/**
*/
private byte[] ComputeOwnerKey(byte[] userPad, byte[] ownerPad)
{
byte[] ownerKey = new byte[32];
byte[] digest = DigestAlgorithms.Digest("MD5", ownerPad);
if (revision == STANDARD_ENCRYPTION_128 || revision == AES_128)
{
byte[] mkey = new byte[keyLength / 8];
// only use for the input as many bit as the key consists of
for (int k = 0; k < 50; ++k)
{
Array.Copy(DigestAlgorithms.Digest("MD5", digest, 0, mkey.Length), 0, digest, 0, mkey.Length);
}
Array.Copy(userPad, 0, ownerKey, 0, 32);
for (int i = 0; i < 20; ++i)
{
for (int j = 0; j < mkey.Length; ++j)
{
mkey[j] = (byte)(digest[j] ^ i);
}
rc4.PrepareARCFOURKey(mkey);
rc4.EncryptARCFOUR(ownerKey);
}
}
else
{
rc4.PrepareARCFOURKey(digest, 0, 5);
rc4.EncryptARCFOUR(userPad, ownerKey);
}
return(ownerKey);
}
protected internal virtual byte[] ComputeOwnerKey(byte[] userPad, byte[] ownerPad)
{
byte[] ownerKey = new byte[32];
byte[] digest = md5.Digest(ownerPad);
arcfour.PrepareARCFOURKey(digest, 0, 5);
arcfour.EncryptARCFOUR(userPad, ownerKey);
return(ownerKey);
}
public OutputStreamEncryption(Stream outc, byte[] key, int off, int len, int revision)
{
this.outc = outc;
aes = (revision == AES_128 || revision == AES_256);
if (aes)
{
byte[] iv = IVGenerator.GetIV();
byte[] nkey = new byte[len];
System.Array.Copy(key, off, nkey, 0, len);
cipher = new AESCipher(true, nkey, iv);
Write(iv, 0, iv.Length);
}
else
{
arcfour = new ARCFOUREncryption();
arcfour.PrepareARCFOURKey(key, off, len);
}
}
/// <summary>Creates a new instance of StandardDecryption</summary>
public StandardDecryptor(byte[] key, int off, int len)
{
arcfour = new ARCFOUREncryption();
arcfour.PrepareARCFOURKey(key, off, len);
}
