src/thread.c

   1 // thread procs for shallot
   2
   3 #include "config.h"
   4
   5 #include <stdint.h> // OpenBSD needs this included before sys/endian.h
   6
   7 #if defined(LINUX_PORT) || defined(OSX) || defined(GENERIC)
   8   #include "linux.h"
   9 #else
  10   #include <sys/param.h> // OpenBSD needs this early on too
  11   #include <sys/endian.h>
  12 #endif
  13
  14 #include "math.h"
  15 #include "print.h"
  16 #include "error.h"
  17 #include "thread.h"
  18 #include "defines.h"
  19 #include "globals.h"
  20
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <pthread.h>
  24 #include <openssl/rsa.h>
  25 #include <openssl/sha.h>
  26
  27 void *worker(void *params) { // life cycle of a cracking pthread
  28   uint64_t e_be; // storage for our "big-endian" version of e
  29   uint8_t buf[SHA1_DIGEST_LEN],
  30           der[RSA_EXP_DER_LEN + 1], // TODO: is the size of this right?
  31           optimum = *(uint8_t*)params;
  32   char onion[BASE32_ONIONLEN];
  33   SHA_CTX hash, copy;
  34   RSA *rsa;
  35
  36   while(!found) {
  37     // keys are only generated every so often
  38     // every 549,755,781,120 tries by default
  39
  40     if(optimum)
  41       rsa = easygen(RSA_OPTM_BITLEN - RSA_PK_E_LENGTH * 8, RSA_PK_E_LENGTH,
  42                     der, RSA_OPT_DER_LEN, &hash);
  43     else
  44       rsa = easygen(RSA_KEYS_BITLEN, RSA_PK_E_LENGTH, der, RSA_EXP_DER_LEN,
  45                     &hash);
  46
  47     if(!rsa) // if key generation fails (no [P]RNG seed?)
  48       error(X_KEY_GEN_FAILS);
  49
  50     uint8_t e_bytes = RSA_PK_E_LENGTH; // number of bytes e occupies
  51     uint64_t e = RSA_PK_EXPONENT;      // public exponent
  52     uint64_t e_byte_thresh;
  53
  54     int_pow(2, e_bytes * 8, &e_byte_thresh);
  55     e_byte_thresh++;
  56
  57     uint8_t *e_ptr = ((uint8_t*)&e_be) + 8 - e_bytes;
  58
  59     while((e <= elim) && !found) { // main loop
  60       // copy the relevant parts of our already set up context
  61       memcpy(&copy, &hash, SHA_REL_CTX_LEN); // 40 bytes here...
  62       copy.num = hash.num;                   // and don't forget the num (9)
  63
  64       // convert e to big-endian format
  65       e_be = htobe64(e);
  66
  67       // compute SHA1 digest (majority of loop time spent here!)
  68       SHA1_Update(&copy, e_ptr, e_bytes);
  69       SHA1_Final(buf, &copy);
  70
  71       base32_onion(onion, buf); // base32-encode SHA1 digest
  72       loop++;                   // keep track of our tries...
  73
  74       if(!regexec(regex, onion, 0, 0, 0)) { // check for a match
  75
  76         // let our main thread know on which thread to wait
  77         lucky_thread = pthread_self();
  78         found = 1; // kill off our other threads, asynchronously
  79
  80         if(monitor)
  81           printf("\n"); // keep our printing pretty!
  82
  83         if(!BN_bin2bn(e_ptr, e_bytes, rsa->e)) // store our e in the actual key
  84           error(X_BIGNUM_FAILED);              // and make sure it got there
  85
  86         if(!sane_key(rsa))        // check our key
  87           error(X_YOURE_UNLUCKY); // bad key :(
  88
  89         print_onion(onion); // print our domain
  90         print_prkey(rsa);   // and more importantly the key
  91
  92         RSA_free(rsa); // free up what's left
  93
  94         return 0;
  95       }
  96
  97       e += 2; // do *** NOT *** forget this!
  98
  99       if(e == e_byte_thresh) { // ASN.1 stuff (hey, it could be worse!)
 100         // calculate our new threshold
 101         int_pow(2, ++e_bytes * 8, &e_byte_thresh);
 102         e_byte_thresh++;
 103
 104         if(optimum) {
 105           RSA_free(rsa);
 106           easygen(RSA_OPTM_BITLEN - e_bytes * 8, e_bytes, der, RSA_OPT_DER_LEN,
 107                   &hash);
 108
 109           if(!rsa)
 110             error(X_KEY_GEN_FAILS);
 111         } else {
 112           // play with our key structure (do not try this at home!)
 113           der[RSA_ADD_DER_OFF]++;
 114           der[RSA_EXP_DER_LEN - RSA_PK_E_LENGTH - 1]++;
 115
 116           // and our prebuilt hash
 117           SHA1_Init(&hash); // TODO: move to a function
 118           SHA1_Update(&hash, der, RSA_EXP_DER_LEN - RSA_PK_E_LENGTH);
 119         }
 120
 121         e_ptr--; // and move the pointer back
 122       }
 123     }
 124     RSA_free(rsa);
 125   }
 126
 127   return 0;
 128 }
 129
 130 void *monitor_proc(void *unused) {
 131   printf("\033[sPlease wait a moment for statistics...");
 132   time_t start = time(NULL);
 133
 134   for(;;) {
 135     fflush(stdout); // make sure it gets printed
 136     sleep(20);
 137
 138     if(found)
 139       return 0;
 140
 141     time_t current = time(NULL);
 142     time_t elapsed = current - start;
 143
 144     if(!elapsed)
 145       continue; // be paranoid and avoid divide-by-zero exceptions
 146
 147     printf("\033[u\033[KHashes: %-20llu  Time: %-10d  Speed: %-llu",
 148            loop, (int)elapsed, loop / elapsed);
 149   }
 150
 151   return 0; // unreachable code, but prevents warnings (!?)
 152 }