Reputation: 115
how to generate a key and key IV and not write them explicitly?
public sealed class MyCryptoClass
{
protected RijndaelManaged myRijndael;
private static string encryptionKey = "142eb4a7ab52dbfb971e18daed7056488446b4b2167cf61187f4bbc60fc9d96d";
private static string initialisationVector ="26744a68b53dd87bb395584c00f7290a";
I try generate encryptionKey and initialisationVector
protected static readonly MyCryptoClass _instance = new MyCryptoClass();
public static MyCryptoClass Instance
{
get { return _instance; }
}
public string EncryptText(string plainText)
{
using (myRijndael = new RijndaelManaged())
{
myRijndael.Key = HexStringToByte(encryptionKey);
myRijndael.IV = HexStringToByte(initialisationVector);
myRijndael.Mode = CipherMode.CBC;
myRijndael.Padding = PaddingMode.PKCS7;
byte[] encrypted = EncryptStringToBytes(plainText, myRijndael.Key, myRijndael.IV);
string encString = Convert.ToBase64String(encrypted);
return encString;
}
}
Upvotes: 2
Views: 9084
Reputation: 1375
Let's do it step by step to keep things simple.
You need two methods to achieve your goal. I'll start with encryption method:
static byte[] Encrypt(string input, byte[] Key, byte[] IV)
{
byte[] encryptedBytes;
using (RijndaelManaged rijndael = new RijndaelManaged())
{
rijndael.Key = Key;
rijndael.IV = IV;
ICryptoTransform encryptor = rijndael.CreateEncryptor(rijndael.Key, rijndael.IV);
using (var memoryStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(memoryStream,
encryptor, CryptoStreamMode.Write))
{
using (var streamWriter = new StreamWriter(cryptoStream))
{
streamWriter.Write(input);
}
encryptedBytes = memoryStream.ToArray();
}
}
}
return encryptedBytes;
}
Then we need a Decrypt method subsequently:
static string Decrypt(byte[] cipher, byte[] Key, byte[] IV)
{
string plaintext = null;
using (RijndaelManaged rijndael = new RijndaelManaged())
{
rijndael.Key = Key;
rijndael.IV = IV;
ICryptoTransform decryptor = rijndael.CreateDecryptor(rijndael.Key, rijndael.IV);
using (var memoryStream = new MemoryStream(cipher))
{
using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
{
using (var streamReader = new StreamReader(cryptoStream))
{
plaintext = streamReader.ReadToEnd();
}
}
}
}
return plaintext;
}
Note: It's better to wrap Encrypt
and Decrypt
methods in a class and then use them.
You can call the methods like below:
string original = "This is what would be encrypted!";
using (RijndaelManaged myRijndael = new RijndaelManaged())
{
myRijndael.GenerateKey(); // this line generates key
myRijndael.GenerateIV(); // this line generates initialization vektor
// This line returns encrypted text
byte[] encryptedBytes = Encrypt(original, myRijndael.Key, myRijndael.IV);
// You can decrypt the encrypted text like so
string decryptedString = Decrypt(encryptedBytes, myRijndael.Key, myRijndael.IV);
}
Upvotes: 4