View difference between Paste ID: WQ5xrYR5 and S8WARrRn

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include <openssl/sha.h>
 
 const char *coin_err;
 #define bail(s) { coin_err = s; return 0; }
 
 int unbase58(const char *s, unsigned char *out) {
     static const char *tmpl = "123456789"
         "ABCDEFGHJKLMNPQRSTUVWXYZ"
         "abcdefghijkmnopqrstuvwxyz";
     int i, j, c;
     const char *p;
 
     memset(out, 0, 40);
     for (i = 0; s[i]; i++) {
         if (!(p = strchr(tmpl, s[i])))
             bail("bad char");
 
         c = p - tmpl;
         for (j = 37; j--; ) {
             c += 58 * out[j];
             out[j] = c % 256;
             c /= 256;
         }
 
         if (c) bail("address too long");
     }
 
     return 1;
 }
 
 int valid(const char *s) {
     unsigned char dec[40], d1[SHA256_DIGEST_LENGTH], d2[SHA256_DIGEST_LENGTH];
 
     coin_err = "";
     if (!unbase58(s, dec)) return 0;
 
     SHA256(SHA256(dec, 33, d1), SHA256_DIGEST_LENGTH, d2);
 
     if (memcmp(dec + 33, d2, 4))
         bail("bad digest");
 
     return 1;
 }
 
 #define C_1_INDEX 6
 #define C_2_INDEX 11
 #define C_3_INDEX 27
 #define C_4_INDEX 34
 #define C_5_INDEX 47
 
 int main (void) {
     const char *chars = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
     char addr[100];
     strcpy(addr, "5HpHag-65TZ-G1PH3CSu63k8Dbp-D8s5ip-nEB3kEsreAnc-uDf");
 
     int i;
     for (i = 0; addr[i]; i++) {
         if (addr[i] == '-') printf("index: %d\n", i);
     }
 
     int c1 = 0, c2 = 0, c3 = 0, c4 = 0, c5 = 0, status;
     float startTime, endTime;
     for (c1 = 0; c1 < 58; c1++) {
         addr[C_1_INDEX] = chars[c1];
         for (c2 = 0; c2 < 58; c2++) {
             addr[C_2_INDEX] = chars[c2];
             printf("Test: %c%c...", chars[c1], chars[c2]);fflush(stdout);
             startTime = (float)clock()/CLOCKS_PER_SEC;
             for (c3 = 0; c3 < 58; c3++) {
                 addr[C_3_INDEX] = chars[c3];
                 for (c4 = 0; c4 < 58; c4++) {
                     addr[C_4_INDEX] = chars[c4];
                     for (c5 = 0; c5 < 58; c5++) {
                         addr[C_5_INDEX] = chars[c5];
                         status = valid(addr);
                         if (status) {
                             printf("\nFOUND: %s\n", addr);
                             return 1;
                         }
                     }
                 }
             }
             endTime = (float)clock()/CLOCKS_PER_SEC;
             printf("%fs\n", (endTime-startTime));
         }
     }
 
     return 0;
 }