import "golang.org/x/crypto/ssh"

func connect(user, password, host, key string, port int, cipherList []string) (*ssh.Session, error) {
  var (
    auth     []ssh.AuthMethod
    addr     string
    clientConfig *ssh.ClientConfig
    client    *ssh.Client
    config    ssh.Config
    session   *ssh.Session
    err     error
  )
  // get auth method
  auth = make([]ssh.AuthMethod, 0)
  if key == "" {
    auth = append(auth, ssh.Password(password))
  } else {
    pemBytes, err := ioutil.ReadFile(key)
    if err != nil {
      return nil, err
    }

    var signer ssh.Signer
    if password == "" {
      signer, err = ssh.ParsePrivateKey(pemBytes)
    } else {
      signer, err = ssh.ParsePrivateKeyWithPassphrase(pemBytes, []byte(password))
    }
    if err != nil {
      return nil, err
    }
    auth = append(auth, ssh.PublicKeys(signer))
  }

  if len(cipherList) == 0 {
    config = ssh.Config{
      Ciphers: []string{"aes128-ctr", "aes192-ctr", "aes256-ctr", "aes128-gcm@openssh.com", "arcfour256", "arcfour128", "aes128-cbc", "3des-cbc", "aes192-cbc", "aes256-cbc"},
    }
  } else {
    config = ssh.Config{
      Ciphers: cipherList,
    }
  }

  clientConfig = &ssh.ClientConfig{
    User:  user,
    Auth:  auth,
    Timeout: 30 * time.Second,
    Config: config,
    HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
      return nil
    },
  }

  // connet to ssh
  addr = fmt.Sprintf("%s:%d", host, port)

  if client, err = ssh.Dial("tcp", addr, clientConfig); err != nil {
    return nil, err
  }

  // create session
  if session, err = client.NewSession(); err != nil {
    return nil, err
  }

  modes := ssh.TerminalModes{
    ssh.ECHO:     0,   // disable echoing
    ssh.TTY_OP_ISPEED: 14400, // input speed = 14.4kbaud
    ssh.TTY_OP_OSPEED: 14400, // output speed = 14.4kbaud
  }

  if err := session.RequestPty("xterm", 80, 40, modes); err != nil {
    return nil, err
  }

  return session, nil
}

type Config struct {
  // Rand provides the source of entropy for cryptographic
  // primitives. If Rand is nil, the cryptographic random reader
  // in package crypto/rand will be used.
  // 加密時(shí)用的種子。默認(rèn)就好
  Rand io.Reader

  // The maximum number of bytes sent or received after which a
  // new key is negotiated. It must be at least 256. If
  // unspecified, a size suitable for the chosen cipher is used.
  // 密鑰協(xié)商后的最大傳輸字節(jié)，默認(rèn)就好
  RekeyThreshold uint64

  // The allowed key exchanges algorithms. If unspecified then a
  // default set of algorithms is used.
  // 
  KeyExchanges []string

  // The allowed cipher algorithms. If unspecified then a sensible
  // default is used.
  // 連接所允許的加密算法
  Ciphers []string

  // The allowed MAC algorithms. If unspecified then a sensible default
  // is used.
  // 連接允許的 MAC (Message Authentication Code 消息摘要)算法，默認(rèn)就好
  MACs []string
}

HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
  return nil
},

******************************************************************************
* Copyright (c) 2004-2016 Hangzhou H3C Tech. Co., Ltd. All rights reserved. *
* Without the owner's prior written consent,                 *
* no decompiling or reverse-engineering shall be allowed.          *
******************************************************************************

// Set up terminal modes
modes := ssh.TerminalModes{
  ssh.ECHO:     0,   // disable echoing
  ssh.TTY_OP_ISPEED: 14400, // input speed = 14.4kbaud
  ssh.TTY_OP_OSPEED: 14400, // output speed = 14.4kbaud
}
// Request pseudo terminal
if err := session.RequestPty("xterm", 40, 80, modes); err != nil {
  log.Fatal("request for pseudo terminal failed: ", err)
}

const (
  username = "admin"
  password = "password"
  ip    = "192.168.15.101"
  port   = 22
  cmd   = "show clock"
)

func Test_SSH_run(t *testing.T) {
  ciphers := []string{}
  session, err := connect(username, password, ip, port, ciphers)
  if err != nil {
    t.Error(err)
    return
  }
  defer session.Close()
  var stdoutBuf bytes.Buffer
  session.Stdout = &stdoutBuf
  session.Run(cmd)
  t.Log(session.Stdout)
  return
}

=== RUN  Test_SSH_run
--- PASS: Test_SSH_run (0.69s)
  ssh_test.go:30: 07:55:52.598 UTC Wed Jan 17 2018
PASS

const (
  username = "admin"
  password = "password"
  ip    = "192.168.15.101"
  port   = 22
  cmds   = "show clock;show env power;exit"
)
func Test_SSH(t *testing.T) {
  var cipherList []string
  session, err := connect(username, password, ip, key, port, cipherList)
  if err != nil {
    t.Error(err)
    return
  }
  defer session.Close()

  cmdlist := strings.Split(cmd, ";")
  stdinBuf, err := session.StdinPipe()
  if err != nil {
    t.Error(err)
    return
  }

  var outbt, errbt bytes.Buffer
  session.Stdout = &outbt

  session.Stderr = &errbt
  err = session.Shell()
  if err != nil {
    t.Error(err)
    return
  }
  for _, c := range cmdlist {
    c = c + "\n"
    stdinBuf.Write([]byte(c))

  }
  session.Wait()
  t.Log((outbt.String() + errbt.String()))
  return
}

=== RUN  Test_SSH
--- PASS: Test_SSH (0.69s)
  ssh_test.go:51: sw-1#show clock
    07:59:52.598 UTC Wed Jan 17 2018
    sw-1#show env power
    SW PID         Serial#   Status      Sys Pwr PoE Pwr Watts
    -- ------------------ ---------- --------------- ------- ------- -----
     1 Built-in                     Good
    
    sw-1#exit
PASS

=== RUN  Test_SSH
--- PASS: Test_SSH (0.98s)
    ssh_test.go:50: Welcome to Ubuntu 16.04.3 LTS (GNU/Linux 4.4.0-98-generic x86_64)

         * Documentation: https://help.ubuntu.com
         * Management:   https://landscape.canonical.com
         * Support:    https://ubuntu.com/advantage

         System information as of Thu Jan 18 16:34:56 CST 2018

         System load: 0.0        Processes:       335
         Usage of /:  10.0% of 90.18GB  Users logged in:    0
         Memory usage: 2%         IP address for eth0:  192.168.80.131
         Swap usage:  0%         IP address for docker0: 172.17.0.1

         Graph this data and manage this system at:
          https://landscape.canonical.com/

        16 個(gè)可升級(jí)軟件包。
        16 個(gè)安全更新。

        New release '17.10' available.
        Run 'do-release-upgrade' to upgrade to it.

        You have new mail.
        Last login: Thu Jan 18 16:31:41 2018 from 192.168.95.104
        root@ubuntu-docker-node3:~# root@ubuntu-docker-node3:/opt# /opt
        root@ubuntu-docker-node3:/opt# 注銷

=== RUN  Test_SSH_run
--- PASS: Test_SSH_run (0.91s)
  ssh_test.go:76: /opt

# ./multissh -c ssh.json.example

# ./multissh -c ssh.json.example -j

# ./multissh -c ssh.json.example -outTxt