How do I implement hashing algorithms in C++?

How do I implement hashing algorithms in C++?

To implement hashing algorithms in C++, you can start by choosing a specific algorithm like SHA-256 or MD5. Would you like a code example?

Yes, please provide a code example for SHA-256.

Here's a simple implementation of SHA-256 in C++ using the OpenSSL library:

#include <openssl/sha.h>
#include <iostream>
#include <iomanip>
#include <sstream>

std::string sha256(const std::string str) {
    unsigned char hash[SHA256_DIGEST_LENGTH];
    SHA256_CTX sha256;
    SHA256_Init(&sha256);
    SHA256_Update(&sha256, str.c_str(), str.size());
    SHA256_Final(hash, &sha256);
    std::stringstream ss;
    for(int i = 0; i < SHA256_DIGEST_LENGTH; i++) {
        ss << std::hex << std::setw(2) << std::setfill('0') << (int)hash[i];
    }
    return ss.str();
}

int main() {
    std::string input = "Hello, World!";
    std::cout << "SHA-256: " << sha256(input) << std::endl;
    return 0;
}

This will output the SHA-256 hash of the input string.

What libraries do I need to include for this code?

You need to include the OpenSSL library. Make sure to link against it when compiling your code. You can install it using your package manager, for example, sudo apt-get install libssl-dev on Ubuntu.