In .NET Core, you can use cryptographic functions to encrypt passwords and securely store them in a database. One common approach is to use a one-way hashing algorithm with a salt. Here's a simplified example of how you can accomplish this:
1. Add the necessary NuGet package: Install the System.Security.Cryptography package to gain access to cryptographic functions.
2. Generate a salt: A salt is a random value that adds uniqueness to each hashed password, making it harder to crack. You can generate a salt using a cryptographic random number generator. Here's an example:
byte[] salt = new byte[16];
using (var rng = RandomNumberGenerator.Create())
{
rng.GetBytes(salt);
}
3. Hash the password: Use a secure hashing algorithm, such as bcrypt, PBKDF2, or Argon2, to hash the password along with the salt. The salt should be stored alongside the hashed password in the database. Here's an example using the bcrypt algorithm:
string password = "myPassword";
string hashedPassword = BCrypt.Net.BCrypt.HashPassword(password, salt: salt);
4. Verify a password: When a user attempts to log in, you can verify their password by comparing the stored hashed password with the newly hashed password using the same salt. Here's an example:
string userEnteredPassword = "myPassword";
bool passwordMatches = BCrypt.Net.BCrypt.Verify(userEnteredPassword, hashedPassword);
By following these steps, even a DBA with access to the database would not be able to see the original password, as it is never stored in plain text. Only the hashed password and the salt are stored, and the verification process compares the hashed values.
