Pseudo Code for Simple Log In Function

Overview

This pseudo code outlines a simple log in function that connects to a database to authenticate a user. It includes steps for capturing user input, querying the database, and validating credentials.

Main Steps

1. Collect user input (username and password).
2. Connect to the database.
3. Query the database to find a matching user.
4. Validate the password.
5. Return the authentication result.

Pseudo Code

FUNCTION logIn(username, password):
    BEGIN
        // Step 1: Validate input
        IF username is NULL OR password is NULL THEN
            RETURN "Error: Username and password cannot be empty."
        ENDIF

        // Step 2: Connect to the database
        dbConnection = CONNECT TO database

        // Step 3: Prepare SQL query to retrieve user data
        sqlQuery = "SELECT password_hash FROM users WHERE username = username"

        // Step 4: Execute the query
        result = EXECUTE sqlQuery ON dbConnection

        // Step 5: Check if user exists
        IF result is EMPTY THEN
            RETURN "Error: User not found."
        ENDIF 

        // Step 6: Retrieve the stored password hash from the result
        storedPasswordHash = result.password_hash

        // Step 7: Validate the provided password against the stored hash
        IF VERIFY PASSWORD(password, storedPasswordHash) THEN
            RETURN "Success: User authenticated."
        ELSE
            RETURN "Error: Incorrect password."
        ENDIF 

        // Step 8: Close database connection
        CLOSE dbConnection
    END

Functions Described

• logIn(username, password): Main function that orchestrates the log in process.
• CONNECT TO database: Connects to the database.
• EXECUTE sqlQuery ON dbConnection: Executes the SQL query and returns results.
• VERIFY PASSWORD(password, storedPasswordHash): Compares the provided password with the stored password hash.
• CLOSE dbConnection: Closes the connection to the database to free resources.

Comments

• The function begins by validating user input to ensure that both username and password are provided.
• It then establishes a connection to an existing database.
• An SQL query is constructed to search for a user by username.
• Once the user data is retrieved, it checks if the password provided matches the stored password hash.
• Finally, it returns appropriate messages based on the authentication outcome.

This pseudo code aims for clarity and serves as a guide for implementing a simple log in functionality within a software application.