public static byte[] GenerateHash(HashingStrategy strategy, string password, byte[] salt, int iterations = 1000)
{
var bytes = Encoding.UTF8.GetBytes(password).Concat(salt);
switch (strategy)
{
case HashingStrategy.SHA256:
using (var sha256 = new SHA256Managed())
{
return sha256.ComputeHash(bytes.ToArray());
}
case HashingStrategy.SHA512:
using (var sha512 = new SHA512Managed())
{
return sha512.ComputeHash(bytes.ToArray());
}
case HashingStrategy.PBKDF2:
using (var pbkdf2 = new Rfc2898DeriveBytes(password, salt) { IterationCount = iterations })
{
return pbkdf2.GetBytes(salt.Length);
}
}
throw new NotImplementedException();
}
/// <summary>
/// Builds a hash set around a strategy for hashing and returns it to the user.
/// </summary>
/// <param name="the_strategy"></param>
/// <returns></returns>
public static HashSet <T> getHashSet(HashingStrategy the_strategy)
{
//go through the strategies and build a hash set accordingly
switch (the_strategy)
{
case HashingStrategy.ModTableSize:
return(new StrategyHashSet <T>(modTableSize, "Math.abs( item.GetHashCode() ) % my_table.length;"));
case HashingStrategy.MultiplyPrimeModPrimeModTable:
return(new StrategyHashSet <T>(multiplyPrimeModPrime, "int hash = item.GetHashCode();" +
" Math.abs( 37 * hash + hash % 37 ) % my_table.length;"));
default:
throw new ArgumentException("No such enum value found.");
}
}
public static byte[] GenerateSalt(HashingStrategy strategy)
{
int length = 0;
switch (strategy)
{
case HashingStrategy.SHA256: length = 32; break;
case HashingStrategy.SHA512: length = 64; break;
case HashingStrategy.PBKDF2: length = 64; break;
}
using (var random = new RNGCryptoServiceProvider())
{
var bytes = new byte[length];
random.GetBytes(bytes);
return bytes;
}
}
