crypto.cpp

/*
    Scrypt is a string crypto for AES-CBC-Padding designed by ilshookim
    MIT License

    https://github.com/ilshookim/scrypt
*/

#include <cryptopp/aes.h>
#include <cryptopp/modes.h>
#include <cryptopp/filters.h>
#include <cryptopp/base64.h>

#include "crypto.h"

namespace Scrypt {

std::string encrypt(std::string plain, std::string key, bool base64)
{
	std::string iv = "";
	return encrypt(plain, key, iv, base64);
}

std::string decrypt(std::string cipher, std::string key, bool base64)
{
	std::string iv = "";
	return decrypt(cipher, key, iv, base64);
}

std::string encrypt(std::string plain, std::string key, std::string iv, bool base64)
{
	std::string encrypted;
	try {
		CryptoPP::byte KEY[CryptoPP::AES::DEFAULT_KEYLENGTH] = { 0, };
		CryptoPP::byte IV[CryptoPP::AES::BLOCKSIZE] = { 0x00, };
		for (int i=0; i<key.length() && i<CryptoPP::AES::DEFAULT_KEYLENGTH; i++) KEY[i] = key[i];
		for (int i=0; i<iv.length() && i<CryptoPP::AES::BLOCKSIZE; i++) IV[i] = iv[i];
		CryptoPP::AES::Encryption encryption(KEY, CryptoPP::AES::DEFAULT_KEYLENGTH);
		CryptoPP::CBC_Mode_ExternalCipher::Encryption mode(encryption, IV);
		CryptoPP::StreamTransformationFilter encryptor(mode, new CryptoPP::StringSink(encrypted));
		encryptor.Put(reinterpret_cast<const unsigned char*>(plain.c_str()), plain.length());
		encryptor.MessageEnd();
		if (base64) {
			std::string encoded;
			CryptoPP::StringSource(encrypted, true, new CryptoPP::Base64Encoder(new CryptoPP::StringSink(encoded)));
			encrypted = encoded;
		}
	}
    catch (...) {
		encrypted.clear();
    }
	return encrypted;
}

std::string decrypt(std::string cipher, std::string key, std::string iv, bool base64)
{
	std::string decrypted;
	try {
		CryptoPP::byte KEY[CryptoPP::AES::DEFAULT_KEYLENGTH] = { 0, };
		CryptoPP::byte IV[CryptoPP::AES::BLOCKSIZE] = { 0x00, };
		for (int i=0; i<key.length() && i<CryptoPP::AES::DEFAULT_KEYLENGTH; i++) KEY[i] = key[i];
		for (int i=0; i<iv.length() && i<CryptoPP::AES::BLOCKSIZE; i++) IV[i] = iv[i];
		if (base64) {
			std::string decoded;
			CryptoPP::StringSource(cipher, true, new CryptoPP::Base64Decoder(new CryptoPP::StringSink(decoded)));
			cipher = decoded;
		}
		CryptoPP::AES::Decryption decryption(KEY, CryptoPP::AES::DEFAULT_KEYLENGTH);
		CryptoPP::CBC_Mode_ExternalCipher::Decryption mode(decryption, IV);
		CryptoPP::StreamTransformationFilter decryptor(mode, new CryptoPP::StringSink(decrypted));
		decryptor.Put(reinterpret_cast<const unsigned char*>(cipher.c_str()), cipher.size());
		decryptor.MessageEnd();
	}
    catch (...) {
		decrypted.clear();
    }
	return decrypted;
}

} // namespace Scrypt