Extend the new EC interface and fix two bugs.

* src/ec-context.h (mpi_ec_ctx_s): Add field NEED_SYNC.
* mpi/ec.c (ec_p_sync): New.
(ec_p_init): Only set NEED_SYNC.
(_gcry_mpi_ec_set_mpi): Set NEED_SYNC for 'p' and 'a'.
(_gcry_mpi_ec_dup_point, _gcry_mpi_ec_add_points)
(_gcry_mpi_ec_mul_point): Call ec_p_sync.
(_gcry_mpi_ec_get_point): Recompute 'q' is needed.
(_gcry_mpi_ec_get_mpi): Ditto.  Also allow for names 'q', 'q.x',
'q.y', and 'g'.
* cipher/ecc.c (_gcry_mpi_ec_ec2os): New.

* cipher/ecc.c (_gcry_mpi_ec_new): Fix init from parameters 'Q'->'q',
'G'->'q'.
--

Note that the parameter names are all lowercase.  This patch fixes an
inconsistency.

The other bug was that changing the parameters D or A may have
resulted in wrong computations because helper variables were not
updated.  Now we delay the computation of those helper variables until
we need them.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/mpi.h b/src/mpi.h
index b727d5f9..fd265bf2 100644
--- a/src/mpi.h
+++ b/src/mpi.h
@@ -289,6 +289,8 @@ void _gcry_mpi_ec_mul_point (mpi_point_t result,
                              gcry_mpi_t scalar, mpi_point_t point,
                              mpi_ec_t ctx);
 
+gcry_mpi_t _gcry_mpi_ec_ec2os (gcry_mpi_point_t point, mpi_ec_t ectx);
+
 gpg_err_code_t _gcry_mpi_ec_p_new (gcry_ctx_t *r_ctx,
                                    gcry_mpi_t p, gcry_mpi_t a);
 gpg_err_code_t _gcry_mpi_ec_new (gcry_ctx_t *r_ctx,