certificates

unable to verify the first certificate – KONG

techhadoop , , , ,

unable to verify the first certificate

The error “unable to verify the first certificate” typically indicates that the client (or server) cannot verify the certificate because it does not have the correct root certificate, intermediate certificate, or the certificate chain is incomplete. Here’s how you can troubleshoot and resolve this issue:

Common Causes of the Error:

  1. Missing Root or Intermediate Certificates
    • The server or client lacks the necessary CA certificates to complete the chain of trust.
  2. Self-Signed Certificate
    • If the certificate is self-signed, the server or client must explicitly trust the certificate.
  3. Incomplete Certificate Chain
    • The server might not be sending the entire certificate chain (intermediate certificates) along with the server certificate.
  4. Incorrect Client/Server Configuration
    • The client or server may not be configured to trust the CA that issued the certificate.

Steps to Fix the Issue:

1. Verify the Certificate Chain

Check whether the certificate chain is complete. You can use openssl to check the chain from the client side:

openssl s_client -connect your-kong-api:443 -showcerts

This will show the certificates presented by the server. Verify if the server provides the full chain, including the intermediate certificates.

2. Install Missing CA Certificates on the Client

If the client does not trust the CA that issued the server certificate, you need to install the root CA certificate on the client. For example, on most systems, you can install the CA certificates by adding them to the trusted certificate store.

  • Linux (e.g., Ubuntu/Debian): Copy the CA certificate (e.g., ca.crt) to the /usr/local/share/ca-certificates/ directory and then update the certificate store:

sudo cp ca.crt /usr/local/share/ca-certificates/

sudo update-ca-certificates

  • Windows: Import the root certificate into the Trusted Root Certification Authorities store via the Certificate Manager.
  • macOS: You can import the CA certificate into Keychain Access and mark it as trusted.

3. Verify the Server-Side Configuration

If you’re managing the server (e.g., Kong API Gateway), ensure that the server is sending the complete certificate chain. You can provide both the server certificate and any intermediate certificates in the configuration.

For example, in Kong, you can configure SSL certificates like this:

curl -i -X POST http://localhost:8001/certificates \

–form “cert=@/path/to/server.crt” \

–form “key=@/path/to/server.key” \

–form “cert_alt=@/path/to/intermediate.crt”

Ensure that the server certificate and intermediate certificates are included in the cert field.

4. Test the Connection with the Correct CA

When testing using curl, ensure you include the correct root CA or intermediate CA:

curl -v –cacert /path/to/ca.crt https://your-kong-api/your-route

This will make curl use the specified CA certificate for validation.

5. Check for Self-Signed Certificates

If you’re using self-signed certificates, you’ll need to make sure that both the client and server are explicitly configured to trust the self-signed certificate.

For example, when using curl:

curl -v –key client.key –cert client.crt –cacert ca.crt https://your-kong-api/

If the certificate is self-signed and you want to bypass certificate verification (not recommended in production), you can use:

curl -v –insecure https://your-kong-api/

6. Include the Correct Intermediate Certificates

If the server is not sending the intermediate certificate (or you forgot to add it), make sure that the intermediate certificate is included in the chain. You can concatenate the server certificate and intermediate certificate into one file:

cat server.crt intermediate.crt > full_chain.crt

Then, use the full chain certificate for your server configuration.

Summary of Steps:

  1. Check the certificate chain using openssl s_client to see if all necessary certificates are presented.
  2. Ensure the client trusts the root CA by installing the root or intermediate CA on the client.
  3. Ensure the server presents the full certificate chain (server certificate + intermediate certificates).
  4. Test the connection using the correct CA with curl or another tool.
  5. Handle self-signed certificates by explicitly trusting them or bypassing verification in non-production environments.

By following these steps, you should be able to resolve the “unable to verify the first certificate” issue.

com.pingidentity.pf.datastore an error occured while testing the connection Error PKIX path building failed

techhadoop , , , ,

The error you’re encountering, PKIX path building failed, is related to SSL certificate validation in PingIdentity while attempting to establish a connection. Specifically, it indicates that the system could not verify the certificate path back to a trusted root certificate authority (CA). This is a common issue when a server certificate is either self-signed or not recognized by the trust store.

Here’s a breakdown of the error:

  1. PKIX path building failed: This means that Java’s SSL/TLS system could not build a valid certificate chain back to a trusted root certificate authority.
  2. SunCertPathBuilderException: unable to find valid certification path to requested target: This suggests that the certificate presented by the remote system is not trusted by the client making the request. The client’s trust store (Java keystore) does not have the necessary CA certificates to validate the server certificate.

Causes:

  • Self-signed certificate: If the server you’re trying to connect to uses a self-signed certificate, it won’t be trusted automatically.
  • Untrusted CA: The certificate is signed by a CA that’s not included in the default trust store of the Java Virtual Machine (JVM).
  • Missing intermediate certificates: The certificate chain might be incomplete, missing intermediate certificates between the server’s certificate and the trusted root.
  • Expired or revoked certificates: The server certificate could be expired or revoked, leading to validation failure.

Solutions:

1. Import the Server’s Certificate to the Java Truststore

You need to import the server’s certificate (or the intermediate CA certificates) into the Java trust store to ensure it’s recognized as a trusted certificate.

Steps:

  • Obtain the server certificate:

openssl s_client -connect <server-host>:<port> -showcerts

This will return the server’s SSL certificate chain. Copy the relevant certificate (in PEM format).

  • Save the certificate as server.crt.
  • Import the certificate into the Java trust store:

keytool -import -alias <alias_name> -keystore <path_to_java_home>/lib/security/cacerts -file server.crt

The default password for the trust store is usually changeit, but this can vary.

  • Restart your PingFederate server or application to ensure the new trust store is loaded.

2. Use a Valid SSL Certificate

  • If the server is using a self-signed certificate, consider replacing it with one signed by a trusted public CA (e.g., Let’s Encrypt, GlobalSign, etc.).
  • Ensure the entire certificate chain, including intermediate certificates, is properly configured on the server.

3. Disable SSL Validation (Not Recommended in Production)

You can temporarily disable SSL validation to allow connections without certificate verification. This is usually done in testing environments or when working with self-signed certificates.

Example: In Java, you can disable SSL certificate validation by setting a custom trust manager, but this approach is not secure and should be avoided in production:

import javax.net.ssl.*;

import java.security.SecureRandom;

import java.security.cert.X509Certificate;

TrustManager[] trustAllCerts = new TrustManager[]{

    new X509TrustManager() {

        public X509Certificate[] getAcceptedIssuers() {

            return null;

        }

        public void checkClientTrusted(X509Certificate[] certs, String authType) {}

        public void checkServerTrusted(X509Certificate[] certs, String authType) {}

    }

};

SSLContext sc = SSLContext.getInstance(“SSL”);

sc.init(null, trustAllCerts, new SecureRandom());

HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());

This solution is not recommended for production environments.

4. Verify the Server Certificate

Ensure that the certificate on the server is not expired, properly configured, and includes all intermediate certificates. You can use tools like:

openssl s_client -connect <server-host>:<port> -showcerts

5. Update the JVM Truststore (if outdated)

If you are using an old version of Java, the default trust store may not include modern root CAs. You can update your JVM or manually update the CA certificates:

  • Download a fresh version of the cacerts file from the latest JVM or a trusted source.
  • Replace your current cacerts file (located in JAVA_HOME/lib/security) with the new one.

6. Proxy Configuration

If you’re using a proxy, make sure the proxy server has the necessary CA certificates and that PingFederate is properly configured to connect through the proxy.

Conclusion

To resolve the PKIX path building failed error, you will likely need to add the server certificate (or its CA) to your Java trust store. Ensure the server’s certificate chain is correctly configured and, if using self-signed certificates, import them into the trust store. Avoid disabling SSL validation in production environments due to security risks.

PING Identity

techhadoop , , , ,

The error you’re encountering is related to certificate validation and occurs when the system is unable to establish a valid certificate chain to the requested target (usually an external service or API). Specifically, the error message:

SunCertPathBuilderException: unable to find valid certification path to requested target

indicates that the Java application (in this case, Ping Identity) is trying to connect to an HTTPS service, but the service’s SSL/TLS certificate is either:

  • Self-signed, or
  • Issued by a Certificate Authority (CA) that is not trusted by the Java trust store.

Here’s how you can troubleshoot and resolve this issue:

Step 1: Verify the SSL/TLS Certificate

  1. Check the service’s certificate: Use a browser or a tool like openssl to verify the service’s certificate chain:

openssl s_client -connect <hostname>:<port> -showcerts

This will display the certificate chain used by the server. Ensure that the server certificate is valid and that intermediate and root certificates are also included.

  1. Check if the certificate is self-signed: If the service is using a self-signed certificate or a certificate from a CA not included in the default Java trust store, you’ll need to manually trust it.

Step 2: Add the Certificate to the Java Trust Store

You’ll need to import the certificate into the Java trust store so that Java can trust it.

  1. Export the server certificate:
    • Save the certificate to a file using your browser or the openssl command.

For example:

echo | openssl s_client -connect <hostname>:<port> | sed -ne ‘/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p’ > server-cert.pem

  1. Import the certificate into Java’s trust store: Use the keytool command to import the certificate:

sudo keytool -import -alias <alias-name> -file <path-to-cert> -keystore $JAVA_HOME/lib/security/cacerts

Replace:

  1. <alias-name>: A unique alias for the certificate.
  2. <path-to-cert>: The path to the certificate file you saved.

The default password for the Java trust store is usually changeit.

  1. Verify the certificate import: You can verify if the certificate has been successfully imported by listing the contents of the trust store:

sudo keytool -list -keystore $JAVA_HOME/lib/security/cacerts

Step 3: Test the Connection Again

After importing the certificate, restart your application and test the connection again to ensure the error is resolved.

Additional Considerations:

  • Custom Trust Store: If your application is using a custom trust store (not the default Java trust store), ensure that the certificate is added to that trust store instead.
  • CA Certificates: If the certificate is from a trusted CA, ensure that your system has the correct root CA certificates in its trust store.

By importing the certificate into the Java trust store, you should be able to resolve the PKIX path building failed error and establish a successful connection.

How to verify mtls client cert via curl in Kong API gateway

techhadoop , , , ,

To verify mTLS (Mutual TLS) client certificates in Kong API Gateway using curl, you will need to have:

  1. A valid client certificate and key that the server can verify.
  2. The server’s CA certificate to trust the server’s certificate.

Here’s a step-by-step guide to verify the mTLS setup using curl:

1. Ensure mTLS is enabled in Kong

Make sure that the mTLS authentication plugin is enabled on the route, service, or globally in your Kong instance. For example, you can check if the mtls-auth plugin is applied:

curl http://localhost:8001/plugins

If it’s not enabled, you can add the mTLS plugin to a specific route or service:

curl -i -X POST http://localhost:8001/services/{service-id}/plugins \

    –data “name=mtls-auth”

2. Ensure the Client Certificate is Associated with a Consumer

To match the client certificate with a consumer in Kong, you need to associate the Common Name (CN) or Subject Alternative Name (SAN) in the certificate with a consumer.

curl -i -X POST http://localhost:8001/consumers/{consumer-id}/mtls_auth \

    –data “subject_name=client.example.com”

This ensures that when the client presents the certificate, Kong will map the request to the correct consumer based on the CN.

3. Verify mTLS using curl

To perform mTLS using curl, you will need:

  • The client certificate and client key.
  • The CA certificate that Kong uses to verify the client certificate.

Use the following curl command to verify mTLS:

bash

Copy code

curl -v https://{KONG_HOST}:{KONG_PORT}/{route-path} \

    –cert /path/to/client-cert.pem \

    –key /path/to/client-key.pem \

    –cacert /path/to/ca-cert.pem

  • –cert /path/to/client-cert.pem: Path to the client certificate file.
  • –key /path/to/client-key.pem: Path to the client private key file.
  • –cacert /path/to/ca-cert.pem: Path to the CA certificate that Kong uses to verify the client certificate.
  • -v: Verbose output to see the handshake details.

4. Example Command

For example, if Kong is running on localhost, the route is /secure-service, and you have the client certificate and key:

curl -v https://localhost:8443/secure-service \

    –cert /etc/ssl/client-cert.pem \

    –key /etc/ssl/client-key.pem \

    –cacert /etc/ssl/ca-cert.pem

5. Check the Response

  • If the client certificate is valid and trusted, Kong will allow the request, and you will see a 200 OK response (or the relevant service response).
  • If the certificate validation fails, you may see errors like:
    • 400 Bad Request: Indicates issues with the certificate verification.
    • 403 Forbidden: Indicates the certificate was valid but the client was not authorized for the route.

6. Common Errors and Troubleshooting

  • 400 Bad Request: SSL certificate validation failed: This usually happens when the client certificate is not signed by the trusted CA or doesn’t match the subject name expected by Kong.
  • 403 Forbidden: mTLS authentication failed: This happens if the certificate’s CN or SAN does not match any configured consumers in Kong.

Conclusion

Verifying mTLS in Kong API Gateway via curl involves ensuring that the client certificate and key are properly configured and Kong is set up to validate them. If configured correctly, Kong will authenticate the client using the certificate, and the request will proceed.

How to integrate mTLS Kong certificate with secrets management infrastructure

techhadoop , , , ,

To integrate mTLS (Mutual TLS) certificates used in Kong API Gateway with a secrets management infrastructure (such as HashiCorp Vault, AWS Secrets Manager, or other secret management tools), you can follow a systematic approach to store, retrieve, and rotate the certificates securely.

Key Steps:

  1. Generate mTLS certificates.
  2. Store certificates securely in the secrets management infrastructure.
  3. Configure Kong to retrieve and use certificates for mTLS.
  4. Automate certificate rotation for secure management.

Step 1: Generate mTLS Certificates

You need to generate the client and server certificates that Kong will use for mTLS.

  1. Generate a Certificate Authority (CA): First, generate a CA to sign the certificates.

openssl genrsa -out ca.key 2048

openssl req -x509 -new -nodes -key ca.key -sha256 -days 365 -out ca.crt \

-subj “/CN=Kong-CA”

  1. Generate the Server Certificate: Generate a private key and a certificate signing request (CSR) for Kong, and sign it with your CA.

openssl genrsa -out kong-server.key 2048

openssl req -new -key kong-server.key -out kong-server.csr -subj “/CN=kong-server”

openssl x509 -req -in kong-server.csr -CA ca.crt -CAkey ca.key -CAcreateserial \

-out kong-server.crt -days 365 -sha256

  1. Generate the Client Certificate: You also need a client certificate to authenticate incoming requests.

openssl genrsa -out kong-client.key 2048

openssl req -new -key kong-client.key -out kong-client.csr -subj “/CN=kong-client”

openssl x509 -req -in kong-client.csr -CA ca.crt -CAkey ca.key -CAcreateserial \

-out kong-client.crt -days 365 -sha256

Step 2: Store Certificates Securely in a Secrets Management Infrastructure

Use a secrets management service like HashiCorp Vault, AWS Secrets Manager, or another system to store the mTLS certificates securely.

Example: Store Certificates in HashiCorp Vault

  1. Start by enabling the secrets engine in Vault:

vault secrets enable -path=pki pki

vault secrets tune -max-lease-ttl=87600h pki

  1. Store the CA certificate in Vault:

vault write pki/config/ca pem_bundle=@ca.crt

  1. Store the server certificate and key in Vault:

vault kv put secret/kong/server cert=@kong-server.crt key=@kong-server.key

  1. Store the client certificate and key:

vault kv put secret/kong/client cert=@kong-client.crt key=@kong-client.key

Example: Store Certificates in AWS Secrets Manager

  1. Use AWS CLI to store the server certificate:

aws secretsmanager create-secret –name kong/server \

–secret-string file://kong-server.json

The kong-server.json file contains:

{

  “certificate”: “—–BEGIN CERTIFICATE—– …”,

  “private_key”: “—–BEGIN PRIVATE KEY—– …”

}

  1. Store the client certificate similarly in AWS Secrets Manager:

aws secretsmanager create-secret –name kong/client \

–secret-string file://kong-client.json

Step 3: Configure Kong to Retrieve and Use Certificates for mTLS

Once the certificates are securely stored, you need to configure Kong to retrieve and use these certificates from your secrets management infrastructure.

Option 1: Use HashiCorp Vault with Kong

  1. Install the Vault Plugin for Kong (or use an external script to retrieve certificates from Vault).
  2. Write a Lua script or custom plugin to dynamically retrieve the certificates from Vault.
    • Use the vault kv get API to retrieve certificates from Vault.
    • Load the certificates into Kong’s SSL configuration dynamically.
  3. Configure Kong to use the certificates:
    • Add the mTLS plugin to your service or route to enable mutual authentication using the retrieved certificates.

Example to configure the mTLS plugin:

curl -i -X POST http://localhost:8001/services/my-service/plugins \

–data “name=mtls-auth” \

–data “config.trusted_ca_ids=ca_id” \

–data “config.client_verify=true”

Option 2: Use AWS Secrets Manager with Kong

  1. Install the AWS SDK (or a script) on your Kong instances to fetch the certificates from Secrets Manager.
  2. Create a script or custom plugin to:
    • Retrieve the server and client certificates from AWS Secrets Manager using the AWS CLI or SDK:

aws secretsmanager get-secret-value –secret-id kong/server

aws secretsmanager get-secret-value –secret-id kong/client

  1. Dynamically load the certificates into Kong’s SSL configuration using Lua or custom logic.
  2. Configure mTLS in Kong:
    • Set up the mTLS plugin in Kong to verify client certificates:

curl -i -X POST http://localhost:8001/services/my-service/plugins \

–data “name=mtls-auth” \

–data “config.trusted_ca_ids=<ca-id>”

Step 4: Automate Certificate Rotation

To ensure secure and automated certificate management, integrate certificate rotation.

  1. Automated Certificate Renewal in Vault:
    • Configure Vault’s PKI secrets engine to automate certificate issuance and rotation.

Example:

vault write pki/roles/kong \

allowed_domains=example.com \

allow_subdomains=true \

max_ttl=72h

Use Vault’s pki/issue endpoint to automatically rotate certificates and replace them in Kong.

  1. Automate AWS Secrets Manager Rotation:
    • Set up AWS Secrets Manager’s built-in rotation feature for SSL certificates.
  2. Trigger Updates in Kong:
    • Use a periodic task (e.g., a cron job or Ansible playbook) to update the certificates in Kong without restarting the gateway:

kong reload

This ensures Kong always uses the latest mTLS certificates from the secrets manager.

Conclusion

To integrate Kong API Gateway’s mTLS certificates with a secrets management infrastructure, follow these steps:

  1. Generate the mTLS certificates and store them securely in a secrets management tool (e.g., HashiCorp Vault, AWS Secrets Manager).
  2. Configure Kong to retrieve the certificates dynamically from the secret manager.
  3. Implement automation for certificate renewal and rotation to ensure that Kong always uses up-to-date certificates without manual intervention.

This approach enhances security by managing sensitive SSL certificates in a centralized and automated manner.

generate CA certificate for Kong API gateway and configure with mTLS

techhadoop , , , ,

To generate a Certificate Authority (CA) certificate for Kong Gateway and configure it for mTLS (Mutual TLS), follow these steps. This process involves creating a root CA, generating client certificates, and setting up Kong to use them for mTLS authentication.

Steps Overview:

  1. Generate your own Certificate Authority (CA).
  2. Use the CA to sign client certificates.
  3. Upload the CA certificate to Kong.
  4. Configure Kong to enforce mTLS using the CA.
  5. Test the mTLS setup.

1. Generate a Certificate Authority (CA)

1.1. Generate the CA’s Private Key

openssl genrsa -out ca.key 2048

This command generates a 2048-bit RSA private key for your CA.

1.2. Create a Self-Signed Certificate for the CA

openssl req -x509 -new -nodes -key ca.key -sha256 -days 3650 -out ca.crt \

-subj “/C=US/ST=State/L=City/O=Organization/OU=OrgUnit/CN=Your-CA-Name”

  • This command creates a self-signed certificate valid for 10 years (3650 days).
  • Customize the -subj fields with your information.

You now have two files:

  • ca.key: The CA’s private key (keep this secure).
  • ca.crt: The CA’s self-signed certificate, which you will use to sign client certificates.

2. Generate and Sign Client Certificates

2.1. Generate the Client’s Private Key

openssl genrsa -out client.key 2048

2.2. Create a Certificate Signing Request (CSR) for the Client

openssl req -new -key client.key -out client.csr -subj “/C=US/ST=State/L=City/O=Organization/OU=OrgUnit/CN=Client-Name”

2.3. Sign the Client’s Certificate with the CA

openssl x509 -req -in client.csr -CA ca.crt -CAkey ca.key -CAcreateserial -out client.crt -days 365 -sha256

This command signs the client certificate (client.crt) with your CA. The client.crt is valid for 1 year (365 days).

You now have:

  • client.key: The client’s private key.
  • client.crt: The client’s signed certificate.

3. Upload the CA Certificate to Kong

Kong needs the CA certificate to validate the client certificates during mTLS authentication. You can upload the CA certificate to Kong as follows:

curl -i -X POST http://localhost:8001/ca_certificates \

  –data “cert=@/path/to/ca.crt”

This will make Kong aware of the trusted CA certificate, enabling it to validate client certificates that are signed by this CA.

4. Enable the mTLS Plugin in Kong

Now, configure Kong to enforce mTLS for a service or route using the mTLS Authentication plugin. This plugin requires clients to present a certificate signed by the CA.

4.1. Enable mTLS for a Service

To enable mTLS authentication on a specific service:

curl -i -X POST http://localhost:8001/services/<service_id>/plugins \

  –data “name=mtls-auth”

Replace <service_id> with the actual service ID.

4.2. Enable mTLS for a Route

Alternatively, you can enable mTLS for a specific route:

curl -i -X POST http://localhost:8001/routes/<route_id>/plugins \

  –data “name=mtls-auth”

By default, the plugin will validate the client certificate against the CA certificate you uploaded in Step 3.

5. Configure Trusted Certificate IDs (Optional)

If you have multiple CA certificates, you can specify which ones to trust. You can update the mTLS plugin configuration to use the correct CA certificate ID:

curl -i -X PATCH http://localhost:8001/plugins/<plugin_id&gt; \

  –data “config.trusted_certificate_ids=<ca_certificate_id>”

6. Test the mTLS Setup

6.1. Test Using Curl

To test the mTLS setup, make a request to your Kong service or route while providing the client certificate and private key:

curl -v –cert client.crt –key client.key https://<kong-gateway-url>/your-service-or-route

This request should succeed if the client certificate is valid. If the client certificate is invalid or not provided, the request will fail with an error.

Summary

  1. Generate a Certificate Authority (CA): Use OpenSSL to generate a root CA (ca.key and ca.crt).
  2. Create and sign client certificates: Sign client certificates using the CA (client.crt and client.key).
  3. Upload the CA certificate to Kong (ca.crt).
  4. Enable the mTLS Authentication plugin for services or routes in Kong.
  5. Test mTLS by making requests using the client certificates.

By following these steps, Kong Gateway will be configured to enforce mTLS, ensuring that only clients with valid certificates signed by your CA can access your services.

Configure mTLS plugin for kong api gateway

techhadoop , , , ,
Kong API Gateway offers a few plugins to handle mutual TLS (mTLS) authentication and related features. These plugins ensure that clients are authenticated using certificates, providing an additional layer of security beyond standard TLS encryption. Key mTLS Plugins for Kong API Gateway mtls-auth Plugin (Kong Enterprise) Mutual TLS Authentication Plugin (Kong Gateway OSS) Basic Authentication with mTLS (Combined Usage) Custom mTLS Logic with Lua (Advanced Use Case) 1. mtls-auth Plugin (Kong Enterprise) Description: This plugin is available in Kong Enterprise and is specifically designed for mTLS authentication. It validates the client certificate presented during the TLS handshake against a set of CA certificates stored in Kong. Features: Validates client certificates using specified CA certificates. Supports multiple CA certificates. Can pass the client certificate information to upstream services. Configurable to allow or restrict access based on client certificate IDs. Configuration Options: config.ca_certificates: List of CA certificate IDs used to verify client certificates. config.allowed_client_certificates: List of client certificate IDs allowed to access the service or route. config.pass_client_cert: Boolean to decide whether to pass client certificate info to upstream services. 2. Mutual TLS Authentication Plugin (Kong Gateway OSS) Description: This plugin provides basic mTLS functionality in the open-source version of Kong. It requires client certificates for authentication and validates them against the provided CA certificates. Features: Validates client certificates using CA certificates. Simpler than the mtls-auth plugin and may not support advanced enterprise features. Configuration Options: ca_certificates: Array of CA certificate IDs for validation. allowed_client_certificates: Array of specific client certificates IDs. 3. Basic Authentication with mTLS (Combined Usage) Description: Although not an mTLS plugin by itself, Kong allows combining basic authentication plugins (like basic-auth) with mTLS for a two-layered authentication approach. Usage: Apply both the basic-auth plugin and the mtls-auth plugin to a service or route. Requires both a valid client certificate and a valid basic authentication credential. 4. Custom mTLS Logic with Lua (Advanced Use Case) Description: For advanced use cases where you need custom mTLS handling beyond what the plugins provide, you can use Kong’s serverless capabilities to write custom logic using Lua in a plugin like serverless-functions. Use Cases: Custom certificate validation logic. Dynamic CA certificate selection. Additional logging and monitoring for mTLS events. Choosing the Right Plugin For Enterprise Needs: If you have a Kong Enterprise license, the mtls-auth plugin is the most feature-rich option, offering advanced mTLS configurations and management capabilities. For Open Source Users: The Mutual TLS Authentication Plugin is available in Kong Gateway OSS but with fewer features. It’s suitable for basic mTLS needs. For Custom Logic: If your use case requires custom logic, consider using Lua scripting with serverless-functions to implement advanced mTLS workflows. Conclusion These plugins allow Kong to enforce mTLS for enhanced security. The choice between them depends on your version of Kong (Enterprise vs. OSS) and your specific security requirements. Configure mTLS plugin for kong api gateway

To configure mTLS (mutual TLS) in Kong API Gateway, you need to use the mtls-auth plugin, which validates client certificates against a set of trusted Certificate Authorities (CA). This process involves uploading the CA certificate to Kong, enabling the mtls-auth plugin for a service or route, and testing the configuration.
Steps to Configure mTLS in Kong
1. Upload CA Certificate to Kong
2. Enable the mtls-auth Plugin for a Service or Route
3. Test the mTLS Configuration
Step 1: Upload CA Certificate to Kong
You must upload the CA certificate to Kong so it can validate the client certificates.
1. Upload the CA Certificate using Kong Admin API:

curl -i -X POST http://:8001/ca_certificates \
–data “cert=@/path/to/ca.crt”
o Replace with your Kong Admin URL.
o This will upload the CA certificate to Kong, which will then be used to verify client certificates.
2. Check the Uploaded CA Certificate: Verify that the CA certificate has been uploaded correctly by listing all CA certificates:

curl -i -X GET http://:8001/ca_certificates
Step 2: Enable the mtls-auth Plugin
1. Enable the Plugin on a Service: You can apply the mtls-auth plugin to a specific service in Kong.

curl -i -X POST http://:8001/services//plugins \
–data “name=mtls-auth” \
–data “config.ca_certificates=” \
–data “config.allow_any_client_cert=true”
o Replace with the name or ID of the service you want to protect.
o Replace with the ID of the CA certificate you uploaded in step 1.
o allow_any_client_cert=true allows any client certificate issued by the uploaded CA to access the service.
2. Enable the Plugin on a Route: Alternatively, you can apply the plugin to a specific route.

curl -i -X POST http://:8001/routes//plugins \
–data “name=mtls-auth” \
–data “config.ca_certificates=” \
–data “config.allow_any_client_cert=true”
o Replace with the ID of the route you want to protect.
3. Optional Configuration Options:
o config.pass_client_cert=false: By default, the plugin does not pass the client certificate to the upstream service. Set this to true if you want to pass it.
o config.allowed_client_certificates: You can specify individual client certificate IDs if you want to allow only specific certificates.
Step 3: Test the mTLS Configuration
1. Test with a Valid Client Certificate: Make a request to the service or route using a client certificate signed by the trusted CA.
curl -v https://:/ \
–cert /path/to/client.crt \
–key /path/to/client.key
o If everything is configured correctly, you should receive a successful response.
2. Test with an Invalid or No Client Certificate: Try making a request without a client certificate or with an invalid one.
curl -v https://:/
o You should receive a 401 Unauthorized or 403 Forbidden response, indicating that the client certificate validation failed.
Additional Considerations
• Certificate Renewal: If you update your CA or client certificates, remember to update them in Kong as well.
• Multiple CA Certificates: You can upload multiple CA certificates to Kong and specify them in the config.ca_certificates array when configuring the plugin.
• Error Handling: If you encounter errors, check the Kong logs for detailed messages that can help diagnose issues.
Summary
1. Upload CA Certificate: Use the Admin API to upload the CA certificate.
2. Enable mTLS Plugin: Configure the mtls-auth plugin on your desired service or route, specifying the CA certificate.
3. Test and Verify: Ensure that the setup is correct by testing with valid and invalid client certificates.
By following these steps, you can configure mTLS in Kong to secure your API services, ensuring that only clients with trusted certificates can access them.