From 29c0d8156629a988db5a4af30704736579f7c313 Mon Sep 17 00:00:00 2001 From: Tomas Mraz Date: Wed, 18 Oct 2023 15:50:30 +0200 Subject: bn: Properly error out if aliasing return value with modulus Test case amended from code initially written by Bernd Edlinger. Fixes #21110 Reviewed-by: Dmitry Belyavskiy Reviewed-by: Paul Dale Reviewed-by: Hugo Landau (Merged from https://github.com/openssl/openssl/pull/22421) (cherry picked from commit af0025fc40779cc98c06db7e29936f9d5de8cc9e) --- test/bntest.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) (limited to 'test') diff --git a/test/bntest.c b/test/bntest.c index 9c0633d7f1..2ffff10ef1 100644 --- a/test/bntest.c +++ b/test/bntest.c @@ -3165,6 +3165,108 @@ err: return res; } +static int test_mod_inverse(void) +{ + int res = 0; + char *str = NULL; + BIGNUM *a = NULL; + BIGNUM *b = NULL; + BIGNUM *r = NULL; + + if (!TEST_true(BN_dec2bn(&a, "5193817943"))) + goto err; + if (!TEST_true(BN_dec2bn(&b, "3259122431"))) + goto err; + if (!TEST_ptr(r = BN_new())) + goto err; + if (!TEST_ptr_eq(BN_mod_inverse(r, a, b, ctx), r)) + goto err; + if (!TEST_ptr_ne(str = BN_bn2dec(r), NULL)) + goto err; + if (!TEST_int_eq(strcmp(str, "2609653924"), 0)) + goto err; + + /* Note that this aliases the result with the modulus. */ + if (!TEST_ptr_null(BN_mod_inverse(b, a, b, ctx))) + goto err; + + res = 1; + +err: + BN_free(a); + BN_free(b); + BN_free(r); + OPENSSL_free(str); + return res; +} + +static int test_mod_exp_alias(int idx) +{ + int res = 0; + char *str = NULL; + BIGNUM *a = NULL; + BIGNUM *b = NULL; + BIGNUM *c = NULL; + BIGNUM *r = NULL; + + if (!TEST_true(BN_dec2bn(&a, "15"))) + goto err; + if (!TEST_true(BN_dec2bn(&b, "10"))) + goto err; + if (!TEST_true(BN_dec2bn(&c, "39"))) + goto err; + if (!TEST_ptr(r = BN_new())) + goto err; + + if (!TEST_int_eq((idx == 0 ? BN_mod_exp_simple + : BN_mod_exp_recp)(r, a, b, c, ctx), 1)) + goto err; + if (!TEST_ptr_ne(str = BN_bn2dec(r), NULL)) + goto err; + if (!TEST_str_eq(str, "36")) + goto err; + + OPENSSL_free(str); + str = NULL; + + BN_copy(r, b); + + /* Aliasing with exponent must work. */ + if (!TEST_int_eq((idx == 0 ? BN_mod_exp_simple + : BN_mod_exp_recp)(r, a, r, c, ctx), 1)) + goto err; + if (!TEST_ptr_ne(str = BN_bn2dec(r), NULL)) + goto err; + if (!TEST_str_eq(str, "36")) + goto err; + + OPENSSL_free(str); + str = NULL; + + /* Aliasing with modulus should return failure for the simple call. */ + if (idx == 0) { + if (!TEST_int_eq(BN_mod_exp_simple(c, a, b, c, ctx), 0)) + goto err; + } else { + if (!TEST_int_eq(BN_mod_exp_recp(c, a, b, c, ctx), 1)) + goto err; + if (!TEST_ptr_ne(str = BN_bn2dec(c), NULL)) + goto err; + if (!TEST_str_eq(str, "36")) + goto err; + } + + res = 1; + +err: + BN_free(a); + BN_free(b); + BN_free(c); + BN_free(r); + OPENSSL_free(str); + return res; +} + static int file_test_run(STANZA *s) { static const FILETEST filetests[] = { @@ -3274,6 +3376,8 @@ int setup_tests(void) ADD_ALL_TESTS(test_signed_mod_replace_ab, OSSL_NELEM(signed_mod_tests)); ADD_ALL_TESTS(test_signed_mod_replace_ba, OSSL_NELEM(signed_mod_tests)); ADD_TEST(test_mod); + ADD_TEST(test_mod_inverse); + ADD_ALL_TESTS(test_mod_exp_alias, 2); ADD_TEST(test_modexp_mont5); ADD_TEST(test_kronecker); ADD_TEST(test_rand); -- cgit v1.2.3