private static string DecryptPassword(CryptoPassword cp)
{
// Restore Buffer for IV.
var bufferIV = CryptographicBuffer.CreateFromByteArray(cp.IV);
// Restore Buffer for Encrypted Password.
var bufferEncryptedPassword = CryptographicBuffer.CreateFromByteArray(cp.EncryptedPassword);
// Restore Buffer for Key.
var bufferKeyMaterial = CryptographicBuffer.CreateFromByteArray(cp.KeyMaterial);
// Rebuild key.
var key = CreateSymmetricKey(bufferKeyMaterial);
// Get buffer for decrypted Password.
var bufferDecrypt = CryptographicEngine.Decrypt(key, bufferEncryptedPassword, bufferIV);
return(CryptographicBuffer.ConvertBinaryToString(_encoding, bufferDecrypt));
}
public static CryptoPassword Encrypt(string password, string publicKeyPhrase)
{
var cp = new CryptoPassword {
KeyPhrase = publicKeyPhrase
};
// Create a random Salt.
cp.Salt = CreateSalt();
// Create an Initialization Vector for our chosen algorithm.
cp.IV = CreateInitializationVector();
// Derive key material from the designated password-based key derivation function using the provided public key phrase.
cp.KeyMaterial = DeriveKeyMaterial(cp);
// Encrypt the password.
cp.EncryptedPassword = EncryptPassword(password, cp);
return(cp);
}
private static byte[] EncryptPassword(string password, CryptoPassword cp)
{
// Create a buffer that contains the encoded password to be encrypted.
IBuffer bufferedPassword = CryptographicBuffer.ConvertStringToBinary(password, _encoding);
// Restore Initialization Vector as buffer.
IBuffer bufferIV = CryptographicBuffer.CreateFromByteArray(cp.IV);
// Restore KeyMaterial and create symmetric key
var bufferedKey = CryptographicBuffer.CreateFromByteArray(cp.KeyMaterial);
var key = CreateSymmetricKey(bufferedKey);
// Encrypt the password
IBuffer bufferEncrypted = CryptographicEngine.Encrypt(key, bufferedPassword, bufferIV);
// Convert the buffered encryption and return it.
byte[] result;
//CryptographicBuffer.EncodeToBase64String(bufferEncrypted);
CryptographicBuffer.CopyToByteArray(bufferEncrypted, out result);
return(result);
}
private static byte[] DeriveKeyMaterial(CryptoPassword cp)
{
// Open the specified algorithm.
var provider = KeyDerivationAlgorithmProvider.OpenAlgorithm(_keyDerivationAlgorithmName);
// Create a buffer that contains the keyPhrase for use during derivation.
IBuffer bufferedSecret = CryptographicBuffer.ConvertStringToBinary(cp.KeyPhrase, _encoding);
// Restore salt bytes as buffer.
var bufferedSalt = CryptographicBuffer.CreateFromByteArray(cp.Salt);
// Create the required derivation parameters.
var pbkdf2Parameter = KeyDerivationParameters.BuildForPbkdf2(bufferedSalt, _iterationCount);
// Create a key from the buffered secret.
var keyOriginal = provider.CreateKey(bufferedSecret);
// Derive a key from the original created key and the derivation parameters.
var keyMaterial = CryptographicEngine.DeriveKeyMaterial(keyOriginal, pbkdf2Parameter, _targetKeySize);
return(CopyBufferToByteArray(keyMaterial));
}
public static string Decrypt(CryptoPassword cp)
{
cp.KeyMaterial = DeriveKeyMaterial(cp);
return(DecryptPassword(cp));
}
