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| author | Shane Lontis <shane.lontis@oracle.com> | 2021-08-11 12:23:08 +1000 |
|---|---|---|
| committer | Tomas Mraz <tomas@openssl.org> | 2021-08-13 10:35:56 +0200 |
| commit | 254957f768a61c91c14d89566224173d0831c2ce (patch) | |
| tree | 7ccf094aee6826b7252da1471154cf15d61ee3a5 /crypto/rsa | |
| parent | a5f4099d275520caf90a28a88e889cb36683b412 (diff) | |
| download | openssl-new-254957f768a61c91c14d89566224173d0831c2ce.tar.gz | |
Allow small RSA exponents in the default provider
Fixes #16255
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/16285)
Diffstat (limited to 'crypto/rsa')
| -rw-r--r-- | crypto/rsa/rsa_sp800_56b_check.c | 27 |
1 files changed, 9 insertions, 18 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 */ } /* |