Hi I compiled your code and your stopping on the last BLOCKSIZE boundary. Bet your losing the remainder and only getting even BLOCKSIZE out put.
In other words your not losing 16 bytes your losing the last < 16 bytes. don I will see if I can find out why. On Jun 11, 10:54 am, Tom <[email protected]> wrote: > Hi, > > To answer my own previous question (http://groups.google.com/group/ > cryptopp-users/browse_thread/thread/721dbd6fa5992a57) I wrote the code > given at the end of this post. > > However it appears that DecryptFile() is not attempting to decrypt the > last 16 bytes (block size) of the encrypted file. Can anybody tell me > what I am doing wrong? > > Yours truly, > > Tom > > -------------------------------------------------------------------------------- > > // Runtime Includes > #include <iostream> > > // Crypto++ Includes > #include "aes.h" > #include "modes.h" // xxx_Mode< > > #include "filters.h" // StringSource and > // StreamTransformation > #include "files.h" > > using namespace std; > > class CryptStreamBuffer: public std::streambuf { > > public: > > CryptStreamBuffer(istream& encryptedInput, > CryptoPP::StreamTransformation& c); > > CryptStreamBuffer(ostream& encryptedOutput, > CryptoPP::StreamTransformation& c); > > protected: > virtual int_type overflow(int_type ch = traits_type::eof()); > > virtual int_type uflow(); > > virtual int_type underflow(); > > virtual int_type pbackfail(int_type ch); > > virtual int sync(); > > private: > int GetNextChar(); > > int m_NextChar; // Buffered character > > CryptoPP::StreamTransformationFilter* > m_StreamTransformationFilter; > > CryptoPP::FileSource* m_Source; > > CryptoPP::FileSink* m_Sink; > > }; // class CryptStreamBuffer > > CryptStreamBuffer::CryptStreamBuffer(istream& encryptedInput, > CryptoPP::StreamTransformation& c) : > m_NextChar(traits_type::eof()), > m_StreamTransformationFilter(0), > m_Source(0), > m_Sink(0) { > > m_StreamTransformationFilter = new > CryptoPP::StreamTransformationFilter(c); > m_Source = new CryptoPP::FileSource(encryptedInput, false, > m_StreamTransformationFilter); > > } > > CryptStreamBuffer::CryptStreamBuffer(ostream& encryptedOutput, > CryptoPP::StreamTransformation& c) : > m_NextChar(traits_type::eof()), > m_StreamTransformationFilter(0), > m_Source(0), > m_Sink(0) { > > m_Sink = new CryptoPP::FileSink(encryptedOutput); > m_StreamTransformationFilter = new > CryptoPP::StreamTransformationFilter(c, m_Sink); > > } > > CryptStreamBuffer::int_type CryptStreamBuffer::overflow(int_type ch) { > > return m_StreamTransformationFilter->Put((byte)ch); > > } > > CryptStreamBuffer::int_type CryptStreamBuffer::uflow() { > > int_type result = GetNextChar(); > > // Reset the buffered character > m_NextChar = traits_type::eof(); > > return result; > > } > > CryptStreamBuffer::int_type CryptStreamBuffer::underflow() { > > return GetNextChar(); > > } > > CryptStreamBuffer::int_type CryptStreamBuffer::pbackfail(int_type ch) > { > > return traits_type::eof(); > > } > > int CryptStreamBuffer::sync() { > > if (m_Sink) { > m_StreamTransformationFilter->MessageEnd(); > } > > } > > int CryptStreamBuffer::GetNextChar() { > > // If we have a buffered character do nothing > if (m_NextChar != traits_type::eof()) { > return m_NextChar; > } > > // If there are no more bytes currently available then pump the > source > if (m_StreamTransformationFilter->MaxRetrievable() == 0) { > m_Source->Pump(1024); > } > > // Retrieve the next byte > byte nextByte; > size_t noBytes = m_StreamTransformationFilter->Get(nextByte); > if (0 == noBytes) { > return traits_type::eof(); > } > > // Buffer up the next character > m_NextChar = nextByte; > > return m_NextChar; > > } > > void InitKey(byte key[]) { > > key[0] = -62; > key[1] = 102; > key[2] = 78; > key[3] = 75; > key[4] = -96; > key[5] = 125; > key[6] = 66; > key[7] = 125; > key[8] = -95; > key[9] = -66; > key[10] = 114; > key[11] = 22; > key[12] = 48; > key[13] = 111; > key[14] = -51; > key[15] = 112; > > } > > void DecryptFile(const char* sourceFileName, const char* destFileName) > { > > ifstream ifs(sourceFileName, ios::in | ios::binary); > ofstream ofs(destFileName, ios::out | ios::binary); > > byte key[CryptoPP::AES::DEFAULT_KEYLENGTH]; > InitKey(key); > CryptoPP::ECB_Mode<CryptoPP::AES>::Decryption decryptor(key, > sizeof(key)); > > if (ifs) { > if (ofs) { > CryptStreamBuffer cryptBuf(ifs, decryptor); > std::istream decrypt(&cryptBuf); > > int c; > while (EOF != (c = decrypt.get())) { > ofs << (char)c; > } > ofs.flush(); > } > else { > std::cerr << "Failed to open file '" << destFileName << > "'." << endl; > } > } > else { > std::cerr << "Failed to open file '" << sourceFileName << "'." > << endl; > } > > } > > void EncryptFile(const char* sourceFileName, const char* destFileName) > { > > ifstream ifs(sourceFileName, ios::in | ios::binary); > ofstream ofs(destFileName, ios::out | ios::binary); > > byte key[CryptoPP::AES::DEFAULT_KEYLENGTH]; > InitKey(key); > > CryptoPP::ECB_Mode<CryptoPP::AES>::Encryption encryptor(key, > sizeof(key)); > > if (ifs) { > if (ofs) { > CryptStreamBuffer cryptBuf(ofs, encryptor); > std::ostream encrypt(&cryptBuf); > > int c; > while (EOF != (c = ifs.get())) { > encrypt << (char)c; > } > encrypt.flush(); > } > else { > std::cerr << "Failed to open file '" << destFileName << > "'." << endl; > } > } > else { > std::cerr << "Failed to open file '" << sourceFileName << "'." > << endl; > } > > } > > int main(int argc, char* argv[]) > { > EncryptFile(argv[1], "encrypted.out"); > DecryptFile("encrypted.out", "decrypted.out"); > return 0; > > } > > -------------------------------------------------------------------------------- -- You received this message because you are subscribed to the "Crypto++ Users" Google Group. To unsubscribe, send an email to [email protected]. More information about Crypto++ and this group is available at http://www.cryptopp.com.
