ecc-redc-test.c 2.27 KB
Newer Older
Niels Möller's avatar
Niels Möller committed
1
2
#include "testutils.h"

3
4
5
6
7
8
9
10
#if NETTLE_USE_MINI_GMP
void
test_main (void)
{
  SKIP();
}
#else /* ! NETTLE_USE_MINI_GMP */

Niels Möller's avatar
Niels Möller committed
11
12
13
14
15
16
17
18
19
20
static void
ref_redc (mp_limb_t *rp, const mp_limb_t *ap, const mp_limb_t *mp, mp_size_t mn)
{
  mpz_t t;
  mpz_t m, a;
  mp_size_t an;

  mpz_init (t);
  mpz_setbit (t, mn * GMP_NUMB_BITS);

21
  mpz_roinit_n (m, mp, mn);
Niels Möller's avatar
Niels Möller committed
22
23
24
25
26

  an = 2*mn;
  while (an > 0 && ap[an-1] == 0)
    an--;

27
  mpz_roinit_n (a, ap, an);
Niels Möller's avatar
Niels Möller committed
28
29
30
31
32
  
  mpz_invert (t, t, m);
  mpz_mul (t, t, a);
  mpz_mod (t, t, m);

33
  mpz_limbs_copy (rp, t, mn);
Niels Möller's avatar
Niels Möller committed
34
35
36
37
38
39

  mpz_clear (t);
}

#define MAX_ECC_SIZE (1 + 521 / GMP_NUMB_BITS)
#define MAX_SIZE (2*MAX_ECC_SIZE)
40
#define COUNT 50000
Niels Möller's avatar
Niels Möller committed
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69

void
test_main (void)
{
  gmp_randstate_t state;
  mp_limb_t a[MAX_SIZE];
  mp_limb_t m[MAX_SIZE];
  mp_limb_t ref[MAX_SIZE];
  unsigned i;
  mpz_t r;

  gmp_randinit_default (state);
  
  mpz_init (r);
  
  for (i = 0; ecc_curves[i]; i++)
    {
      const struct ecc_curve *ecc = ecc_curves[i];
      unsigned j;
      if (!ecc->redc)
	continue;

      for (j = 0; j < COUNT; j++)
	{
	  if (j & 1)
	    mpz_rrandomb (r, state, 2*ecc->size * GMP_NUMB_BITS);
	  else
	    mpz_urandomb (r, state, 2*ecc->size * GMP_NUMB_BITS);

70
	  mpz_limbs_copy (a, r, 2*ecc->size);
Niels Möller's avatar
Niels Möller committed
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108

	  ref_redc (ref, a, ecc->p, ecc->size);

	  mpn_copyi (m, a, 2*ecc->size);
	  ecc->redc (ecc, m);
	  if (mpn_cmp (m, ecc->p, ecc->size) >= 0)
	    mpn_sub_n (m, m, ecc->p, ecc->size);

	  if (mpn_cmp (m, ref, ecc->size))
	    {
	      fprintf (stderr, "ecc->redc failed: bit_size = %u\n",
		       ecc->bit_size);
	      gmp_fprintf (stderr, "a   = %Nx\n", a, 2*ecc->size);
	      gmp_fprintf (stderr, "m   = %Nx (bad)\n", m, ecc->size);
	      gmp_fprintf (stderr, "ref = %Nx\n", ref, ecc->size);
	      abort ();
	    }

	  mpn_copyi (m, a, 2*ecc->size);
	  ecc_generic_redc (ecc, m);
	  if (mpn_cmp (m, ecc->p, ecc->size) >= 0)
	    mpn_sub_n (m, m, ecc->p, ecc->size);

	  if (mpn_cmp (m, ref, ecc->size))
	    {
	      fprintf (stderr, "ecc_generic_redc failed: bit_size = %u\n",
		       ecc->bit_size);
	      gmp_fprintf (stderr, "a   = %Nx\n", a, 2*ecc->size);
	      gmp_fprintf (stderr, "m   = %Nx (bad)\n", m, ecc->size);
	      gmp_fprintf (stderr, "ref = %Nx\n", ref, ecc->size);
	      abort ();
	    }
	}
    }

  mpz_clear (r);
  gmp_randclear (state);
}
109
#endif /* ! NETTLE_USE_MINI_GMP */