view libtomcrypt/testprof/ecc_test.c @ 1788:1fc0012b9c38

Fix handling of replies to global requests (#112) The current code assumes that all global requests want / need a reply. This isn't always true and the request itself indicates if it wants a reply or not. It causes a specific problem with [email protected] messages. These are sent by OpenSSH after authentication to inform the client of potential other host keys for the host. This can be used to add a new type of host key or to rotate host keys. The initial information message from the server is sent as a global request, but with want_reply set to false. This means that the server doesn't expect an answer to this message. Instead the client needs to send a prove request as a reply if it wants to receive proof of ownership for the host keys. The bug doesn't cause any current problems with due to how OpenSSH treats receiving the failure message. It instead treats it as a keepalive message and further ignores it. Arguably this is a protocol violation though of Dropbear and it is only accidental that it doesn't cause a problem with OpenSSH. The bug was found when adding host keys support to libssh, which is more strict protocol wise and treats the unexpected failure message an error, also see https://gitlab.com/libssh/libssh-mirror/-/merge_requests/145 for more information. The fix here is to honor the want_reply flag in the global request and to only send a reply if the other side expects a reply.
author Dirkjan Bussink <d.bussink@gmail.com>
date Thu, 10 Dec 2020 16:13:13 +0100
parents f849a5ca2efc
children
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#include <tomcrypt_test.h>

#ifdef LTC_MECC

static int sizes[] = {
#ifdef ECC112
14,
#endif
#ifdef ECC128
16,
#endif
#ifdef ECC160
20,
#endif
#ifdef ECC192
24,
#endif
#ifdef ECC224
28,
#endif
#ifdef ECC256
32,
#endif
#ifdef ECC384
48,
#endif
#ifdef ECC521
65
#endif
};

#ifdef LTC_ECC_SHAMIR
int ecc_test_shamir(void)
{
   void *modulus, *mp, *kA, *kB, *rA, *rB;
   ecc_point *G, *A, *B, *C1, *C2;
   int x, y, z;
   unsigned char buf[ECC_BUF_SIZE];

   DO(mp_init_multi(&kA, &kB, &rA, &rB, &modulus, NULL));
   LTC_ARGCHK((G  = ltc_ecc_new_point()) != NULL);
   LTC_ARGCHK((A  = ltc_ecc_new_point()) != NULL);
   LTC_ARGCHK((B  = ltc_ecc_new_point()) != NULL);
   LTC_ARGCHK((C1 = ltc_ecc_new_point()) != NULL);
   LTC_ARGCHK((C2 = ltc_ecc_new_point()) != NULL);

   for (x = 0; x < (int)(sizeof(sizes)/sizeof(sizes[0])); x++) {
       /* get the base point */
       for (z = 0; ltc_ecc_sets[z].name; z++) {
           if (sizes[z] < ltc_ecc_sets[z].size) break;
       }
       LTC_ARGCHK(ltc_ecc_sets[z].name != NULL);

       /* load it */
       DO(mp_read_radix(G->x, ltc_ecc_sets[z].Gx, 16));
       DO(mp_read_radix(G->y, ltc_ecc_sets[z].Gy, 16));
       DO(mp_set(G->z, 1));
       DO(mp_read_radix(modulus, ltc_ecc_sets[z].prime, 16));
       DO(mp_montgomery_setup(modulus, &mp));

       /* do 100 random tests */
       for (y = 0; y < 100; y++) {
          /* pick a random r1, r2 */
          LTC_ARGCHK(yarrow_read(buf, sizes[x], &yarrow_prng) == sizes[x]);
          DO(mp_read_unsigned_bin(rA, buf, sizes[x]));
          LTC_ARGCHK(yarrow_read(buf, sizes[x], &yarrow_prng) == sizes[x]);
          DO(mp_read_unsigned_bin(rB, buf, sizes[x]));

          /* compute rA * G = A */
          DO(ltc_mp.ecc_ptmul(rA, G, A, modulus, 1));
       
          /* compute rB * G = B */
          DO(ltc_mp.ecc_ptmul(rB, G, B, modulus, 1));

          /* pick a random kA, kB */
          LTC_ARGCHK(yarrow_read(buf, sizes[x], &yarrow_prng) == sizes[x]);
          DO(mp_read_unsigned_bin(kA, buf, sizes[x]));
          LTC_ARGCHK(yarrow_read(buf, sizes[x], &yarrow_prng) == sizes[x]);
          DO(mp_read_unsigned_bin(kB, buf, sizes[x]));

          /* now, compute kA*A + kB*B = C1 using the older method */
          DO(ltc_mp.ecc_ptmul(kA, A, C1, modulus, 0));
          DO(ltc_mp.ecc_ptmul(kB, B, C2, modulus, 0));
          DO(ltc_mp.ecc_ptadd(C1, C2, C1, modulus, mp));
          DO(ltc_mp.ecc_map(C1, modulus, mp));

          /* now compute using mul2add */
          DO(ltc_mp.ecc_mul2add(A, kA, B, kB, C2, modulus));

          /* is they the sames?  */
          if ((mp_cmp(C1->x, C2->x) != LTC_MP_EQ) || (mp_cmp(C1->y, C2->y) != LTC_MP_EQ) || (mp_cmp(C1->z, C2->z) != LTC_MP_EQ)) {
             fprintf(stderr, "ECC failed shamir test: size=%d, testno=%d\n", sizes[x], y);
             return 1;
          }
      }
      mp_montgomery_free(mp);
  }
  ltc_ecc_del_point(C2);
  ltc_ecc_del_point(C1);
  ltc_ecc_del_point(B);
  ltc_ecc_del_point(A);
  ltc_ecc_del_point(G);
  mp_clear_multi(kA, kB, rA, rB, modulus, NULL);
  return 0;
}
#endif

int ecc_tests (void)
{
  unsigned char buf[4][4096];
  unsigned long x, y, z, s;
  int           stat, stat2;
  ecc_key usera, userb, pubKey, privKey;
	
  DO(ecc_test ());
  DO(ecc_test ());
  DO(ecc_test ());
  DO(ecc_test ());
  DO(ecc_test ());

  for (s = 0; s < (sizeof(sizes)/sizeof(sizes[0])); s++) {
     /* make up two keys */
     DO(ecc_make_key (&yarrow_prng, find_prng ("yarrow"), sizes[s], &usera));
     DO(ecc_make_key (&yarrow_prng, find_prng ("yarrow"), sizes[s], &userb));

     /* make the shared secret */
     x = sizeof(buf[0]);
     DO(ecc_shared_secret (&usera, &userb, buf[0], &x));

     y = sizeof(buf[1]);
     DO(ecc_shared_secret (&userb, &usera, buf[1], &y));

     if (y != x) {
       fprintf(stderr, "ecc Shared keys are not same size.");
       return 1;
     }

     if (memcmp (buf[0], buf[1], x)) {
       fprintf(stderr, "ecc Shared keys not same contents.");
       return 1;
     }

     /* now export userb */
     y = sizeof(buf[0]);
     DO(ecc_export (buf[1], &y, PK_PUBLIC, &userb));
     ecc_free (&userb);

     /* import and make the shared secret again */
     DO(ecc_import (buf[1], y, &userb));

     z = sizeof(buf[0]);
     DO(ecc_shared_secret (&usera, &userb, buf[2], &z));

     if (z != x) {
       fprintf(stderr, "failed.  Size don't match?");
       return 1;
     }
     if (memcmp (buf[0], buf[2], x)) {
       fprintf(stderr, "Failed.  Contents didn't match.");
       return 1;
     }

     /* export with ANSI X9.63 */
     y = sizeof(buf[1]);
     DO(ecc_ansi_x963_export(&userb, buf[1], &y));
     ecc_free (&userb);

     /* now import the ANSI key */
     DO(ecc_ansi_x963_import(buf[1], y, &userb));

     /* shared secret */
     z = sizeof(buf[0]);
     DO(ecc_shared_secret (&usera, &userb, buf[2], &z));

     if (z != x) {
       fprintf(stderr, "failed.  Size don't match?");
       return 1;
     }
     if (memcmp (buf[0], buf[2], x)) {
       fprintf(stderr, "Failed.  Contents didn't match.");
       return 1;
     }

     ecc_free (&usera);
     ecc_free (&userb);

     /* test encrypt_key */
     DO(ecc_make_key (&yarrow_prng, find_prng ("yarrow"), sizes[s], &usera));

     /* export key */
     x = sizeof(buf[0]);
     DO(ecc_export(buf[0], &x, PK_PUBLIC, &usera));
     DO(ecc_import(buf[0], x, &pubKey));
     x = sizeof(buf[0]);
     DO(ecc_export(buf[0], &x, PK_PRIVATE, &usera));
     DO(ecc_import(buf[0], x, &privKey));

     for (x = 0; x < 32; x++) {
        buf[0][x] = x;
     }
     y = sizeof (buf[1]);
     DO(ecc_encrypt_key (buf[0], 32, buf[1], &y, &yarrow_prng, find_prng ("yarrow"), find_hash ("sha256"), &pubKey));
     zeromem (buf[0], sizeof (buf[0]));
     x = sizeof (buf[0]);
     DO(ecc_decrypt_key (buf[1], y, buf[0], &x, &privKey));
     if (x != 32) {
       fprintf(stderr, "Failed (length)");
       return 1;
     }
     for (x = 0; x < 32; x++) {
        if (buf[0][x] != x) {
           fprintf(stderr, "Failed (contents)");
           return 1;
        }
     }
     /* test sign_hash */
     for (x = 0; x < 16; x++) {
        buf[0][x] = x;
     }
     x = sizeof (buf[1]);
     DO(ecc_sign_hash (buf[0], 16, buf[1], &x, &yarrow_prng, find_prng ("yarrow"), &privKey));
     DO(ecc_verify_hash (buf[1], x, buf[0], 16, &stat, &pubKey));
     buf[0][0] ^= 1;
     DO(ecc_verify_hash (buf[1], x, buf[0], 16, &stat2, &privKey));
     if (!(stat == 1 && stat2 == 0)) { 
        fprintf(stderr, "ecc_verify_hash failed %d, %d, ", stat, stat2);
        return 1;
     }
     ecc_free (&usera); 
     ecc_free (&pubKey);
     ecc_free (&privKey);
  }
#ifdef LTC_ECC_SHAMIR
  return ecc_test_shamir();
#else
  return 0;
#endif
}

#else

int ecc_tests(void)
{
   fprintf(stderr, "NOP");
   return 0;
}

#endif

/* $Source$ */
/* $Revision$ */
/* $Date$ */