public int DecryptFinal(byte[] input, int inputOffset, byte[] output, int outputOffset)
{
SecurityBufferAssert.AssertBuffer(input, inputOffset, TagLength);
SecurityBufferAssert.AssertBuffer(output, outputOffset, bufferOffset);
var total = 0;
if (bufferOffset != 0)
{
total += bufferOffset;
inputOffset += bufferOffset;
DecryptBlock(output, outputOffset);
}
var tagCiphertextPaddingLength = (16 - (int)(cSize / 8) % 16) % 16;
tagHash.Update(new byte[tagCiphertextPaddingLength], 0, tagCiphertextPaddingLength);
tagHash.Update(EndianBitConverter.Big.GetBytes(aSize), 0, sizeof(long));
tagHash.Update(EndianBitConverter.Big.GetBytes(cSize), 0, sizeof(long));
var ctr = new CTRBlockCipher(Cipher);
ctr.Init(new IVParameter(null, j0));
var calculatedTag = new byte[16];
ctr.EncryptBlock(tagHash.Digest(), 0, calculatedTag, 0);
var tag = new byte[16];
Array.Copy(input, inputOffset, tag, 0, TagLength);
SecurityAssert.HashAssert(calculatedTag, tag);
return total;
}
public int EncryptFinal(byte[] output, int offset)
{
var total = 0;
if (bufferOffset != 0)
{
var len = bufferOffset;
EncryptBlock(output, offset);
total += len;
offset += len;
}
var tagCiphertextPaddingLength = (16 - (int)(cSize / 8) % 16) % 16;
tagHash.Update(new byte[tagCiphertextPaddingLength], 0, tagCiphertextPaddingLength);
tagHash.Update(EndianBitConverter.Big.GetBytes(aSize), 0, sizeof(long));
tagHash.Update(EndianBitConverter.Big.GetBytes(cSize), 0, sizeof(long));
var ctr = new CTRBlockCipher(Cipher);
ctr.Init(new IVParameter(null, j0));
ctr.EncryptBlock(tagHash.Digest(), 0, output, offset);
total += BlockLength;
return total;
}