ecc: Add cofactor to domain parameters.

* src/ec-context.h (mpi_ec_ctx_s): Add cofactor 'h'.
* cipher/ecc-common.h (elliptic_curve_t): Add cofactor 'h'.
(_gcry_ecc_update_curve_param): New API adding cofactor.

* cipher/ecc-curves.c (ecc_domain_parms_t): Add cofactor 'h'.
(ecc_domain_parms_t domain_parms): Add cofactors.
(_gcry_ecc_fill_in_curve, _gcry_ecc_update_curve_param)
(_gcry_ecc_get_curve, _gcry_mpi_ec_new, _gcry_ecc_get_param_sexp)
(_gcry_ecc_get_mpi): Handle cofactor.
* cipher/ecc-eddsa.c (_gcry_ecc_eddsa_genkey): Likewise.
* cipher/ecc-misc.c (_gcry_ecc_curve_free)
(_gcry_ecc_curve_copy): Likewise.
* cipher/ecc.c (nist_generate_key, ecc_generate)
(ecc_check_secret_key, ecc_sign, ecc_verify, ecc_encrypt_raw)
(ecc_decrypt_raw, _gcry_pk_ecc_get_sexp, _gcry_pubkey_spec_ecc):
Likewise.
(compute_keygrip): Handle cofactor, but skip it for its computation.
* mpi/ec.c (ec_deinit): Likewise.
* tests/t-mpi-point.c (context_param): Likewise.
(test_curve): Add cofactors.
* tests/curves.c (sample_key_1, sample_key_2): Add cofactors.
* tests/keygrip.c (key_grips): Add cofactors.
--

We keep compatibility of compute_keygrip in cipher/ecc.c.

1 files changed, 1 insertions, 0 deletions

diff --git a/cipher/ecc-eddsa.c b/cipher/ecc-eddsa.c
index 65024a30..a12ebab3 100644
--- a/cipher/ecc-eddsa.c
+++ b/cipher/ecc-eddsa.c
@@ -525,6 +525,7 @@ _gcry_ecc_eddsa_genkey (ECC_secret_key *sk, elliptic_curve_t *E, mpi_ec_t ctx,
   point_init (&sk->E.G);
   point_set (&sk->E.G, &E->G);
   sk->E.n = mpi_copy (E->n);
+  sk->E.h = mpi_copy (E->h);
   point_init (&sk->Q);
   point_set (&sk->Q, &Q);