/// <summary>
/// Capitalizes characters on the password.
/// </summary>
/// <param name="password">The password.</param>
/// <param name="capitalizationType">The capitalization type.</param>
/// <returns>The capitalized password.</returns>
private static string CapitalizePassword(string password, CapitalizationTypes capitalizationType, RandomNumber randomNumber)
{
if (capitalizationType == CapitalizationTypes.None)
return password;
char[] passwordChars = password.ToCharArray();
if (capitalizationType == CapitalizationTypes.FirstLetter)
{
// Loop through charactes and make the first letter upercase.
for (int i = 0; i < passwordChars.Length; i++)
{
if (char.IsLetter(passwordChars[i]) && char.IsLower(passwordChars[i]))
{
passwordChars[i] = char.ToUpper(passwordChars[i]);
break;
}
}
}
else
{
// First let's make sure this can be applied to the current string
bool hasLetter = false;
for (int i = 0; i < passwordChars.Length; i++)
{
if (char.IsLetter(passwordChars[i]))
{
hasLetter = true;
break;
}
}
// Get a random letter from the password and make it uppercase
if (hasLetter)
{
while (true)
{
int i = randomNumber.Next(passwordChars.Length);
if (char.IsLetter(passwordChars[i]) && char.IsLower(passwordChars[i]))
{
passwordChars[i] = char.ToUpper(passwordChars[i]);
break;
}
}
}
}
return new string(passwordChars);
}
/// <summary>
/// Generate a random dictionary password.
/// </summary>
/// <param name="prf">The password profile to use.</param>
/// <param name="crsRandomSource">The cryptographic stream.</param>
/// <returns>A generated ProtectedString password.</returns>
public override ProtectedString Generate(PwProfile prf, CryptoRandomStream crsRandomSource)
{
// Get the generator options.
GeneratorOptions options = new GeneratorOptions(prf.CustomAlgorithmOptions);
// Check if a word dictionary has already been loaded, if not, load it.
if (_wordDictionary == null || _currentWordLength != options.WordLength)
{
_wordDictionary = ExtractWordDictionary(options.WordLength);
_currentWordLength = options.WordLength;
}
// Get a random word from the dictionary
RandomNumber randomNumber = new RandomNumber(crsRandomSource);
string password = _wordDictionary.Count > 0 ? _wordDictionary[randomNumber.Next(_wordDictionary.Count)] : string.Empty;
_wordDictionary.Remove(password);
// Substitute characters if specified.
if (options.SubstituteCharacters && !string.IsNullOrEmpty(options.SubstitutionList))
password = SubstituteCharacters(password, options.SubstitutionList);
// Capitalize if necessary
if (options.CapitalizationType != CapitalizationTypes.None)
password = CapitalizePassword(password, options.CapitalizationType, randomNumber);
return new ProtectedString(false, password);
}
