C zCoin miner - LOTF

/* C zCoin miner using OpenSSL
 * author: sirius_black (LOTFREE)
 * date: 24/12/2013
 * compilation: gcc -o LOTF_zcoin_miner LOTF_zcoin_miner.c -lcrypto
 * use -fast or -Ofast for better performance
 *
 * Donate zCoins to Zd41uSXLL0pDwDd0bQwoAAfpHeiex4GunjNte38cuDnh8llqqD0
 */
#include <stdio.h>
#include <string.h>
#include <openssl/evp.h>
#include <unistd.h>
#include <fcntl.h>
#include <limits.h> // for ULLONG_MAX. len("18446744073709551615") = 20
#include <unistd.h>

// This one is for OSX as Apple think they can write something better than OpenSSL.
// (can you feel the NSA touch, Apple fanb0yz ?)
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"


int main(int argc, char *argv[])
{
  EVP_MD_CTX *mdctx;
  const EVP_MD *md;
  unsigned char md_value[EVP_MAX_MD_SIZE];
  unsigned int i;
  char * alphanum = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
  unsigned char data[6] ;
  unsigned char starter[6] ;
  int fd;
  char plaintext[26];
  char digest[129] ;

  printf("LOTF zCoin miner - Merry xMas zCoinistas !\n");

  OpenSSL_add_all_digests();
  md = EVP_get_digestbyname("sha512");

  fd = open("/dev/random", O_RDONLY);

  while(1) {
    unsigned long long n = 0;

    read(fd, data, 5);
    starter[5] = '\0' ;
    for (i=0; i<5; i++) {
      starter[i] = alphanum[data[i] % 62] ;
    }

    printf("Starter = %s\n", starter);

    while(1) {
      snprintf(plaintext, 26, "%s%llu", starter, n);
      mdctx = EVP_MD_CTX_create();
      EVP_DigestInit_ex(mdctx, md, NULL);
      EVP_DigestUpdate(mdctx, plaintext, strlen(plaintext));
      EVP_DigestFinal_ex(mdctx, md_value, NULL);
      EVP_MD_CTX_destroy(mdctx);

      for (i=0; i<64; i++) {
        snprintf(digest + i*2, 3, "%02x", md_value[i]);
      }

      if (!strncmp(digest, "1111111", 7)) {
        printf("Matching hash %s for plaintext %s\n", digest, plaintext);
      }

      if (n == ULLONG_MAX) break;
      n++;
    }
  }

  close(fd);
  return 0;
}