为什么此base64解码/编码功能不能正常工作？

Question

I am using the base64 function from here to try and run a simple program. I want to convert binary to base64 using this code:

int x = 1;
std::string data = base64_encode(reinterpret_cast<unsigned char *>((void *)&x), 4);
std::string out = base64_decode(data);
int y = reinterpret_cast<int>(out.data());

The encode function is called, and generates this string "AQAAAA==" . From my understanding, this would should convert to 01 00 00 0 if decoded and converted to bytes (I actually don't understand why it's 7 bytes). When the decode function is called, I expect 01 00 00 00 , which would then be reinterpret_castable back into the integer 1, but rather I get "\\001\\000\\000" , which is not what I expect. I tried increasing the second parameter of the encode function, funnily, it gives me the proper answer of "\\001\\000\\000\\000" after decode.

Answer 1

Assuming you are using this code for base64, I suspect the following will work:

int x = 1;
std::string data = base64_encode(reinterpret_cast<unsigned char *>(&x), 4);
std::string out = base64_decode(data);
int y= *(reinterpret_cast<int*>(out.c_str()));

On whatever side is doing the decode logic, it should probably validate that out.size() == sizeof(int) before doing this conversion.