protected virtual void CheckMac(long seqNo, byte type, byte[] recBuf, int recStart, int recEnd, byte[] calcBuf, int calcOff, int calcLen)
{
byte[] a = Arrays.CopyOfRange(recBuf, recStart, recEnd);
byte[] b = readMac.CalculateMac(seqNo, type, calcBuf, calcOff, calcLen);
if (!Arrays.ConstantTimeAreEqual(a, b))
{
throw new TlsFatalAlert(20);
}
}
public virtual byte[] EncodePlaintext(long seqNo, byte type, byte[] plaintext, int offset, int len)
{
if (usesNonce)
{
UpdateIV(encryptCipher, forEncryption: true, seqNo);
}
byte[] array = new byte[len + writeMac.Size];
encryptCipher.ProcessBytes(plaintext, offset, len, array, 0);
byte[] array2 = writeMac.CalculateMac(seqNo, type, plaintext, offset, len);
encryptCipher.ProcessBytes(array2, 0, array2.Length, array, len);
return(array);
}
public virtual byte[] EncodePlaintext(long seqNo, byte type, byte[] plaintext, int offset, int len)
{
if (writeMac == null)
{
return(Arrays.CopyOfRange(plaintext, offset, offset + len));
}
byte[] array = writeMac.CalculateMac(seqNo, type, plaintext, offset, len);
byte[] array2 = new byte[len + array.Length];
Array.Copy(plaintext, offset, array2, 0, len);
Array.Copy(array, 0, array2, len, array.Length);
return(array2);
}
public virtual byte[] DecodeCiphertext(long seqNo, byte type, byte[] ciphertext, int offset, int len)
{
if (readMac == null)
{
return(Arrays.CopyOfRange(ciphertext, offset, offset + len));
}
int size = readMac.Size;
if (len < size)
{
throw new TlsFatalAlert(50);
}
int num = len - size;
byte[] a = Arrays.CopyOfRange(ciphertext, offset + num, offset + len);
byte[] b = readMac.CalculateMac(seqNo, type, ciphertext, offset, num);
if (!Arrays.ConstantTimeAreEqual(a, b))
{
throw new TlsFatalAlert(20);
}
return(Arrays.CopyOfRange(ciphertext, offset, offset + num));
}
public virtual byte[] DecodeCiphertext(long seqNo, byte type, byte[] ciphertext, int offset, int len)
{
int blockSize = decryptCipher.GetBlockSize();
int size = mReadMac.Size;
int num = blockSize;
num = ((!encryptThenMac) ? Math.Max(num, size + 1) : (num + size));
if (useExplicitIV)
{
num += blockSize;
}
if (len < num)
{
throw new TlsFatalAlert(50);
}
int num2 = len;
if (encryptThenMac)
{
num2 -= size;
}
if (num2 % blockSize != 0)
{
throw new TlsFatalAlert(21);
}
if (encryptThenMac)
{
int num3 = offset + len;
byte[] b = Arrays.CopyOfRange(ciphertext, num3 - size, num3);
byte[] a = mReadMac.CalculateMac(seqNo, type, ciphertext, offset, len - size);
if (!Arrays.ConstantTimeAreEqual(a, b))
{
throw new TlsFatalAlert(20);
}
}
if (useExplicitIV)
{
decryptCipher.Init(forEncryption: false, new ParametersWithIV(null, ciphertext, offset, blockSize));
offset += blockSize;
num2 -= blockSize;
}
for (int i = 0; i < num2; i += blockSize)
{
decryptCipher.ProcessBlock(ciphertext, offset + i, ciphertext, offset + i);
}
int num4 = CheckPaddingConstantTime(ciphertext, offset, num2, blockSize, (!encryptThenMac) ? size : 0);
bool flag = num4 == 0;
int num5 = num2 - num4;
if (!encryptThenMac)
{
num5 -= size;
int num6 = num5;
int num7 = offset + num6;
byte[] b2 = Arrays.CopyOfRange(ciphertext, num7, num7 + size);
byte[] a2 = mReadMac.CalculateMacConstantTime(seqNo, type, ciphertext, offset, num6, num2 - size, randomData);
flag |= !Arrays.ConstantTimeAreEqual(a2, b2);
}
if (flag)
{
throw new TlsFatalAlert(20);
}
return(Arrays.CopyOfRange(ciphertext, offset, offset + num5));
}
public virtual byte[] EncodePlaintext(long seqNo, byte type, byte[] plaintext, int offset, int len)
{
int blockSize = encryptCipher.GetBlockSize();
int size = mWriteMac.Size;
ProtocolVersion serverVersion = context.ServerVersion;
int num = len;
if (!encryptThenMac)
{
num += size;
}
int num2 = blockSize - 1 - num % blockSize;
if (!serverVersion.IsDtls && !serverVersion.IsSsl)
{
int max = (255 - num2) / blockSize;
int num3 = ChooseExtraPadBlocks(context.SecureRandom, max);
num2 += num3 * blockSize;
}
int num4 = len + size + num2 + 1;
if (useExplicitIV)
{
num4 += blockSize;
}
byte[] array = new byte[num4];
int num5 = 0;
if (useExplicitIV)
{
byte[] array2 = new byte[blockSize];
context.NonceRandomGenerator.NextBytes(array2);
encryptCipher.Init(forEncryption: true, new ParametersWithIV(null, array2));
Array.Copy(array2, 0, array, num5, blockSize);
num5 += blockSize;
}
int num6 = num5;
Array.Copy(plaintext, offset, array, num5, len);
num5 += len;
if (!encryptThenMac)
{
byte[] array3 = mWriteMac.CalculateMac(seqNo, type, plaintext, offset, len);
Array.Copy(array3, 0, array, num5, array3.Length);
num5 += array3.Length;
}
for (int i = 0; i <= num2; i++)
{
array[num5++] = (byte)num2;
}
for (int j = num6; j < num5; j += blockSize)
{
encryptCipher.ProcessBlock(array, j, array, j);
}
if (encryptThenMac)
{
byte[] array4 = mWriteMac.CalculateMac(seqNo, type, array, 0, num5);
Array.Copy(array4, 0, array, num5, array4.Length);
num5 += array4.Length;
}
return(array);
}