#include <iostream>
#include <fstream>
#include <ostream>
#include <string>
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/ssl.h>
#define _CRT_SECURE_NO_WARNINGS

using namespace std;
typedef std::basic_string<unsigned char> u_string;


static u_string decode(u_string key, u_string data)
{
	EVP_CIPHER_CTX* ctx = EVP_CIPHER_CTX_new();
    EVP_CIPHER_CTX_init(ctx);
    EVP_DecryptInit_ex(ctx, EVP_aes_128_ecb(), NULL, key.c_str(), NULL);
	EVP_CIPHER_CTX_set_padding(ctx, false);
    unsigned char buffer[1024], * pointer = buffer;
    int outlen;
    EVP_DecryptUpdate(ctx, pointer, &outlen, data.c_str(), data.length()) or abort;
    pointer += outlen;
    EVP_DecryptFinal_ex(ctx, pointer, &outlen) or abort;
    pointer += outlen;
    return u_string(buffer, pointer - buffer);
}

std::string hexToASCII(string hex)
{
	int len = hex.length();
	std::string newString;
	for (int i = 0; i < len; i += 2)
	{
		string byte = hex.substr(i, 2);
		char chr = (char)(int)strtol(byte.c_str(), nullptr, 16);
		newString.push_back(chr);
	}
	return newString;
}

string getFileName(const string& s) {

	char sep = '/';

	size_t i = s.rfind(sep, s.length());
	if (i != string::npos) {
		return(s.substr(i + 1, s.length() - i));
	}

	return("");
}

int main(int argc, char* argv[])
{
	u_string key = (unsigned char *) (hexToASCII("1c4c1ea3a12531ae491b21bb31613c11")).c_str();
	const char* path = "C:\\Users\\mauro\\source\\repos\\testifstream\\RMX1901EX_11_OTA_0060_all_RkncSf3tpNqEtest.ozip";
	int pk = 0;
	if (argc != 1)
	{
		printf("Usage: ozipdecrypt [*.ozip]");
		return 0;
	}
	else
	{


		FILE* fp;
		char magic[13];
		char data[17];
		FILE* fp2;

		fp = fopen(path, "rb");
		fgets(magic, sizeof(magic), fp);


		if (strcmp(magic, "OPPOENCRYPT!") == 0)
		{
			fseek(fp, 4176, SEEK_SET);
			fgets(data, sizeof(data), fp);
			u_string test = decode(key, (unsigned char*)data);
			u_string checktest = test.substr(0, 4);
			if (checktest == ((unsigned char*) "\x50\x4B\x03\x04") || checktest ==((unsigned char*) "\x41\x4E\x44\x52"))
			{
				printf("Key is good!");
				const char* destpath = "romdecrypted.zip";
				fp2 = fopen(destpath, "wb");
				fseek(fp, 4176, SEEK_SET);
				char data2[16385];
				string temp;
				u_string temp2;
				long check = ftell(fp);
				while (true)
				{
					check = ftell(fp);
					fgets(data, sizeof(data), fp);
					if (sizeof(data) == 0)
					{
						break;
					}
					temp2 = decode(key, (unsigned char*)data);
					const char* ddata=(const char*)temp2.c_str();
					fwrite(ddata, sizeof(char), sizeof(ddata), fp2);

					fseek(fp, check + 16, SEEK_SET);
					fgets(data2, sizeof(data2), fp);
					if (sizeof(data2) == 0)
					{
						break;
					}
					fwrite(data2, sizeof(char), sizeof(data2), fp2);

					fseek(fp, check+16384+16, SEEK_SET);
				}
				fclose(fp2);
			}
			else
			{
				printf("Key is not good!");
				return 0;
			}
		}
		else
		{
			pk = 1;
		}
		fclose(fp);
		return 0;
	}
}