Go SSH Client/Server Implementation

A simple SSH client and server implementation that supports connections to remote SSH servers like AWS or the bundled local server. It offers remote command execution and interactive shell sessions.

Prerequisites

• Go 1.16 or later
• golang.org/x/crypto/ssh package

Project Structure

go-ssh/
├── server/
│   ├── main.go
│   └── id_rsa     # Server private key (will be generated)
├── client/
│   └── main.go
└── README.md

Installation

1. Clone the repository:

git clone https://github.com/emad-siddiq/simple_ssh
cd simple_ssh

1. Generate SSH key for the server:

# From the project root directory
ssh-keygen -t rsa -f server/id_rsa

Building

Server

cd server
go build -o ssh-server

Client

cd client
go build -o ssh-client

Running

1. Start the server:

# If built:
./server/ssh-server

# Or run directly:
cd server
go run main.go

2. In another terminal, start the client:

# If built:
./client/ssh-client -key ~/.ssh/aws.pem -user ubuntu -host <aws-host-url>

# Or run directly:
cd client
go run . -key ~/.ssh/aws.pem -user ubuntu -host <aws-host-url>

Default Configuration

• Server port: 2222
• Default username: "testuser"
• Default password: "password123"
• Server host: localhost

Usage Examples

After connecting with the client, you can run various shell commands:

$ ls -la
$ pwd
$ date
$ echo "Hello, World!"
$ exit    # to close the session

Security Considerations

This implementation is for educational purposes and includes several security compromises:

1. Uses hardcoded credentials
2. Uses InsecureIgnoreHostKey in the client
3. No encryption of sensitive configuration
4. No rate limiting
5. No audit logging
6. No command sanitization

For production use, one should:

• Implement proper user authentication
• Use proper host key verification
• Implement proper logging
• Add timeout mechanisms
• Add resource limits
• Implement proper error handling

License

This work is licensed under a Creative Commons Attribution 4.0 International License.