SSH-Port-Forwarder

SSH-Port-Forwarder is a .NET Standard library implementing AddSshTunnel extension method for the interface Microsoft.Extensions.DependencyInjection.IServiceCollection. AddSshTunnel establishes SSH tunnel using connection info stored in the app configuration. It can be used, for example, to establish secure connection to the database in ASP.NET Core applications. It uses SSH.NET library internally.

Usage

To use in an ASP.NET application, add the following code to the Startup.ConfigureServices method:

services.AddSshTunnel(configuration.GetSection("SshTunnel"));

Then add a constructor parameter SshClientWrapper _ in a class where you will use a tunneled connection (for example, in a class derived from Microsoft.EntityFrameworkCore.DbContext).

Then add a configuration, sample:

{
  "SshTunnel": {
    "ExpectedHostKeyBase64": "AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBIE154JCCcw7PeuX/z2MiIX0u9BFeVpn4ZDUGVZVzUZcsFKfrC01vQAw/fzns7u6LfoxjuNgL6ZXKdcZY/AtZNU=",
    "ForwardedPorts": [
      {
        "IgnorePortInUseError": true,
        "LocalPort": 3306,
        "RemotePort": 3306
      }
    ],
    "Host": "sshserver.net",
    "PrivateKeyFilePath": "C:\\Users\\Username\\.ssh\\id_rsa",
    "Username": "username"
  }
}

Configuration options

Name	Description
Host	SSH server's hostname or IP address. Required.
Port	SSH server's port. Default: 22.
Username	SSH server's username. Required.
ExpectedHostKeyBase64	SSH server's host key. Used to verify that the SSH server is legitimate. After you first connected to SSH server via OpenSSH command line, you will find a value for this setting in ~/.ssh/known_hosts in your user profile folder in the line having your SSH server's host name or IP address.
ProxyType	Specifies the type of proxy SSH client will use to connect to server. Available options: None, Socks4, Socks5, Http. Default: None.
ProxyHost	Proxy server's hostname or IP address.
ProxyPort	Proxy server's port.
ProxyUsername	Proxy server's username.
ProxyPassword	Proxy server's password.
Password	Authentication option 1: using password.
PrivateKey	Authentication option 2: using private key stored in configuration.
PrivateKeyFilePath	Authentication option 3: using path of a file containing private key.
PrivateKeyPassPhrase	Passphrase for private key authentication.
ReconnectAfterSeconds	If connection interrupts, try reconnecting every X seconds. Default: 15 seconds.
ForwardedPorts	Collection of ports to be forwarded. Required.

ForwardedPorts configuration options

Name	Description
LocalHost	Local IP address which will accept connections. Default: 127.0.0.1.
LocalPort	Local port which will accept connections.
RemoteHost	Remote host in SSH server's network to which incoming connections will be forwarded. Default: 127.0.0.1.
RemotePort	Remote port to which incoming connections will be forwarded.
IgnorePortInUseError	Proceed if port is already busy. Default: false.