willcool4ever • sha1sum

#include "openssl/sha.h"
#include "openssl/crypto.h"
#include <iostream>
#include <sstream>
#include <fstream>

using namespace std;

void sha1sum(const char *body, const int len, const char *file_name) {
    std::stringstream ss;

    SHA_CTX c;
    unsigned char md[SHA_DIGEST_LENGTH] = {0};

    SHA1_Init(&c);
    SHA1_Update(&c, (unsigned char *) body, (len));
    SHA1_Final(md, &c);
    OPENSSL_cleanse(&c, sizeof(c));

    ss << file_name << "   ";
    //////
    for (int i = 0; i < SHA_DIGEST_LENGTH; i++) {
        //printf("[%02x]", md[i]);
        ss << std::hex << std::setfill('0') << std::setw(2) << (int) md[i];
    }

    printf("%s\n", ss.str().c_str());
}

int main(int argc, const char **argv) {
    if (argc != 2) {
        cerr << "argc err" << endl;
        return 1;
    }

    std::ifstream is(argv[1], std::ifstream::binary);
    if (is) {
        // get length of file:
        is.seekg(0, is.end);
        int length = is.tellg();
        is.seekg(0, is.beg);

        char *buffer = new char[length];

        //std::cout << "Reading " << length << " characters... ";
        // read data as a block:
        is.read(buffer, length);

        if (is) {
            //std::cout << "all characters read successfully.";
            sha1sum(buffer, length, argv[1]);
        } else
            std::cout << "error: only " << is.gcount() << " could be read";

        is.close();

        // ...buffer contains the entire file...

        delete[] buffer;
    }
    return 0;
}