Access Manager API for PubNub Python-Twisted SDK

Access Manager v2

This is the outdated Access Manager v2 API. For details about the latest version, see Access Manager v3.

Deprecated

NOTICE: Based on current web trends and our own usage data, PubNub's Python Twisted SDK is deprecated as of May 1, 2019. Deprecation means we will no longer be updating the Python Twisted SDK but will continue to support users currently using it. Please feel free to use our other Python SDK offerings as they will continue to be supported and maintained. If you would like to use the Python Twisted SDK specifically, we would love to work with you on keeping this project alive!

PubNub Access Manager (Access Manager) v2 allows you to enforce secure controls for client access to resources within the PubNub network. With Access Manager, 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 Access Manager 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 Access Manager, refer to Managing Permissions with Access Manager.

Grant

Requires Access Manager add-on

This method requires that the Access Manager add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your 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.

Permissions

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.

ResourcePermissions
channelread, write, get, manage, update, join, delete
uuidget, update, delete
channelGroupread, manage

Wildcard Permissions

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 with a..
  • * or a.b.* won't work this way. If you grant on * or a.b.*, the grant treats * or a.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.*.

Grant Levels

When a user attempts to access a PubNub resource, Access Manager will evaluate any existing rules using the following order of precedence before access to a channel is granted to the user:

  1. Application Level - Access Manager privileges are always evaluated first at the Application level. If either read or write attribute is set to True for a subscribe_key, Access Manager will immediately grant access for that attribute without proceeding to check permissions at either Channel or User levels. If an attribute is set to False at the Application level, Access Manager proceeds to evaluate the attribute at the next most granular level.
  2. Channel Level - After first verifying an attribute at the Application level, Access Manager evaluates the attribute at the Channel level. If an attribute is set to True for a combination of subscribe_key, and channel, Access Manager grants access for that attribute at the Channel level without proceeding to check whether there may be user level permissions.
  3. User Level (Recommended) - As a final step Access Manager evaluates the attributes at the User level. If an attribute is set to True for subscribe_key, channel and auth_key, access is granted for that attribute. Similarly, user level grants also allow you granting an auth_key access to channelGroups and uuids. User level grants require auth_key and are the recommended approach if you need to manage permissions for individual users within your application. Each user should be assigned a unique auth_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-Twisted 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)
ParameterTypeRequiredDefaultDescription
auth_keysString | List | TupleOptionalSpecifies auth Key to grant permissions. It is possible to specify multiple auth keys as comma separated list in combination with a single channel name. You can also grant access to a single auth key for multiple channels at the same time. Zero or more channels with zero or more auth tokens are allowed.
channelsString | List | TupleOptionalSpecifies the channels on which to grant permissions. If no channels/channelGroups are specified, then the grant applies to any and all channels/channelGroups that have been or will be created for that publish/subscribe key set. Furthermore, any existing or future grants on specific channels are ignored, until the all channels grant is revoked. It is possible to grant permissions to multiple channels simultaneously by specifying the channels as a comma separated list. Wildcard notation like a.* can be used to grant access on channels. You can grant one level deep.
  • a.* - you can grant on this.
  • * and a.b.* - grant will not work on these levels. If you grant on * or a.b.*, the grant will treat * or a.b.* as a single channel named either * or a.b.*.
channel_groupsString | List | TupleOptionalSpecifies the channelGroups to grant permissions. If no channels/channelGroups are specified, then the grant applies to any and all channels/channelGroups that have been or will be created for that publish/subscribe key set. Furthermore, any existing or future grants on specific channelGroups are ignored, until the all channelGroups grant is revoked. It is possible to grant permissions to multiple channelGroups simultaneously by specifying the channelGroups as a comma separated list.
readBooleanOptionalFalseRead permissions.
writeBooleanOptionalFalseWrite permissions.
manageBooleanOptionalFalseManage permissions.
deleteBooleanOptionalFalseDelete permissions.
ttlIntOptionalNoneTime to live for permission to be valid.

Basic Usage

Grant Access Manager Permissions for channel and auth_key

d = pubnub.grant().channels(["ch1", "ch2", "ch3"]).\
channel_groups(["cg1", "cg2"]).\
auth_keys(["key1", "key2"]).\
read(True).write(True).manage(True).\
deferred()

d.addCallback(my_callback)

Returns

The grant() operation returns a PNAccessManagerGrantResult which contains the following fields

FieldTypeDescription
levelStringPermissions level, one of subkey, subkey+auth, channel, channel-group, channel-group+auth level.
ttlIntttl of grant
subscribe_keyStringThe subscribe key.
channelsDictAccess rights per channel. See PNAccessManagerChannelData for more details.
groupsDictAccess rights per group. See PNAccessManagerGroupData for more details.
read_enabledBooleansubkey level read permissions.
write_enabledBooleansubkey level write permissions.
manage_enabledBooleansubkey level manage permissions.
delete_enabledBooleansubkey level delete permissions.
ttlIntTime to live value.

PNAccessManagerChannelData and PNAccessManagerGroupData has the same fields structure

FieldTypeDescription
auth_keysListAccess rights per auth-key. See PNAccessManagerKeyData for more details.
nameStringChannel or group name.
read_enabledBooleanChannel or group level read permissions.
write_enabledBooleanChannel or group level write permissions.
manage_enabledBooleanChannel or group level manage permissions.
delete_enabledBooleanChannel or group level delete permissions.
ttlIntTime to live value.

PNAccessManagerKeyData

FieldTypeDescription
read_enabledBooleanread permissions
write_enabledBooleanwrite permissions
manage_enabledBooleanmanage permissions
delete_enabledBooleandelete permissions
ttlIntTime to live value

read, write, manage, and delete permissions have 3 states:

  • True if enabled.
  • False if disabled.
  • None if not explicitly set.
Caution

Access Manager 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.

https://support.pubnub.com/hc/en-us/articles/360051973331-Why-do-I-get-Invalid-Timestamp-when-I-try-to-grant-permission-using-Access-Manager-

Other Examples

Grant subscribe privileges to all users on all channel(s) with default ttl (1440 minutes)

d = pubnub.grant().read(True).write(True).deferred()
d.addCallback(my_callback)

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)

d = pubnub.grant().channels("my_channel").read(True).write(True).deferred()
d.addCallback(my_callback)

Grant subscribe access to a channel only for clients with a specific auth_key with a 5 minute ttl

d = pubnub.grant().channels("my_channel").read(True).write(False).\
auth_keys("my_ro_authkey").ttl(5).deferred()
d.addCallback(my_callback)

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"
show all 18 lines

Allow access to a specific channel for Presence

d = pubnub.grant().\
channels("my_channel-pnpres").read(True).write(True).deferred()

Grant Access Manager Permissions for channel group

d = pubnub.grant().\
channel_groups(["cg1", "cg2", "cg3"]).\
auth_keys(["auth1", "auth2", "auth3"]).\
read(True).write(True).manage(True).\
ttl(12237).\
.deferred()

d.addCallback(my_callback)

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"
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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 using grant() is 200.

Application Level Grant

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.

d = pubnub.grant().\
read(True).write(True).\
.deferred()

d.addCallback(my_callback)

Channel Level Grant

d = pubnub.grant().channels("my_channel").\
read(True).write(True).\
.deferred()

d.addCallback(my_callback)

User Level Grant

d = pubnub.grant().channels("my_channel").\
auth_keys("my_authkey").\
read(True).write(True).\
ttl(5).\
.deferred()

d.addCallback(my_callback)
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