PASETO (Platform-Agnostic Security Tokens) plugin for Kong

Paseto (Platform-Agnostic SEcurity TOkens) is a specification and reference implementation for secure stateless tokens.

"Paseto is everything you love about JOSE (JWT, JWE, JWS) without any of the many design deficits that plague the JOSE standards."

— paragonie/paseto

Plugin Description

Verify requests containing signed PASETOs (as specified in PASETO RFC). Each of your Consumers will have PASETO credentials (public and secret keys) which must be used to sign their PASETOs. A token can then be passed through:

• a query string parameter,
• a cookie,
• or the Authorization header.

The plugin will either proxy the request to your upstream services if the token's signature is verified, or discard the request if not. The plugin can also perform verifications on registered claims and custom claims.

Feature Support

• v2.public JSON payload PASETOs
• Registered claims validation
• Custom claims validation

Installation

Sodium Crypto Library

This plugin uses the PASETO for Lua library, which in turn depends on the Sodium crypto library (libsodium). The following is a convenient way to install libsodium via LuaRocks. Alternatively, see libsodium's documentation for full installation instructions.

luarocks install libsodium

Note: The Sodium Crypto Library must be installed on each node in your Kong cluster.

PASETO Kong Plugin

Install the plugin on each node in your Kong cluster via luarocks:

luarocks install kong-plugin-paseto

Add to the custom_plugins list in your Kong configuration (on each Kong node):

custom_plugins = paseto

Configuration

Enabling the plugin on a Service

Configure this plugin on a Service by making the following request:

$ curl -X POST http://kong:8001/services/{service}/plugins \
    --data "name=paseto"

service: the id or name of the Service that this plugin configuration will target.

Enabling the plugin on a Route

Configure this plugin on a Route with:

$ curl -X POST http://kong:8001/routes/{route_id}/plugins \
    --data "name=paseto"

route_id: the id of the Route that this plugin configuration will target.

Enabling the plugin on an API

If you are using an older version of Kong with the legacy API entity (deprecated since 0.13.0), you can configure this plugin on top of such an API by making the following request:

$ curl -X POST http://kong:8001/apis/{api}/plugins \
    --data "name=paseto"

api: either id or name of the API that this plugin configuration will target.

Global plugins

All plugins can be configured using the http://kong:8001/plugins/ endpoint. A plugin which is not associated to any Service, Route or Consumer (or API, if you are using an older version of Kong) is considered "global", and will be run on every request.

Parameters

Here's a list of all the parameters which can be used in this plugin's configuration:

Parameter		Default	Description
name			The name of the plugin to use, in this case paseto.
service_id			The id of the Service which this plugin will target.
route_id			The id of the Route which this plugin will target.
enabled		true	Whether this plugin will be applied.
api_id			The id of the API which this plugin will target. Note: The API Entity is deprecated since Kong 0.13.0.
config.uri_param_names	optional	paseto	A list of querystring parameters that the plugin will inspect to retrieve PASETOs.
config.cookie_names	optional		A list of cookie names that the plugin will inspect to retrieve PASETOs.
config.claims_to_verify.{claim_name}	optional		This is a list of custom objects that you can set, with arbitrary names set in the {claim_name} placeholder, like config.claims_to_verify.claim_1.claim=ForAudience if your object is called "claim_1".
config.claims_to_verify.{claim_name}.claim			The claim rule or name of your custom claim. See below for a description of the claim rules.
config.claims_to_verify.{claim_name}.value			The value to verify against.
config.kid_claim_name	optional	kid	The name of the claim in which the kid identifying the PASETO key pair must be passed. The plugin will attempt to read this claim from the PASETO footer.
config.anonymous	optional		An optional string (consumer uuid) value to use as an "anonymous" consumer if authentication fails. If empty (default), the request will fail with an authentication failure 4xx. Please note that this value must refer to the Consumer id attribute which is internal to Kong, and not its custom_id.
config.run_on_preflight	optional	true	A boolean value that indicates whether the plugin should run (and try to authenticate) on OPTIONS preflight requests, if set to false then OPTIONS requests will always be allowed.

Claim Rules

• ForAudience which compares the payload-provided aud claim with an expected value.
• IdentifiedBy which compares the payload-provided jti claim with an expected value.
• IssuedBy which compares the payload-provided iss claim with an expected value.
• NotExpired which verifies that the current time is less than or equal to the DateTime stored in the exp claim.
• Subject which compares the payload-provided sub claim with an expected value.
• ValidAt which verifies all of the following:
  • The current time is less than or equal to the DateTime stored in the exp claim.
  • The current time is greater than or equal to the DateTime stored in the iat claim.
  • The current time is greater than or equal to the DateTime stored in the nbf claim.
• ContainsClaim which verifies that the payload contains a claim with the specified name.
• {custom_claim} which verifies that the payload contains a claim with the name set in the {claim_name} placeholder and with an expected value.

Usage

In order to use the plugin, you first need to create a Consumer and associate one or more PASETO credentials (holding the public key used to verify the token) to it. The Consumer represents a developer using the final service.

Create a Consumer

You need to associate a credential to an existing Consumer object. To create a Consumer, you can execute the following request:

$ curl -X POST http://kong:8001/consumers \
    --data "username=<USERNAME>" \
    --data "custom_id=<CUSTOM_ID>"
HTTP/1.1 201 Created

Parameter		Default	Description
username	semi-optional		The username for this Consumer. Either this field or custom_id must be specified.
custom_id	semi-optional		A custom identifier used to map the Consumer to an external database. Either this field or username must be specified.

A Consumer can have many PASETO credentials.

Create a PASETO credential

You can provision a new PASETO credential by issuing the following HTTP request:

$ curl -X POST http://kong:8001/consumers/{consumer}/paseto -H "Content-Type: application/x-www-form-urlencoded"
HTTP/1.1 201 Created

{
   "consumer_id": "94c058d0-f5f1-4afc-ab18-eab487492a03",
   "created_at": 1530751342000,
   "id": "f99c0041-6271-43d3-bebd-32479c2746b6",
   "kid": "ikypl5x7QEKShEoEzFxfz5axONlgjdza",
   "public_key": "8SQDqtA5yx4atQEg0uH3Rit3nLq+EAQF4A1Zkvwh5TU=",
   "secret_key": "hbJbxFK3xFL1YlrcqodKqt0FvVyZjmPXQqOIexzxsVbxJAOq0DnLHhq1ASDS4fdGK3ecur4QBAXgDVmS/CHlNQ=="
}

• consumer: The id or username property of the Consumer entity to associate the credentials to.

Parameter		Default	Description
kid	optional		A unique string identifying the credential. If left out, it will be auto-generated.
secret_key	optional		The 64 byte secret key base64 encoded.
public_key	optional		The 32 byte public key base64 encoded. If left out and a secret_key is supplied, the public_key is assumed to be the last 32 bytes of the secret_key.

If neither secret_key or public_key are supplied the plugin will generate a new key pair.

Delete a PASETO credential

You can remove a Consumer's PASETO credential by issuing the following HTTP request:

$ curl -X DELETE http://kong:8001/consumers/{consumer}/paseto/{id}
HTTP/1.1 204 No Content

• consumer: The id or username property of the Consumer entity to associate the credentials to.
• id: The id of the PASETO credential.

List PASETO credentials

You can list a Consumer's PASETO credentials by issuing the following HTTP request:

$ curl -X GET http://kong:8001/consumers/{consumer}/paseto
HTTP/1.1 200 OK

• consumer: The id or username property of the Consumer entity to list credentials for.

{
    "data": [
        {
           "consumer_id": "94c058d0-f5f1-4afc-ab18-eab487492a03",
           "created_at": 1530751342000,
           "id": "f99c0041-6271-43d3-bebd-32479c2746b6",
           "kid": "ikypl5x7QEKShEoEzFxfz5axONlgjdza",
           "public_key": "8SQDqtA5yx4atQEg0uH3Rit3nLq+EAQF4A1Zkvwh5TU=",
           "secret_key": "hbJbxFK3xFL1YlrcqodKqt0FvVyZjmPXQqOIexzxsVbxJAOq0DnLHhq1ASDS4fdGK3ecur4QBAXgDVmS/CHlNQ=="
        }
    ],
    "total": 1
}

Send a request with a PASETO

PASETOs can now be included in a request to Kong by adding it to the Authorization header:

$ curl http://kong:8000/{route path} \
    -H 'Authorization: Bearer v2.public.eyJuYmYiOiIyMDE4LTAxLTAxVDAwOjAwOjAwKzAwOjAwIiwiaWF0IjoiMjAxOC0wMS0wMVQwMDowMDowMCswMDowMCIsImlzcyI6InBhcmFnb25pZS5jb20iLCJhdWQiOiJzb21lLWF1ZGllbmNlLmNvbSIsImRhdGEiOiJ0aGlzIGlzIGEgc2lnbmVkIG1lc3NhZ2UiLCJleHAiOiIyMDk5LTAxLTAxVDAwOjAwOjAwKzAwOjAwIiwianRpIjoiODdJRlNHRmdQTnRRTk51dzBBdHVMdHRQIiwic3ViIjoidGVzdCIsIm15Y2xhaW0iOiJyZXF1aXJlZCB2YWx1ZSJ9-8bFBx9Z5665JK3Rfwl3v2rx-etZ0H-EAkmbOdt1VI4h3gDzMsqUR2pRRdBvzPiv5cPDQqmaJ1gcqnXR3P0BDQ.eyJraWQiOiJzaWduYXR1cmVfdmVyaWZpY2F0aW9uX3N1Y2Nlc3MifQ'

as a querystring parameter, if configured in config.uri_param_names (which contains paseto by default):

$ curl http://kong:8000/{route path}?paseto=v2.public.eyJuYmYiOiIyMDE4LTAxLTAxVDAwOjAwOjAwKzAwOjAwIiwiaWF0IjoiMjAxOC0wMS0wMVQwMDowMDowMCswMDowMCIsImlzcyI6InBhcmFnb25pZS5jb20iLCJhdWQiOiJzb21lLWF1ZGllbmNlLmNvbSIsImRhdGEiOiJ0aGlzIGlzIGEgc2lnbmVkIG1lc3NhZ2UiLCJleHAiOiIyMDk5LTAxLTAxVDAwOjAwOjAwKzAwOjAwIiwianRpIjoiODdJRlNHRmdQTnRRTk51dzBBdHVMdHRQIiwic3ViIjoidGVzdCIsIm15Y2xhaW0iOiJyZXF1aXJlZCB2YWx1ZSJ9-8bFBx9Z5665JK3Rfwl3v2rx-etZ0H-EAkmbOdt1VI4h3gDzMsqUR2pRRdBvzPiv5cPDQqmaJ1gcqnXR3P0BDQ.eyJraWQiOiJzaWduYXR1cmVfdmVyaWZpY2F0aW9uX3N1Y2Nlc3MifQ

or as cookie, if the name is configured in config.cookie_names (which is not enabled by default):

curl --cookie paseto=v2.public.eyJuYmYiOiIyMDE4LTAxLTAxVDAwOjAwOjAwKzAwOjAwIiwiaWF0IjoiMjAxOC0wMS0wMVQwMDowMDowMCswMDowMCIsImlzcyI6InBhcmFnb25pZS5jb20iLCJhdWQiOiJzb21lLWF1ZGllbmNlLmNvbSIsImRhdGEiOiJ0aGlzIGlzIGEgc2lnbmVkIG1lc3NhZ2UiLCJleHAiOiIyMDk5LTAxLTAxVDAwOjAwOjAwKzAwOjAwIiwianRpIjoiODdJRlNHRmdQTnRRTk51dzBBdHVMdHRQIiwic3ViIjoidGVzdCIsIm15Y2xhaW0iOiJyZXF1aXJlZCB2YWx1ZSJ9-8bFBx9Z5665JK3Rfwl3v2rx-etZ0H-EAkmbOdt1VI4h3gDzMsqUR2pRRdBvzPiv5cPDQqmaJ1gcqnXR3P0BDQ.eyJraWQiOiJzaWduYXR1cmVfdmVyaWZpY2F0aW9uX3N1Y2Nlc3MifQ http://kong:8000/{route path}

Note: When the PASETO is valid and proxied to the upstream service, Kong makes no modification to the request other than adding headers identifying the Consumer. The PASETO will be forwarded to your upstream service, which can assume its validity. It is now the role of your service to base64 decode the PASETO claims and make use of them.

License

MIT License - see the LICENSE file for details