public void EnhancedMemoryStream_Bytes()
{
var es = new EnhancedMemoryStream();
byte[] read, write;
es.WriteBytes16(null);
es.Seek(0, SeekOrigin.Begin);
read = es.ReadBytes16();
Assert.IsNull(read);
write = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
es.Seek(0, SeekOrigin.Begin);
es.WriteBytes16(write);
es.Seek(0, SeekOrigin.Begin);
read = es.ReadBytes16();
CollectionAssert.AreEqual(write, read);
write = new byte[40000];
for (int i = 0; i < write.Length; i++)
{
write[i] = (byte)i;
}
es.Seek(0, SeekOrigin.Begin);
es.WriteBytes16(write);
es.Seek(0, SeekOrigin.Begin);
read = es.ReadBytes16();
CollectionAssert.AreEqual(write, read);
}
public void EnhancedMemoryStream_VerifyBufLength()
{
var es = new EnhancedMemoryStream();
es.WriteInt16(5000);
es.Seek(0, SeekOrigin.Begin);
try
{
es.ReadBytes16();
Assert.Fail();
}
catch
{
}
es.Seek(0, SeekOrigin.Begin);
try
{
es.ReadString16();
Assert.Fail();
}
catch
{
}
es.Seek(0, SeekOrigin.Begin);
es.WriteInt32(500000);
try
{
es.ReadBytes32();
Assert.Fail();
}
catch
{
}
es.Seek(0, SeekOrigin.Begin);
try
{
es.ReadString32();
Assert.Fail();
}
catch
{
}
}
/// <summary>
/// Decrypts and deserializes a message from a byte buffer.
/// </summary>
/// <param name="buffer">The buffer.</param>
/// <param name="sharedKey">The shared encryption key.</param>
/// <exception cref="FormatException">Thrown if the buffer does not contain a valid message.</exception>
public UdpBroadcastMessage(byte[] buffer, SymmetricKey sharedKey)
{
try
{
using (var ms = new EnhancedMemoryStream(Crypto.Decrypt(buffer, sharedKey)))
{
if (ms.ReadInt32Le() != Magic)
{
throw new Exception();
}
this.TimeStampUtc = new DateTime(ms.ReadInt64Le());
this.SourceAddress = new IPAddress(ms.ReadBytes(4));
this.MessageType = (UdpBroadcastMessageType)ms.ReadByte();
this.BroadcastGroup = ms.ReadByte();
this.Payload = ms.ReadBytes16();
}
}
catch (Exception e)
{
throw new FormatException("Invalid UDP broadcast message.", e);
}
}
/// <summary>
/// Decrypts a byte array encrypted using <see cref="Encrypt(string ,byte[],string,int,int,out SymmetricKey)" />.
/// </summary>
/// <param name="rsaKey">The decrypting RSA key as XML or as a secure key container name.</param>
/// <param name="cipherText">The encrypted data.</param>
/// <param name="symmetricKey">Returns as the symmetric encryption algorithm arguments.</param>
/// <returns>The decrypted data.</returns>
/// <exception cref="CryptographicException">Thrown is the encrypted data block is incorrectly formatted.</exception>
/// <remarks>
/// Note that applications should take some care to ensure that the <paramref name="symmetricKey" />
/// value return is disposed so that the symmetric encryption key will be cleared.
/// </remarks>
public static byte[] Decrypt(string rsaKey, byte[] cipherText, out SymmetricKey symmetricKey)
{
EnhancedMemoryStream input = new EnhancedMemoryStream(cipherText);
EnhancedMemoryStream ms = new EnhancedMemoryStream(cipherText.Length);
BlockDecryptor decryptor = null;
byte[] symKey;
byte[] symIV;
string algorithm;
try
{
// Read the header fields
if (input.ReadInt32() != Magic)
{
throw new CryptographicException(BadFormatMsg);
}
if (input.ReadInt32() != 0)
{
throw new CryptographicException("Unsupported secure data format version.");
}
// Decrypt the encryption info
ms.WriteBytesNoLen(AsymmetricCrypto.Decrypt(CryptoAlgorithm.RSA, rsaKey, input.ReadBytes16()));
ms.Position = 0;
algorithm = ms.ReadString16();
symKey = ms.ReadBytes16();
symIV = ms.ReadBytes16();
symmetricKey = new SymmetricKey(algorithm, symKey, symIV);
decryptor = new BlockDecryptor(algorithm, symKey, symIV);
// Decrypt the contents
ms.SetLength(0);
ms.WriteBytesNoLen(decryptor.Decrypt(input.ReadBytes32()));
ms.Position = 0;
if (ms.ReadInt32() != Magic)
{
throw new CryptographicException("Secure data content is corrupt.");
}
ms.Position += 8; // Skip over the salt
return(ms.ReadBytes32());
}
finally
{
if (decryptor != null)
{
decryptor.Dispose();
}
input.Close();
ms.Close();
}
}
