public IMac CreateEngine(EngineUsage usage)
{
IMac mac = new GMac(new GcmBlockCipher(baseProvider.CreateEngine(EngineUsage.ENCRYPTION)), parameters.MacSizeInBits);
mac.Init(new Internal.Parameters.ParametersWithIV(null, parameters.GetIV()));
return(mac);
}
private void testInvalidMacSize(int size)
{
try
{
GMac mac = new GMac(new GcmBlockCipher(new AesFastEngine()), size);
mac.Init(new ParametersWithIV(null, new byte[16]));
Fail("Expected failure for illegal mac size " + size);
}
catch (ArgumentException)
{
}
}
private void testInvalidMacSize(int size)
{
try
{
GMac mac = new GMac(new GcmBlockCipher(new AesEngine()), size);
mac.Init(new ParametersWithIV(null, new byte[16]));
Fail("Expected failure for illegal mac size " + size);
}
catch (ArgumentException e)
{
if (!e.Message.StartsWith("Invalid value for MAC size"))
{
Fail("Illegal mac size failed with unexpected message");
}
}
}
public override void PerformTest()
{
for (int i = 0; i < TEST_VECTORS.Length; i++)
{
TestCase testCase = TEST_VECTORS[i];
IMac mac = new GMac(new GcmBlockCipher(new AesEngine()), testCase.getTag().Length * 8);
ICipherParameters key = new KeyParameter(testCase.getKey());
mac.Init(new ParametersWithIV(key, testCase.getIv()));
testSingleByte(mac, testCase);
testMultibyte(mac, testCase);
}
// Invalid mac size
testInvalidMacSize(97);
testInvalidMacSize(136);
testInvalidMacSize(24);
}
public static byte[] AddGmacToBuffer(GmacInfo gmacInfo, uint keyPos, byte[] buffer, int gmacPositionInBuffer)
{
//keyPos = (uint) System.Net.IPAddress.HostToNetworkOrder((int)keyPos);
byte[] iv = new byte[16];
SetGmacCounter(iv, gmacInfo.Iv, keyPos / 0x10);
byte[] gmacKey = gmacInfo.KeyGmacCurrent;
long keyIndex = (keyPos > 0 ? keyPos - 1 : 0) / GmacKeyRefreshKeyPosition;
if (keyIndex > gmacInfo.GmacCurrentIndex)
{
gmacKey = GenerateNewGmacKey(gmacInfo, keyIndex);
gmacInfo.KeyGmacCurrent = gmacKey;
gmacInfo.GmacCurrentIndex = keyIndex;
gmacKey = gmacInfo.KeyGmacCurrent;
}
else if (keyIndex < gmacInfo.GmacCurrentIndex)
{
gmacKey = GenerateTmpGmacKey(gmacInfo, keyIndex);
}
IMac mac = new GMac(new GcmBlockCipher(new AesEngine()), 32);
ICipherParameters key = new KeyParameter(gmacKey);
mac.Init(new ParametersWithIV(key, iv));
mac.BlockUpdate(buffer, 0, buffer.Length);
int macSize = mac.GetMacSize();
byte[] gmac = new byte[macSize];
mac.DoFinal(gmac, 0);
for (int i = 0; i < gmac.Length; i++)
{
buffer[gmacPositionInBuffer + i] = gmac[i];
}
return(gmac);
}
