Cntlm安装和配置心得

对于那些使用NTLM进行身份验证的网络代理环境（即设置上除需要代理主机和端口之外还需要提供域用户和密码）来说，通过代理上网是一件头痛的事情，这主要是因为很多软件不支持NTLM验证的代理（比如目前的GIT就不能支持NTLM验证，即使在代理中指定了域帐号和密码，在连接过程中依然报： Received HTTP code 407 from proxy after CONNECT ，说明验证并未通过），如果有这样一种工具能封装NTLM验证然后对外提供普通的HTTP代理服务，那么第三方应用就可以通过配置普通的代理访问网络了，这就是Cntlm (项目官网：http://cntlm.sourceforge.net/）所要解决的问题！ 由于Cntlm也有linux版本，这意味着在linux系统上通过NTLM身份验证的网络代理也是可行的。本文原文出处: http://blog.csdn.net/bluishglc/article/details/37600773 严禁任何形式的转载，否则将委托CSDN官方维护权益！

配置

下载安装Cntlm之后，只需要修改cntlm.ini文件，提供身份认证必要的信息，然后以服务的方式启动cntlm就可以了。在cntlm.ini中有如下几个重要的配置是可能需要修改的：

• Username - your domain/proxy account name

• Domain - the actual domain name

• Workstation - NetBIOS name of your workstation; Cntlm tries to autodetect it, but you might want to set it explicitly should dialect detection fail (see below)

• Proxy - IP address (or ping-able hostname) of your proxy; if you use several alternative proxies or know of backup ones, use this option multiple times; if one stops working, Cntlm will move on to the next

• Listen - local port number which Cntlm should bind to; the default is OK, but remember you can't have more than one application per port; you can use netstat to list used up ports (lines with LISTEN)

其中Listen配置项是cntlm将在本地打开的作为普通代理的端口，假如我的windows域是abc,帐号是laurence,密码是123，代理服务器是192.168.0.1：80，则cntlm.ini应该如下配置：

#
# Cntlm Authentication Proxy Configuration
#
# NOTE: all values are parsed literally, do NOT escape spaces,
# do not quote. Use 0600 perms if you use plaintext password.
#

Username	laurence
Domain		abc
Password	123
# NOTE: Use plaintext password only at your own risk
# Use hashes instead. You can use a "cntlm -M" and "cntlm -H"
# command sequence to get the right config for your environment.
# See cntlm man page
# Example secure config shown below.
# PassLM          1AD35398BE6565DDB5C4EF70C0593492
# PassNT          77B9081511704EE852F94227CF48A793
### Only for user 'testuser', domain 'corp-uk'
# PassNTLMv2      D5826E9C665C37C80B53397D5C07BBCB

# Specify the netbios hostname cntlm will send to the parent
# proxies. Normally the value is auto-guessed.
#
# Workstation	netbios_hostname

# List of parent proxies to use. More proxies can be defined
# one per line in format <proxy_ip>:<proxy_port>
#
Proxy		192.168.0.1:80

# List addresses you do not want to pass to parent proxies
# * and ? wildcards can be used
#
NoProxy		localhost, 127.0.0.*, 10.*, 192.168.*

# Specify the port cntlm will listen on
# You can bind cntlm to specific interface by specifying
# the appropriate IP address also in format <local_ip>:<local_port>
# Cntlm listens on 127.0.0.1:3128 by default
#
Listen		3128

# If you wish to use the SOCKS5 proxy feature as well, uncomment
# the following option. It can be used several times
# to have SOCKS5 on more than one port or on different network
# interfaces (specify explicit source address for that).
#
# WARNING: The service accepts all requests, unless you use
# SOCKS5User and make authentication mandatory. SOCKS5User
# can be used repeatedly for a whole bunch of individual accounts.
#
#SOCKS5Proxy	8010
#SOCKS5User	dave:password

# Use -M first to detect the best NTLM settings for your proxy.
# Default is to use the only secure hash, NTLMv2, but it is not
# as available as the older stuff.
#
# This example is the most universal setup known to man, but it
# uses the weakest hash ever. I won't have it's usage on my
# conscience. :) Really, try -M first.
#
#Auth		LM
#Flags		0x06820000

# Enable to allow access from other computers
#
#Gateway	yes

# Useful in Gateway mode to allow/restrict certain IPs
# Specifiy individual IPs or subnets one rule per line.
#
#Allow		127.0.0.1
#Deny		0/0

# GFI WebMonitor-handling plugin parameters, disabled by default
#
#ISAScannerSize     1024
#ISAScannerAgent    Wget/
#ISAScannerAgent    APT-HTTP/
#ISAScannerAgent    Yum/

# Headers which should be replaced if present in the request
#
#Header		User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows 98)

# Tunnels mapping local port to a machine behind the proxy.
# The format is <local_port>:<remote_host>:<remote_port>
# 
#Tunnel		11443:remote.com:443

其中对于监听端口使用默认的端口3128就可以了。我们可以通过命令来验证配置是否正确：

cntlm -c /path/to/cntlm.ini -I -M http://www.baidu.com

如果能正常返回就表示各项配置都是正确的，接下就可以启动cntlm服务在后台运行了，使用命令：

net start cntlm

服务启动之后，我们就可以在第三方应用的代理配置上这样设定了：代理服务器：127.0.0.1 （即本机），代理服务器端口：3128（即cntlm.ini文件中配置的Listen端口）

日志与常见错误

cntlm绝大多数错误表现为服务无法启动，具体原因有很多，好在cntlm有较好的日志信息可以帮助我们找到问题的根源，查看cntlm日志的方法是：Start -> Settings -> Control Panel -> Administrative Tools -> Event Viewer, 然后在左侧面板的目录树中选择：Windows Logs -> Application, 再在右侧面板中配置一下过虑项，将事件源设定为cntlm就可以过滤出所有的cntlm日志了。

这里我们介绍两种可能的错误：

1. cntlm: PID XXXX: Possible duplicate cygwin1.dll: /socat-1.7.2.1/cygwin1.dll.



类似这样的错误是由于cygwin1.dll冲突引起的，有多种工具会携带自己的cygwin1.dll，如果版本不兼容就会报如上的错误，最简单的方是先移除它们。

2. cntlm: Parent proxy address missing



这是一个容易造成误导的错误，如果多数情况下并不是因为你在cntlm.ini中错误地制定了Proxy而是cntlm程序启动时根本没用找到cntlm.ini文件，造成这种问题的可能诱因之一是在安装cntlm时修改了默认的安装目录，这应该是cntlm的一个bug。不知道在启动cntlm服务的配置界面（Control Panel -> Administrative Tools -> Services）上指定-c参数是否有效，有兴趣的朋友可以尝试一下，我是按默认配置重装了cntlm解决的问题。