Python paramiko 修改源码实现用户命令抓取

paramiko 源码修改

　　paramiko主要用来实现ssh客户端、服务端链接，上一节我们说到了堡垒机，堡垒机内有一个需求是“用户行为审计”，在这里我们就可以通过修改paramiko内文件的源码来实现相关要求。

paramiko 源码包安装测试

• 下载地址：https://github.com/ 下载源码包paramiko
• 解压源码包 paramiko-master.zip
• 使用目录：paramiko-masterparamiko-masterdemos
• python3启动：python paramiko-masterparamiko-masterdemosdemos.py

注：paramiko demos.py启动 不支持python3 ，由于python3默认是bays类型，需要修改源码。

demosinteractive.py",
 line 84, in writeall
    sys.stdout.write(data)
TypeError: write() argument must be str, not bytes

修改源代码（demos.py 添加 python3 支持）

注:interactive.py文件内（77~85 行）

def writeall(sock):
    while True:
        data = sock.recv(256)
        if not data:
            sys.stdout.write('
*** EOF ***

')
            sys.stdout.flush()
            break
  　　　 # 修改为编译为UTF-8
        sys.stdout.write(data.decode())
        sys.stdout.flush()

C:UsersAdministratordemos>python3 demo.py
Hostname: 192.168.1.100
*** Unable to open host keys file
*** WARNING: Unknown host key!
Username [Administrator]: root
Auth by (p)assword, (r)sa key, or (d)ss key? [p] p
Password for root@192.168.1.100:
*** Here we go!

Line-buffered terminal emulation. Press F6 or ^Z to send EOF.

Last login: Mon Jan 22 11:24:35 2018 from 192.168.1.150

[root@localhost ~]# 
注：登陆成功

修改源码（实现抓取用户操作指令）

注：paramiko-masterparamiko-masterdemosdemos.py 文件源码、简要说明

import base64
from binascii import hexlify
import getpass
import os
import select
import socket
import sys
import time
import traceback
from paramiko.py3compat import input

import paramiko
try:
    import interactive
except ImportError:
    from . import interactive


def agent_auth(transport, username):
    """
    Attempt to authenticate to the given transport using any of the private
    keys available from an SSH agent.
    """
    
    agent = paramiko.Agent()
    agent_keys = agent.get_keys()
    if len(agent_keys) == 0:
        return
        
    for key in agent_keys:
        # 尝试将本地key验证，验证不了就用密码
        print('Trying ssh-agent key %s' % hexlify(key.get_fingerprint()))
        try:
            transport.auth_publickey(username, key)
            print('... success!')
            return
        except paramiko.SSHException:
            print('... nope.')


def manual_auth(username, hostname):
    default_auth = 'p'
    auth = input('Auth by (p)assword, (r)sa key, or (d)ss key? [%s] ' % default_auth)
    if len(auth) == 0:
        auth = default_auth

    # r非对称秘钥
    if auth == 'r':
        default_path = os.path.join(os.environ['HOME'], '.ssh', 'id_rsa')
        path = input('RSA key [%s]: ' % default_path)
        if len(path) == 0:
            path = default_path
        try:
            key = paramiko.RSAKey.from_private_key_file(path)
        except paramiko.PasswordRequiredException:
            password = getpass.getpass('RSA key password: ')
            key = paramiko.RSAKey.from_private_key_file(path, password)
        t.auth_publickey(username, key)
    # 使用DSA 秘钥
    elif auth == 'd':
        default_path = os.path.join(os.environ['HOME'], '.ssh', 'id_dsa')
        path = input('DSS key [%s]: ' % default_path)
        if len(path) == 0:
            path = default_path
        try:
            key = paramiko.DSSKey.from_private_key_file(path)
        except paramiko.PasswordRequiredException:
            password = getpass.getpass('DSS key password: ')
            key = paramiko.DSSKey.from_private_key_file(path, password)
        t.auth_publickey(username, key)
    else:
        pw = getpass.getpass('Password for %s@%s: ' % (username, hostname))
        t.auth_password(username, pw)


# setup logging
paramiko.util.log_to_file('demo.log')

username = ''
if len(sys.argv) > 1:
    hostname = sys.argv[1]
    if hostname.find('@') >= 0:
        username, hostname = hostname.split('@')
else:
    # 输入IP
    hostname = input('Hostname: ')
if len(hostname) == 0:
    # 不输入打印错误
    print('*** Hostname required.')
    sys.exit(1)
# 端口号22
port = 22
if hostname.find(':') >= 0:
    hostname, portstr = hostname.split(':')
    port = int(portstr)

# now connect
try:
    # 创建socket对象
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    # 链接IP端口号
    sock.connect((hostname, port))
except Exception as e:
    # 登陆错误就报错
    print('*** Connect failed: ' + str(e))
    # 打印错误行
    traceback.print_exc()
    sys.exit(1)

try:
    # ssh实例化传入socket
    t = paramiko.Transport(sock)
    try:
        t.start_client()
    except paramiko.SSHException:
        print('*** SSH negotiation failed.')
        sys.exit(1)

    try:
        keys = paramiko.util.load_host_keys(os.path.expanduser('~/.ssh/known_hosts'))
    except IOError:
        try:
            # 生成rsa 防止证书校验
            keys = paramiko.util.load_host_keys(os.path.expanduser('~/ssh/known_hosts'))
        except IOError:
            print('*** Unable to open host keys file')
            keys = {}

    # check server's host key -- this is important.
    key = t.get_remote_server_key()
    if hostname not in keys:
        print('*** WARNING: Unknown host key!')
    elif key.get_name() not in keys[hostname]:
        print('*** WARNING: Unknown host key!')
    elif keys[hostname][key.get_name()] != key:
        print('*** WARNING: Host key has changed!!!')
        sys.exit(1)
    else:
        print('*** Host key OK.')

    # get username
    if username == '':
        # getuser取出当前用户名
        default_username = getpass.getuser()
        username = input('Username [%s]: ' % default_username)
        if len(username) == 0:
            username = default_username

    agent_auth(t, username)
    # key验证 没通过继续往下走
    if not t.is_authenticated():
        manual_auth(username, hostname)
    if not t.is_authenticated():
        print('*** Authentication failed. :(')
        # 认证成功就关闭
        t.close()
        sys.exit(1)

    # ssh_session交互
    chan = t.open_session()
    # get终端  vt100 终端模式
    chan.get_pty()
    chan.invoke_shell()
    print('*** Here we go!
')

    # 交互
    # chan是双方打开的一个通道
 # 调用interactive文件
    interactive.interactive_shell(chan)
    chan.close()
    t.close()

# 表村错误数据关闭链接
except Exception as e:
    print('*** Caught exception: ' + str(e.__class__) + ': ' + str(e))
    traceback.print_exc()
    try:
        t.close()
    except:
        pass
    sys.exit(1)

注：paramiko-masterparamiko-masterdemosinteractive.py 文件源码修改，实现用户审计

import socket
import sys
from paramiko.py3compat import u

# windows does not have termios...
try:
    # 不出错代表这是一个linux系统
    import termios
    import tty
    has_termios = True
except ImportError:
    has_termios = False


def interactive_shell(chan):
    if has_termios:
        # linux链接
        posix_shell(chan)
    else:
        windows_shell(chan)

# chan是传入的通道
def posix_shell(chan):
    import select
    
    oldtty = termios.tcgetattr(sys.stdin)
    try:
        tty.setraw(sys.stdin.fileno())
        tty.setcbreak(sys.stdin.fileno())
        chan.settimeout(0.0)


#-----------------1.源码修改---------------------#


# 创建列表用来存放客户端输入命令
cmd = []

#----------------------------------------------#

        while True:
            # stdin标准输入，stdout标准输出，标准错误
            r, w, e = select.select([chan, sys.stdin], [], [])

            # 如果chan在r里面就代表有数据过来了
            if chan in r:
                try:
                    # 数据过来就收数据
                    x = u(chan.recv(1024))
                    # 如果数据等于0，代表断开链接
                    if len(x) == 0:
                        sys.stdout.write('
*** EOF
')
                        break
                    # 发送数据
                    sys.stdout.write(x)
                    # 刷新数据
                    sys.stdout.flush()
                except socket.timeout:
                    pass
            # 没进行一次动作就select就执行返回一次
            if sys.stdin in r:
                x = sys.stdin.read(1)
                if len(x) == 0:
                    break

#-----------------2.源码修改---------------------#


            # 判断用户是否使用回车键
                if x == "
":
                    # 将列表字符拼接
                    cmd_str="".join(cmd)
                    # 获取出用户执行命令
                    print("-->",cmd_str)
                    # 清空列表
                    cmd = []
                else:
                    # 没有回车就将字符添加列表内
                    cmd.append(x)

#----------------------------------------------#
                chan.send(x)

    finally:
        termios.tcsetattr(sys.stdin, termios.TCSADRAIN, oldtty)

    
# thanks to Mike Looijmans for this code
def windows_shell(chan):
    import threading

    sys.stdout.write("Line-buffered terminal emulation. Press F6 or ^Z to send EOF.

")
        
    def writeall(sock):
        while True:
            data = sock.recv(256)
            if not data:
                sys.stdout.write('
*** EOF ***

')
                sys.stdout.flush()
                break
            sys.stdout.write(data.decode())
            sys.stdout.flush()
        
    writer = threading.Thread(target=writeall, args=(chan,))
    writer.start()
        
    try:
        while True:
            d = sys.stdin.read(1)
            if not d:
                break
            chan.send(d)
    except EOFError:
        # user hit ^Z or F6
        pass