gRPC SSL/TLS

Configuring SSL/TLS in Babel Licensing Service

Securing the gRPC channel in the Babel Licensing Service with SSL/TLS is essential for ensuring encrypted and secure communication between the client applications and the server. SSL/TLS (Secure Sockets Layer/Transport Layer Security) provides a secure communication protocol that protects data integrity, confidentiality, and authenticity.

To configure SSL/TLS in the Babel Licensing Service, you need to follow a few steps. First, you need to generate or obtain a valid SSL/TLS certificate. This certificate is used to establish the identity of the server and encrypt the communication.

Once you have the SSL/TLS certificate, you need to configure the Babel Licensing Service to utilize it. This involves specifying the certificate's path and password in the configuration settings of the Babel Licensing Service and client applications.

Self Signed Certificates

Self-signed certificates are digital certificates that are generated and signed by the same entity without involving a trusted third-party certificate authority. Unlike certificates issued by recognized CAs, self-signed certificates are not inherently trusted by default in web browsers or operating systems.

Self-signed certificates are particularly useful during development as they allow for secure communication without the need to obtain a certificate from a trusted authority, which can be time-consuming and costly. They are ideal for testing and development scenarios, where the main objective is to establish an encrypted channel for communication.

To create a self-signed certificate, you can use PowerShell, a powerful scripting language and command-line shell. The following PowerShell code snippet demonstrates how to generate a self-signed certificate:

# Create cert
$certname = "<cert name>"
$certpassword = "<cert password>"

$cert = New-SelfSignedCertificate -Subject "CN=$certname" -CertStoreLocation "Cert:\CurrentUser\My" -KeyExportPolicy Exportable -KeySpec Signature -KeyLength 2048 -KeyAlgorithm RSA -HashAlgorithm SHA256

# Export PFX
Export-Certificate -Cert $cert -FilePath "$certname.cer"
$mypwd = ConvertTo-SecureString -String "$certpassword" -Force -AsPlainText
Export-PfxCertificate -Cert $cert -FilePath "$certname.pfx" -Password $mypwd

# Delete from local store
$thumbprint = Get-ChildItem -Path "Cert:\CurrentUser\My" | Where-Object {$_.Subject -Match "$certname"} | Select-Object -ExpandProperty Thumbprint
Remove-Item -Path "Cert:\CurrentUser\My\$thumbprint" -DeleteKey

This PowerShell code generates a self-signed certificate with the given certname and certpassword. The New-SelfSignedCertificate cmdlet is used to create the certificate with specific parameters, such as the subject name, key length, and hash algorithm.

The certificate is then exported in both .cer and .pfx formats using the Export-Certificate and Export-PfxCertificate cmdlets, respectively. The .cer file contains the public key, while the .pfx file contains the private key along with the certificate.

Finally, the certificate is deleted from the local certificate store using the Remove-Item cmdlet. This step is optional and can be done to ensure that the self-signed certificate is not present in the local certificate store after it has been exported.

By using this PowerShell code to create a self-signed certificate, you can easily configure SSL/TLS in the Babel Licensing Service during development, allowing for secure communication over encrypted channels.

Server

Secure Socket Layer (SSL) and Transport Layer Security (TLS) protocols play a vital role in ensuring secure communication between clients and servers. Babel Licensing Service offers seamless integration with gRPC SSL/TLS, allowing you to establish a secure channel for transmitting data over the network.

The "Certificate" subsection within the gRPC endpoint configuration allows you to specify the SSL/TLS certificate details.

"Endpoints": {
  "gRPC": {
    "Url": "https://localhost:5005",
    "Protocols": "Http1AndHttp2",
    "Certificate": {
      "AllowInvalid": true,
      "Path": "<cert file>.pfx",
      "Password": "<cert password>"
    }
  }
}

Here, you can set the "AllowInvalid" parameter to true when using a self-signed certificate. This configuration accommodates development and testing scenarios where self-signed certificates are commonly used.

Protocols

Enabling HTTP1AndHttp2 protocols in the gRPC SSL/TLS configuration provides enhanced flexibility and compatibility for your Babel Licensing Service. This configuration option is specifically available when SSL/TLS is enabled, as it leverages the protocol negotiation capabilities provided by the TLS extension layer ALPN (Application-Layer Protocol Negotiation).

When SSL/TLS is enabled, the TLS layer acts as a protocol mediator, allowing both HTTP/1 and HTTP/2 protocols to coexist on the same port. This means that clients using either HTTP/1 or HTTP/2 can communicate with the Babel Licensing Service seamlessly without the need for separate ports or configurations.

The HTTP/1 protocol is a widely adopted protocol used for communication on the web. It follows a request/response model, where clients send requests to servers and receive corresponding responses. The HTTP/1 protocol is known for its compatibility with various client applications and frameworks.

On the other hand, the HTTP/2 protocol brings significant performance improvements over its predecessor. It introduces features such as multiplexing, header compression, and server push, resulting in faster and more efficient communication between clients and servers. By enabling HTTP/2, you can take advantage of these advanced capabilities for enhanced performance and responsiveness.

Client

To configure a client application to secure the gRPC channel with SSL/TLS, you can use the following code:

BabelLicensing.Configure(config =>
{
    config.ServiceUrl = "https://localhost:5005";
    var certificate = new X509Certificate2("<cert file>.pfx", "<cert password>");

    config.ChannelOptions = new GrpcChannelOptions();
    config.ChannelOptions.HttpHandler = new HttpClientHandler()
    {
        ClientCertificates = { certificate },
        ServerCertificateCustomValidationCallback = HttpClientHandler.DangerousAcceptAnyServerCertificateValidator
    };
});

In this code snippet, the config object represents the configuration for the Babel Licensing Service. The ServiceUrl property is set to the URL of the service, which includes the https scheme to indicate the use of SSL/TLS.

The certificate variable is created by loading the certificate file (in .pfx format) and providing the corresponding password. This certificate will be used within the HttpClientHandler, to set the ClientCertificates property. This ensures that the client presents the appropriate certificate during the SSL/TLS handshake.

Additionally, the ServerCertificateCustomValidationCallback is set to HttpClientHandler.DangerousAcceptAnyServerCertificateValidator. This callback bypasses the default server certificate validation, accepting any server certificate presented by the Babel Licensing Service. This is suitable for development and testing purposes but should be handled with caution in production environments.

By configuring the client application in this way, you establish a secure gRPC channel using SSL/TLS to communicate with the Babel Licensing Service.