Hi Dillon,
I'm new around here and new to the cryptography world.
I'm using VC++ 6.0 SP5 on a WinXP SP2 machine (I have a legacy code
base that I'd like to secure).
I tried to follow your (and originally Hugo's) example, but I'm having
the same runtime error in both cases.
I'm posting my problem here instead of in Hugo's thread in order to
narrow the differences between our executables (since you embedded
your keys into the source code).
The code crashes in oaep.cpp, line 91: memcpy(output, M, maskedDB
+dbLen-M);
The 'output' value is 0 (NULL).
I attached the call stack below.
Any ideas?
Avi.
--
CryptoPP::OAEP_Base::Unpad(const unsigned char * 0x0032b7f1, unsigned
int 255, unsigned char * 0x00000000, const CryptoPP::NameValuePairs &
{...}) line 91 + 20 bytes
CryptoPP::TF_DecryptorBase::Decrypt(CryptoPP::RandomNumberGenerator &
{...}, const unsigned char * 0x0032bbd8, unsigned int 257, unsigned
char * 0x00000000, const CryptoPP::NameValuePairs & {...}) line 142 +
59 bytes
CryptoPP::PK_DefaultDecryptionFilter::Put2(const unsigned char *
0x00000000, unsigned int 0, int -1, unsigned char 1) line 626 + 75
bytes
CryptoPP::BufferedTransformation::MessageEnd(int -1, unsigned char 1)
line 763 + 78 bytes
CryptoPP::SimpleProxyFilter::LastPut(const unsigned char * 0x00000000,
const unsigned char * 0x00000000) line 513 + 51 bytes
CryptoPP::FilterWithBufferedInput::PutMaybeModifiable(unsigned char *
0x00326d68, unsigned int 0, int -2, unsigned char 1, unsigned char 0)
line 410
CryptoPP::FilterWithBufferedInput::Put2(const unsigned char *
0x00326d68, unsigned int 0, int -2, unsigned char 1) line 156
CryptoPP::Filter::Output(int 2, const unsigned char * 0x00326d68,
unsigned int 0, int -2, unsigned char 1, const
std::basic_string<char,std::char_traits<char>,std::allocator<char> > &
{0x00000000 ""}) line 115 + 44 bytes
CryptoPP::BaseN_Decoder::Put2(const unsigned char * 0x00000000,
unsigned int 0, int -1, unsigned char 1) line 163 + 42 bytes
CryptoPP::BufferedTransformation::ChannelPut2(const
std::basic_string<char,std::char_traits<char>,std::allocator<char> > &
{0x00000000 ""}, const unsigned char * 0x00000000, unsigned int 0, int
-1, unsigned char 1) line 250 + 27 bytes
CryptoPP::BufferedTransformation::ChannelMessageEnd(const
std::basic_string<char,std::char_traits<char>,std::allocator<char> > &
{0x00000000 ""}, int -1, unsigned char 1) line 938 + 63 bytes
CryptoPP::BufferedTransformation::TransferMessagesTo2
(CryptoPP::BufferedTransformation & {...}, unsigned int & 0, const
std::basic_string<char,std::char_traits<char>,std::allocator<char> > &
{0x00000000 ""}, unsigned char 1) line 407 + 28 bytes
CryptoPP::BufferedTransformation::TransferAllTo2
(CryptoPP::BufferedTransformation & {...}, const
std::basic_string<char,std::char_traits<char>,std::allocator<char> > &
{0x00000000 ""}, unsigned char 1) line 448 + 24 bytes
CryptoPP::SourceTemplate<CryptoPP::StringStore>::PumpAll2(unsigned
char 1) line 718 + 73 bytes
CryptoPP::Source::PumpAll() line 689 + 47 bytes
CryptoPP::Source::SourceInitialize(unsigned char 1, const
CryptoPP::NameValuePairs & {...}) line 701
CryptoPP::StringSource::StringSource(const char * 0x0012fbd8, unsigned
char 1, CryptoPP::BufferedTransformation * 0x00326b10) line 737 + 173
bytes
stubClass::AES_CTR_Decrypt(const char * 0x0012ff48, const char *
0x0012ff30) line 128 + 364 bytes
main() line 92
--
On Jan 23, 4:34 am, Dillon Beresford <[email protected]>
wrote:
> Hugo shared a class he coded up earlier this month which he gave to the group
> and while searching for information regarding an idea I came up with about
> self decrypting stubs using Crypto++, which I needed for my own project I
> found his thread. I was actually able to code up a little function which I
> added to the class to load keys using
> CryptoPP::ArraySource as opposed to LoadFile. For my project I needed to be
> able to generate stubs on the fly which would handle all of the decryption.
> I'm also currently writing up some code that will actually add two extra
> layers of protection to both keys inside the executable to avoid reverse code
> engineering from dumping keys in memory We simply store our keys in the stub.
>
> If we add stub + *.enc file to SFX we can have our stub do all the work for
> us. :)
>
> I would suggest to anyone storing keys inside a binary to compress the
> executable using something other than UPX or ASPack. ;-) keys get gen all the
> time so it's best to use something with tons of instructions for
> anti-debugging, strip TLS, exports, and CRC protection and aPlib for
> compression.
>
> Dillon's code reading from CryptoPP::ArraySource as opposed to
> CryptoPP::FileSource
>
> void stubClass::LoadKey(const char *bufferPub, const char *bufferPri) {
>
> CryptoPP::ArraySource(bufferPub, true,
>
> new CryptoPP::StringSink(pubString));
>
> CryptoPP::ArraySource(bufferPri, true,
>
> new CryptoPP::StringSink(priString));
>
> }
>
> Hugo's class using CryptoPP::FileSource
> /*
>
> void stubClass::LoadKey(const char *pubFilename, const char *privFilename) {
>
> CryptoPP::FileSource (pubFilename, true,
>
> new CryptoPP::StringSink(pubString));
>
> CryptoPP::FileSource (privFilename, true,
>
> new CryptoPP::StringSink(priString));
>
> }
>
> */
>
> We can store our keys in bufferPub and bufferPri and call this from the
> main() in our stub.
>
> const char bufferPri[]="308..."
> const char bufferPub[]="308..."
>
> int main() {
> char EFile[]="dob.enc";
> char DFile[]="dec.exe";
>
> stubClass stubDecrypt;
> // grab our keys from memory.
> stubDecrypt.LoadKey(bufferPub,bufferPri);
> // decrypt our file
> stubDecrypt.AES_CTR_Decrypt(EFile, DFile);
>
> return 0;
>
> }
>
> thanks Hugo!
>
> linked back to the original thread where Hugo posted his class.
>
> http://groups.google.com/group/cryptopp-users/browse_thread/thread/48...
>
> regards,
>
> Dillon Beresford
>
> stub.cpp
> 4KViewDownload
>
> stubClass.cpp
> 3KViewDownload
>
> stubClass.h
> < 1KViewDownload
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