/****************************************************************************************************
* @fn CheckPacketSanity
* Initial correctness checks for Host Interface Packet.
*
* Returns OSP_STATUS_OK if sanity checks pass, otherwise returns negative error code.
***************************************************************************************************/
static int32_t CheckPacketSanity( const uint8_t *pPacket )
{
/* Buffer check */
if (pPacket == NULL)
{
return SET_ERROR( OSP_STATUS_NULL_POINTER );
}
/* Version check */
if (!(PACKET_VERSION_1_SUPPORTED) && GetPacketVersion(pPacket))
{
return SET_ERROR( OSP_STATUS_UNSUPPORTED_FEATURE );
}
return SET_ERROR( OSP_STATUS_OK );
}
// returns true if Check is successful
// generic binary file signature checking
bool CheckDependentBinaryFileSignature(const char *InputSig, const char *FileNameAndPath)
{
// must be explicitly cleared to succeed
bool SigInvalid = true;
// Handle repeated calls via caching
// (avoids expensive RSA decryption and file reads for MD5 calculation for
// sequential calls for the same object)
if(PreviousSigValid)
{
if(PreviousCachedSigText[0])
{
if(!strcmp(InputSig, PreviousCachedSigText))
{
if(!strcmp(FileNameAndPath, PreviousCachedFileText))
{
return(PreviousSigSuccess);
} // if
} // if
} // if
} // if
if(InputSig && InputSig[0] && FileNameAndPath && FileNameAndPath[0])
{
unsigned char NVWMD5Sixteen[17], SigSixteen[17];
int PacketVersion = 0, MaxLength = 0;
PacketVersion = GetPacketVersion((unsigned char *)InputSig);
if(PacketVersion == 1) MaxLength = 0;
if(PacketVersion == 2) MaxLength = 16384;
if(CalcHashOfFileFromName(FileNameAndPath, NVWMD5Sixteen, MaxLength, 1)) // calculate hash using binary method (allow ECW hash)
{
unsigned char DBuf[48], NBuf[48];
// Try VNS2 signature first
memcpy(DBuf, NV_KEY_VNS_D, 48);
memcpy(NBuf, NV_KEY_VNS_N, 48);
// this makes debugging easier
NVWMD5Sixteen[16] = SigSixteen[16] = 0;
if(DecryptPacket((unsigned char *)InputSig, SigSixteen, DBuf, NBuf))
{
// update cache
strcpy(PreviousCachedSigText, InputSig);
strcpy(PreviousCachedFileText, FileNameAndPath);
PreviousSigValid = 1;
if(memcmp(NVWMD5Sixteen, SigSixteen, 16))
{
PreviousSigSuccess = 0;
//UserMessageOK(NVW_NATUREVIEW_NAMETEXT, "Signatures differ!", REQUESTER_ICON_EXCLAMATION);
} // if
else
{
SigInvalid = false;
PreviousSigSuccess = 1;
//UserMessageOK(NVW_NATUREVIEW_NAMETEXT, "Signatures match!");
} // else
} // if
// if that fails, try WCS6
if(SigInvalid)
{
memcpy(DBuf, NV_KEY_WCS_D, 48);
memcpy(NBuf, NV_KEY_WCS_N, 48);
// this makes debugging easier
NVWMD5Sixteen[16] = SigSixteen[16] = 0;
if(DecryptPacket((unsigned char *)InputSig, SigSixteen, DBuf, NBuf))
{
// update cache
strcpy(PreviousCachedSigText, InputSig);
strcpy(PreviousCachedFileText, FileNameAndPath);
PreviousSigValid = 1;
if(memcmp(NVWMD5Sixteen, SigSixteen, 16))
{
PreviousSigSuccess = 0;
//UserMessageOK(NVW_NATUREVIEW_NAMETEXT, "Signatures differ!", REQUESTER_ICON_EXCLAMATION);
} // if
else
{
SigInvalid = false;
PreviousSigSuccess = 1;
//UserMessageOK(NVW_NATUREVIEW_NAMETEXT, "Signatures match!");
} // else
} // if
} // if
} // if
} // if
return(!SigInvalid);
} // CheckDependentBinaryFileSignature
