NullOpsDevs.LibSsh

A modern, cross-platform .NET library providing managed bindings for libssh2, enabling SSH operations including remote command execution, SCP file transfers, and advanced terminal (PTY) features.

Features

Category	Feature	Method(s)	Supported
Authentication
	Password authentication	Authenticate(PasswordCredential)	✅
	Public key authentication	Authenticate(PublicKeyCredential)	✅
	SSH agent authentication	Authenticate(SshAgentCredential)	✅
	Host-based authentication	Authenticate(HostBasedCredential)	✅
	Keyboard-interactive authentication	-	❌
Session Management
	Connection	Connect, ConnectAsync	✅
	Host key retrieval	GetHostKey	✅
	Host key verification	GetHostKeyHash	✅
	Session timeout configuration	SetSessionTimeout, DisableSessionTimeout	✅
	Keepalive configuration	ConfigureKeepAlive, SendKeepAlive	✅
	Method preference configuration	SetMethodPreferences	✅
	Secure default algorithms	SetSecureMethodPreferences	✅
	Negotiated method inspection	GetNegotiatedMethod	✅
File Transfer (SCP)
	File upload	WriteFile, WriteFileAsync	✅
	File download	ReadFile, ReadFileAsync	✅
Command Execution
	One-shot command execution	ExecuteCommand, ExecuteCommandAsync	✅
	Streaming command execution	ExecuteCommandStreaming, ExecuteCommandStreamingAsync	✅
	Exit code retrieval	SshCommandResult.ExitCode	✅
	Exit signal retrieval	SshCommandResult.ExitSignal	✅
	stdout/stderr separation	SshCommandResult.Stdout, SshCommandResult.Stderr	✅
Terminal (PTY)
	PTY allocation	CommandExecutionOptions.RequestPty	✅
	Terminal type selection	CommandExecutionOptions.TerminalType	✅
	Terminal modes	CommandExecutionOptions.TerminalModes	✅
	Window size configuration	CommandExecutionOptions.TerminalWidth/Height	✅
	Interactive shell mode	-	❌
Error Handling
	Typed exceptions	SshException	✅
	Detailed error messages	SshException.Message	✅
	60+ error code mappings	SshError enum	✅
Advanced Features
	Host key type detection	SshHostKey.Type	✅
	Microsoft.Extensions.Logging integration	Constructor ILogger parameter	✅
	Cross-platform native binaries	Bundled in NuGet package	✅
	Global library cleanup	LibSsh2.Exit()	✅
Thread Safety
	SshSession is NOT thread-safe.	-	❌
	Multiple SshSessions are supported.	-	✅

Installation

Install via NuGet Package Manager:

dotnet add package NullOpsDevs.LibSsh

Or via Package Manager Console:

Install-Package NullOpsDevs.LibSsh

Supported Platforms

• .NET 9.0+
• Windows (x64)
• Linux (x64, ARM64)
• macOS (x64, ARM64/Apple Silicon)

Quick Start

Quickstart guide is available here.

Building from Source

Prerequisites

• .NET 9.0 SDK or later
• Git

Build Steps

# Clone the repository
git clone https://github.com/NullOpsDevs/LibSshNet.git
cd LibSshNet

# Restore dependencies and build
dotnet restore
dotnet build

# Run tests
cd NullOpsDevs.LibSsh.Test
docker compose up -d
dotnet run

Architecture

The library consists of three layers:

1. Managed Layer: Clean, idiomatic C# API with async/await support (not true async)
2. Interop Layer: P/Invoke bindings to libssh2 native library
3. Native Layer: Pre-compiled libssh2 binaries for all supported platforms

All native dependencies are bundled in the NuGet package for zero-configuration deployment.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Acknowledgments

This library uses libssh2, a client-side C library implementing the SSH2 protocol.

libssh2 is licensed under BSD License.