How to encrypt password with hash function in Java?

Question

Hello, everybody!
I will need to store user passwords in a database, but for stronger security I want to store these passwords hashed, so I know I will need a column for the password and for the salt value.
So, I'd like that you indicate me a very good article or tutorial (preferable from Sun) that shows me how to use Java to encrypt and decrypt passwords with hash. It doesn't necessarily need to deal with database. I can implement this part myself after seeing how Java manage encryption with hash functions.
Thank you very much.
Marcos

Answer 1

I will tell you more precisely what I want to get better for you to help me.
As I said I implemented in .NET what I need to implement in Java now. In my
database I have a table with this structure (I omitted that columns that are not
necessary to our discussion):
CREATE TABLE EMPLOYEES
ID NOT NULL PRIMARY KEY,
PASSWORD VARCHAR(40), -- password encrypted
HASH_SALT VARCHAR(10) -- salt value used to encrypt password
So, in the table I have a column to store the password encrypted and a column to
store the salt value.
Below is a little utility class (in C#) that I use to generate the salt and
the hashed password.
public static class PasswordUtilities
    public static string GenerateSalt()
        RNGCryptoServiceProvider encoder = new RNGCryptoServiceProvider();
        byte[] buffer = new byte[5];
        encoder.GetBytes(buffer);
        return Convert.ToBase64String(buffer);
    public static string EncryptPassword(string password, string salt)
        string encryptedPassword =
            FormsAuthentication.HashPasswordForStoringInConfigFile(
            password + salt, "SHA1");
        return encryptedPassword;
}As you can see, the class is fairly simple. It only has two methods: one to
generate the salt value that will be used to encrypt the password and another
one to encrypt the password. The method HashPasswordForStoringInConfigFile of
the FormsAuthentication class is what really hash the password with the salt
value. This class belongs to the .NET library, so we can't see its source code,
but it doesn't matter for our discussion as I know that we can implement
something similar in Java.
Below is a little sample code showing the use of the utility class above to
encrypt a password.
public class Encrypt
    public static void Main(string args[])
        string password = "Secret";
        string salt = PasswordUtilities.GenerateSalt();
        string encryptedPassword = PasswordUtilities.EncryptPassword(password, salt);
        // now I store 'encryptedPassword' in the PASSWORD column and 'salt'
        // in the HASH_SALT column in the EMPLOYEES table.
}To verify if a password is correct I can use the code below:
public class VerifyPassword
    public static void Main(string args[])
        string password = GetPasswordFromUser();
        // Let's assume that employee is an instance that corresponds to a row
        // in the database and the properties HashSalt and Password correspond
        // to the HASH_SALT and PASSWORD columns respectively.
        Employee employee = GetEmployeeFromDatabase(1);
        string salt = employee.HashSalt;
        string encryptedPassword = PasswordUtilities.EncryptPassword(password, salt);
        bool passwordMatch = employee.Password.Equals(encryptedPassword);
        System.Console.WriteLine(passwordMatch);
}The only thing that interest me in this discussion is the PasswordUtilities class.
As you saw its code is in C#, using the .NET framework libraries.
What I want is to have this same little class coded in Java, to generate the salt
value and to encrypt the password passed in using salt value generated. If you could
help me to do that with articles that have what I want or with code that already do
that I would really appreciate.
Thank you in advance.
Marcos