1 #include <stdint.h>
    2 #include <stdio.h>
    3 #include <stdlib.h>
    4 #include <string.h>
    5 #include <gmp.h>
    6 #include <curl/curl.h>
    7 #define ASSERT(x, c, f) if (!(x)) { f; exit(c); }
    8 void get_random_safe_prime(mpz_t p, mpz_t q, size_t bits) {
    9   ASSERT(bits >= 10, 1,
   10     fprintf(stderr, "<bit-size> must be at least 10.\n"));
   11   FILE * f = fopen("/dev/urandom", "rb");
   12   ASSERT(f, 2, perror("Failed to open /dev/urandom"));
   13   size_t nbytes = (bits + 7) >> 3, mask = 1 << ((bits + 7) & 7);
   14   uint8_t buf[nbytes];  mpz_t two;  mpz_init_set_ui(two, 2);
   15   uint64_t P = 5ul * 7ul * 11ul * 13ul * 17ul * 19ul * 23ul * 37ul;
   16   for (;;) {
   17     ASSERT(fread(buf, 1, nbytes, f) == nbytes, 3,
   18       perror("Failed to read random bytes"));
   19     buf[0] = (buf[0] & (mask - 1)) | mask;
   20     mpz_import(p, nbytes, 1, 1, 0, 0, buf);
   21     mpz_sub_ui(p, p, ((unsigned) mpz_fdiv_ui(p, 12) + 1u) % 12u);
   22     uint64_t r = mpz_fdiv_ui(p, P);
   23     if ((r % 5u) >> 1 == 0 || (r % 7u) >> 1 == 0 ||
   24         (r % 11u) >> 1 == 0 || (r % 13u) >> 1 == 0 ||
   25         (r % 17u) >> 1 == 0 || (r % 19u) >> 1 == 0 ||
   26         (r % 23u) >> 1 == 0 || (r % 37u) >> 1 == 0) continue;
   27     r = mpz_fdiv_ui(p, 29ul * 31ul * 41ul * 43ul * 47ul * 53ul);
   28     if ((r % 29u) >> 1 == 0 || (r % 31u) >> 1 == 0 ||
   29         (r % 41u) >> 1 == 0 || (r % 43u) >> 1 == 0 ||
   30         (r % 47u) >> 1 == 0 || (r % 53u) >> 1 == 0) continue;
   31     r = mpz_fdiv_ui(p, 59ul * 61ul * 67ul * 71ul * 73ul);
   32     if ((r % 59u) >> 1 == 0 || (r % 61u) >> 1 == 0 ||
   33         (r % 67u) >> 1 == 0 || (r % 71u) >> 1 == 0 ||
   34         (r % 73u) >> 1 == 0) continue;
   35     mpz_powm(q, two, p, p);
   36     if (mpz_cmp(q, two) != 0) continue;
   37     mpz_fdiv_q_2exp(q, p, 1);
   38     if (mpz_tstbit(p, bits - 1) && mpz_probab_prime_p(q, 40) &&
   39         mpz_probab_prime_p(p, 50))
   40       break;
   41   }
   42 }
   43 typedef struct { char * ptr; size_t len; } rstr;
   44 size_t cwrite(void * ptr, size_t size, size_t nmemb, rstr * s) {
   45   size_t new_len = s->len + size * nmemb;
   46   s->ptr = realloc(s->ptr, new_len + 1);
   47   ASSERT(s->ptr, 5, perror("Failed to reallocate memory"));
   48   memcpy(s->ptr + s->len, ptr, size * nmemb);
   49   s->ptr[new_len] = 0;  s->len = new_len;
   50   return size * nmemb;
   51 }
   52 int main(int argc, char * argv[]) {
   53   ASSERT(argc == 3, 6,
   54     fprintf(stderr, "Usage: %s <bits-1> <submitter>\n", argv[0]));
   55   int bits = atoi(argv[1]);  char * submitter = argv[2];
   56   ASSERT(strlen(submitter) < 16, 7,
   57     fprintf(stderr, "Submitter name too long\n"));
   58   mpz_t p, q;  mpz_inits(p, q, NULL);
   59   get_random_safe_prime(p, q, bits);
   60   char * q_str = mpz_get_str(NULL, 10, q);
   61   CURL * curl = curl_easy_init();
   62   ASSERT(curl, 8,
   63     fprintf(stderr, "Failed to initialize libcurl\n"));
   64   size_t sz = strlen(q_str) + strlen(submitter) + 128;
   65   char * post = malloc(sz);
   66   snprintf(post, sz, "prime=%s&submitter=%s", q_str, submitter);
   67   rstr response; response.len = 0; response.ptr = NULL;
   68   curl_easy_setopt(curl, CURLOPT_URL,
   69     "https://palaiologos.rocks/sophie-germain/submit");
   70   curl_easy_setopt(curl, CURLOPT_POST, 1L);
   71   curl_easy_setopt(curl, CURLOPT_POSTFIELDS, post);
   72   curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, cwrite);
   73   curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response);
   74   curl_easy_setopt(curl, CURLOPT_USERAGENT, "sophie-c-client/1.0");
   75   CURLcode res = curl_easy_perform(curl);
   76   ASSERT(res == CURLE_OK, 9,
   77     fprintf(stderr, "curl: %s\n", curl_easy_strerror(res)));
   78   long http_code = 0;
   79   curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &http_code);
   80   printf("Server response:\n%s\n", response.ptr);
   81   ASSERT(http_code == 200, 10,
   82     fprintf(stderr, "HTTP error: %ld\n", http_code));
   83 }

    1 #!/bin/bash
    2 cc search.c -o search -lgmp -lcurl -O2
    3 seq 1 5000 | parallel -j$(nproc) ./search 2048 "${USER:0:16}"