• Overview
• Desktop app capabilities
  • Admin Service
  • WireGuard Service
  • Banyan Proxy Service
  • Multi-user accounts
  • One-click SSH access
  • One-click Kubernetes access
• Desktop app components
  • Browser-based authentication flow
  • Short-lived certificates

Overview

The desktop app allows end users to register their devices with SonicWall Cloud Secure Edge (CSE) and access CSE-secured services.

Desktop app capabilities

Admin Service

Note: In order for the Admin Service to collect your org’s user directory, the Registry Key Trust Factor requires the desktop app to launch at least once. Subsequently, the Admin Service does not require the app to be open and running in order to work (i.e., your end users do not need to open their desktop app in order for the Admin Service to function).

The Admin Service (banyanapp-admin) accounts for any functionalities in the desktop app that require administrative privileges; it also collects Trust Factors and enables Internet Threat Protection (ITP) policies. It’s installed with the app (by the installer) and run as a service on the machine. It functions independently but contains select command line utilities in the case of an emergency.

WireGuard Service

In order for end users to connect to Service Tunnels, the app must install the WireGuard Service which creates and maintains the WireGuard tunnel interface. This one-time installation requires admin privileges and is triggered when an end user connects to their first Service Tunnel. The service runs on port 8119.

When an ITP policy is applied to a device, SonicWall takes over the device’s DNS service. All DNS queries will then be routed to the WireGuard Service on the device, listening on 127.0.0.5 port 53. The WireGuard Service will then route these queries to name servers monitored by SonicWall.

Currently, Linux users must install the WireGuard tools manually via https://www.wireguard.com/install/. We are looking to automate this via the app in an upcoming release.

Banyan Proxy Service

In order for end users to access Infrastructure Services, they need to use the banyanproxy component of the desktop app. When an admin runs the installer, the desktop app places the banyanproxy executable in a specific directory. Then, when the desktop app is running, and the user connects, it launches the banyanproxy executable to set up the connection.

The banyanproxy executable location depends on the Operating System in use:

The banyanproxy functions as a forward proxy to establish the secure connection, using the TrustCert, between the end user’s device and the TCP service, via Netagent.

The banyanproxy has the following capabilities, in order to support any type of TCP client and service:

Multi-user accounts

Multiple users (with separate accounts) can access CSE-protected services via the desktop app on a single device. This may be useful in work environments where employees rotate use of a single device.

One-click SSH access

Admins can define an SSH service for end users. Now, when end users select Connect in the desktop app to connect to the SSH service, the desktop app will automatically update the device’s SSH Config file with the banyanproxy settings needed.

The desktop app uses an SSH config location depending on the Operating System of the device:

When an end user connects to an SSH service, the app places CSE’s SSH configurations in a file called bnn.config in the SSH config location. The app also adds the SSH Include command to the .config file to incorporate Cloud Secure Edge’s SSH configurations.

Prior to Desktop app v3.0.0, the app would place CSE’s SSH configurations in a file called banyan.config. In desktop app versions 3.0.0 and later, the app places CSE’s SSH configurations in a file called bnn.config.

If the SSH Config directory or file doesn’t exist, the desktop app will automatically create it. However, if the SSH Config file or directory is not writable, end users will see an error message when they try to connect to an SSH service.

One-click Kubernetes access

Admins can define a Kubernetes service for end users. Once completed, and end users connect to the Kubernetes API service, the desktop app will automatically create the Kube Config file with the banyanproxy and token settings needed.

The Kubernetes config location depends on the Operating System of the device:

When an end user connects to a Kubernetes service, the app creates a Kube config file, banyan, in the Kube Config location. To make the Kubernetes Service the default method to access their cluster, end users can set the KUBECONFIG env variable and then use the config use-context commands as detailed in the kubectl docs.

This feature uses the proxy-url capability available in kubectl v1.19+. If end users are using an older version of kubectl, they will need to add https_proxy env var in front of their kubectl commands.

Desktop app components

Browser-based authentication flow

Cloud Secure Edge’s desktop app listens on a local port at localhost:8118 to facilitate user authentication via a browser-based standards-compliant OpenID Connect flow. However, if the device has another application running on port 8118, the desktop app will raise an error. In this scenario, the end user must stop the application that is using port 8118 before the desktop app authentication flow can proceed.

Short-lived certificates

When an end user logs in via the desktop app, a cryptographic key-pair is generated and two short-lived certificates are obtained for use in authenticating the user and device. The X.509 format TrustCert is used for Mutually-authenticated TLS. The SSH format SSHCert is used for SSH certificate authentication.

In addition to short-lived certificates, Cloud Secure Edge (CSE) requires a valid device certificate in order to access protected services. Upon registering a device, CSE issues a trusted device certificate to the device and places it in the device’s keychain or certificate manager.

Both the short-lived X.509 certificate login-cert.pem and the short-lived SSH certificate login-key.pem-cert.pub use the same private key login-key.pem.

The desktop app places the certs and key files in a specific directory depending on your Operating System. Since these certificates are short-lived, they can be stored safely in the file system (instead of your device certificate manager).

Admins can use standard openssl and ssh-keygen commands to examine the short-lived certificates.

$> openssl x509 -in login-cert.pem -noout -text

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            17:dd:b3:7c:3a:aa:71:42:90:1d:a7:ab:43:db:2d:df:69:fc:52:3d
        Signature Algorithm: sha512WithRSAEncryption
        Issuer: O = novpntest, OU = Certificate Authority, CN = testorg Banyan Private Root CA
        Validity
            Not Before: Jul  2 04:57:00 2020 GMT
            Not After : Jul  3 03:57:00 2020 GMT
        Subject: OU = "Banyan Client carly@banyanops.com", CN = Banyan Client carly@banyanops.com
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                RSA Public-Key: (2048 bit)
                Modulus:
                    00:c7:10:a7:8d:9f:18:06:f3:4e:1f:4b:20:f6:27:

...

$> ssh-keygen -L -f login-key.pem-cert.pub

login-key.pem-cert.pub:
        Type: ssh-rsa-cert-v01@openssh.com user certificate
        Public key: RSA-CERT SHA256:yv/nypkONDQF+rS8pJd5pJvItB7Y7wol1KjJfIxhMdE
        Signing CA: RSA SHA256:LGvtbCthk48jqxuggCJKAw6stao7VDIvd2OuRipczcs
        Key ID: "carly@banyanops.com ABCD8BL00KH"
        Serial: 0
        Valid: from 2020-07-01T22:02:21 to 2020-07-02T21:02:21
        Principals:
                ANY
                new-role
        Critical Options: (none)
        Extensions:
                permit-X11-forwarding
                permit-agent-forwarding
                permit-port-forwarding
                permit-pty
                permit-user-rc