Question

Input validation is one of the main things you can do to prevent a variety of different types of attacks. C#

program that accepts an e-mail address and a password as input and validates it using the following methods (Please note, this is not all-inclusive.):

For the E-Mail Address:

Best practice for validating an email address:

• It is case sensitive in the local portion of the address (left of the rightmost @ character)
• Has non-alphanumeric characters in the local-part (including + and @)
• Has zero or more labels
• Check for presence of at least one @ symbol in the address

For Passwords:

You will need to make sure that all passwords meet the company's criteria.

• Data Type validation
• Format validation
• That the password has at least 10 characters, 1 upper case, 1 lower case, 1 number between 1 and 20.
• That it doesn't use semicolons or quotes.

PART OF THE CODE IS LISTED BELOW:

using System;

using System.Net.Mail;

using System.Linq;

using System.Collections.Generic;

namespace EmailVerifier

{

class Program

{

static void ValidateEmail(string emailAddress)

{

Console.WriteLine("Hello and welcome to the email address verifier");

Console.WriteLine("When prompter, please enter your email address for verification");

Console.WriteLine("The program will then verify the address.");

   try {

       MailAddress testmail = new MailAddress (emailAddress);

   }

   catch(ArgumentNullException ex) {

       Console.WriteLine("nnAddress is null!: " + ex.Message + "n");

   }

   catch(ArgumentException ex) {

       Console.WriteLine("nnAddress is emty!: " + ex.Message + "n");

   }

   catch(FormatException ex) {

       Console.WriteLine("nnAddress is not in the correct format!: " + ex.Message + "n");

   }

   catch {

       Console.WriteLine("nnEmail is verified!");

   }

}

}

}