public static Stream Decrypt(Stream source,
Headers headers, byte[] masterKey)
{
byte[] easKey;
using (var buffer = new MemoryStream())
{
var masterSeed = headers.MasterSeed;
buffer.Write(masterSeed, 0, masterSeed.Length);
buffer.Write(masterKey, 0, masterKey.Length);
easKey = BufferEx.GetHash(buffer.ToArray());
}
var eas = new AesManaged
{
KeySize = 256,
Key = BufferEx.Clone(easKey),
IV = BufferEx.Clone(headers.EncryptionIV)
};
Stream stream = new CryptoStream(source,
eas.CreateDecryptor(),
CryptoStreamMode.Read);
if (!VerifyStartBytes(headers, stream))
return null;
stream = new HashedBlockStream(stream, true);
return headers.Compression == Compressions.GZip
? new GZipInputStream(stream) : stream;
}
public static Stream Decrypt(Stream source,
Headers headers, byte[] masterKey)
{
byte[] easKey;
using (var buffer = new MemoryStream())
{
var masterSeed = headers.MasterSeed;
buffer.Write(masterSeed, 0, masterSeed.Length);
buffer.Write(masterKey, 0, masterKey.Length);
easKey = BufferEx.GetHash(buffer.ToArray());
}
var eas = new AesManaged
{
KeySize = 256,
Key = BufferEx.Clone(easKey),
IV = BufferEx.Clone(headers.EncryptionIV)
};
Stream stream = new CryptoStream(source,
eas.CreateDecryptor(),
CryptoStreamMode.Read);
if (!VerifyStartBytes(headers, stream))
{
return(null);
}
stream = new HashedBlockStream(stream, true);
return(headers.Compression == Compressions.GZip
? new GZipInputStream(stream) : stream);
}
internal static Stream Encrypt(Stream source,
Headers headers, byte[] masterKey)
{
byte[] easKey;
using (var buffer = new MemoryStream())
{
var masterSeed = headers.MasterSeed;
buffer.Write(masterSeed, 0, masterSeed.Length);
buffer.Write(masterKey, 0, masterKey.Length);
easKey = BufferEx.GetHash(buffer.ToArray());
}
var eas = new AesManaged
{
KeySize = 256,
Key = BufferEx.Clone(easKey),
IV = BufferEx.Clone(headers.EncryptionIV)
};
Stream stream = new CryptoStream(source,
eas.CreateEncryptor(),
CryptoStreamMode.Write);
stream.Write(headers.StreamStartBytes, 0,
headers.StreamStartBytes.Length);
stream = new HashedBlockStream(stream, false);
return headers.Compression == Compressions.GZip
? new GZipOutputStream(stream) : stream;
}
