ERP Login Module

A python package/module to automate login process in ERP for IIT-KGP.

Table of Contents

• Description
  • Endpoints
    • About
    • Usage
    • Usage in login workflow
  • Login
    • Input
    • Output
    • Usage
  • Session status check
    • Input
    • Output
    • Usage
• Usage
  • Prerequisites
    • ERP credentials file
      • Creating
      • Using
    • Generating token for GMail enabled googleapi
  • Example

Description

iitkgp_erp_login
   ├── endpoints.py
   ├── erp.py
   └── read_mail.py

read_mail.py contains the implementation of the getOTP(OTP_WAIT_INTERVAL) function, along with various helper functions. These functions are not intended to be used by you, the user. The only case where OTP is required is during the login process, which is handled by functions in erp.py. Hence, let this script serve as an abstraction for general users. If you want to modify the OTP fetching process, feel free to refer to the read_mail.py script.

Endpoints

The endpoints.py file includes all the necessary endpoints for the ERP login workflow.

About

• HOMEPAGE_URL: The URL of the ERP homepage/loginpage.
• SECRET_QUESTION_URL: The URL for retrieving the secret question for authentication.
• OTP_URL: The URL for requesting the OTP (One-Time Password) for authentication.
• LOGIN_URL: The URL for ERP login.
• WELCOMEPAGE_URL: The URL of the welcome page, which is accessible only when the user is NOT logged in, and behaves exactly like the HOMEPAGE_URL. However, when the user is logged in, it returns a 404 error.

Usage

from iitkgp_erp_login.endpoints import *

print(HOMEPAGE_URL)
# Output: https://erp.iitkgp.ac.in/IIT_ERP3/

print(LOGIN_URL)
# Output: https://erp.iitkgp.ac.in/SSOAdministration/auth.htm

Usage in login workflow

To automate the login process into ERP, the endpoints are hit in the following order:

1. Hit HOMEPAGE_URL using session.get(HOMEPAGE_URL). This step establishes the initial session and retrieves sessionToken.
2. Hit SECRET_QUESTION_URL using session.post(SECRET_QUESTION_URL, data={'user_id': erp_creds.ROLL_NUMBER}, headers=headers). This step fetches the secret question required for authentication.
3. Hit OTP_URL using session.post(OTP_URL, data={'typeee': 'SI', 'loginid': erp_creds.ROLL_NUMBER}, headers=headers). This step requests an OTP (One-Time Password) for authentication.
4. Finally, hit LOGIN_URL using session.post(LOGIN_URL, data=login_details, headers=headers). This step performs the actual ERP login with the provided login details and OTP.

Note session = requests.Session() is used to persist the session parameters throughout the workflow

Login

ERP login workflow is implemented in login(headers, erp_creds, OTP_WAIT_INTERVAL, session) function in erp.py. The input and output specifications for the function are mentioned below.

Input

The function requires following arguments:

1. headers: Headers for the post requests. An example is given below.

   headers = {
      'timeout': '20',
      'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/51.0.2704.79 Chrome/51.0.2704.79 Safari/537.36',
   }

2. erp_creds: ERP Login Credentials file, which is imported into python file.

   import erpcreds

3. OTP_WAIT_INTERVAL: The interval after which the API continuously checks for new OTP mail.
4. session: A requests.Session() object, to persist the session parameters throughout the workflow.

   import requests
   
   session = requests.Session()

Output

1. The function returns the following in the order of occurrence as here (sessionToken, ssoToekn):
   1. sessionToken
   2. ssoToken
2. It also modifies the session object, which now includes parameters for the logged-in session. These parameters can be utilized for further navigation within the ERP system.
3. It incorporates comprehensive logging. It prints the status of each step, providing detailed information throughout the process.

Usage

It is recommended to use the login function in the following manner:

# importing the erp.py file
import iitkgp_erp_login.erp as erp

# using the login function inside erp.py
sessionToken, ssoToken = erp.login(headers, erpcreds, 2, session)

Here's an example combining all the aspects we have discussed so far about the login function:

import requests
import erpcreds
import iitkgp_erp_login.erp as erp

headers = {
   'timeout': '20',
    'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/51.0.2704.79 Chrome/51.0.2704.79 Safari/537.36',
}

session = requests.Session()

sessionToken, ssoToken = erp.login(headers, erpcreds, 2, session)
   
print(sessionToken, ssoToken)

Note The code snippet above will not work unless the prerequisites are fulfilled

Session status check

The logic for checking the status of the session is implemented in the session_alive(session) function n erp.py. This function determines whether the given session is valid/alive or not. The input and output specifications for the function are mentioned below.

Input

The function requires following argument:

• session: requests.Session() object, to persist the session parameters throughout the workflow.

  import requests
  
  session = requests.Session()

Output

The session_alive(session) function returns the status of the session as a boolean value: True if it is alive and False if it is not.

Usage

It is recommended to use the session_alive function in the following manner:

# Importing the erp.py file
import iitkgp_erp_login.erp as erp

# Using the session_alive function inside erp.py
print(erp.session_alive(session))

Here's an example combining all the aspects we have discussed so far about the login function and session_alive function:

import requests
import time
import creds
import iitkgp_erp_login.erp as erp

headers = {
    'timeout': '20',
    'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/51.0.2704.79 Chrome/51.0.2704.79 Safari/537.36',
}

session = requests.Session()

while True:
    if not erp.session_alive(session):
        erp.login(headers, creds, 2, session)
    else:
        print("Session is alive.")

    time.sleep(2)

Note The code snippet above will not work unless the prerequisites are fulfilled

Usage

Prerequisites

The following scripts are required and MUST be present in the same directory as the script where iitkgp_erp_login module is being imported:

• erpcreds.py
• token.json

ERP credentials file

Creating

Create a .py file with your ERP credentials stored in it. Please follow the instructions below to create this file:

• You can choose any valid name for the file, adhering to Python's naming conventions.
• Do not change the variable names. Simply copy the format provided below and update the values inside the double quotes (").

  # ERP Credentials
  ROLL_NUMBER = "XXYYXXXXX"
  PASSWORD = "**********"
  SECURITY_QUESTIONS_ANSWERS = {
      "Q1" : "A1",
      "Q2" : "A2",
      "Q3" : "A3",
  }

Using

Let's suppose you have saved the ERP credentials file as erpcreds.py. To use it, you can simply import it in your Python script using the following code:

import erpcreds

print(erpcreds.ROLL_NUMBER)
# Output: XXYYXXXXX

print(erpcreds.SECURITY_QUESTIONS_ANSWERS["Q2"])
# Output: A2

Generating token for GMail enabled googleapi

1. Follow the steps in the Gmail API - Python Quickstart guide to obtain credentials.json file.

   Note The credentials.json file is permanent unless you manually delete its reference in your Google Cloud Console.

2. To generate the token.json file, follow the steps below:

   • Download the gentokenjson.py file and place it in the same folder that contains the credentials.json file

   • Import the required module, google-auth-oauthlib

     pip install google-auth-oauthlib

   • Execute gentokenjson.py with the readonly argument

     python3 gentokenjson.py readonly

   • A browser window will open, prompting you to select the Google account associated with receiving OTP for login.

   • Grant permission to the selected email address to utilize the newly enabled Gmail API.

     • Click on Continue instead of Back To Safety
     • Then, press Continue again

   • The token.json file will be generated in the same folder as the credentials.json file

   Warning The token.json file has an expiration time, so it's important to periodically check and refresh it in your projects to ensure uninterrupted access.

Example

Now, we will create a script that opens the ERP system on your default browser with a logged-in session.

1. Install the package.

   pip install iitkgp_erp_login

2. Make sure that erpcreds.py & token.json files exist in the same directory as the script we are about to create.

3. Create a file named open_erp.py and include the following code:

   import requests
   import webbrowser
   import erpcreds
   import iitkgp_erp_login.erp as erp
   from iitkgp_erp_login.endpoints import HOMEPAGE_URL
   
   headers = {
       'timeout': '20',
       'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/51.0.2704.79 Chrome/51.0.2704.79 Safari/537.36',
   }
   
   session = requests.Session()
   
   _, ssoToken = erp.login(headers, erpcreds, 2, session)
   
   logged_in_url = f"{HOMEPAGE_URL}?ssoToken={ssoToken}"
   webbrowser.open(logged_in_url)

4. Run the script.

   python3 open_erp.py