Re: StreamTransformationFilter Class.

[Cornel Maftuleac]

Wei Dai wrote: This code looks fine and works for me with the current Crypto++ code in CVS. What version of Crypto++ are you using? And also I need a stack trace. After the debugger breaks at the exception, hit Alt-7 to open a call stack window and copy the information for me. On Thu, Jun 24, 2004 at 06:47:09PM +0300, Cornel Maftuleac wrote: Hello everybody. I have discovered strange errors when working with StreamTransformationFilter class. If something is wrong in the following example please correct me. (OS: WinNT, Compiler: VC6.0) The follofing example throws exception when returning from main() //compiled with Debug Multithreaded DLL #include <cryptopp/dll.h> using namespace CryptoPP; extern "C" { void __declspec( dllexport ) GetNewAndDeleteForCryptoPP(PNew &pnew, PDelete &pdelete) { pnew = malloc; pdelete = free; } } int main() { AutoSeededRandomPool rng; unsigned char m_Key[DES::DEFAULT_KEYLENGTH]; unsigned char m_iv[DES::BLOCKSIZE]; rng.GenerateBlock(m_Key,sizeof(m_Key)); rng.GenerateBlock(m_iv,sizeof(m_iv)); std::string EncryptionBuffer; ECB_Mode<DES>::Encryption ChiperEncrypt(m_Key,DES::DEFAULT_KEYLENGTH,m_iv); StreamTransformationFilter STFilterEncrypt(ChiperEncrypt,new StringSink(EncryptionBuffer)); unsigned char plaintext[] = "test bla bla bla"; STFilterEncrypt.Put(plaintext,sizeof(plaintext)); STFilterEncrypt.MessageEnd(); //well it should exit here without problems I guess ... :) return 0; } The exception occurs when the "std::string EncryptionBuffer" is destructed, in this example on exit. Try using dynamic std::string instead of stack, and the exception will occur allso on destructor. Using CryptoPP Version 5.1 3/20/2003 Call stack: NTDLL! 77fa144b() NTDLL! 77fb6bcc() NTDLL! 77f81d44() KERNEL32! 7c4fb252() _CrtIsValidHeapPointer(const void * 0x002f41e8) line 1697 _free_dbg_lk(void * 0x002f41e8, int 1) line 1044 + 9 bytes _free_dbg(void * 0x002f41e8, int 1) line 1001 + 13 bytes free(void * 0x002f41e8) line 956 + 11 bytes operator delete(void * 0x002f41e8) line 7 + 9 bytes std::allocator<char>::deallocate(void * 0x002f41e8, unsigned int 33) line 64 + 38 bytes std::basic_string<char,std::char_traits<char>,std::allocator<char> >::_Tidy(unsigned char 1) line 592 std::basic_string<char,std::char_traits<char>,std::allocator<char> >::~basic_string<char,std::char_traits<char>,std::allocator<char> >() line 59 + 39 bytes main() line 33 + 62 bytes mainCRTStartup() line 206 + 25 bytes KERNEL32! 7c4e87f5()