JWT Validation

Overview

The JWT Validation Traffic Policy action enables you to validate JSON Web Tokens (JWT) on your endpoints before routing traffic to your upstream service.

A useful tool for working with JWTs is provided at jwt.io.

Guides

We have created guides for configuring this action with the following providers:

• Auth0

Configuration Reference

This is the Traffic Policy configuration reference for this action.

Action Type

jwt-validation

Configuration Fields

Parameter	Type	Description
issuer	JWTIssuerConfig	Required. Configuration object for the Issuer(s) of the JWTs.
audience	JWTAudienceConfig	Required. Configuration object for the Audience(s) of the JWTs.
http	JWTHTTPConfig	Required. Configuration object for the HTTP requests containing JWTs.
jws	JWTSigningConfig	Required. Configuration object for signed JWTs (JWS).

JWTIssuerConfig Parameters

Parameter	Type	Description
allow_list	[]JWTIssuer	Required. List of allowed issuers. Minimum 1.

JWTIssuer Parameters

Parameter	Type	Description
value	string	Required. Issuer URL. This can be found in the iss claim after decoding the JWT or from the /.well-known/openid-configuration endpoint in your Identity Provider.

JWTAudienceConfig Parameters

Parameter	Type	Description
allow_list	[]JWTAudience	Required. List of allowed audiences. Minimum 1.

JWTAudience Parameters

Parameter	Type	Description
value	string	Required. Audience claim value. This can be found in the aud claim after decoding the JWT or from the request used to create the token in the first place.

JWTHTTPConfig Parameters

Parameter	Type	Description
tokens	[]JWTHTTPToken	Required. List of tokens to validate. Minimum 1.

JWTHTTPToken Parameters

Parameter	Type	Description
type	string	Required. Type of the JWT, which acts as a hint about how ngrok should parse the token. Must be one of "access_token", "at+jwt", "id_token", "it+jwt", "plain", or "jwt".
method	string	Required. Location in the request to expect the JWT. Must be one of "header" or "body". We do not support including a token as a URL query parameter. When choosing body, the method must be POST, PUT, or PATCH and the content-type header must be set to either application/json or application/x-www-form-urlencoded.
name	string	Required. Name of the header or body field where the JWT is expected (Example: "Authorization"). This is not case sensitive.
prefix	string	Any prefix to strip from the header or body field before parsing the JWT (Example: "Bearer ").

JWTSigningConfig Parameters

Parameter	Type	Description
allowed_algorithms	[]string	Required. List of allowed signing algorithms. We do not support none as a value here because it is insecure. Minimum 1.
keys	[]JWTSigningKeys	Required. Configuration for the JWT signing keys.

JWTSigningKeys Parameters

Parameter	Type	Description
sources	[]JWTSigningKeySources	Required. Configuration for the key material used to verify the signed JWTs.

JWTSigningKeySources Parameters

Parameter	Type	Description
additional_jkus	[]string	Required. List of URLs which serve the possible signing keys in JWKS format. These urls are cached and refreshed roughly every 15 minutes.

Supported Directions

• inbound

Supported Schemes

• https
• http

Behavior

Request Validation

The request is allowed only if it has been correctly signed by the issuer and the defined claims match.

Multiple Issuers

You can specify multiple issuers for JWT validation. A request is considered validated if it presents a JWT signed by any of the specified issuers.

The issuer must exactly match the one provided in the JWT, including any trailing slashes (/) present in the iss claim.

Multiple Audience Claims

You can specify multiple audience claims for JWT validation.

The JWT must contain at least one of the specified audience claims and exactly match for validation to succeed.

Multiple Signing Keys

You can provide multiple JSON Web Key Set (JWKS) URLs and signing algorithms.

During JWT validation the list of JWKS and algorithms provided will be used in an attempt to validate the JWT. The list will be tried in order and is cached for performance. The cache is refreshed roughly every 15 minutes.

Multiple Tokens

If multiple tokens are defined within the HTTP configuration parameter, all tokens must be present in the request. If all tokens are not present, a 401 Unauthorized status code will be returned.

Examples

Basic Example

The following Traffic Policy configuration is an example configuration of the jwt-validation action for a more real world example check out our Auth0 guide.

Example Traffic Policy Document

YAML

---
inbound:
  - actions:
      - type: "jwt-validation"
        config:
          issuer:
            allow_list:
              - value: "https://example.com/issuer"
          audience:
            allow_list:
              - value: "urn:example:api"
          http:
            tokens:
              - type: "access_token"
                method: "header"
                name: "Authorization"
                prefix: "Bearer "
              - type: "it+jwt"
                method: "body"
                name: "_id_token"
          jws:
            allowed_algorithms:
              - "RS256"
              - "ES256"
            keys:
              sources:
                additional_jkus:
                  - "https://example.com/issuer/jku"

JSON

{
  "inbound": [
    {
      "actions": [
        {
          "type": "jwt-validation",
          "config": {
            "issuer": {
              "allow_list": [
                {
                  "value": "https://example.com/issuer"
                }
              ]
            },
            "audience": {
              "allow_list": [
                {
                  "value": "urn:example:api"
                }
              ]
            },
            "http": {
              "tokens": [
                {
                  "type": "access_token",
                  "method": "header",
                  "name": "Authorization",
                  "prefix": "Bearer "
                },
                {
                  "type": "it+jwt",
                  "method": "body",
                  "name": "_id_token"
                }
              ]
            },
            "jws": {
              "allowed_algorithms": [
                "RS256",
                "ES256"
              ],
              "keys": {
                "sources": {
                  "additional_jkus": [
                    "https://example.com/issuer/jku"
                  ]
                }
              }
            }
          }
        }
      ]
    }
  ]
}

Example Request

$ curl --request GET \
  --url http://example-api.ngrok.app/ \
  --header 'authorization: Bearer <VALID-JWT>'

HTTP/2 200 OK
content-type: text/html

...

In this example, we are sending a request to our API with a valid JWT token in the Authorization header with the Bearer prefix and getting back a 200 OK response.

Action Result Variables

The following variables are made available for use in subsequent expressions and CEL interpolations after the action has run. Variable values will only apply to the last action execution, results are not concatenated.

Name	Type	Description
actions.ngrok.jwt_validation.tokens	[]JWT	The JWTs processed by the action.
actions.ngrok.jwt_validation.tokens[i].header	map[string]string	The header portion of the JWT, parsed into a key value map.
actions.ngrok.jwt_validation.tokens[i].location	string	The location in the request where the JWT was included.
actions.ngrok.jwt_validation.tokens[i].location_property	string	The name of the header or body field where the JWT was included.
actions.ngrok.jwt_validation.tokens[i].payload	map[string]string	The payload portion of the JWT, parsed into a key value map.
actions.ngrok.jwt_validation.tokens[i].signature	string	The signature portion of the JWT, in base64 encoded format.
actions.ngrok.jwt_validation.tokens[i].verified	boolean	Set to true if token was verified.
actions.ngrok.jwt_validation.error.code	string	Code for an error that occurred during the invocation of an action.
actions.ngrok.jwt_validation.error.message	string	Message for an error that occurred during the invocation of an action.