package main
import (
"fmt"
"io"
"io/ioutil"
"log"
"code.google.com/p/go.crypto/ssh"
"code.google.com/p/go.crypto/ssh/terminal"
)
func main() {
// An SSH server is represented by a ServerConfig, which holds
// certificate details and handles authentication of ServerConns.
config := &ssh.ServerConfig{
PasswordCallback: func(conn *ssh.ServerConn, user, pass string) bool {
return user == "testuser" && pass == "tiger"
},
}
pemBytes, err := ioutil.ReadFile("id_rsa")
if err != nil {
log.Fatal("Failed to load private key:", err)
}
if err = config.SetRSAPrivateKey(pemBytes); err != nil {
log.Fatal("Failed to parse private key:", err)
}
// Once a ServerConfig has been configured, connections can be
// accepted.
conn, err := ssh.Listen("tcp", "0.0.0.0:2022", config)
if err != nil {
log.Fatal("failed to listen for connection")
}
for {
// A ServerConn multiplexes several channels, which must
// themselves be Accepted.
log.Println("accept")
sConn, err := conn.Accept()
if err != nil {
log.Println("failed to accept incoming connection")
continue
}
if err := sConn.Handshake(); err != nil {
log.Println("failed to handshake")
continue
}
go handleServerConn(sConn)
}
}
func handleServerConn(sConn *ssh.ServerConn) {
defer sConn.Close()
for {
// Accept reads from the connection, demultiplexes packets
// to their corresponding channels and returns when a new
// channel request is seen. Some goroutine must always be
// calling Accept; otherwise no messages will be forwarded
// to the channels.
ch, err := sConn.Accept()
if err == io.EOF {
return
}
if err != nil {
log.Println("handleServerConn Accept:", err)
break
}
// Channels have a type, depending on the application level
// protocol intended. In the case of a shell, the type is
// "session" and ServerShell may be used to present a simple
// terminal interface.
if ch.ChannelType() != "session" {
ch.Reject(ssh.UnknownChannelType, "unknown channel type")
break
}
go handleChannel(ch)
}
}
func handleChannel(ch ssh.Channel) {
term := terminal.NewTerminal(ch, "> ")
serverTerm := &ssh.ServerTerminal{
Term: term,
Channel: ch,
}
ch.Accept()
defer ch.Close()
for {
line, err := serverTerm.ReadLine()
if err == io.EOF {
return
}
if err != nil {
log.Println("handleChannel readLine err:", err)
continue
}
fmt.Println(line)
}
}