Hash a Password and Verify Password Using C# .Net Core (Dot Net Core)

Needed nuget packages :

1. Microsoft.AspNetCore.Cryptography.KeyDerivation

Needed Namespaces :

1. using Microsoft.AspNetCore.Cryptography.KeyDerivation;
2. using System;
3. using System.Security.Cryptography;

There are two functions :

1. HashPassword : This function accepts three parameters:
   1. password : Password to hash
   2. salt : the custom salt of 16 byte length
   3. needsOnlyHash : If you don’t want to return salt with hash
2. VerifyPassword : This function accepts two parameters:
   1. hashedPasswordWithSalt : Password and salt in format hasedPassword:salt
   2. passwordToCheck: The password that is to be checked for correctness.

The HashPassword function returns the result in format :
hasedPassword:salt Or hasedPassword

        private string HashPassword(string password, byte[] salt = null, bool needsOnlyHash = false)
        {
            if (salt == null || salt.Length != 16)
            {
                // generate a 128-bit salt using a secure PRNG
                salt = new byte[128 / 8];
                using (var rng = RandomNumberGenerator.Create())
                {
                    rng.GetBytes(salt);
                }
            }

            string hashed = Convert.ToBase64String(KeyDerivation.Pbkdf2(
                password: password,
                salt: salt,
                prf: KeyDerivationPrf.HMACSHA256,
                iterationCount: 10000,
                numBytesRequested: 256 / 8));

            if (needsOnlyHash) return hashed;
            // password will be concatenated with salt using ':'
            return $"{hashed}:{Convert.ToBase64String(salt)}";
        }

        private bool VerifyPassword(string hashedPasswordWithSalt, string passwordToCheck)
        {
            // retrieve both salt and password from 'hashedPasswordWithSalt'
            var passwordAndHash = hashedPasswordWithSalt.Split(':');
            if (passwordAndHash == null || passwordAndHash.Length != 2)
                return false;
            var salt = Convert.FromBase64String(passwordAndHash[1]);
            if (salt == null)
                return false;
            // hash the given password
            var hashOfpasswordToCheck = HashPassword(passwordToCheck, salt, true);
            // compare both hashes
            if (String.Compare(passwordAndHash[0], hashOfpasswordToCheck) == 0)
            {
                return true;
            }
            return false;
        }