diff options
| author | Hugo Landau <hlandau@openssl.org> | 2022-03-01 14:08:12 +0000 |
|---|---|---|
| committer | Tomas Mraz <tomas@openssl.org> | 2022-03-03 10:31:24 +0100 |
| commit | 43135a5d2274c24e97f50e16ce492c22eb717ab2 (patch) | |
| tree | 83bc81c47f6ead004d720fbfd3a56b5997075998 /test | |
| parent | df5c86e9f80d14d699bad4c8889292fd9b4bd7ba (diff) | |
Fix NULL pointer dereference for BN_mod_exp2_mont
This fixes a bug whereby BN_mod_exp2_mont can dereference a NULL pointer
if BIGNUM argument m represents zero.
Regression test added. Fixes #17648.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/17783)
Diffstat (limited to 'test')
| -rw-r--r-- | test/bntest.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/test/bntest.c b/test/bntest.c index efdb3ef963..f129c71ab8 100644 --- a/test/bntest.c +++ b/test/bntest.c @@ -3012,6 +3012,50 @@ static int test_mod_exp_consttime(int i) return res; } +/* + * Regression test to ensure BN_mod_exp2_mont fails safely if argument m is + * zero. + */ +static int test_mod_exp2_mont(void) +{ + int res = 0; + BIGNUM *exp_result = NULL; + BIGNUM *exp_a1 = NULL, *exp_p1 = NULL, *exp_a2 = NULL, *exp_p2 = NULL, + *exp_m = NULL; + + if (!TEST_ptr(exp_result = BN_new()) + || !TEST_ptr(exp_a1 = BN_new()) + || !TEST_ptr(exp_p1 = BN_new()) + || !TEST_ptr(exp_a2 = BN_new()) + || !TEST_ptr(exp_p2 = BN_new()) + || !TEST_ptr(exp_m = BN_new())) + goto err; + + if (!TEST_true(BN_one(exp_a1)) + || !TEST_true(BN_one(exp_p1)) + || !TEST_true(BN_one(exp_a2)) + || !TEST_true(BN_one(exp_p2))) + goto err; + + BN_zero(exp_m); + + /* input of 0 is even, so must fail */ + if (!TEST_int_eq(BN_mod_exp2_mont(exp_result, exp_a1, exp_p1, exp_a2, + exp_p2, exp_m, ctx, NULL), 0)) + goto err; + + res = 1; + +err: + BN_free(exp_result); + BN_free(exp_a1); + BN_free(exp_p1); + BN_free(exp_a2); + BN_free(exp_p2); + BN_free(exp_m); + return res; +} + static int file_test_run(STANZA *s) { static const FILETEST filetests[] = { @@ -3154,6 +3198,7 @@ int setup_tests(void) ADD_TEST(test_gcd_prime); ADD_ALL_TESTS(test_mod_exp, (int)OSSL_NELEM(ModExpTests)); ADD_ALL_TESTS(test_mod_exp_consttime, (int)OSSL_NELEM(ModExpTests)); + ADD_TEST(test_mod_exp2_mont); if (stochastic) ADD_TEST(test_rand_range); } else { |