package main

import (
    "fmt"
    "log"
    "os"
    "io/ioutil"
    "golang.org/x/crypto/ssh"
)

func main() {
    if len(os.Args) != 4 {
        log.Fatalf("Usage: %s <user> <host:port> <command>", os.Args[0])
    }

    client, session, err := connectToHost(os.Args[1], os.Args[2])
    if err != nil {
        panic(err)
    }
    out, err := session.CombinedOutput("ls")
    if err != nil {
        panic(err)
    }
    fmt.Println(string(out))
    client.Close()
}

func PublicKeyFile(file string) (ssh.AuthMethod, error) {
    buffer, err := ioutil.ReadFile(file)
    if err != nil {
        return nil, err
    }

    key, err := ssh.ParsePrivateKey(buffer)
    if err != nil {
        return nil, err
    }
    return ssh.PublicKeys(key), nil
}

func connectToHost(user, host string) (*ssh.Client, *ssh.Session, error) {
    var pass string
    fmt.Print("Password: ")
    fmt.Scanf("%sn", &pass)

    publicKey, err := PublicKeyFile(`./key.pem`)
    if err != nil {
        log.Println(err)
    }

    sshConfig := &ssh.ClientConfig{
        User: user,
        Auth: []ssh.AuthMethod{publicKey},
    }
    sshConfig.HostKeyCallback = ssh.InsecureIgnoreHostKey()

    client, err := ssh.Dial("tcp", host, sshConfig)
    if err != nil {
        return nil, nil, err
    }

    session, err := client.NewSession()
    if err != nil {
        client.Close()
        return nil, nil, err
    }

    return client, session, nil
}