Get request with Python 2.7 - python

I'm trying to send a get request with python 2.7. The server I'm trying to access has basic authentication and the url I'm accessing is just displaying a string I want my script to print that string.
So basically my code is sending a get request to this server and it saves the string it receives from the server, which also has basic auth.
The problem is that it prints out the html page for the login page not the string.
username = 'username'
password = 'password'
server = "http://someserver/update"
def get_auth():
request = urllib2.Request(server)
base64string = base64.encodestring('%s:%s' % (username, password)).replace('\n', '')
request.add_header("Authorization", "Basic %s" % base64string)
result = urllib2.urlopen(request)
# print(result)
def get_string():
f = urllib2.urlopen(server)
print f.read()
def main():
get_auth()
get_string()
if __name__ == '__main__':
main()

They way you are using get_string() never actually sends the authentication header.
Rather than fiddling with urllib2, you might want to try the requests library instead::
import requests
requests.get('http://someserver/update', auth=('username', 'password'))
see: http://docs.python-requests.org/en/latest/user/authentication/

Related

Python - urllib - Server is not getting everything after '?' in URL

I am writing a Python3 script to trigger an Axis camera via their HTTP API. The string they need in the url to trigger the Digital Input (with authorization) is:
"http://{ip}/axis-cgi/param.cgi?action=update&IOPort.I0.Input.Trig={open/closed}"
If I put this in a browser it works AKA response 200 - OK. When I run this on my Linux machine using the urllib request.
#encode user,pass
values = { 'username': username,'password': password }
data = urllib.urlencode(values)
#Axis param.cgi action
action = "update"
trig = "closed"
cgi_args = {"action": action, "IOPort.I0.Input.Trig": trig}
cgi_data = urllib.urlencode(cgi_args)
url = "http://{ip}/axis-cgi/param.cgi?{data}".format(ip=ip, data=cgi_data)
req = urllib2.Request(url, data, headers={'Content-type': 'text/html'})
print(req.get_full_url())
response = urllib2.urlopen(req)
result = response.read()
print (result)
The output is:
http://192.168.50.191/axis-cgi/param.cgi?action=update&IOPort.I0.Input.Trig=closed
action must be specified
I know that I am authenticated otherwise I get Unauthorized response from server.
As you can see for debugging I print the req.get_full_url() to make sure I've built the url string correctly, however the server responds with action must be specified which is what I get in the browser when I just have http://192.168.50.191/axis-cgi/param.cgi? in the address bar. So the action portion of the URL appears to not be making it to the server.
I've tried:
Using %3F as the ? character, but I get 404 error
Embedding the data in the data parameter does not work either
Anything I am missing here?
used pycurl with digest authorization for a GET request with auth:
def configCurl():
username = "user"
password = "pass"
auth_mode = pycurl.HTTPAUTH_DIGEST
curl = pycurl.Curl()
curl.setopt(pycurl.HTTPAUTH, auth_mode)
curl.setopt(pycurl.USERPWD, "{}:{}".format(username, password))
curl.setopt(pycurl.WRITEFUNCTION, lambda x: None)
return curl
curl = configCurl()
curl.setopt(curl.URL, url)
curl.perform()
curl.close()

Base64 Encoding issue - Python vs Powershell

I am trying to encode an auth token and pass it to a REST API, this works fine with powershell but applying the same method to python script throws 'unauthorized' exception.
I suspect there is a problem in encoded value. Not able to figure out the solution. Any ideas ?
The rest endpoint is IBM uDeploy.
Powershell
$tokenEncoded = [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes( "PasswordIsAuthToken:{`"token`":`"$pass`"}" ))
$basicAuthValue = "Basic $tokenEncoded"
$headers = #{}
$headers.Add("Authorization", $basicAuthValue)
$response = Invoke-RestMethod -Method Put -Headers $headers -Uri $requestUri -Body $jsonRequest
Python
epass = base64.b64encode("PasswordIsAuthToken:{\"token\":\"$password\"}")
print 'base64 encoded: ' + epass
opener = urllib2.build_opener(urllib2.HTTPHandler)
req = urllib2.Request(reqUrl,json.dumps(json_data))
req.add_header('Authorization', 'Basic '+epass)
req.get_method = lambda: 'PUT'
resp = opener.open(req)
You are sending the literal string $password as the token, not the contents of a variable named password.
You only need to include the PasswordIsAuthToken and your token in a Basic Auth HTTP header (PasswordIsAuthToken forms the username, and token the password):
epass = base64.b64encode("PasswordIsAuthToken:" + password)
opener = urllib2.build_opener(urllib2.HTTPHandler)
req = urllib2.Request(reqUrl,json.dumps(json_data))
req.add_header('Authorization', 'Basic ' + epass)
If you reall need to wrap the token in a JSON-like structure then you'd need to use string formatting (which the Powershell code also does, but you omitted):
epass = base64.b64encode('PasswordIsAuthToken:{"token":"%s"}' % password)
or you could use the json module:
epass = base64.b64encode('PasswordIsAuthToken:' + json.dumps({'token': password}))
However, I believe the system should accept the token unwrapped.
I strongly recommend you use the requests library instead, which makes using a REST API vastly cleaner:
import requests
auth = ('PasswordIsAuthToken', password)
# or alternatively
# auth = ('PasswordIsAuthToken', '{"token":"%s"}' % password)
response = requests.put(json=json_data, auth=auth)
Note that there is no need to encode the JSON body yourself, nor do you have to encode the Basic Auth header.

How to authenticate a site with Python using urllib2?

After much reading here on Stackoverflow as well as the web I'm still struggling with getting things to work.
My challenge: to get access to a restricted part of a website for which I'm a member using Python and urllib2.
From what I've read the code should be like this:
mgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
url = 'http://www.domain.com'
mgr.add_password(None, url, 'username', 'password')
handler = urllib2.HTTPBasicAuthHandler(mgr)
opener = urllib2.build_opener(handler)
urllib2.install_opener(opener)
try:
response = urllib2.urlopen('http://www.domain.com/restrictedpage')
page = response.read()
print page.geturl()
except IOError, e:
print e
The print doesn't print "http://www.domain.com/restrictedpage", but shows "http://www.domain.com/login" so my credentials aren't stored/processed and I'm being redirected.
How can I get this to work? I've been trying for days and keep hitting the same dead ends. I've tried all the examples I could find to no avail.
My main question is: what's needed to authenticate to a website using Python and urllib2?
Quick question: what am I doing wrong?
Check first manually what is really happening when you are successfully authenticated (instructions with Chrome):
Open develper tools in Chrome (Ctrl + Shift + I)
Click Network tab
Go and do the authentication manually (go the the page, type user + passwd + submit)
check the POST method in the Network tab of the developer tools
check the Request Headers, Query String Parameters and Form Data. There you find all the information needed what you need to have in your own POST.
Then install "Advanced Rest Client (ARC)" Chrome extension
Use the ARC to construct a valid POST for authentication.
Now you know what to have in your headers and form data. Here's a sample code using Requests that worked for me for one particular site:
import requests
USERNAME = 'user' # put correct usename here
PASSWORD = 'password' # put correct password here
LOGINURL = 'https://login.example.com/'
DATAURL = 'https://data.example.com/secure_data.html'
session = requests.session()
req_headers = {
'Content-Type': 'application/x-www-form-urlencoded'
}
formdata = {
'UserName': USERNAME,
'Password': PASSWORD,
'LoginButton' : 'Login'
}
# Authenticate
r = session.post(LOGINURL, data=formdata, headers=req_headers, allow_redirects=False)
print r.headers
print r.status_code
print r.text
# Read data
r2 = session.get(DATAURL)
print "___________DATA____________"
print r2.headers
print r2.status_code
print r2.text
For HTTP Basic Auth you can refer this : http://www.voidspace.org.uk/python/articles/authentication.shtml

does urllib2 support preemptive authentication authentication?

I am trying access a REST API.
I can get it working in Curl/REST Client (the UI tool), with preemptive authentication enabled.
But, using urllib2, it doesn't seem to support this by default and I can't find a way to turn it on.
Thanks :)
Here's a simple Preemptive HTTP basic auth handler, based on the code from urllib2.HTTPBasicAuthHandler. It can be used in the exact same manner, except an Authorization header will be added to every request with a matching URL. Note that this handler should be used with a HTTPPasswordMgrWithDefaultRealm. That's because there is no realm coming back in a WWW-Authenticate challenge since you're being preemptive.
class PreemptiveBasicAuthHandler(urllib2.BaseHandler):
def __init__(self, password_mgr=None):
if password_mgr is None:
password_mgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
self.passwd = password_mgr
self.add_password = self.passwd.add_password
def http_request(self,req):
uri = req.get_full_url()
user, pw = self.passwd.find_user_password(None,uri)
#logging.debug('ADDING REQUEST HEADER for uri (%s): %s:%s',uri,user,pw)
if pw is None: return req
raw = "%s:%s" % (user, pw)
auth = 'Basic %s' % base64.b64encode(raw).strip()
req.add_unredirected_header('Authorization', auth)
return req
similar to #thom-nichols's answer; but subclassing HTTPBasicAuthHandler also handling HTTPS requests.
import urllib2
import base64
class PreemptiveBasicAuthHandler(urllib2.HTTPBasicAuthHandler):
'''Preemptive basic auth.
Instead of waiting for a 403 to then retry with the credentials,
send the credentials if the url is handled by the password manager.
Note: please use realm=None when calling add_password.'''
def http_request(self, req):
url = req.get_full_url()
realm = None
# this is very similar to the code from retry_http_basic_auth()
# but returns a request object.
user, pw = self.passwd.find_user_password(realm, url)
if pw:
raw = "%s:%s" % (user, pw)
auth = 'Basic %s' % base64.b64encode(raw).strip()
req.add_unredirected_header(self.auth_header, auth)
return req
https_request = http_request
here is an example for dealing with a jenkins server which does not send you 401 http errors (retry with auth). I'm using urllib2.install_opener to make things easy.
jenkins_url = "https://jenkins.example.com"
username = "johndoe"
api_token = "some-cryptic-value"
auth_handler = PreemptiveBasicAuthHandler()
auth_handler.add_password(
realm=None, # default realm.
uri=jenkins_url,
user=username,
passwd=api_token)
opener = urllib2.build_opener(auth_handler)
urllib2.install_opener(opener)
Depending on what kind of authentication is required, you can send the Authorization headers manually by adding them to your request before you send out a body.

Python urllib2 Basic Auth Problem

Update: based on Lee's comment I decided to condense my code to a really simple script and run it from the command line:
import urllib2
import sys
username = sys.argv[1]
password = sys.argv[2]
url = sys.argv[3]
print("calling %s with %s:%s\n" % (url, username, password))
passman = urllib2.HTTPPasswordMgrWithDefaultRealm()
passman.add_password(None, url, username, password)
urllib2.install_opener(urllib2.build_opener(urllib2.HTTPBasicAuthHandler(passman)))
req = urllib2.Request(url)
f = urllib2.urlopen(req)
data = f.read()
print(data)
Unfortunately it still won't generate the Authorization header (per Wireshark) :(
I'm having a problem sending basic AUTH over urllib2. I took a look at this article, and followed the example. My code:
passman = urllib2.HTTPPasswordMgrWithDefaultRealm()
passman.add_password(None, "api.foursquare.com", username, password)
urllib2.install_opener(urllib2.build_opener(urllib2.HTTPBasicAuthHandler(passman)))
req = urllib2.Request("http://api.foursquare.com/v1/user")
f = urllib2.urlopen(req)
data = f.read()
I'm seeing the following on the Wire via wireshark:
GET /v1/user HTTP/1.1
Host: api.foursquare.com
Connection: close
Accept-Encoding: gzip
User-Agent: Python-urllib/2.5
You can see the Authorization is not sent, vs. when I send a request via curl: curl -u user:password http://api.foursquare.com/v1/user
GET /v1/user HTTP/1.1
Authorization: Basic =SNIP=
User-Agent: curl/7.19.4 (universal-apple-darwin10.0) libcurl/7.19.4 OpenSSL/0.9.8k zlib/1.2.3
Host: api.foursquare.com
Accept: */*
For some reason my code seems to not send the authentication - anyone see what I'm missing?
thanks
-simon
The problem could be that the Python libraries, per HTTP-Standard, first send an unauthenticated request, and then only if it's answered with a 401 retry, are the correct credentials sent. If the Foursquare servers don't do "totally standard authentication" then the libraries won't work.
Try using headers to do authentication:
import urllib2, base64
request = urllib2.Request("http://api.foursquare.com/v1/user")
base64string = base64.b64encode('%s:%s' % (username, password))
request.add_header("Authorization", "Basic %s" % base64string)
result = urllib2.urlopen(request)
Had the same problem as you and found the solution from this thread: http://forums.shopify.com/categories/9/posts/27662
(copy-paste/adapted from https://stackoverflow.com/a/24048772/1733117).
First you can subclass urllib2.BaseHandler or urllib2.HTTPBasicAuthHandler, and implement http_request so that each request has the appropriate Authorization header.
import urllib2
import base64
class PreemptiveBasicAuthHandler(urllib2.HTTPBasicAuthHandler):
'''Preemptive basic auth.
Instead of waiting for a 403 to then retry with the credentials,
send the credentials if the url is handled by the password manager.
Note: please use realm=None when calling add_password.'''
def http_request(self, req):
url = req.get_full_url()
realm = None
# this is very similar to the code from retry_http_basic_auth()
# but returns a request object.
user, pw = self.passwd.find_user_password(realm, url)
if pw:
raw = "%s:%s" % (user, pw)
auth = 'Basic %s' % base64.b64encode(raw).strip()
req.add_unredirected_header(self.auth_header, auth)
return req
https_request = http_request
Then if you are lazy like me, install the handler globally
api_url = "http://api.foursquare.com/"
api_username = "johndoe"
api_password = "some-cryptic-value"
auth_handler = PreemptiveBasicAuthHandler()
auth_handler.add_password(
realm=None, # default realm.
uri=api_url,
user=api_username,
passwd=api_password)
opener = urllib2.build_opener(auth_handler)
urllib2.install_opener(opener)
Here's what I'm using to deal with a similar problem I encountered while trying to access MailChimp's API. This does the same thing, just formatted nicer.
import urllib2
import base64
chimpConfig = {
"headers" : {
"Content-Type": "application/json",
"Authorization": "Basic " + base64.encodestring("hayden:MYSECRETAPIKEY").replace('\n', '')
},
"url": 'https://us12.api.mailchimp.com/3.0/'}
#perform authentication
datas = None
request = urllib2.Request(chimpConfig["url"], datas, chimpConfig["headers"])
result = urllib2.urlopen(request)
The second parameter must be a URI, not a domain name. i.e.
passman = urllib2.HTTPPasswordMgrWithDefaultRealm()
passman.add_password(None, "http://api.foursquare.com/", username, password)
I would suggest that the current solution is to use my package urllib2_prior_auth which solves this pretty nicely (I work on inclusion to the standard lib.

Categories

Resources