在 Linux 上从 Python 连接到受保护的 WiFi
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【中文标题】在 Linux 上从 Python 连接到受保护的 WiFi【英文标题】:Connecting to a protected WiFi from Python on Linux 【发布时间】:2013-02-06 22:52:12 【问题描述】:我正在为需要连接到 WiFi AP 的 Ubuntu Linux 创建一个软件。 WiFi 网络不是预定义的,并且可以在软件的单次运行期间更改多次(用户是下令更改的人)。想法是这样的:给定一组 SSID 及其 WPA 或 WEP 密码,软件应该能够随心所欲地在网络之间切换,而无需更改系统中任何位置的任何配置文件。
看起来,最大的问题是将密码传递给连接。到目前为止,我一直在使用以下方法:
Ubuntu 12.10 机器配备 WiFi 加密狗。 Python,运行软件,用于请求连接 康曼 0.79 wpa_supplicant v1.0 d-总线起初我认为可以通过 d-bus 将密码传递给 connman,但是这个版本的 connman 和 1.11 似乎都没有公开任何方法。然后我发现可以将service_<SSID>.conf
文件转储到/var/lib/connman/
目录。该文件的内容非常简单,如下所示:
[service_SSID]
Type=wifi
Name=Network-SSID
Passphrase=here-goes-the-passphrase
创建此文件后,连接到网络需要在适当的服务中简单调用 net.connman.Service.Connect() 方法。问题是 connman 除非重新启动,否则不会解析配置文件。这需要 sudo 权限、额外的时间,并增加了所有“现在可能出错”的事情发生的风险。然后我发现密码可以以某种方式传递给 wpa_supplicant d-bus API,但我什么也没找到。
Google 搜索也让我失望了。好像从来没有人尝试过这样做。
命令sudo iwconfig wlan0 essid <SSID> key s:<PASSPHRASE>
导致SET failed on device wlan0 ; Invalid argument.
错误。此外,它需要我想避免的 sudo。
我试图弄清楚 wpa_gui 程序是如何发挥它的魔力的。首先我发现它也需要 sudo,而且它会直接向/var/run/wpa_supplicant/wlan0
发送一堆命令。如果我没有找到更简单的方法,复制这种行为对我来说是最后的手段。
那么,最大的问题是:如何使用 Python 连接到受 WEP/WPA 保护的 WiFi 网络? 我还想知道在这里使用 connman 是否是一个好方法,我是否不应该恢复到网络管理器,这是 Ubuntu 的默认设置。
【问题讨论】:
【参考方案1】:这显示了如何为 WPA 执行此操作。
首先,抛弃 connman 并使用 NetworkManager。下面的示例脚本显示了如何启用无线支持,检查具有给定 SSID 的网络是否可用,使用 WPA 密码连接到该 SSID,然后断开与网络的连接并禁用无线。我相当确定这个脚本可以改进,但当前版本足以作为示例:
#!/usr/bin/python
# This script shows how to connect to a WPA protected WiFi network
# by communicating through D-Bus to NetworkManager 0.9.
#
# Reference URLs:
# http://projects.gnome.org/NetworkManager/developers/
# http://projects.gnome.org/NetworkManager/developers/settings-spec-08.html
import dbus
import time
SEEKED_SSID = "skynet"
SEEKED_PASSPHRASE = "qwertyuiop"
if __name__ == "__main__":
bus = dbus.SystemBus()
# Obtain handles to manager objects.
manager_bus_object = bus.get_object("org.freedesktop.NetworkManager",
"/org/freedesktop/NetworkManager")
manager = dbus.Interface(manager_bus_object,
"org.freedesktop.NetworkManager")
manager_props = dbus.Interface(manager_bus_object,
"org.freedesktop.DBus.Properties")
# Enable Wireless. If Wireless is already enabled, this does nothing.
was_wifi_enabled = manager_props.Get("org.freedesktop.NetworkManager",
"WirelessEnabled")
if not was_wifi_enabled:
print "Enabling WiFi and sleeping for 10 seconds ..."
manager_props.Set("org.freedesktop.NetworkManager", "WirelessEnabled",
True)
# Give the WiFi adapter some time to scan for APs. This is absolutely
# the wrong way to do it, and the program should listen for
# AccessPointAdded() signals, but it will do.
time.sleep(10)
# Get path to the 'wlan0' device. If you're uncertain whether your WiFi
# device is wlan0 or something else, you may utilize manager.GetDevices()
# method to obtain a list of all devices, and then iterate over these
# devices to check if DeviceType property equals NM_DEVICE_TYPE_WIFI (2).
device_path = manager.GetDeviceByIpIface("wlan0")
print "wlan0 path: ", device_path
# Connect to the device's Wireless interface and obtain list of access
# points.
device = dbus.Interface(bus.get_object("org.freedesktop.NetworkManager",
device_path),
"org.freedesktop.NetworkManager.Device.Wireless")
accesspoints_paths_list = device.GetAccessPoints()
# Identify our access point. We do this by comparing our desired SSID
# to the SSID reported by the AP.
our_ap_path = None
for ap_path in accesspoints_paths_list:
ap_props = dbus.Interface(
bus.get_object("org.freedesktop.NetworkManager", ap_path),
"org.freedesktop.DBus.Properties")
ap_ssid = ap_props.Get("org.freedesktop.NetworkManager.AccessPoint",
"Ssid")
# Returned SSID is a list of ASCII values. Let's convert it to a proper
# string.
str_ap_ssid = "".join(chr(i) for i in ap_ssid)
print ap_path, ": SSID =", str_ap_ssid
if str_ap_ssid == SEEKED_SSID:
our_ap_path = ap_path
break
if not our_ap_path:
print "AP not found :("
exit(2)
print "Our AP: ", our_ap_path
# At this point we have all the data we need. Let's prepare our connection
# parameters so that we can tell the NetworkManager what is the passphrase.
connection_params =
"802-11-wireless":
"security": "802-11-wireless-security",
,
"802-11-wireless-security":
"key-mgmt": "wpa-psk",
"psk": SEEKED_PASSPHRASE
,
# Establish the connection.
settings_path, connection_path = manager.AddAndActivateConnection(
connection_params, device_path, our_ap_path)
print "settings_path =", settings_path
print "connection_path =", connection_path
# Wait until connection is established. This may take a few seconds.
NM_ACTIVE_CONNECTION_STATE_ACTIVATED = 2
print """Waiting for connection to reach """ \
"""NM_ACTIVE_CONNECTION_STATE_ACTIVATED state ..."""
connection_props = dbus.Interface(
bus.get_object("org.freedesktop.NetworkManager", connection_path),
"org.freedesktop.DBus.Properties")
state = 0
while True:
# Loop forever until desired state is detected.
#
# A timeout should be implemented here, otherwise the program will
# get stuck if connection fails.
#
# IF PASSWORD IS BAD, NETWORK MANAGER WILL DISPLAY A QUERY DIALOG!
# This is something that should be avoided, but I don't know how, yet.
#
# Also, if connection is disconnected at this point, the Get()
# method will raise an org.freedesktop.DBus.Error.UnknownMethod
# exception. This should also be anticipated.
state = connection_props.Get(
"org.freedesktop.NetworkManager.Connection.Active", "State")
if state == NM_ACTIVE_CONNECTION_STATE_ACTIVATED:
break
time.sleep(0.001)
print "Connection established!"
#
# Connection is established. Do whatever is necessary.
# ...
#
print "Sleeping for 5 seconds ..."
time.sleep(5)
print "Disconnecting ..."
# Clean up: disconnect and delete connection settings. If program crashes
# before this point is reached then connection settings will be stored
# forever.
# Some pre-init cleanup feature should be devised to deal with this problem,
# but this is an issue for another topic.
manager.DeactivateConnection(connection_path)
settings = dbus.Interface(
bus.get_object("org.freedesktop.NetworkManager", settings_path),
"org.freedesktop.NetworkManager.Settings.Connection")
settings.Delete()
# Disable Wireless (optional step)
if not was_wifi_enabled:
manager_props.Set("org.freedesktop.NetworkManager", "WirelessEnabled",
False)
print "DONE!"
exit(0)
【讨论】:
你能告诉我 WEP 的安全命令是什么吗? 抱歉,不需要研究如何使用 WEP 执行此操作,因此我无法在此为您提供帮助。不过,我不认为会有太大的不同。 @ZalewaPL 我知道距离上次回复已经快一年了,但是根据link,您甚至不需要输入安全类型(WEP、WPA2 等),您只需需要提供密码(psk)。 AddAndActivateConnection 的第一个参数的引用:Connection settings and properties; if incomplete missing settings will be automatically completed using the given device and specific object.
所以我从 connection_params 中删除了 security 和 key-mgmt 并成功连接。 :)
@kv1dr 很高兴知道。很高兴听到这个 SO 条目正在帮助其他人,因为我的计划发生了变化,我没有在任何地方的任何真正的解决方案中使用它。
为未来的读者添加更多信息。可以在here 找到连接设置和属性的完整列表。您主要想查看802-11-wireless-security 设置。以上是关于在 Linux 上从 Python 连接到受保护的 WiFi的主要内容,如果未能解决你的问题,请参考以下文章
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