public static string GetSaltedPassword(string password, string salt, SaltMethod saltMethod = SaltMethod.DoubleSalt)
{
if (string.IsNullOrWhiteSpace(password))
{
throw new ArgumentNullException("password");
}
if (string.IsNullOrWhiteSpace(salt))
{
throw new ArgumentNullException("salt");
}
switch (saltMethod)
{
case SaltMethod.PreSalt:
return(salt + password);
case SaltMethod.PostSalt:
return(password + salt);
case SaltMethod.SplitSalt:
int saltSize = salt.Length;
int halfSaltSize = saltSize / 2;
string preSalt = salt.Substring(0, halfSaltSize);
string postSalt = salt.Substring(halfSaltSize);
return(preSalt + password + postSalt);
case SaltMethod.SparseSalt:
string result = "";
char[] passwordChars = password.ToCharArray();
char[] saltChars = salt.ToCharArray();
int maxLoop = Math.Min(passwordChars.Length, saltChars.Length);
for (int i = 0; i < maxLoop; i++)
{
result += passwordChars[i] + saltChars[i];
}
if (passwordChars.Length > maxLoop)
{
result += password.Substring(maxLoop);
}
else if (saltChars.Length > maxLoop)
{
result += salt.Substring(maxLoop);
}
return(result);
default: //DoubleSalt
return(salt + password + salt);
}
}
public static string ComputeHash(string password, string salt, SaltMethod saltMethod = SaltMethod.DoubleSalt, HashSize hashSize = HashSize.S160)
{
if (string.IsNullOrWhiteSpace(password))
{
throw new ArgumentNullException("password");
}
if (string.IsNullOrWhiteSpace(salt))
{
throw new ArgumentNullException("salt");
}
string saltedPassword = GetSaltedPassword(password, salt, saltMethod);
byte[] bytesOfString = RandomStringGenerator.GetBytesFromString(saltedPassword);
byte[] hash = ComputeHash(bytesOfString, hashSize);
return(RandomStringGenerator.ToEncodedString(hash));
}
public static bool VerifyPassword(string password, string salt, string storedHash, SaltMethod saltMethod = SaltMethod.DoubleSalt, HashSize hashSize = HashSize.S160)
{
if (string.IsNullOrWhiteSpace(password))
{
throw new ArgumentNullException("password");
}
if (string.IsNullOrWhiteSpace(salt))
{
throw new ArgumentNullException("salt");
}
string verifyHash = ComputeHash(password, salt, saltMethod, hashSize);
return(verifyHash == storedHash);
}
