Commit adf65243 authored by Matt Caswell's avatar Matt Caswell
Browse files

Test that a ^ 0 mod -1 is always 0 



Check all functions that do this.

Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6355)
parent 4aa5b725

test/bntest.c

+48 −0
Original line number Diff line number Diff line
@@ -2063,6 +2063,53 @@ err: 
    return st;

}



static int test_expmodone(void)

{

    int ret = 0, i;

    BIGNUM *r = BN_new();

    BIGNUM *a = BN_new();

    BIGNUM *p = BN_new();

    BIGNUM *m = BN_new();



    if (!TEST_ptr(r)

            || !TEST_ptr(a)

            || !TEST_ptr(p)

            || !TEST_ptr(p)

            || !TEST_ptr(m)

            || !TEST_true(BN_set_word(a, 1))

            || !TEST_true(BN_set_word(p, 0))

            || !TEST_true(BN_set_word(m, 1)))

        goto err;



    /* Calculate r = 1 ^ 0 mod 1, and check the result is always 0 */

    for (i = 0; i < 2; i++) {

        if (!TEST_true(BN_mod_exp(r, a, p, m, NULL))

                || !TEST_BN_eq_zero(r)

                || !TEST_true(BN_mod_exp_mont(r, a, p, m, NULL, NULL))

                || !TEST_BN_eq_zero(r)

                || !TEST_true(BN_mod_exp_mont_consttime(r, a, p, m, NULL, NULL))

                || !TEST_BN_eq_zero(r)

                || !TEST_true(BN_mod_exp_mont_word(r, 1, p, m, NULL, NULL))

                || !TEST_BN_eq_zero(r)

                || !TEST_true(BN_mod_exp_simple(r, a, p, m, NULL))

                || !TEST_BN_eq_zero(r)

                || !TEST_true(BN_mod_exp_recp(r, a, p, m, NULL))

                || !TEST_BN_eq_zero(r))

            goto err;

        /* Repeat for r = 1 ^ 0 mod -1 */

        if (i == 0)

            BN_set_negative(m, 1);

    }



    ret = 1;

err:

    BN_free(r);

    BN_free(a);

    BN_free(p);

    BN_free(m);

    return ret;

}



static int test_smallprime(void)

{

    static const int kBits = 10;
@@ -2189,6 +2236,7 @@ int setup_tests(void) 
        ADD_TEST(test_negzero);

        ADD_TEST(test_badmod);

        ADD_TEST(test_expmodzero);

        ADD_TEST(test_expmodone);

        ADD_TEST(test_smallprime);

        ADD_TEST(test_swap);

#ifndef OPENSSL_NO_EC2M