sshchat

README

ssh-chat

Custom SSH server written in Go. Instead of a shell, you get a chat prompt.

Compiling / Developing

You can compile ssh-chat by using make build. The resulting binary is portable and can be run on any system with a similar OS and CPU arch. Go 1.3 or higher is required to compile.

If you're developing on this repo, there is a handy Makefile that should set things up with make run.

Additionally, make debug runs the server with an http pprof server. This allows you to open http://localhost:6060/debug/pprof/ and view profiling data. See pprof for more information about pprof.

Quick Start

Usage:
  ssh-chat [OPTIONS]

Application Options:
  -v, --verbose    Show verbose logging.
      --version    Print version and exit.
  -i, --identity=  Private key to identify server with. (~/.ssh/id_rsa)
      --bind=      Host and port to listen on. (0.0.0.0:2022)
      --admin=     Fingerprint of pubkey to mark as admin.
      --whitelist= Optional file of pubkey fingerprints that are allowed to connect
      --motd=      Message of the Day file (optional)
      --log=       Write chat log to this file.
      --pprof=     enable http server for pprof

Help Options:
  -h, --help       Show this help message

After doing go get github.com/shazow/ssh-chat/... on this repo, you should be able to run a command like:

ssh-chat --verbose --bind ":22" --identity ~/.ssh/id_dsa

To bind on port 22, you'll need to make sure it's free (move any other ssh daemons to another port) and run ssh-chat as root (or with sudo).

Frequently Asked Questions

The FAQs can be found on the project's Wiki page. Feel free to submit more questions to be answered and added to the page.

License

This project is licensed under the MIT open source license.

Documentation

Overview

sshchat package is an implementation of an ssh server which serves a chat room instead of a shell.

sshd subdirectory contains the ssh-related pieces which know nothing about chat.

chat subdirectory contains the chat-related pieces which know nothing about ssh.

The Host type is the glue between the sshd and chat pieces.

Index

• Variables
• func GetPrompt(user *message.User) string
• func SetLogger(l *golog.Logger)
• type Auth
  • func NewAuth() *Auth
  • func (a *Auth) AllowAnonymous() bool
  • func (a *Auth) Ban(key ssh.PublicKey, d time.Duration)
  • func (a *Auth) BanAddr(addr net.Addr, d time.Duration)
  • func (a *Auth) BanFingerprint(authkey string, d time.Duration)
  • func (a *Auth) Check(addr net.Addr, key ssh.PublicKey) (bool, error)
  • func (a *Auth) IsOp(key ssh.PublicKey) bool
  • func (a *Auth) Op(key ssh.PublicKey, d time.Duration)
  • func (a *Auth) Whitelist(key ssh.PublicKey, d time.Duration)
• type Host
  • func NewHost(listener *sshd.SSHListener, auth *Auth) *Host
  • func (h *Host) AutoCompleteFunction(u *message.User) func(line string, pos int, key rune) (newLine string, newPos int, ok bool)
  • func (h *Host) Connect(term *sshd.Terminal)
  • func (h *Host) GetUser(name string) (*message.User, bool)
  • func (h *Host) InitCommands(c *chat.Commands)
  • func (h *Host) Serve()
  • func (h *Host) SetMotd(motd string)
  • func (h *Host) SetTheme(theme message.Theme)
• type Identity
  • func NewIdentity(conn sshd.Connection) *Identity
  • func (i Identity) ID() string
  • func (i Identity) Name() string
  • func (i *Identity) SetID(id string)
  • func (i *Identity) SetName(name string)
  • func (i Identity) Whois() string
  • func (i Identity) WhoisAdmin() string

Variables

var ErrBanned = errors.New("banned")

The error returned a key is checked that is banned.

var ErrNotWhitelisted = errors.New("not whitelisted")

The error returned a key is checked that is not whitelisted, with whitelisting required.

Functions

func GetPrompt

func GetPrompt(user *message.User) string

GetPrompt will render the terminal prompt string based on the user.

func SetLogger

func SetLogger(l *golog.Logger)

Types

type Auth

type Auth struct {
	// contains filtered or unexported fields
}

Auth stores lookups for bans, whitelists, and ops. It implements the sshd.Auth interface.

func NewAuth

func NewAuth() *Auth

NewAuth creates a new empty Auth.

func (*Auth) AllowAnonymous

func (a *Auth) AllowAnonymous() bool

AllowAnonymous determines if anonymous users are permitted.

func (*Auth) Ban

func (a *Auth) Ban(key ssh.PublicKey, d time.Duration)

Ban will set a public key as banned.

func (*Auth) BanAddr

func (a *Auth) BanAddr(addr net.Addr, d time.Duration)

Ban will set an IP address as banned.

func (*Auth) BanFingerprint

func (a *Auth) BanFingerprint(authkey string, d time.Duration)

BanFingerprint will set a public key fingerprint as banned.

func (*Auth) Check

func (a *Auth) Check(addr net.Addr, key ssh.PublicKey) (bool, error)

Check determines if a pubkey fingerprint is permitted.

func (*Auth) IsOp

func (a *Auth) IsOp(key ssh.PublicKey) bool

IsOp checks if a public key is an op.

func (*Auth) Op

func (a *Auth) Op(key ssh.PublicKey, d time.Duration)

Op sets a public key as a known operator.

func (*Auth) Whitelist

func (a *Auth) Whitelist(key ssh.PublicKey, d time.Duration)

Whitelist will set a public key as a whitelisted user.

type Host

type Host struct {
	*chat.Room

	// Version string to print on /version
	Version string
	// contains filtered or unexported fields
}

Host is the bridge between sshd and chat modules TODO: Should be easy to add support for multiple rooms, if we want.

func NewHost

func NewHost(listener *sshd.SSHListener, auth *Auth) *Host

NewHost creates a Host on top of an existing listener.

func (*Host) AutoCompleteFunction

func (h *Host) AutoCompleteFunction(u *message.User) func(line string, pos int, key rune) (newLine string, newPos int, ok bool)

AutoCompleteFunction returns a callback for terminal autocompletion

func (*Host) Connect

func (h *Host) Connect(term *sshd.Terminal)

Connect a specific Terminal to this host and its room.

func (*Host) GetUser

func (h *Host) GetUser(name string) (*message.User, bool)

GetUser returns a message.User based on a name.

func (*Host) InitCommands

func (h *Host) InitCommands(c *chat.Commands)

InitCommands adds host-specific commands to a Commands container. These will override any existing commands.

func (*Host) Serve

func (h *Host) Serve()

Serve our chat room onto the listener

func (*Host) SetMotd

func (h *Host) SetMotd(motd string)

SetMotd sets the host's message of the day.

func (*Host) SetTheme

func (h *Host) SetTheme(theme message.Theme)

SetTheme sets the default theme for the host.

type Identity

type Identity struct {
	sshd.Connection
	// contains filtered or unexported fields
}

Identity is a container for everything that identifies a client.

func NewIdentity

func NewIdentity(conn sshd.Connection) *Identity

NewIdentity returns a new identity object from an sshd.Connection.

func (Identity) ID

func (i Identity) ID() string

func (Identity) Name

func (i Identity) Name() string

func (*Identity) SetID

func (i *Identity) SetID(id string)

func (*Identity) SetName

func (i *Identity) SetName(name string)

func (Identity) Whois

func (i Identity) Whois() string

Whois returns a whois description for non-admin users.

func (Identity) WhoisAdmin

func (i Identity) WhoisAdmin() string

WhoisAdmin returns a whois description for admin users.