Access Manager v2 API for PubNub Dart SDK
PubNub Access Manager (PAM) 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-onRequires 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 subscribeKey
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 asubscribeKey
, 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 ofsubscribeKey
, 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
forsubscribeKey
,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 Dart SDK:
pubnub.grant(
Set<String> authKeys,
{Set<String>? channels,
Set<String>? channelGroups,
Set<String>? uuids,
bool? write,
bool? read,
bool? manage,
bool? delete,
bool? get,
bool? update,
bool? join,
int? ttl,
Keyset? keyset,
String? using}
)
Parameter | Type | Required | Default | Description |
---|---|---|---|---|
authKeys | Set<String> | Optional | Specifies authKey to grant permissions to.It's possible to specify multiple auth keys. You can also grant access to a single authKey for multiple channels at the same time. Zero or more channels with zero or more auth tokens are allowed. | |
channels | List<String> | Optional | Specifies the channels on which to grant permissions.If no channels /channelGroups are specified, then the grant applies to 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's possible to grant permissions to multiple channels simultaneously.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.* . | |
channelGroups | List<String> | Optional | Specifies the channelGroups to grant permissions. If no channels /channelGroups are specified, then the grant applies to 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's possible to grant permissions to multiple channelGroups simultaneously. | |
write | Boolean | Optional | false | Write permission. |
read | Boolean | Optional | false | Read permission. |
manage | Boolean | Optional | false | Manage permission. |
delete | Boolean | Optional | false | Delete permission. |
get | Boolean | Optional | false | Get permission. |
update | Boolean | Optional | false | Update permission. |
join | Boolean | Optional | false | Join permission. |
ttl | Long | Optional | Not set | Time in minutes for which granted permissions are valid. Setting ttl to 0 will apply the grant indefinitely, which is also the default behavior. |
keyset | Keyset | Optional | default keyset | Override for the PubNub default keyset configuration. |
using | String | Optional | Keyset name from the keysetStore to be used for this method call. |
Basic Usage
Grant PAM Permissions for channel and auth_key
var result = await pubnub.grant({'my_authKey'},
channels: {'my_channel'}, read: true);
Returns
The grant()
operation returns a PamGrantResult
which contains the following properties:
Property Name | Type | Description |
---|---|---|
warning | Boolean | Warning status. |
message | String | Information whether operation was successful or not. |
level | String | Access rights level. |
ttl | int | ttl of grant . |
permissions | List | Access rights per resource. |
Permission
contains the following properties:
Property Name | Type | Description |
---|---|---|
channel | String | Channel name for which permission is set. |
uuid | String | UUID for which permission is set. |
read | Boolean | true if the resource has read rights. |
write | Boolean | true if the resource has write rights. |
manage | Boolean | true if the resource has manage rights. |
delete | Boolean | true if the resource has delete rights. |
get | Boolean | true if the resource has get rights. |
update | Boolean | true if the resource has update rights. |
join | Boolean | true if the resource has join rights. |
Other Examples
Grant subscribe access to a channel only for clients with a specific auth_key with a 5 minute ttl:
var result = await pubnub.grant({'my_authKey'}, channels: {'my_channel'}, read: true, write: false, ttl: 5);
The above code returns the following response to the client:
{ "status" : 200, "message" : "Success", "payload" : { "ttl" : 5, "auths" : { "my_authkey" : { "r" : 1, "w" : 1, "m" : 0, "d" : 0, "g" : 0, "u" : 0, "j" : 0 } }, "subscribe_key" : "my_subkey", "channel" : "my_channel" }, "service" : "Access Manager" }
Allow access to a specific channel for Presence:
var result = await pubnub.grant({'my_authKey'}, channels: {'my_channel-pnpres'}, read: true, write: true);
Grant PAM Permissions for channel group:
var result = await pubnub.grant({'my_authKey'}, channelGroups: {'my_channelGroup'}, read: true, manage: true, ttl: 5);
The above code returns the following response to the client:
{ "status" : 200, "message" : "Success", "payload" : { "ttl" : 5, "auths" : { "my_authkey" : { "r" : 1, "w" : 0, "m" : 1, "d" : 0, "g" : 0, "u" : 0, "j" : 0 } }, "subscribe_key" : "my_subkey", "level":"user", "channel" : "my_channel" }, "service" : "Access Manager" }
-
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.
var result = await pubnub.grant({}, write: true, read: true, delete: true);
-
var result = await pubnub.grant({}, channels: {'my_channel'}, read: true, write: true, delete: true, ttl: 1440);
-
var result = await pubnub.grant({'my_authKey'}, channels: {'my_channel'}, ttl: 1440, get: true, update: true, delete: true);