void cpDecodeSecret(const vlPoint vlPrivateKey, const vlPoint vlMessage, vlPoint d) {
ecPoint q;
ecUnpack(&q, vlMessage);
ecMultiply(&q, vlPrivateKey);
gfPack(q.x, d);
} /* ecDecodeSecret */
void cpEncodeSecret(const vlPoint vlPublicKey, vlPoint vlMessage, vlPoint vlSecret) {
ecPoint q;
ecCopy(&q, &curve_point);
ecMultiply(&q, vlSecret);
ecPack(&q, vlMessage);
ecUnpack(&q, vlPublicKey);
ecMultiply(&q, vlSecret);
gfPack(q.x, vlSecret);
} /* cpMakeSecret */
int cpVerify(const vlPoint vlPublicKey, const vlPoint vlMac, cpPair * sig) {
ecPoint t1, t2;
vlPoint t3, t4;
ecCopy(&t1, &curve_point);
ecMultiply(&t1, sig->s);
ecUnpack(&t2, vlPublicKey);
ecMultiply(&t2, sig->r);
ecAdd(&t1, &t2);
gfPack(t1.x, t4);
vlRemainder(t4, prime_order);
vlCopy(t3, sig->r);
if (vlGreater(t4, t3)) vlAdd(t3, prime_order);
vlSubtract(t3, t4);
return vlEqual(t3, vlMac);
} /* cpVerify */
int ecSelfTest (int test_count)
/* perform test_count self tests */
{
int i, yb, nfail = 0, afail = 0, sfail = 0, cfail = 0, qfail = 0, pfail = 0, yfail = 0;
ecPoint f, g, x, y;
vlPoint m, n, p;
clock_t elapsed = 0L;
srand ((unsigned)(time(NULL) % 65521U));
printf ("Executing %d curve self tests...", test_count);
for (i = 0; i < test_count; i++) {
ecRandom (&f);
ecRandom (&g);
vlRandom (m);
vlRandom (n);
/* negation test: -(-f) = f */
ecCopy (&x, &f);
ecNegate (&x);
ecNegate (&x);
if (!ecEqual (&x, &f)) {
nfail++;
/* printf ("Addition test #%d failed!\n", i); */
}
/* addition test: f+g = g+f */
ecCopy (&x, &f); ecAdd (&x, &g);
ecCopy (&y, &g); ecAdd (&y, &f);
if (!ecEqual (&x, &y)) {
afail++;
/* printf ("Addition test #%d failed!\n", i); */
}
/* subtraction test: f-g = f+(-g) */
ecCopy (&x, &f); ecSub (&x, &g);
ecCopy (&y, &g); ecNegate (&y); ecAdd (&y, &f);
if (!ecEqual (&x, &y)) {
sfail++;
/* printf ("Subtraction test #%d failed!\n", i); */
}
/* quadruplication test: 2*(2*f) = f + f + f + f */
ecCopy (&x, &f); ecDouble (&x); ecDouble (&x);
ecClear (&y); ecAdd (&y, &f); ecAdd (&y, &f); ecAdd (&y, &f); ecAdd (&y, &f);
if (!ecEqual (&x, &y)) {
qfail++;
/* printf ("Quadruplication test #%d failed!\n", i); */
}
/* scalar multiplication commutativity test: m*(n*f) = n*(m*f) */
ecCopy (&x, &f);
ecCopy (&y, &f);
elapsed -= clock ();
ecMultiply (&x, n); ecMultiply (&x, m);
ecMultiply (&y, m); ecMultiply (&y, n);
elapsed += clock ();
if (!ecEqual (&x, &y)) {
cfail++;
/* printf ("Commutativity test #%d failed!\n", i); */
}
/* y calculation test: */
yb = ecYbit (&f);
ecClear (&x);
gfCopy (x.x, f.x);
ecCalcY (&x, yb);
if (!ecEqual (&f, &x)) {
yfail++;
/* printf ("Y calculation test #%d failed!\n", i); */
}
/* packing test: unpack (pack (f)) = f */
ecPack (&f, p);
ecUnpack (&x, p);
if (!ecEqual (&f, &x)) {
pfail++;
/* printf ("Packing test #%d failed!\n", i); */
}
}
printf (" done, scalar multiplication time: %.3f s/op.\n",
(float)elapsed/CLOCKS_PER_SEC/(test_count?4*test_count:4));
if (nfail) printf ("---> %d negations failed <---\n", nfail);
if (afail) printf ("---> %d additions failed <---\n", afail);
if (sfail) printf ("---> %d subtractions failed <---\n", sfail);
if (qfail) printf ("---> %d quadruplications failed <---\n", qfail);
if (cfail) printf ("---> %d commutativities failed <---\n", cfail);
if (yfail) printf ("---> %d y calculations failed <---\n", yfail);
if (pfail) printf ("---> %d packings failed <---\n", pfail);
return nfail || afail || sfail || qfail || cfail || yfail || pfail;
} /* ecSelfTest */
