C++ - EncryptMessage not encrypting the correct data - c++

Question

I've been following this tutorial for SSL/TLS online (well its more of reading the guys source code and following along) but I've hit a bumpy road with this EncryptMessage part because it pushes the data out of the way and encrypts the wrong info.
The pbloBuffer that I send it is:
GET / HTTP/1.1\r\n
HOST: www.google.com\r\n\r\n
But when I do pbMessage = pbloBuffer + Sizes.cbHeader; I end up with (even the microsoft websites says to do this)
1\r\n
HOST: www.google.com\r\n\r\n
Now pbMessage is the code above, and that's inserted under SECBUFFER_DATA so it's not even getting the full data. From what I understand SECBUFFER_DATA is the "user" data that the Webserver will decode and process.
Can you find out how to fix this and properly send the encrypted data?
Full source: (This code is experimental as I am trying to understand it before I makes changes)
int Adaptify::EncryptSend(PBYTE pbloBuffer, int Size) {
SECURITY_STATUS scRet{ 0 };
SecBufferDesc Message{ 0 };
SecBuffer Buffers[4]{ 0 };
DWORD cbMessage = 0, cbData = 0;
PBYTE pbMessage = nullptr;
SecPkgContext_StreamSizes Sizes = { 0 };
QueryContextAttributesW(&hContext, SECPKG_ATTR_STREAM_SIZES, &Sizes);
pbMessage = pbloBuffer + Sizes.cbHeader;
cbMessage = (DWORD)strlen((const char*)pbMessage);
Buffers[0].BufferType = SECBUFFER_STREAM_HEADER;
Buffers[0].cbBuffer = Sizes.cbHeader;
Buffers[0].pvBuffer = pbloBuffer;
Buffers[1].BufferType = SECBUFFER_DATA;
Buffers[1].pvBuffer = pbMessage;
Buffers[1].cbBuffer = cbMessage;
Buffers[2].BufferType = SECBUFFER_STREAM_TRAILER;
Buffers[2].cbBuffer = Sizes.cbTrailer;
Buffers[2].pvBuffer = pbMessage + cbMessage;
Buffers[3].BufferType = SECBUFFER_EMPTY;
Buffers[3].cbBuffer = SECBUFFER_EMPTY;
Buffers[3].pvBuffer = SECBUFFER_EMPTY;
Message.cBuffers = 4;
Message.pBuffers = Buffers;
Message.ulVersion = SECBUFFER_VERSION;
scRet = EncryptMessage(&hContext, 0, &Message, 0);
if (send(hSocket, (const char*)pbloBuffer, Buffers[0].cbBuffer + Buffers[1].cbBuffer + Buffers[2].cbBuffer, 0) < 0) {
MessageBox(0, L"Send error", 0, 0);
}
return 0;
}

Answer 1

first - you need call QueryContextAttributesW only once after InitializeSecurityContextW return SEC_E_OK - no sense call it every time, when you need send data. and save result. say inherit your class from SecPkgContext_StreamSizes - class Adaptify : SecPkgContext_StreamSizes; and call on end handshake (once) QueryContextAttributesW(&hContext, SECPKG_ATTR_STREAM_SIZES, this);
about send send data - in your case Buffers[1].pvBuffer of course must point to your actual data pbloBuffer but not to pbloBuffer + Sizes.cbHeader code can be like this:
int Adaptify::EncryptSend(PBYTE pbloBuffer, int Size) {
SECURITY_STATUS ss = SEC_E_INSUFFICIENT_MEMORY;
if (PBYTE Buffer = new BYTE[cbHeader + Size + cbTrailer]) {
memcpy(Buffer + cbHeader, pbloBuffer, Size);
SecBuffer sb[4] = {
{ cbHeader, SECBUFFER_STREAM_HEADER, Buffer},
{ Size, SECBUFFER_DATA, Buffer + cbHeader},
{ cbTrailer, SECBUFFER_STREAM_TRAILER, Buffer + cbHeader + Size},
};
SecBufferDesc sbd = {
SECBUFFER_VERSION, 4, sb
};
if (SEC_E_OK == (ss = ::EncryptMessage(this, 0, &sbd, 0)))) {
if (SOCKET_ERROR == send(hSocket, (const char*)Buffer, sb[0].cbBuffer+sb[1].cbBuffer+sb[2].cbBuffer+sb[3].cbBuffer, 0))
ss = WSAGetLastError();
}
delete [] Buffer;
}
return ss;
}
so you need allocate new buffer with cbHeader + Size + cbTrailer size (wher Size is your actual message Size and copy your message at Buffer + cbHeader