Access Manager v2 API for Kotlin SDK

Breaking changes in v9.0.0

PubNub Kotlin SDK version 9.0.0 unifies the codebases for Kotlin and Java SDKs, introduces a new way of instantiating the PubNub client, and changes asynchronous API callbacks and emitted status events. These changes can impact applications built with previous versions (< 9.0.0 ) of the Kotlin SDK.

For more details about what has changed, refer to Java/Kotlin SDK migration guide.

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.

Request execution

Most PubNub Kotlin SDK method invocations return an Endpoint object, which allows you to decide whether to perform the operation synchronously or asynchronously.

You must invoke the .sync() or .async() method on the Endpoint to execute the request, or the operation will not be performed.

val channel = pubnub.channel("channelName")

channel.publish("This SDK rules!").async { result ->
    result.onFailure { exception ->
        // Handle error
    }.onSuccess { value ->
        // Handle successful method result
    }
}

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 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.

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:

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.
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.
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 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 Kotlin SDK:

this.pubnub.grant(
    authKeys: List<String>,
    channels: List<String>,
    channelGroups: List<String>,
    write: Boolean,
    read: Boolean,
    manage: Boolean,
    delete: Boolean,
    ttl: Int
).async { result -> }

* required

Parameter	Description
`authKeys` Type: `List<String>` Default: n/a	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` Type: `List<String>` Default: n/a	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` Type: `List<String>` Default: n/a	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` Type: `Boolean` Default: `false`	Write permission
`read` Type: `Boolean` Default: `false`	Read permission
`manage` Type: `Boolean` Default: `false`	Manage permission
`delete` Type: `Boolean` Default: `false`	Delete permission
`ttl` Type: `Long` Default: `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.
`sync` Type: `PNAccessManagerGrantResult?` Default: n/a	Fires the request, locks the thread, and throws an exception if something goes wrong.
`async` Type: `{PNAccessManagerGrantResult?, PNStatus} ->` Default: n/a	Fires the request asynchronously and reports back with a callback.

Basic Usage

Grant Access Manager Permissions for channel and auth_key

pubnub.grant(
    channels = listOf("ch1", "ch2", "ch3"), //channels to allow grant on
    channelGroups = listOf("cg1", "cg2", "cg3"), // groups to allow grant on
    authKeys = listOf("key1", "key2", "key3"), // the keys we are provisioning
    write = true, // allow those keys to write (false by default)
    manage = true, // allow those keys to manage channel groups (false by default)
    read = true, // allow keys to read the subscribe feed (false by default)
    delete = true, // allow keys to delete messages (false by default)
    ttl = 12337 // how long those keys will remain valid (0 for eternity)
).async { result ->
    // result is a parsed and abstracted response from server
}

Returns

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

Method	Description
`level` Type: `String`	Permissions level, one of `subkey`, `subkey+auth`, `channel`, `channel-group`, `channel-group+auth` level.
`subscribeKey` Type: `String`	The `subscribeKey`.
`channels` Type: `Map<String, Map<String, PNAccessManagerKeyData>?>`	Access rights per channel. See PNAccessManagerKeyData for more details.
`channelGroups` Type: `Map<String, Map<String, PNAccessManagerKeyData>?>`	Access rights per channel group. See PNAccessManagerKeyData for more details.

PNAccessManagerKeyData

Method	Description
`readEnabled` Type: `Boolean`	Is `true` if read rights are granted
`writeEnabled` Type: `Boolean`	Is `true` if write rights are granted
`manageEnabled` Type: `Boolean`	Is `true` if manage rights are granted
`deleteEnabled` Type: `Boolean`	Is `true` if delete rights are granted

Size of revoke requests

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.

NTP configuration

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. Read the support article for more details.

Other Examples

pubnub.grant(
    channels = listOf("my_channel"),
    write = false,
    read = true,
    authKeys = listOf("my_ro_authkey"),
    ttl = 5
).async { result -> }

The above code returns the following response to the client:

if (!status.error) {
    result!!.ttl // 5
    result.level // user
} else {
    // handle error
    status.exception?.printStackTrace()
}

Allow access to a specific channel for Presence

pubnub.grant(
    channels = listOf("my_channel-pnpres"),
    write = true,
    read = true
).async { result -> }

Grant Access Manager Permissions for channel group

pubnub.grant(
    channelGroups = listOf("cg1", "cg2", "cg3"), // groups to allow grant on
    authKeys = listOf("key1", "key2", "key3"), // the keys we are provisioning
    write = true, // allow those keys to write (false by default)
    manage = true, // allow those keys to manage channel groups (false by default)
    read = true, // allow keys to read the subscribe feed (false by default)
    ttl = 12337 // how long those keys will remain valid (0 for eternity)
).async { result -> }

The above code returns the following response to the client:

if (!status.error) {
    result!!.ttl // 12337
    result.level // user
} else {
    // handle error
    status.exception?.printStackTrace()
}

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.

pubnub.grant(
    write = true,
    read = true
).async { result -> }

Channel Level Grant

pubnub.grant(
    channels = listOf("my_channel"),
    write = true,
    read = true
).async { result -> }

User Level Grant

pubnub.grant(
    channels = listOf("my_channel"),
    authKeys = listOf("my_authkey"),
    write = true,
    read = true,
    ttl = 5
).async { result -> }

Breaking changes in v9.0.0

Request execution

Grant​

Requires Access Manager add-on

Permissions​

Wildcard Permissions​

Wildcard revokes

Grant Levels​

Method(s)​

Basic Usage​

Grant Access Manager Permissions for channel and auth_key​

Returns​

PNAccessManagerKeyData​

Size of revoke requests

NTP configuration

Other Examples​

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

Allow access to a specific channel for Presence​

Grant Access Manager Permissions for channel group​

Application Level Grant​