#include <cstring>
#include <iostream>
#include <openssl/x509.h>

static const char b64_table[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

static const char reverse_table[128] = {
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
	64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64,
	64, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64,
	64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64
};


::std::string base64_decode(const ::std::string& ascdata)
{
	using ::std::string;
	string retval;
	const string::const_iterator last = ascdata.end();
	int bits_collected = 0;
	unsigned int accumulator = 0;

	for (string::const_iterator i = ascdata.begin(); i != last; ++i)
	{
		const int c = *i;
		if (::std::isspace(c) || c == '=')
		{
			// Skip whitespace and padding. Be liberal in what you accept.
			continue;
		}
		if ((c > 127) || (c < 0) || (reverse_table[c] > 63))
		{
			throw ::std::invalid_argument("This contains characters not legal in a base64 encoded string.");
		}
		accumulator = (accumulator << 6) | reverse_table[c];
		bits_collected += 6;
		if (bits_collected >= 8)
		{
			bits_collected -= 8;
			retval += static_cast<char>((accumulator >> bits_collected) & 0xffu);
		}
	}
	return retval;
}


X509* get_x509(const std::string pem)
{
	std::string decoded = base64_decode(pem);

	X509* x = nullptr;
	unsigned char* buf = nullptr;
	const unsigned char* p = (const unsigned char*) decoded.c_str();
	int len = decoded.size();

	if (d2i_X509(&x, &p, len) == NULL)
	{
		std::cout << "mistake" << std::endl;
	}

	return x;
}


int main()
{
	const std::string pem("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");

	X509* x1 = get_x509(pem);
	X509* x2 = get_x509(pem);

	if (X509_cmp(x1, x2) == 0)
	{
		std::cout << "works" << std::endl;
		X509_free(x1);
		X509_free(x2);
		return 0;
	}

	X509_free(x1);
	X509_free(x2);

	std::cout << "broken" << std::endl;
	return 1;
}