diff options
| author | Tomas Mraz <tomas@openssl.org> | 2022-06-06 10:22:00 +0200 |
|---|---|---|
| committer | Hugo Landau <hlandau@openssl.org> | 2022-07-18 08:06:17 +0100 |
| commit | ddb13b283be84d771deba1e964610b1670641f03 (patch) | |
| tree | bb021170034f9fcbafbbfd8e46a48b7884aa3d9d /include | |
| parent | 358103b4a651ab3f392f088d86cd30469dccce2e (diff) | |
Use as small dh key size as possible to support the security
Longer private key sizes unnecessarily raise the cycles needed to
compute the shared secret without any increase of the real security.
We use minimum key sizes as defined in RFC7919.
For arbitrary parameters we cannot know whether they are safe
primes (we could test but that would be too inefficient) we have
to keep generating large keys.
However we now set a small dh->length when we are generating safe prime
parameters because we know it is safe to use small keys with them.
That means users need to regenerate the parameters if they
want to take the performance advantage of small private key.
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18480)
Diffstat (limited to 'include')
| -rw-r--r-- | include/internal/ffc.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/internal/ffc.h b/include/internal/ffc.h index 79cb06aba3..50673efb89 100644 --- a/include/internal/ffc.h +++ b/include/internal/ffc.h @@ -112,6 +112,8 @@ typedef struct ffc_params_st { */ const char *mdname; const char *mdprops; + /* Default key length for known named groups according to RFC7919 */ + int keylength; } FFC_PARAMS; void ossl_ffc_params_init(FFC_PARAMS *params); @@ -205,8 +207,9 @@ const DH_NAMED_GROUP *ossl_ffc_numbers_to_dh_named_group(const BIGNUM *p, int ossl_ffc_named_group_get_uid(const DH_NAMED_GROUP *group); const char *ossl_ffc_named_group_get_name(const DH_NAMED_GROUP *); #ifndef OPENSSL_NO_DH +int ossl_ffc_named_group_get_keylength(const DH_NAMED_GROUP *group); const BIGNUM *ossl_ffc_named_group_get_q(const DH_NAMED_GROUP *group); -int ossl_ffc_named_group_set_pqg(FFC_PARAMS *ffc, const DH_NAMED_GROUP *group); +int ossl_ffc_named_group_set(FFC_PARAMS *ffc, const DH_NAMED_GROUP *group); #endif #endif /* OSSL_INTERNAL_FFC_H */ |