SshTools

Introduction

The ssh config file is a very powerful tool to specify a ssh connection. In C# we have access to the awesome ssh library SSH.NET, but this library does not aim for providing config file parsing support or a very intuitive way of defining hosts. Inspired by the Ssh-Config-Parser library the goal was to provide a library, that links the world of config files to ssh in c#.

Features

• Configure custom Keywords, Tokens or Criteria
• Parse or create a new SshConfig
• Edit this config and it's Hosts / Matches / Arguments
• Find a matching Host
• Use this Host to connect with the help of Ssh.Net
• Save the edited config back to the disk
• Usage of FluentResults to explain failure
• Using IEnumerable as base for the config, so LINQ can be used to query parameters

Usage

Creating a new config

A new config can be created directly from a ssh file on the disk

var configRes = SshConfig.FromFile("path/to/config");
if (configRes.IsFailed)
{
    configRes.Errors; // Parsing errors can be found here
    return;
}
var config = configRes.Value;

Alternatively a config can be created from a string representing the config

var configRes = SshConfig.Deserialize("Host test\n  User testuser");
if (configRes.IsFailed)
{
    configRes.Errors; // Parsing errors can be found here
    return;
}
var config = configRes.Value;
var testHost = config.Find("test"); // An uncoupled host containing the "User" argument
var testUser = testHost.User; // testuser

A config can also be created directly from code

var config = new SshConfig();

Editing the config

A new Argument can be inserted easily anywhere by providing

• index (negative numbers will count from the end)
• The argument's Keyword (e.g. User, Port, Host, etc)
• The value, that is complementary to the Keyword's expected type

var config = new SshConfig();
var insertionRes = config.Insert<ushort>(0, Keyword.Port, 1234);

Nodes (Host / Match) can be inserted too, but there is an overload, where the matchString can be defined

var config = new SshConfig();
config.Insert(-1, Keyword.Match, "user testuser host testhost");

Additionally there are many other ways, that provide a cleaner way to edit

var config = new SshConfig();
config.Port = 1234;
config.Set<ushort>(Keyword.Port, 1234);
config.PushHost("hostName", host =>
{
    host.User = "username";
});

Of course values can be removed again

var config = new SshConfig();
config.Port = 1234;
config.Remove(Keyword.Port);

config.PushHost("testHost");
config.Remove(parameter => parameter.IsHost());

Getting values from the config

Values can be queried in various different ways

var config = new SshConfig();
config.Port = 123;
config.IdentityFile = "~/.ssh/id_rsa1"
config.Insert(-1, Keyword.IdentityFile, "~/.ssh/id_rsa2");

var port = config.Port;
port = config.Get<ushort>(Keyword.Port);

var numberOfIdentities = config.Count(parameter => parameter.Is(Keyword.IdentityFile));
// [ "~/.ssh/id_rsa1", "~/.ssh/id_rsa2" ]
var identityFiles = config.WhereParam(Keyword.IdentityFile).ToList();
var id_rsa2 = config
    .WhereParam(Keyword.IdentityFile)
    .SelectArg()
    .First(fileName => fileName.EndsWith("2"));

Export the config

var config = new SshConfig();
config.PushHost("hostName");
config.WriteFile("path/to/output/config");