private static string Encrypt_Private_v1(string plainText, SecureString passPhrase, int iterations, bool useBase36)
{
// in version 1, we use UTF8 for our plain text value to bytes
byte[] unencryptedBytes = Encoding.UTF8.GetBytes(plainText);
var passPhraseAsBytes = passPhrase.ToByteArray();
var payload = Encrypt_Private_v1(unencryptedBytes, passPhraseAsBytes, iterations);
passPhraseAsBytes.ClearByteArray(); // modify the byte array
string cipherText;
if (useBase36)
{
cipherText = Base36.ByteArrayToBase36String(payload);
cipherText = cipherText.ToLower();
}
else
{
cipherText = Convert.ToBase64String(payload);
}
// Return encrypted string witht the leading 8 characters as the salt
return(cipherText);
}
private static string Encrypt_Private(string plainText, string passPhrase, bool useBase36)
{
RandomGenerator randGen = new RandomGenerator();
string strSalt = randGen.RandomAlphaNumeric(8);
byte[] saltValueBytes;
saltValueBytes = Encoding.ASCII.GetBytes(strSalt);
// Convert our plaintext into a byte array.
// Let us assume that plaintext contains UTF8-encoded characters.
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
// First, we must create a password, from which the key will be derived.
// This password will be generated from the specified passphrase and
// salt value. The password will be created using the specified hash
// algorithm. Password creation can be done in several iterations.
Rfc2898DeriveBytes pw = new Rfc2898DeriveBytes(passPhrase, saltValueBytes, 2);
// Use the password to generate pseudo-random bytes for the encryption
// key. Specify the size of the key in bytes (instead of bits).
byte[] keyBytes = pw.GetBytes(256 / 8);
// Create uninitialized Rijndael encryption object.
RijndaelManaged symmetricKey = new RijndaelManaged();
RandomGenerator randGen2 = new RandomGenerator();
string strIv = randGen2.RandomAlphaNumeric(16);
// Convert strings into byte arrays.
// Let us assume that strings only contain ASCII codes.
// If strings include Unicode characters, use Unicode, UTF7, or UTF8
// encoding.
byte[] initVectorBytes;
initVectorBytes = Encoding.ASCII.GetBytes(strIv);
// It is reasonable to set encryption mode to Cipher Block Chaining
// (CBC). Use default options for other symmetric key parameters.
symmetricKey.Mode = CipherMode.CBC;
// Generate encryptor from the existing key bytes and initialization
// vector. Key size will be defined based on the number of the key
// bytes.
ICryptoTransform encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes);
// Define memory stream which will be used to hold encrypted data.
MemoryStream memoryStream = new MemoryStream();
// Define cryptographic stream (always use Write mode for encryption).
CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write);
// Start encrypting.
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
// Finish encrypting.
cryptoStream.FlushFinalBlock();
// Convert our encrypted data from a memory stream into a byte array.
byte[] cipherTextBytes = memoryStream.ToArray();
// Close both streams.
memoryStream.Close();
cryptoStream.Close();
// Convert encrypted data into a base64-encoded string.
string cipherText;
if (useBase36)
{
cipherText = Base36.ByteArrayToBase36String(cipherTextBytes);
cipherText = cipherText.ToLower();
}
else
{
cipherText = Convert.ToBase64String(cipherTextBytes);
}
// Return encrypted string.
string strReturn = strIv + strSalt + cipherText;
return(strReturn);
//Return cipherText
}