Access Manager v2 API for PubNub Go SDK

PubNub Access Manager (Access Manager) 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-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 AuthKey. 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.

Resource	Permissions
channel	read, write, get, manage, update, join, delete
uuid	get, update, delete
channelGroup	read, 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 SubscribeKey, 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 SubscribeKey, 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 SubscribeKey, channel and AuthKey, access is granted for that attribute. Similarly, user level grants also allow you granting an AuthKey access to channelGroups and uuids. User level grants require AuthKey and are the recommended approach if you need to manage permissions for individual users within your application. Each user should be assigned a unique AuthKey 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 Go V4 SDK:

1. pn.Grant()
   .Uuids([]string)
   .Channels([]string)
   .ChannelGroups([]string)
   .AuthKeys([]string)
   .Read(bool)
   .Write(bool)
   .Manage(bool)
   .Get(bool)
   .Update(bool)
   .Join(bool)
   .TTL(int)
   .QueryParam(queryParam)
   .Execute()
   

   Parameter	Type	Required	Default	Description
   Uuids	[]string	Optional		Specifies a list of uuids on which to grant permissions. You can't grant permissions to channels and channel groups in the same request if you decide to use uuids. This parameter does not support wildcards.
   Channels	[]string	Optional		Specifies 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. 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	[]string	Optional		Specifies 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. This parameter does not support wildcards.
   AuthKeys	[]string	Optional		Specifies auth Key to grant permissions. It is possible to specify multiple auth keys. 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.
   Read	bool	Optional	false	Read permissions are granted by setting to true. Read permissions are removed by setting to false.
   Write	bool	Optional	false	Write permissions are granted by setting to true. Write permissions are removed by setting to false.
   Delete	bool	Optional	false	Delete permissions are granted by setting to true. Delete permissions are removed by setting to false.
   Manage	bool	Optional	false	Manage permissions are granted by setting to true. Manage permissions are removed by setting to false.
   Get	bool	Optional	false	Get permissions are granted by setting to true. Get permissions are removed by setting to false.
   Update	bool	Optional	false	Update permissions are granted by setting to true. Update permissions are removed by setting to false.
   Join	bool	Optional	false	Join permissions are granted by setting to true. Join permissions are removed by setting to false.
   TTL	int	Optional	1440 (24hrs)	Time in minutes for which granted permissions are valid. Default is 1440 (24hrs), Max is 525600 , Min is 1. Setting TTL to 0 will apply the grant indefinitely.
   QueryParam	map[string]string	Optional	nil	QueryParam accepts a map, the keys and values of the map are passed as the query string parameters of the URL called by the API.

Basic Usage

Grant Access Manager Permissions for channel and AuthKey

res, status, err := pn.Grant().
    Channels([]string{"ch1", "ch2", "ch3"}). // channels to allow grant on
    ChannelGroups([]string{"cg1", "cg2", "cg3"}). // groups to allow grant on
    AuthKeys([]string{"my-key"}). // the keys we are provisioning
    Read(true). // allow those keys to write (false by default)
    Write(true). // allow those keys to manage channel groups (false by default)
    Manage(true). // allow keys to read the subscribe feed (false by default)
    TTL(123). // how long those keys will remain valid (0 for eternity)
    Execute()

fmt.Println(res, status, err)

Response

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

Method	Type	Description
Level	string	Permissions level, one of subkey, subkey+auth, channel, channel-group, channel-group+auth level.
TTL	int	TTL of grant.
SubscribeKey	string	The subscribe key.
Channels	map[string]*PNPAMEntityData	Access rights per channel. See PNAccessManagerChannelData for more details.
ChannelGroups	map[string]*PNPAMEntityData	Access rights per channel groups. See PNAccessManagerChannelData for more details.
ReadEnabled	bool	subkey level read permissions.
WriteEnabled	bool	subkey level write permissions.
DeleteEnabled	bool	subkey level delete permissions.
ManageEnabled	bool	subkey level manage permissions.

PNPAMEntityData:

Method	Type	Description
AuthKeys	map[string]*PNAccessManagerKeyData	Access rights per auth-key. See PNAccessManagerKeyData for more details.
Name	string	Channel or group name.
ReadEnabled	bool	Channel or group level read permissions.
WriteEnabled	bool	Channel or group level write permissions.
DeleteEnabled	bool	Channel or group level delete permissions.
ManageEnabled	bool	Channel or group level manage permissions.
TTL	int	Time to live value.

PNAccessManagerKeyData:

Method	Type	Description
ReadEnabled	bool	auth-key read permissions
WriteEnabled	bool	auth-key write permissions.
ManageEnabled	bool	auth-key managepermissions.
DeleteEnabled	bool	auth-key delete permissions.
TTL	int	Time to live value.

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

1. Grant subscribe privileges to all users on all channel(s) with default TTL (1440 minutes):

   res, status, err := pn.Grant().
       Read(true).
       Execute()
   
   fmt.Println(res, status, err)
   

2. Allow subscribe and publish to a specific Grant subscribe and publish to a specific channel for all users (no AuthKey required) with default TTL (1440 minutes):

   res, status, err := pn.Grant().
       Channels([]string{"my_channel"}).
       Read(true).
       Write(true).
       Execute()
   
   fmt.Println(res, status, err)
   

3. Grant subscribe access to a channel only for clients with a specific AuthKey with a 5 minute TTL:

   res, status, err := pn.Grant().
       Channels([]string{"my_channel"}).
       Read(true).
       Write(false).
       AuthKeys([]string{"my_authkeys"}).
       TTL(5).
       Execute()
   
   fmt.Println(res, status, err)
   

   The above code would return the following response to the client:

   {
       Level:user
       SubscribeKey:sub-c-90c51098-c040-11e5-a316-0619f8945a4f
       Ttl:1440
       Channels:map[
           my_channel:{
               Name:ch1
               AuthKeys:map[
                   my_authkeys:{
                       ReadEnabled:true
                       WriteEnabled:false
                       ManageEnabled:<nil>
                       Ttl:5
                   }
               ]
               ReadEnabled:false
               WriteEnabled:false
               ManageEnabled:false
               Ttl:1440
           }
       ]
       ChannelGroups:map[]
       ReadEnabled:false
       WriteEnabled:false
       ManageEnabled:false
   }
   

4. Allow access to a specific channel for Presence:

   res, status, err := pn.Grant().
       Channels([]string{"my_channel-pnpres"}).
       Read(false).
       Write(true).
       Execute()
   
   fmt.Println(res, status, err)
   

5. Grant Access Manager Permissions for channel group:

   res, status, err := pn.Grant().
       ChannelGroups([]string{"cg1", "cg2", "cg3"}).
       AuthKeys([]string{"my-key"}).
       Read(true).
       Write(true).
       Manage(true).
       TTL(123).
       Execute()
   
   fmt.Println(res, status, err)
   

   The above code would return the following response to the client:

   {
       Level:channel-group+auth
       SubscribeKey:sub-c-90c51098-c040-11e5-a316-0619f8945a4f
       Ttl:123
       Channels:map[
           my_channel-pnpres:{
               Name:my_channel-pnpres
               AuthKeys:map[
                   my-key:{
                       ReadEnabled:true
                       WriteEnabled:true
                       ManageEnabled:false
                       Ttl:0
                   }
               ]
               ReadEnabled:false
               WriteEnabled:false
               ManageEnabled:false
               Ttl:123
           }
       ]
       ChannelGroups:map[]
       ReadEnabled:false
       WriteEnabled:false
       ManageEnabled:false
   }
   

6. Grant get and update access to a uuid only for clients with a specific AuthKeys with a 24 hrs ttl:

   res, status, err := pn.Grant().
       Uuids([]string{"my_uuid"}).
       Get(true).
       Update(false).
       AuthKeys([]string{"my_authkeys"}).
       TTL(1440).
       Execute()
   
   fmt.Println(res, status, err)
   

7. 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.

   res, status, err := pn.Grant().
       Read(true).
       Write(true).
       Execute()
   
   fmt.Println(res, status, err)
   

8. Channel Level Grant

   res, status, err := pn.Grant().
       Channels([]string{"my_channel"}).
       Read(true).
       Write(true).
       Execute()
   
   fmt.Println(res, status, err)
   

9. User Level Grant

   res, status, err := pn.Grant().
       Channels([]string{"my_channel"}).
       AuthKeys([]string{"my_key"}).
       Read(true).
       Write(true).
       TTL(5).
       Execute()
   
   fmt.Println(res, status, err)