Example of using ssh-agent forwarding patch on go.crypto/ssh

ssh_forward_example.go

package main
import "errors"
import "fmt"
import "io"
import "net"
import "os"
import "code.google.com/p/go.crypto/ssh"
 
func connectToAgent() (io.ReadWriteCloser, error) {
    socketLocation := os.Getenv("SSH_AUTH_SOCK")
    if socketLocation == "" {
        return nil, errors.New("SSH_AUTH_SOCK not set")
    }
    // handle XXX no SSH AUTH SOCK
    c, err := net.Dial("unix", socketLocation)
    if err != nil {
        return nil, err
    }
    return c, nil
}
 
func connectToSsh() net.Conn {
    c, err := net.Dial("tcp", "bastion:22")
    if err != nil {
        panic(err)
    }
    return c
}
 
type Connector struct {
}
 
func (c *Connector) Connect() (io.ReadWriteCloser, error) {
    return connectToAgent()
}
 
func main() {
    c, err := connectToAgent()
    if err != nil {
        panic(err)
    }
    agent := ssh.NewAgentClient(c)
    config := &ssh.ClientConfig{
        User: "jamwt",
        Auth: []ssh.ClientAuth{
            ssh.ClientAuthAgent(agent),
        },
        // Comment out to disable key forwarding
        AgentConnector: &Connector{},
    }
    c2 := connectToSsh()
    client, err := ssh.Client(c2, config)
 
    if err != nil {
        panic(err)
    }
 
    ses, err := client.NewSession()
 
    if err != nil {
        panic(err)
    }
 
    res, err := ses.CombinedOutput("ssh -o PasswordAuthentication=no next-server ls")
 
    if err != nil {
    }
 
    fmt.Printf("Remote Said:\n%s", res)
 
}