code.cpp

template<typename F>
std::string hash_file(std::string filename) {
	F hash;

	std::string digest;

	CryptoPP::FileSource f(filename.c_str(), true,
			new CryptoPP::HashFilter(hash, new CryptoPP::StringSink(digest)));

	return digest;
}

template<typename F>
bool verify(const std::string &digest, const std::string &filename) {

	/*	// Create a verifier with DEFAULT_FLAGS
	 CryptoPP::byte result = 0;
	 {
	 CryptoPP::HashVerificationFilter verifier(hash,
	 new CryptoPP::ArraySink(&result, sizeof(result)));
	 // Wrap the data in sources
	 CryptoPP::StringSource ss(digest, true);
	 CryptoPP::FileSource fs(filename.c_str(), true);
	 // Add the data to the filter. The digest is added first due to HASH_AT_BEGIN
	 ss.TransferTo(verifier);
	 fs.TransferTo(verifier);
	 // Signal end of data. The verifier will finish calculating
	 // the digest, and compare the expected and calculated digests.
	 verifier.MessageEnd();
	 }*/
        // Keeping the program memory under control.
	return digest == hash_file<F>(filename);
}