Powershell Invoke-WebRequest login

Question

I'm having an issue using the example given in powershell for invoke-WebRequest my code below:

$wr = Invoke-WebRequest -URi "http://localhost:51880/Users/Login.aspx" -SessionVariable SMSession
$SMSession
$dbForm = $wr.Forms[0]
$dbForm
$dbForm.fields

$dbForm.Fields["Login1_Username"] = "johnsmith"
$dbForm.Fields["Login1_Password"] = "password1"



$r = invoke-WebRequest -Uri "http://localhost:51880/Users/Login.aspx"  -WebSession $SMSession -Method Post -Body $dbForm.Fields

I'm getting an error saying "Cannot bind parameter 'Uri'. Cannot covert value to System.Uri.

I've had a look about and although there are different examples of this code none seem to work for me. Could someone please help me, i don't under stand what this final part is doing ($r) all it seems to be doing is calling the same page again and not actually logging in.

Thanks

Answer 1

I had the very same issue and I think my solution should work for you too.

First, install Fiddler. Then while fiddler is running, login to the website manually. You should see the login request in the fiddler trace - If you look at the WebForms tab on the trace you should see the Username and Password fields populated there.

For some reason, when logging in manually, the field names were different! The field names had "$" character in places that powerShell had shown as "_" characters, e.g. ContentPlaceHolder$txtUserName, not ContentPlaceHolder_txtUserName that PowerShell displayed.

So, instead of assigning values to the Username and password fields that powerShell claimed were part of the form, I deleted those, created new fields with the same names shown in Fiddler, then populated those new fields.

Also, since "$" is a special character within powerShell, you need to prefix that with ` in order to use it simply as a dollar sign, to prevent powerShell thinking you are referring to the start of a variable name.

See code below :-

$webRequest = Invoke-WebRequest -URi "http://YourWebsite/Login.aspx" -SessionVariable SMSession 

$dbForm = $webRequest.Forms[0] 

# For some reason, the field values returned have underscores instead of $ signs! Need to delete this, then recreate
# with the correct values, using ` to allow $ to be passed without treating it as a variable.
$dbForm.fields.Remove("ContentPlaceHolder_txtUserName")
$dbForm.fields.Remove("ContentPlaceHolder_txtPassword")

$dbform.fields.Add("ContentPlaceHolder`$txtUserName", "admin")
$dbform.fields.Add("ContentPlaceHolder`$txtPassword", "Password2")

#$dbform.fields

$r = invoke-WebRequest -Uri ("http://YourWebsite/Login.aspx") -WebSession $SMSession -Method Post -Body $dbForm.Fields 

$r.RawContent

Answer 2

There are a couple of problems with your script.

1. If you check which fields are available in $dbForm.Fields, you will see:

   Key                     Value      
   ---                     -----      
   lsd                     AVq5lobS   
   display                            
   enable_profile_selector            
   isprivate                          
   legacy_return           0          
   profile_selector_ids               
   return_session                     
   skip_api_login                     
   signed_next                        
   trynum                  1          
   u_0_0                              
   u_0_1                              
   lgnrnd                  065033_QxW1
   lgnjs                   n          
   email                     
   pass                      
   persistent                         
   default_persistent      1    
   

   So you probably need to replace the lines where you pass the login details with:

   $dbForm.Fields["email"] = "johnsmith"
   $dbForm.Fields["pass"] = "password1"
   

2. Not sure if it's a typo or not but the bracket in your last line doesn't need to be there (after removing that I can run the script without any errors).

I think what the script is trying to do is, with the first Invoke-WebRequest, it retrieves the login page, so that we know which fields are available to to us (e.g. email and pass). The next Invoke-WebRequest is then supposed to send the values we entered back to the page using the Post method.