SHA256 Hashing Challenge Program

hashingSHA256.cpp

#include <stdio.h>
#include <stdlib.h> 
#include <iostream>

#include <openssl/sha.h>


static const char alphabet[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

int main(){

    srand (time(NULL));
    //printf("%d\n",SHA256_DIGEST_LENGTH);
	
    unsigned char hash[SHA256_DIGEST_LENGTH];

    const int N = 4000000;
    const int M = 12;

    char randString[M];
    char maxHash[M];
    int maxVal=0;

    int i;
    for(i=0;i<N;i++){

        int j;
        for (j=0;j<M;j++) {
            randString[j] = alphabet[rand() % (sizeof(alphabet) - 1)];
        }
        randString[M] = 0;

        SHA256_CTX sha256;
        SHA256_Init(&sha256);
        SHA256_Update(&sha256, randString, M);
        SHA256_Final(hash, &sha256);

        j=0;
        while(hash[j]==0){
            j++;
        }
	
        if(j>maxVal){
            maxVal = j;
            for(j=0;j<M;j++){
                maxHash[j] = randString[j];
            }
            printf("%s\t%d\t",maxHash,maxVal);

            for(j=0;j<SHA256_DIGEST_LENGTH;j++){
                printf("%x", hash[j]);
            }
            printf("\n");		
        }
    }
    return 0;
}