The TLS Metadata Header plugin detects client certificates in requests, retrieves the TLS metadata, such as the URL encoded client certificate, and proxies this metadata via HTTP headers.
This is useful when an upstream service performs some validation for the proxied TLS client certificate.
The plugin itself does not perform any validation on the client certificate.
Used in conjunction with any plugin which requests a client certificate, such as the mTLS Authentication or TLS Handshake Modifier plugins.
Configuration Reference
This plugin is compatible with DB-less mode.
In DB-less mode, you configure Kong Gateway
declaratively.
Therefore, the Admin API is mostly read-only. The only tasks it can perform are all
related to handling the declarative config, including:
- Setting a target's health status in the load balancer
- Validating configurations against schemas
- Uploading the declarative configuration using the
/config
endpoint
Example plugin configuration
Enable on a service
Enable on a route
Enable globally
The following examples provide some typical configurations for enabling
the tls-metadata-headers
plugin on a
service.
Admin API
Kubernetes
Declarative (YAML)
Konnect Cloud
Kong Manager
Make the following request:
curl -X POST http://localhost:8001/services/SERVICE_NAME|SERVICE_ID/plugins \
--data "name=tls-metadata-headers" \
--data "config.inject_client_cert_details=true" \
--data "config.client_cert_header_name=X-Forwarded-Client-Cert"
Replace SERVICE_NAME|SERVICE_ID
with the id
or name
of the service that this plugin configuration will target.
First, create a KongPlugin
resource:
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
name: tls-metadata-headers-example
config:
inject_client_cert_details: true
client_cert_header_name: X-Forwarded-Client-Cert
plugin: tls-metadata-headers
Next, apply the KongPlugin resource to a
service by annotating the
service as follows:
apiVersion: v1
kind: Service
metadata:
name: SERVICE_NAME|SERVICE_ID
labels:
app: SERVICE_NAME|SERVICE_ID
annotations:
konghq.com/plugins: tls-metadata-headers-example
spec:
ports:
- port: 80
targetPort: 80
protocol: TCP
name: SERVICE_NAME|SERVICE_ID
selector:
app: SERVICE_NAME|SERVICE_ID
Replace SERVICE_NAME|SERVICE_ID
with the id
or name
of the service that this plugin configuration will target.
Note: The KongPlugin resource only needs to be defined once
and can be applied to any service, consumer, or route in the namespace. If you
want the plugin to be available cluster-wide, create the resource as a
KongClusterPlugin
instead of KongPlugin
.
Add this section to your declarative configuration file:
plugins:
- name: tls-metadata-headers
service: SERVICE_NAME|SERVICE_ID
config:
inject_client_cert_details: true
client_cert_header_name: X-Forwarded-Client-Cert
Replace SERVICE_NAME|SERVICE_ID
with the id
or name
of the service that this plugin configuration will target.
You can configure this plugin through the Konnect UI.
From the
Service Hub, select a service version, then set up the plugin:
- In the Plugins section, click Add Plugin.
- Find and select the TLS Metadata Headers plugin.
-
Configure the plugin’s parameters.
You can test out the plugin with the following sample configuration:
- Config.Inject Client Cert Details: select checkbox
- Config.Client Cert Header Name:
X-Forwarded-Client-Cert
- Click Create.
You can configure this plugin through the Kong Manager UI.
- In Kong Manager, select the workspace.
- From the Services section, click View for the
service row.
- From the plugin section, click Add Plugin.
- Find and select the TLS Metadata Headers plugin.
Note: If the plugin is greyed out, then it is not available
for your product tier. See Kong Gateway tiers.
- If the option is available, select Scoped.
- Add the service name and ID to the Service field if it
is not already pre-filled.
-
Configure the plugin’s parameters.
You can test out the plugin with the following sample configuration:
- Config.Inject Client Cert Details: select checkbox
- Config.Client Cert Header Name:
X-Forwarded-Client-Cert
- Click Create.
The following examples provide some typical configurations for enabling
the tls-metadata-headers
plugin on a
route.
Admin API
Kubernetes
Declarative (YAML)
Konnect Cloud
Kong Manager
Make the following request:
curl -X POST http://localhost:8001/routes/ROUTE_NAME|ROUTE_ID/plugins \
--data "name=tls-metadata-headers" \
--data "config.inject_client_cert_details=true" \
--data "config.client_cert_header_name=X-Forwarded-Client-Cert"
Replace ROUTE_NAME|ROUTE_ID
with the id
or name
of the route that this plugin configuration will target.
First, create a KongPlugin
resource:
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
name: tls-metadata-headers-example
config:
inject_client_cert_details: true
client_cert_header_name: X-Forwarded-Client-Cert
plugin: tls-metadata-headers
Then, apply it to an ingress (route or routes)
by annotating the ingress as follows:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: ROUTE_NAME|ROUTE_ID
annotations:
kubernetes.io/ingress.class: kong
konghq.com/plugins: tls-metadata-headers-example
spec:
rules:
- host: examplehostname.com
http:
paths:
- path: /bar
backend:
service:
name: echo
port:
number: 80
Replace ROUTE_NAME|ROUTE_ID
with the id
or name
of the route that this plugin configuration will target.
Note: The KongPlugin resource only needs to be defined once
and can be applied to any service, consumer, or route in the namespace. If you
want the plugin to be available cluster-wide, create the resource as a
KongClusterPlugin
instead of KongPlugin
.
Add this section to your declarative configuration file:
plugins:
- name: tls-metadata-headers
route: ROUTE_NAME
config:
inject_client_cert_details: true
client_cert_header_name: X-Forwarded-Client-Cert
Replace ROUTE_NAME|ROUTE_ID
with the id
or name
of the route that this plugin configuration
will target.
You can configure this plugin through the Konnect UI.
From the
Service Hub, select a service version, then set up the plugin:
- Select a route.
- In the Plugins section, click Add Plugin.
- Find and select the TLS Metadata Headers plugin.
-
Configure the plugin’s parameters.
You can test out the plugin with the following sample configuration:
- Config.Inject Client Cert Details: select checkbox
- Config.Client Cert Header Name:
X-Forwarded-Client-Cert
- Click Create.
You can configure this plugin through the Kong Manager UI.
- In Kong Manager, select the workspace.
- Open Routes from the menu, then click View for the
route row.
- From the plugin section, click Add Plugin.
- Find and select the TLS Metadata Headers plugin.
Note: If the plugin is greyed out, then it is not available
for your product tier. See Kong Gateway tiers.
- If the option is available, select Scoped.
- Add the route ID if it is not already prefilled.
-
Configure the plugin’s parameters.
You can test out the plugin with the following sample configuration:
- Config.Inject Client Cert Details: select checkbox
- Config.Client Cert Header Name:
X-Forwarded-Client-Cert
- Click Create.
A plugin which is not associated to any service, route, or consumer is
considered global, and will be run on every request. Read the
Plugin Reference and the Plugin Precedence
sections for more information.
The following examples provide some typical configurations for enabling
the tls-metadata-headers
plugin globally.
Admin API
Kubernetes
Declarative (YAML)
Kong Manager
Make the following request:
curl -X POST http://localhost:8001/plugins/ \
--data "name=tls-metadata-headers" \
--data "config.inject_client_cert_details=true" \
--data "config.client_cert_header_name=X-Forwarded-Client-Cert"
Create a KongClusterPlugin
resource and label it as global:
apiVersion: configuration.konghq.com/v1
kind: KongClusterPlugin
metadata:
name: <global-tls-metadata-headers>
annotations:
kubernetes.io/ingress.class: kong
labels:
global: \"true\"
config:
inject_client_cert_details: true
client_cert_header_name: X-Forwarded-Client-Cert
plugin: tls-metadata-headers
Add a plugins
entry in the declarative
configuration file:
plugins:
- name: tls-metadata-headers
config:
inject_client_cert_details: true
client_cert_header_name: X-Forwarded-Client-Cert
You can configure this plugin through the Kong Manager UI.
- In Kong Manager, select the workspace.
- Open Plugins from the menu, then click New Plugin.
- Find and select the TLS Metadata Headers plugin.
Note: If the plugin is greyed out, then it is not available
for your product tier. See Kong Gateway tiers.
- If the option is available, set the plugin scope to Global.
-
Configure the plugin’s parameters.
You can test out the plugin with the following sample configuration:
- Config.Inject Client Cert Details: select checkbox
- Config.Client Cert Header Name:
X-Forwarded-Client-Cert
- Click Create.
Parameters
Here's a list of all the parameters which can be used in this plugin's configuration:
Form Parameter |
Description |
name
required
Type: string |
The name of the plugin, in this case tls-metadata-headers . |
service.name or service.id
Type: string |
The name or ID of the service the plugin targets.
Set one of these parameters if adding the plugin to a service through the top-level /plugins endpoint.
Not required if using /services/SERVICE_NAME|SERVICE_ID/plugins . |
route.name or route.id
Type: string |
The name or ID of the route the plugin targets.
Set one of these parameters if adding the plugin to a route through the top-level /plugins endpoint.
Not required if using /routes/ROUTE_NAME|ROUTE_ID/plugins . |
enabled
Type: boolean
Default value: true |
Whether this plugin will be applied. |
config.inject_client_cert_details
required
Type: boolean
Default value: false
|
Enables TLS client certificate metadata values to be injected into HTTP headers.
|
config.client_cert_header_name
required
Type: string
Default value: X-Client-Cert
|
Define the HTTP header name used for the PEM format URL encoded client certificate.
|
config.client_serial_header_name
required
Type: string
Default value: X-Client-Cert-Serial
|
Define the HTTP header name used for the serial number of the client certificate.
|
config.client_cert_issuer_dn_header_name
required
Type: string
Default value: X-Client-Cert-Issuer-DN
|
Define the HTTP header name used for the issuer DN of the client certificate.
|
config.client_cert_subject_dn_header_name
required
Type: string
Default value: X-Client-Cert-Subject-DN
|
Define the HTTP header name used for the subject DN of the client certificate.
|
config.client_cert_fingerprint_header_name
required
Type: string
Default value: X-Client-Cert-Fingerprint
|
Define the HTTP header name used for the SHA1 fingerprint of the client certificate.
|
The plugin must be used in conjunction with any plugin which requests a client certificate, such as
the mTLS Authentication or TLS Handshake Modifier plugins.