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Add exhaustive tests for group arithmetic, signing, and ecmult on a small group

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If you compile without ./configure --enable-exhaustive-tests=no,
this will create a binary ./exhaustive_tests which will execute
every function possible on a group of small order obtained by
moving to a twist of our curve and locating a generator of small
order.

Currently defaults to order 13, though by changing some #ifdefs
you can get a couple other ones. (Currently 199, which will take
forever to run, and 14, which won't work because it's composite.)

TODO exhaustive tests for the various modules
This commit is contained in:
Andrew Poelstra
2016-07-07 10:11:30 +00:00
parent 20b8877be1
commit 83836a9547
9 changed files with 360 additions and 30 deletions
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43
src/group_impl.h
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@@ -11,6 +11,31 @@
#include "field.h"
#include "group.h"
/* These points can be generated in sage as follows:
*
* 0. Setup a worksheet with the following parameters.
* b = 4 # whatever CURVE_B will be set to
* F = FiniteField (0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F)
* C = EllipticCurve ([F (0), F (b)])
*
* 1. Determine all the small orders available to you. (If there are
* no satisfactory ones, go back and change b.)
* print C.order().factor(limit=1000)
*
* 2. Choose an order as one of the prime factors listed in the above step.
* (You can also multiply some to get a composite order, though the
* tests will crash trying to invert scalars during signing.) We take a
* random point and scale it to drop its order to the desired value.
* There is some probability this won't work; just try again.
* order = 199
* P = C.random_point()
* P = (int(P.order()) / int(order)) * P
* assert(P.order() == order)
*
* 3. Print the values. You'll need to use a vim macro or something to
* split the hex output into 4-byte chunks.
* print "%x %x" % P.xy()
*/
#if defined(EXHAUSTIVE_TEST_ORDER)
# if EXHAUSTIVE_TEST_ORDER == 199
const secp256k1_ge secp256k1_ge_const_g = SECP256K1_GE_CONST(
@@ -19,6 +44,16 @@ const secp256k1_ge secp256k1_ge_const_g = SECP256K1_GE_CONST(
0x78AC123A, 0x5ED8AEF3, 0x8732BC91, 0x1F3A2868,
0x48DF246C, 0x808DAE72, 0xCFE52572, 0x7F0501ED
);
const int CURVE_B = 4;
# elif EXHAUSTIVE_TEST_ORDER == 13
const secp256k1_ge secp256k1_ge_const_g = SECP256K1_GE_CONST(
0xedc60018, 0xa51a786b, 0x2ea91f4d, 0x4c9416c0,
0x9de54c3b, 0xa1316554, 0x6cf4345c, 0x7277ef15,
0x54cb1b6b, 0xdc8c1273, 0x087844ea, 0x43f4603e,
0x0eaf9a43, 0xf6effe55, 0x939f806d, 0x37adf8ac
);
const int CURVE_B = 2;
# else
# error No known generator for the specified exhaustive test group order.
# endif
@@ -32,6 +67,8 @@ static const secp256k1_ge secp256k1_ge_const_g = SECP256K1_GE_CONST(
0x483ADA77UL, 0x26A3C465UL, 0x5DA4FBFCUL, 0x0E1108A8UL,
0xFD17B448UL, 0xA6855419UL, 0x9C47D08FUL, 0xFB10D4B8UL
);
const int CURVE_B = 7;
#endif
static void secp256k1_ge_set_gej_zinv(secp256k1_ge *r, const secp256k1_gej *a, const secp256k1_fe *zi) {
@@ -188,7 +225,7 @@ static int secp256k1_ge_set_xquad(secp256k1_ge *r, const secp256k1_fe *x) {
secp256k1_fe_sqr(&x2, x);
secp256k1_fe_mul(&x3, x, &x2);
r->infinity = 0;
secp256k1_fe_set_int(&c, 7);
secp256k1_fe_set_int(&c, CURVE_B);
secp256k1_fe_add(&c, &x3);
return secp256k1_fe_sqrt(&r->y, &c);
}
@@ -247,7 +284,7 @@ static int secp256k1_gej_is_valid_var(const secp256k1_gej *a) {
secp256k1_fe_sqr(&x3, &a->x); secp256k1_fe_mul(&x3, &x3, &a->x);
secp256k1_fe_sqr(&z2, &a->z);
secp256k1_fe_sqr(&z6, &z2); secp256k1_fe_mul(&z6, &z6, &z2);
secp256k1_fe_mul_int(&z6, 7);
secp256k1_fe_mul_int(&z6, CURVE_B);
secp256k1_fe_add(&x3, &z6);
secp256k1_fe_normalize_weak(&x3);
return secp256k1_fe_equal_var(&y2, &x3);
@@ -261,7 +298,7 @@ static int secp256k1_ge_is_valid_var(const secp256k1_ge *a) {
/* y^2 = x^3 + 7 */
secp256k1_fe_sqr(&y2, &a->y);
secp256k1_fe_sqr(&x3, &a->x); secp256k1_fe_mul(&x3, &x3, &a->x);
secp256k1_fe_set_int(&c, 7);
secp256k1_fe_set_int(&c, CURVE_B);
secp256k1_fe_add(&x3, &c);
secp256k1_fe_normalize_weak(&x3);
return secp256k1_fe_equal_var(&y2, &x3);