I'm stuck on the last chunk of data. I've tried what seems like every
possible method to insure the mac is seen, The following code runs without
error but will decrypt with MAC Invalid error. Any help will be appreciated.
readchunk.clear();
readchunk.resize((size_t)lwRead);
sourcein->GetStream()->seekg(lastPos,
std::ios::beg);
sourcein->GetStream()->read((char*)readchunk.c_str(),
(std::streamsize)lwRead);
if(bFirst)
{
ef.ChannelPut( AAD_CHANNEL, (const
byte*)aad_data.data(),
aad_data.size());
ef.ChannelPut( DEFAULT_CHANNEL,
(byte*)readchunk.data(), (size_t)lwRead
);
//ef.ChannelMessageEnd(AAD_CHANNEL);
bFirst = false;
}
else if(bLast)
{
e.Resynchronize((byte *)iv.c_str(),
(int)iv.length());
//next ...
e.SetKeyWithIV((byte*)key.c_str(),
key.length(), (byte *)iv.c_str(),
iv.length());
//next ...
//e.SpecifyDataLengths(aad_data.size(),
lwRead, 0);
//e.Update((const
byte*)aad_data.data(), aad_data.size());
//or
e.SpecifyDataLengths(0, lwRead, 0);
e.Update(NULL, 0);
ef.ChannelMessageEnd(AAD_CHANNEL);
//or
//e.SpecifyDataLengths(0, lwRead,
0);//aad_data not needed?
//e.Update(NULL, 0);
//cipher.clear();
//cipher.resize((unsigned int)lwRead);
//e.ProcessString((byte*)cipher.data(),(byte*)readchunk.data(), lwRead
);
//or
//e.ProcessString((byte*)readchunk.data(), lwRead );
//works after ProcessString
//InitBytes4(mac);
//e.TruncatedFinal(mac, TAG_SIZE);
//next ...
ef.PutMessageEnd((byte*)readchunk.data(), (size_t)lwRead);
//e.ProcessString here instead???
//or
//ef.Put((byte*)readchunk.data(),
(size_t)lwRead );//-TAG_SIZE
//ef.MessageEnd();
}
else
ef.Put((byte*)readchunk.data(),
(size_t)lwRead );
maxRetrieve = ef.MaxRetrievable();
cipher.clear();
cipher.resize((unsigned int)maxRetrieve);
ef.Get((byte*)cipher.data(),
(size_t)maxRetrieve );//+ TAG_SIZE
if(maxRetrieve != 0)
{
sinkout->GetStream()->write((char*)cipher.c_str(),
(std::streamsize)maxRetrieve);
sinkout->IsolatedFlush( false, true );
}
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