public void Implement_CBC_mode_Test() //CBC = Cipher Block Chaining
{
var BLOCKSIZE = 16;
//https://cryptopals.com/sets/2/challenges/10
string str = Util.GetFile(10);
string Hex = MyConvert.Base64ToHex(str);
var bytes = MyConvert.HexToByteArray(Hex);
//Initialization Vector (padded to BLOCKSIZE bytes)
string IVHex = Pad.PadHex(BLOCKSIZE * 2, "00");
var IVBytes = MyConvert.HexToByteArray(IVHex);
//The Key
string key = "YELLOW SUBMARINE";
string HexKey = MyConvert.HexEncodePlainText(key);
var Keybytes = MyConvert.HexToByteArray(HexKey);
//Perform my version of CBC
var decryptedBytes = MyCrypto.AES_CBC_Decrypt(bytes, Keybytes, IVBytes, BLOCKSIZE);
var HexResult = MyConvert.BytesToHex(decryptedBytes);
var Plain = MyConvert.HexToAscii(HexResult);
Assert.IsTrue("I'm back and I'm ringin' " == Plain.Substring(0, 25)); //25 is at least two blocks (of16) so i know i have the algo correct
}
public void AESinCBC_Encrypt_Decrypt_Test() //CBC = Cipher Block Chaining
{
int BLOCKSIZE = 16;
string OriginalMessage = "Now I rock a house party at the drop of a hat\nAnd I beat a body down with an aluminum bat";
var bytes = MyConvert.TextToByteArray(OriginalMessage);
var PaddedBytes = Pad.AddPkcs7(bytes, 128); //Pad the message to 128 bytes
//The Key (16 bytes)
string key = "YELLOW SUBMARINE";
string HexKey = MyConvert.HexEncodePlainText(key);
var Keybytes = MyConvert.HexToByteArray(HexKey);
//Initialization Vector (padded to BLOCKSIZE bytes)
string IVHex = Pad.PadHex(BLOCKSIZE * 2, "00");
var IVBytes = MyConvert.HexToByteArray(IVHex);
//Encrypt
var CiperBytes = MyCrypto.AES_CBC_Encrypt(PaddedBytes, Keybytes, IVBytes, BLOCKSIZE);
//Decrypt
var PlainBytes = MyCrypto.AES_CBC_Decrypt(CiperBytes, Keybytes, IVBytes, BLOCKSIZE);
var UnPaddedBytes = Pad.RemovePkcs7(PlainBytes); //Unpad the message
var hexPlain = MyConvert.BytesToHex(UnPaddedBytes);
var PlainText = MyConvert.HexToAscii(hexPlain);
Assert.IsTrue(OriginalMessage == PlainText);
}