diff options
| -rw-r--r-- | crypto/rsa/rsa_sp800_56b_check.c | 27 | ||||
| -rw-r--r-- | test/rsa_sp800_56b_test.c | 15 |
2 files changed, 18 insertions, 24 deletions
diff --git a/crypto/rsa/rsa_sp800_56b_check.c b/crypto/rsa/rsa_sp800_56b_check.c index 9b827d2872..fc8f19b487 100644 --- a/crypto/rsa/rsa_sp800_56b_check.c +++ b/crypto/rsa/rsa_sp800_56b_check.c @@ -218,30 +218,21 @@ int ossl_rsa_check_private_exponent(const RSA *rsa, int nbits, BN_CTX *ctx) return ret; } -#ifndef FIPS_MODULE -static int bn_is_three(const BIGNUM *bn) -{ - BIGNUM *num = BN_dup(bn); - int ret = (num != NULL && BN_sub_word(num, 3) && BN_is_zero(num)); - - BN_free(num); - return ret; -} -#endif /* FIPS_MODULE */ - -/* Check exponent is odd, and has a bitlen ranging from [17..256] */ +/* + * Check exponent is odd. + * For FIPS also check the bit length is in the range [17..256] + */ int ossl_rsa_check_public_exponent(const BIGNUM *e) { +#ifdef FIPS_MODULE int bitlen; - /* For legacy purposes RSA_3 is allowed in non fips mode */ -#ifndef FIPS_MODULE - if (bn_is_three(e)) - return 1; -#endif /* FIPS_MODULE */ - bitlen = BN_num_bits(e); return (BN_is_odd(e) && bitlen > 16 && bitlen < 257); +#else + /* Allow small exponents larger than 1 for legacy purposes */ + return BN_is_odd(e) && BN_cmp(e, BN_value_one()) > 0; +#endif /* FIPS_MODULE */ } /* diff --git a/test/rsa_sp800_56b_test.c b/test/rsa_sp800_56b_test.c index 033983d58e..f5df0e4955 100644 --- a/test/rsa_sp800_56b_test.c +++ b/test/rsa_sp800_56b_test.c @@ -104,26 +104,29 @@ static BIGNUM *bn_load_new(const unsigned char *data, int sz) return ret; } +/* Check that small rsa exponents are allowed in non FIPS mode */ static int test_check_public_exponent(void) { int ret = 0; BIGNUM *e = NULL; ret = TEST_ptr(e = BN_new()) - /* e is too small */ - && TEST_true(BN_set_word(e, 65535)) + /* e is too small will fail */ + && TEST_true(BN_set_word(e, 1)) && TEST_false(ossl_rsa_check_public_exponent(e)) /* e is even will fail */ && TEST_true(BN_set_word(e, 65536)) && TEST_false(ossl_rsa_check_public_exponent(e)) /* e is ok */ + && TEST_true(BN_set_word(e, 3)) + && TEST_true(ossl_rsa_check_public_exponent(e)) + && TEST_true(BN_set_word(e, 17)) + && TEST_true(ossl_rsa_check_public_exponent(e)) && TEST_true(BN_set_word(e, 65537)) && TEST_true(ossl_rsa_check_public_exponent(e)) - /* e = 2^256 is too big */ + /* e = 2^256 + 1 is ok */ && TEST_true(BN_lshift(e, BN_value_one(), 256)) - && TEST_false(ossl_rsa_check_public_exponent(e)) - /* e = 2^256-1 is odd and in range */ - && TEST_true(BN_sub(e, e, BN_value_one())) + && TEST_true(BN_add(e, e, BN_value_one())) && TEST_true(ossl_rsa_check_public_exponent(e)); BN_free(e); return ret; |