internal BlowfishCryptography(BlowfishAlgorithm algorithm)
{
_algorithm = algorithm;
_encryptIv = new byte[8] { 0, 0, 0, 0, 0, 0, 0, 0 };
_decryptIv = new byte[8] { 0, 0, 0, 0, 0, 0, 0, 0 };
bf_key_st key = new bf_key_st();
key.P = new UInt32[16 + 2];
key.S = new UInt32[4 * 256];
_key = Marshal.AllocHGlobal(key.P.Length * sizeof(UInt32) + key.S.Length * sizeof(UInt32));
Marshal.StructureToPtr(key, _key, false);
_encryptNum = 0;
_decryptNum = 0;
}
public Blowfish(BlowfishAlgorithm algorithm)
{
_algorithm = algorithm;
_encryptIv = new byte[8] {
0, 0, 0, 0, 0, 0, 0, 0
};
_decryptIv = new byte[8] {
0, 0, 0, 0, 0, 0, 0, 0
};
bf_key_st key = new bf_key_st();
key.P = new UInt32[16 + 2];
key.S = new UInt32[4 * 256];
_key = Marshal.AllocHGlobal(key.P.Length * sizeof(UInt32) + key.S.Length * sizeof(UInt32));
Marshal.StructureToPtr(key, _key, false);
_encryptNum = 0;
_decryptNum = 0;
}
/// <summary>Creates a new Blowfish stream.</summary>
/// <param name="stm">The stream to read or write to.</param>
/// <param name="mode">Operation mode</param>
/// <param name="key">The buffer with the key material.</param>
/// <param name="ofs">Where the key material starts in the buffer.</param>
/// <param name="len">Length of the key material in bytes.</param>
public static BlowfishStream Create(
Stream stm,
BlowfishStreamMode mode,
byte[] key,
int ofs,
int len)
{
SHA1 sha = new SHA1CryptoServiceProvider();
BlowfishAlgorithm balg = new BlowfishAlgorithm();
balg.Key = sha.ComputeHash(key, ofs, len);
balg.Padding = PaddingMode.PKCS7;
balg.Mode = CipherMode.CBC;
sha.Clear();
if (BlowfishStreamMode.Write == mode)
{
byte[] iv = balg.IV;
stm.Write(iv, 0, iv.Length);
return(new BlowfishStream(stm, balg.CreateEncryptor(), CryptoStreamMode.Write));
}
else
{
byte[] iv = new byte[balg.BlockSize >> 3];
for (int i = 0; i < iv.Length; i++)
{
int ivb = stm.ReadByte();
if (-1 == ivb)
{
throw new IOException(Resources.JAVAIOP_CANNOT_READ_IV);
}
iv[i] = (byte)ivb;
}
balg.IV = iv;
return(new BlowfishStream(stm, balg.CreateDecryptor(), CryptoStreamMode.Read));
}
}
static void Main(string[] args)
{
long lLen;
int nRead, nReadTotal;
byte[] buf = new byte[3];
byte[] encData;
byte[] decData;
SymmetricAlgorithm alg;
MemoryStream sin;
MemoryStream sout;
CryptoStream encStream;
CryptoStream decStream;
// set up the algorithm (false to go with AES for comparison purposes)
alg = MakeAlgo(true);
// we encrypt and decrypt from and to memory stream,
// so first we have to set up a source and a target
int nI, nC = 11;
sin = new MemoryStream();
for (nI = 0; nI < nC; nI++)
{
sin.WriteByte((byte)nI);
}
sin.Position = 0;
sout = new MemoryStream();
// now we create a crypto stream, to show that the
// BlowfishAlgorithm plays together with a standard
// .NET framework security component
encStream = new CryptoStream(
sout,
alg.CreateEncryptor(),
CryptoStreamMode.Write);
lLen = sin.Length;
nReadTotal = 0;
while (nReadTotal < lLen)
{
nRead = sin.Read(buf, 0, buf.Length);
encStream.Write(buf, 0, nRead);
nReadTotal += nRead;
}
encStream.Close();
// show what we got as the encrypted data
encData = sout.ToArray();
Console.WriteLine("plain : " + BufToStr(sin.ToArray()));
Console.WriteLine("encrypted: " + BufToStr(encData));
// reset the streams and do the decryption the same way
sin = new MemoryStream(encData);
sout = new MemoryStream(nC + Blowfish.BLOCKSIZE);
decStream = new CryptoStream(
sin,
alg.CreateDecryptor(),
CryptoStreamMode.Read);
lLen = sin.Length;
nReadTotal = 0;
while (nReadTotal < lLen)
{
nRead = decStream.Read(buf, 0, buf.Length);
if (0 == nRead)
{
break;
}
sout.Write(buf, 0, nRead);
nReadTotal += nRead;
}
decStream.Close();
decData = sout.ToArray();
Console.WriteLine("decrypted: " + BufToStr(decData));
// (NOTE: eventually we get back padding bytes, which we ignore in our test here)
for (nI = 0; nI < nC; nI++)
{
if (decData[nI] != nI)
{
Console.WriteLine("decryption error");
break;
}
}
// last stage: (almost) futile weak key test search (10k attempts)
byte[] testKey = new byte[alg.KeySize];
Random rnd = new Random((int)DateTime.Now.Ticks);
Console.Write("searching for weak keys ");
nC = 10000;
for (nI = 0; nI < nC; nI++)
{
rnd.NextBytes(testKey);
if (BlowfishAlgorithm.IsWeakKey(testKey))
{
Console.WriteLine("\nweak key found after " + nI + " attempt(s)");
Console.WriteLine(BufToStr(testKey));
break;
}
else
{
if (0 == (nI % (nC / 10)))
{
Console.Write(".");
}
}
}
if (nC == nI)
{
Console.WriteLine("\nno weak key found.");
}
}
