How to resolve the algorithm SQL-based authentication step by step in the Julia programming language

Published on 22 June 2024 08:30 PM
#Julia

How to resolve the algorithm SQL-based authentication step by step in the Julia programming language

Table of Contents

Problem Statement

This task has three parts: This is the table definition: (pass_salt and pass_md5 would be binary(16) values, but MySQL versions before 5.0.15 strip trailing spaces when selecting them.)

Let's start with the solution:

Step by Step solution about How to resolve the algorithm SQL-based authentication step by step in the Julia programming language

The code creates a database table called users, containing the following columns:

  • userid: INT PRIMARY KEY AUTO_INCREMENT
  • username: VARCHAR(32) UNIQUE KEY NOT NULL
  • pass_salt: tinyblob NOT NULL
  • pass_md5: tinyblob NOT NULL

The create_user function inserts a new user into the users table. It first generates a random salt value, which is used to hash the password. The hashed password is then stored in the pass_md5 column.

The addusers function iterates over a dictionary of usernames and passwords, calling the create_user function for each user.

The authenticate_user function checks if a given username and password are correct. It retrieves the salt and hashed password for the given username from the database, and then hashes the provided password using the same salt. If the hashed password matches the one stored in the database, the function returns true, indicating that the user is authenticated.

The main program creates a database connection, calls the addusers function to insert some users into the database, and then calls the authenticate_user function to check if two users are authenticated correctly. Finally, it disconnects from the database.

For more information on Julia data types, refer to the official documentation.

Source code in the julia programming language

using MySQL
using Nettle  # for md5

function connect_db(uri, user, pw, dbname)
    mydb = mysql_connect(uri, user, pw, dbname)

    const command = """CREATE TABLE IF NOT EXISTS users (
                          userid INT PRIMARY KEY AUTO_INCREMENT,
                          username VARCHAR(32) UNIQUE KEY NOT NULL,
                          pass_salt tinyblob NOT NULL,
                              -- a string of 16 random bytes
                          pass_md5 tinyblob NOT NULL
                              -- binary MD5 hash of pass_salt concatenated with the password
                  );"""
    mysql_execute(mydb, command)
    mydb
end

function create_user(dbh, user, pw)
    mysql_stmt_prepare(dbh, "INSERT IGNORE INTO users (username, pass_salt, pass_md5) values (?, ?, ?);")
    salt = join([Char(c) for c in rand(UInt8, 16)], "")
    passmd5 = digest("md5", salt * pw)
    mysql_execute(dbh, [MYSQL_TYPE_VARCHAR, MYSQL_TYPE_VARCHAR, MYSQL_TYPE_VARCHAR], [user, salt, passmd5])
end

function addusers(dbh, userdict)
    for user in keys(userdict)
        create_user(dbh, user, userdict[user])
    end
end

"""
    authenticate_user
Note this returns true if password provided authenticates as correct, false otherwise
"""
function authenticate_user(dbh, username, pw)
    mysql_stmt_prepare(dbh, "SELECT pass_salt, pass_md5 FROM users WHERE username = ?;")
    pass_salt, pass_md5 = mysql_execute(dbh, [MYSQL_TYPE_VARCHAR], [username], opformat=MYSQL_TUPLES)[1]   
    pass_md5 == digest("md5", pass_salt * pw)
end

const users = Dict("Joan" => "joanspw", "John" => "johnspw", "Mary" => "marpw", "Mark" => "markpw")
const mydb = connect_db("192.168.1.1", "julia", "julia", "mydb")

addusers(mydb, users)
println("""John authenticates correctly: $(authenticate_user(mydb, "John", "johnspw")==true)""")
println("""Mary does not authenticate with password of 123: $(authenticate_user(mydb, "Mary", "123")==false)""")
mysql_disconnect(mydb)

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