Access Manager API for PubNub Ruby 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 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

Resource	Permissions
channel	read, write, get, manage, update, join, delete
uuid	get, update, delete
channelGroup	read, manage

Wildcard Permissions

To make granting access on multiple channels and channel groups more efficient, you can use the wildcard notation. It doesn't, however, apply to the uuid resource and you can only go one level deep using wildcards.

• * grants access on all channels
• a.* grants access on all channels that begin with a.
• a.b.* doesn't work. If you grant on a.b.*, the grant treats a.b.* as a channel name, not a wildcard

Grant Levels

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:

1. Application Level - PAM privileges are always evaluated first at the Application level. If either read or write attribute is set to True for a subscribe_key, PAM 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, PAM proceeds to evaluate the attribute at the next most granular level.
2. 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 of subscribe_key, and channel, PAM 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 PAM 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 Ruby V4 SDK:

grant(channels: channels, channel_groups: channel_groups, uuids: uuids, auth_key: auth_key, read: read, write: write, get: get, manage: manage, update: update, join: join, delete: delete, ttl: ttl, http_sync: http_sync, callback: callback)

Parameter	Type	Required	Description
channels	String, Symbol, comma separated list	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 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. a.b.* - grant will not work on this. If you grant on a.b.*, the grant will treat a.b.* as a single channel with name a.b.*.
channel_groups	String, Symbol, comma separated list	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 by specifying the channelGroups as a comma separated list.
uuids	String, Symbol, comma-separated list	Optional	Specifies up to 200 uuids on which to grant permissions. Either channels, channelGroups or uuids are required. 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.
auth_key	String, Symbol	Optional	Specifies 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.
read	Boolean	Optional	Read permissions.Default: true.
write	Boolean	Optional	Write permissions.Default: true.
manage	Boolean	Optional	Manage permissions.Default: true.
delete	Boolean	Optional	Delete permissions.Default: false.
get	Boolean	Optional	Get permissions.Default: false.
update	Boolean	Optional	Update permissions.Default: false.
join	Boolean	Optional	Join permissions.Default: false.
ttl	Integer	Optional	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.
http_sync	Boolean	Optional	Default false. Method will be executed asynchronously and will return future, to get it's value you can use value method. If set to true, method will return array of envelopes (even if there's only one envelope). For sync methods Envelope object will be returned.
callback	Lambda accepting one parameter	Optional	Callback that will be called for each envelope. For async methods future will be returned, to retrieve value Envelope object you have to call value method (thread will be locked until the value is returned).

Basic Usage

Grant PAM Permissions for channel and auth_key

pubnub.grant(channels: 'my_channel', ttl: 5, auth_key: 'my_rw_authkey') do |envelope|
    puts envelope
end

Response

#<Pubnub::Envelope:0x007fd384d2c288
    @result = {
        :code => 200,
        :data => {
            "level" => "user",
            "subscribe_key" => "sub-c-5f595120-6fe1-11e7-9980-0619f8945a4f",
            "ttl" => 1440,
            "channel" => "whatever",
            "auths" => {
                "someuser" => {
                    "r" => 1,
                    "w" => 1,
                    "m" => 1
                }
            }
        }
    },
    @status = {
        :code => 200
    }
>

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.

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):

   pubnub.grant(ttl: 60, write: false) do |envelope|
       puts envelope
   end
   

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

   pubnub.grant(channels: 'my_channel') do |envelope|
       puts envelope
   end
   

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

   pubnub.grant(channels: 'my_channel', ttl: 5, auth_key: 'my_ro_authkey', read:true, write: false) do |envelope|
       puts envelope
   end
   

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

   #<Pubnub::Envelope:0x007fd384d671a8
       @result = {
           :code => 200,
           :data => {
               "level" => "user",
               "subscribe_key" => "sub-c-5f595120-6fe1-11e7-9980-0619f8945a4f",
               "ttl" => 5,
               "channel" => "my_channel",
               "auths" => {
                   "my_ro_authkey" => {
                       "r" => 1,
                       "w" => 0,
                       "m" => 1
                   }
               }
           }
       },
       @status = {
           :code => 200
       }
   >
   

4. Allow access to a specific channel for Presence:

   pubnub.grant(presence: 'my_channel') do |envelope|
       puts envelope
   end
   

5. Allow access to all channel groups using wildcard:

   To perform a first level wildcard grant for channel groups you need to specify : (colon) as the parameter for channel_groups. This will ensure that users can read or manage all channel groups.

   pubnub.grant(channel_groups: ':') do |envelope|
       puts envelope
   end
   

6. Allow get and update access to a UUID only for clients with specific auth_keys with a 24 hr ttl

   pubnub.grant(uuids: 'my_uuid', ttl: 1440, auth_key: 'my_ro_authkey', get: true, update: true) do |envelope|
       puts envelope
   end
   

7. Grant to Multiple Channels

   pubnub.grant(channels: 'ch1,ch2,ch3,', ttl: 60, auth_key: 'my_auth_key', read: true) do |envelope|
       puts envelope
   end
   

8. 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.

   # Create PubNub client
   pubnub = Pubnub.new(
       publish_key: 'pub-c-',
       subscribe_key: 'sub-c-',
       secret_key: 'sec-c-'
   )
   
   # Additional optional parameters for grant, see: http://www.pubnub.com/docs/sdks/ruby/api-reference/access-manager#grant_arg_1
   
   pubnub.grant(http_sync: true)
   

9. Channel Level Grant

   # Create PubNub client
   pubnub = Pubnub.new(
       publish_key: 'pub-c-',
       subscribe_key: 'sub-c-',
       secret_key: 'sec-c-'
   )
   
   # Additional optional parameters for grant, see: http://www.pubnub.com/docs/sdks/ruby/api-reference/access-manager#grant_arg_1
   
   pubnub.grant(channels: 'open-channel', http_sync: true)
   

10. User Level Grant

    # Create PubNub client
    pubnub = Pubnub.new(
        publish_key: 'pub-c-',
        subscribe_key: 'sub-c-',
        secret_key: 'sec-c-'
    )
    
    # Additional optional parameters for grant, see: http://www.pubnub.com/docs/sdks/ruby/api-reference/access-manager#grant_arg_1
    
    pubnub.grant(channels: 'private-channel', auth_key: 'authorized-user', http_sync: true)