I’m trying to scrape a page for data, but their login process has me stumped. As it’s a ASP Net site, my searches has me including __VIEWSTATE and __VIEWSTATEGENERATOR, but I cannot find __EVENTTARGET or __EVENTVALIDATION, not sure if they can be missing sometimes.

The Website login page has this form (Personal data get’s prefilled, so * those):

<form method="get" action="./login.aspx" id="validateSubmitForm" autocomplete="off" novalidate="">
<div class="aspNetHidden">
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="*****long viewstate here****" />
</div>

<div class="aspNetHidden">

    <input type="hidden" name="__VIEWSTATEGENERATOR" id="__VIEWSTATEGENERATOR" value="******" />
</div>

                      <div class="row">
                        <div class="form-group col-md-12 mb-4">
                            <!--
                          <input type="email" class="form-control input-lg" id="email" aria-describedby="emailHelp"
                            placeholder="email"> -->
                            <input name="TextBox1N" type="text" value="*******" id="TextBox1N" title="Username" class="form-control input-lg" placeholder="Username" />
                        </div>
                        <div class="form-group col-md-12 ">
                            <!--
                          <input type="password" class="form-control input-lg" id="password" placeholder="Password">
                            -->
                            <input name="TextBox2N" type="password" id="TextBox2N" class="form-control input-lg" placeholder="Password" value="******" />
                        </div>
                        <div class="form-group col-md-12 ">

                        </div>
                        <div class="col-md-12">

                          <div class="d-flex justify-content-between mb-3">

                            <div class="custom-control custom-checkbox mr-3 mb-3">
                                <!--
                              <input type="checkbox" class="custom-control-input" id="customCheck2">
                              <label class="custom-control-label" for="customCheck2">Remember me</label>
                                -->
                                <input id="CheckBox1N" type="checkbox" name="CheckBox1N" checked="checked" />
                                <span id="remember_meN" for="CheckBox1N">Remember me</span>
                            </div>

                            <a class="text-color" href="remember.aspx"> Remember </a>

                          </div>
                            <!--
                          <button type="submit" class="btn btn-primary btn-pill mb-4" style="width:100% !important">Sign In</button>
                            -->
                            <input type="submit" name="Button1N" value="Sign in" id="Button1N" class="btn btn-primary btn-pill mb-4" style="width:100% !important" />
                          <p>
                              Don't have an account yet ?

                            <a class="text-blue" href="registrati.aspx"> Sign</a>
                              <!--
                              <input type="submit" name="Button2N" value="Sign up" id="Button2N" class="text-blue" />
                                      -->
                          </p>
                        </div>
                      </div>
                    </form>

What I’ve cobbled together so far is (url and login info masked):

from bs4 import BeautifulSoup
import requests

#Session Setup
s = requests.Session()
s.headers.update({"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"})
uName='******'
pwd ='******' 

#Load page
url='http://***/login.aspx'
r = s.get(url)
soup = BeautifulSoup(r.text, 'html.parser')

#Set params
paramsPost = {"TextBox1N": uName,
              "TextBox2N": pwd,
              "CheckBox1N": "on",
              "Button1N": "Sign in"
             }

#Add __VIEWSTATE params
paramsPost['__VIEWSTATE'] = soup.find('input', id='__VIEWSTATE')['value']
paramsPost['__VIEWSTATEGENERATOR'] = soup.find('input', id='__VIEWSTATEGENERATOR')['value']

#Login to a GET form
req = requests.Request('GET', url, data=paramsPost)
prep = req.prepare()
pUrl = prep.url+'?'+prep.body #this was mostly done so I could print the full url and verify against a browser generated one
r = s.get(url)

For posterity I have also tried the following:

r = s.post(url, data=paramsPost)
print(r.url)

Both ways just send me to the ./error.aspx page.

Logging in with a browser and inspecting the network shows a GET request was made, __VIEWSTATE, __VIEWSTATEGENERATOR, TextBox1N, TextBox2N, CheckBox1N and Button1N was added to the Request URL. Status 302 returned and then redirected to ./dashboardAssets.aspx

Interestingly, __VIEWSTATE my code returns is shorter than the __VIEWSTATE my browser returns. Is this related?

Everything I Google or Search on SO points to __EVENT params, but I can’t locate them, so not sure this site needs them.

Any other ideas I can try?