simple encrypt

encrypt.cpp

/*!
  simple encrypt
*/
#include <string>
#include <assert.h>

std::string encrypt(const std::string &src, bool encrypt)
{
	assert(!src.empty());
	std::string ret;

	if (encrypt) {
		for (size_t i = 0; i < src.length(); ++i) {
			char tmp[4] = {0};
			sprintf_s(tmp, "%.2x", (unsigned char)src[i] ^ 0xe9);
			ret += tmp;
		}
	} else {
		assert (src.length()%2 == 0);
		for (size_t i = 0; i < src.length(); i+=2) {
			char tmp[4] = {0};
			tmp[0] = src[i];
			tmp[1] = src[i+1];
			assert ((tmp[0] <= '9' && tmp[0] >='0' || tmp[0] <= 'f' && tmp[0] >= 'a') 
				&& (tmp[1] <= '9' && tmp[1] >='0' || tmp[1] <= 'f' && tmp[1] >= 'a'));
			unsigned int c;
			sscanf_s(tmp, "%2X", &c);
			ret += (char)((unsigned char)c ^ 0xe9);
		}
	}

	return ret;
}

int main()
{
	std::string src = "test abvd 1000__ --abc 你妹的。。。";
	std::string dst = encrypt(src, true);
	printf("src = %s\n", src.c_str());
	printf("dst = %s\n", dst.c_str());
	printf("src = %s\n", encrypt(dst, false).c_str());
	return 0;
}