python - Paramiko 在异常后不返回提示(Python 3)

Question

RHEL 6 上的 Python 3.3。

使用下面的代码，如果我第一次获得正确的密码，它会正确打印“已验证”，然后返回到我的 shell。如果我输入的密码错误 3 次，它会正确打印“太多次尝试，抱歉。”，然后返回到我的 shell。但是，如果我一次或两次输错密码，然后改正，它会打印“已验证”，但然后只是卡在那里，不会将我送回 shell。我必须按 CTRL-C 才能退出脚本。

有什么想法吗？

import paramiko
import getpass
authenticated, tries = False, 1
while authenticated == False and tries <= 3:
    try:
        password = getpass.getpass('Password: ')
        ssh = paramiko.SSHClient()
        ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
        ssh.connect(myhost, username=myusername, password=password)
        authenticated = True
    except paramiko.AuthenticationException:
        authenticated = False
        tries += 1
if authenticated == False:
    print('Too many tries, sorry.')
else:
    print('Authenticated')

Answer 1

正如tdelaney所说，您需要添加ssh.close()。使用 Python 3.3 进行测试:

import paramiko
import getpass
authenticated, tries = False, 1
myhost     = 'myserver.mydomain.org'
myusername = 'myuser'
while authenticated == False and tries <= 3:
    try:
        password = getpass.getpass('Password: ')
        ssh = paramiko.SSHClient()
        ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
        ssh.connect(myhost, username=myusername, password=password)
        authenticated = True
    except paramiko.AuthenticationException:
        authenticated = False
        tries += 1
if authenticated == False:
    print('Too many tries, sorry.')
else:
    print('Authenticated')
ssh.close()

如果没有ssh.close()，当我输入一个错误的密码然后输入正确的密码时，脚本会挂起。否则它不会挂起(两次错误的密码，然后正确的密码就可以了，它不会挂起)。

如果导入线程并在最后一行print('Threads:', threading.enumerate())，您可以看到事件线程:

import paramiko
import getpass
import threading

authenticated, tries = False, 1
myhost     = 'myserver.mydomain.org'
myusername = 'myuser'
while authenticated == False and tries <= 3:
    try:
        password = getpass.getpass('Password: ')
        ssh = paramiko.SSHClient()
        ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
        ssh.connect(myhost, username=myusername, password=password)
        authenticated = True
    except paramiko.AuthenticationException:
        authenticated = False
        tries += 1
if authenticated == False:
    print('Too many tries, sorry.')
else:
    print('Authenticated')
#ssh.close()
print('Threads:', threading.enumerate())

当我测试它时，它在一个错误的密码和正确的密码后打印:

Threads: [<_MainThread(MainThread, started 140298690832128)>, <paramiko.Transport at 0x14e3a90 (cipher aes128-ctr, 128 bits) (connected; awaiting auth)>, <paramiko.Transport at 0x147a910 (cipher aes128-ctr, 128 bits) (active; 0 open channel(s))>]

我知道这并不能真正解释为什么会这样做，但我希望它有助于解决您的问题并看看发生了什么。