuser
level permissions. - User Level (Recommended) - As a final step PAM evaluates the attributes at the
User
level. If an attribute is set toTrue
forsubscribe_key
,channel
andauth_key
, access is granted for that attribute. Similarly, user level grants also allow you granting anauth_key
access tochannelGroups
anduuids
. User level grants requireauth_key
and are the recommended approach if you need to manage permissions for individual users within your application. Each user should be assigned a uniqueauth_key
and securely passed back to the user to perform operations on the platform.
Method(s)
To Grant Permissions on a Channel
you can use the following method(s) in the Python-Tornado SDK:
pubnub.grant().auth_keys(String|List|Tuple).channels(String|List|Tuple).channel_groups(String|List|Tuple).read(Boolean).write(Boolean).manage(Boolean).delete(Boolean).ttl(Int)
Parameter Type Required Defaults Description auth_keys
String | List | Tuple Optional Specifies auth
Key to grant permissions. It is possible to specify multipleauth
keys as comma separated list in combination with a singlechannel
name. You can also grant access to a singleauth
key for multiplechannels
at the same time. Zero or morechannels
with zero or moreauth
tokens are allowed.channels
String | List | Tuple Optional Specifies the channels
on which togrant
permissions. If nochannels/channelGroups
are specified, then thegrant
applies to any and allchannels/channelGroups
that have been or will be created for thatpublish/subscribe
key set. Furthermore, any existing or future grants on specificchannels
are ignored, until theall channels
grant is revoked. It is possible togrant
permissions to multiplechannels
simultaneously by specifying thechannels
as a comma separated list. Wildcard notation likea.*
can be used togrant
access on channels. You cangrant
one level deep.a.*
- you can grant on this.*
anda.b.*
- grant will not work on these levels. If you grant on*
ora.b.*
, the grant will treat*
ora.b.*
as a single channel named either*
ora.b.*
.
channel_groups
String | List | Tuple Optional Specifies the channelGroups
togrant
permissions. If nochannels/channelGroups
are specified, then thegrant
applies to any and allchannels/channelGroups
that have been or will be created for thatpublish/subscribe
key set. Furthermore, any existing or future grants on specificchannelGroups
are ignored, until theall channelGroups
grant is revoked. It is possible togrant
permissions to multiplechannelGroups
simultaneously by specifying thechannelGroups
as a comma separated list.read
Boolean Optional False
Read
permissions.write
Boolean Optional False
Write
permissions.manage
Boolean Optional False
Manage
permissions.delete
Boolean Optional False
Delete
permissions.ttl
Int Optional None
Time to live
for permission to be valid.
Basic Usage
Grant PAM Permissions for channel and auth_key
envelope = yield pubnub.grant().channels(["ch1", "ch2", "ch3"]).\
channel_groups(["cg1", "cg2"]).\
auth_keys(["key1", "key2"]).\
read(True).write(True).manage(True).\
future()
Returns
The grant() operation returns a PNAccessManagerGrantResult which contains the following fields:
Field | Type | Description |
---|---|---|
level | String | Permissions level, one of subkey , subkey +auth , channel , channel-group , channel-group +auth level. |
ttl | Int | ttl of grant |
subscribe_key | String | The subscribe key . |
channels | Dict | Access rights per channel. See PNAccessManagerChannelData for more details. |
groups | Dict | Access rights per group. See PNAccessManagerGroupData for more details. |
read_enabled | Boolean | subkey level read permissions. |
write_enabled | Boolean | subkey level write permissions. |
manage_enabled | Boolean | subkey level manage permissions. |
delete_enabled | Boolean | subkey level delete permissions. |
ttl | Int | Time to live value. |
PNAccessManagerChannelData and PNAccessManagerGroupData has the same fields structure:
Field | Type | Description |
---|---|---|
auth_keys | List | Access rights per auth-key . See PNAccessManagerKeyData for more details. |
name | String | Channel or group name . |
read_enabled | Boolean | Channel or group level read permissions. |
write_enabled | Boolean | Channel or group level write permissions. |
manage_enabled | Boolean | Channel or group level manage permissions. |
delete_enabled | Boolean | Channel or group level delete permissions. |
ttl | Int | Time to live value. |
Field | Type | Description |
---|---|---|
read_enabled | Boolean | read permissions |
write_enabled | Boolean | write permissions |
manage_enabled | Boolean | manage permissions |
delete_enabled | Boolean | delete permissions |
ttl | Int | Time to live value |
read
, write
, manage
, and delete
permissions have 3 states:
True
if enabled.False
if disabled.None
if not explicitly set.
Caution
PAM grant or revoke requests must be less than ~32KiB at a time, or the client will return an error. For requests greater than 32KiB, break them into smaller batched requests. When the message size exceeds 32KiB the server returns the HTTP Error code 500, instead of the correct error code 414.
Warning
For NTP synchronization, please ensure that you have configured NTP on your server to keep the clock in sync. This is to prevent system clock drift leading to 400 Invalid Timestamp
error response.
Other Examples
Grant subscribe privileges to all users on all channel(s) with default ttl (1440 minutes):
envelope = yield pubnub.grant().read(True).write(True).future()
Allow subscribe and publish to a specific Grant subscribe and publish to a specific channel for all users (no auth_key required) with default ttl (1440 minutes):
envelope = yield pubnub.grant().channels("my_channel").read(True).write(True).future()
Grant subscribe access to a channel only for clients with a specific auth_key with a 5 minute ttl:
envelope = yield pubnub.grant().channels("my_channel").read(True).write(False).\ auth_keys("my_ro_authkey").ttl(5).future()
The above code would return the following response to the client:
{ "status" : 200, "message" : "Success", "payload" : { "ttl" : 5, "auths" : { "my_ro_authkey" : { "r" : 1, "w" : 0, "d" : 0 } }, "subscribe_key" : "my_subkey", "level" : "user", "channel" : "my_channel" }, "service" : "Access Manager" }
Allow access to a specific channel for Presence:
envelope = yield pubnub.grant().\ channels("my_channel-pnpres").read(True).write(True).future()
Grant PAM Permissions for channel group:
envelope = yield pubnub.grant().\ channel_groups(["cg1", "cg2", "cg3"]).\ auth_keys(["auth1", "auth2", "auth3"]).\ read(True).write(True).manage(True).\ ttl(12237).\ .future()
The above code would return the following response to the client:
{ "status":200, "message":"Success", "payload":{ "ttl":5, "auths":{ "my_rw_authkey":{ "r":1, "w":1, "d":1 } }, "subscribe_key":"my_subkey", "level":"user", "channel":"my_channel" }, "service":"Access Manager" }
Grant Permissions on Multiple Channels:
envelope = pubnub.grant().\ auth_keys("my_rw_authkey").\ channels(["girish", "girish2"]).\ read(True).\ write(True).\ ttl(5).\ sync()
Note
The limit on the total amount of
channels
that you can pass at once when usinggrant()
is200
.-
Use application level grants with caution
When access is granted on an application level,
all channels and users
will have access.Application level grants can also happen due to a bug in your code. For example, Null parameters for channels and auth-keys can cause accidental application level grants.
envelope = yield pubnub.grant().\ read(True).write(True).\ .future()
-
envelope = yield pubnub.grant().channels("my_channel").\ read(True).write(True).\ .future()
-
envelope = yield pubnub.grant().channels("my_channel").\ auth_keys("my_authkey").\ read(True).write(True).\ ttl(5).\ .future()