test.c

#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <sys/time.h>
#include <stdlib.h>
#include <openssl/sha.h>
#include <string.h>
#include <stdbool.h>
 
int main(int argc, const char * argv[])
{
    char *parent = (char *)argv[1];
    char *tree = (char *)argv[2];
    char *difficulty = (char *)argv[3];
    int counter = 0;
    bool lower = false;
    char hash_string[SHA_DIGEST_LENGTH*2];
    chdir(argv[4]);
    int difficulty_length = strlen(difficulty);
   
    struct timeval time;
    gettimeofday(&time, NULL);
   
    char *commit = malloc(sizeof(char) * 1024);
    char *blob = malloc(sizeof(char) * 1024);
   
    while (lower == false) {

//        sprintf(commit, "tree %s\nparent %s\nauthor CTF user <me@example.com> %li +0000\ncommitter CTF user <me@example.com> %li +0000\n\nGive me a Gitcoin! %i", tree, parent, time.tv_sec, time.tv_sec, counter);

      commit = "tree 2e26d427ff8d82f764cec06065edd19689f9bdd8\nparent c356dd2aa0e21938d1e2ea0ac78f6acb2c4c6a4a\nauthor Dan Palmer <dan.palmer@me.com> 1390002604 +0000\ncommitter Dan Palmer <dan.palmer@me.com> 1390002604 +0000\n\nBasic hierarchy layout";
      //commit2 = "tree f7206ae5eb29fde9ec130a50ac8031b055d6db13\nparent 0000002c6c1bd3bd95cc31c6c419f4954eb3abac\nauthor Stripe CTF <ctf@stripe.com> 1390494623 +0000\ncommitter Stripe CTF <ctf@stripe.com> 1390494623 +0000\n\nMined a Gitcoin!\nnonce 00123bea";
       
      sprintf(blob, "commit %dX%s", strlen(commit), commit);
        size_t length = strlen(blob);
        blob[10] = '\0';
        unsigned char hash[SHA_DIGEST_LENGTH];
        SHA1(blob, length, hash);
       
        int i = 0;
        for (i=0; i < SHA_DIGEST_LENGTH; i++) {
            sprintf((char*)&(hash_string[i*2]), "%02x", hash[i]);
        }
       
        lower = strncmp(hash_string, difficulty, difficulty_length) < 0;
	lower = true;
        if (lower == true) {
            char temp[512];
            sprintf(temp, "echo \"%s\" > dfile && git hash-object -t commit --no-filters dfile", commit);
            printf("Expected Hash:\n");
            printf("%s\n", hash_string);
            printf("Actual Hash:\n");
            int output = system(temp);
            printf("\nExit code: %i\n", output);
            printf("%s", commit);
        }
       
        counter++;
       
        if (counter % 10000 == 0) {
            fprintf(stdout, "%i\n", counter);
            gettimeofday(&time, NULL);
        }
 
    }
    //free(commit);
    //free(blob);
}