Hello All:

we are trying to do performance testing of the an Outsystems application using JMeter. We are making a POST request to the login page. But we are not able to get pass login page even we are using correct credentials. We are either redirected to the error page or we get error code 302. We have found that there is an issue with the encryption of __OSVSTATE value. 

It is causing inclusion of extra characters even though we are not using URL encoding on the value. 

Upon disabling the encryption for __OSVSTATE on server, value is still coming encrypted.

When we checked the logs we found that there is an error related to base64 encoding. We got Invalid base64 encoding for the __OSVSTATE value that we are sending back to the server. 

So, Invalid __OSVSTATE parameter's value is not allowing us to test other pages where authentication is needed. Causing JMeter to receive either "internal error" or redirecting back to login page.

Below given are the screen shots of the parameters we are setting in JMeter for making a POST request.

the Value of __OSVSTATE is being extracted from the response using regular expression and storing it in a variable in Jmeter ${osvstate}.

We have crossed checked several times that we are passing the correct __OSVSTATE value in the request but it's not working.

Please can Any One help us out here with this issue?

Thanks