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/ec-context.h b/src/ec-context.h
index 88742bf2..6827e188 100644
--- a/src/ec-context.h
+++ b/src/ec-context.h
@@ -38,6 +38,8 @@ struct mpi_ec_ctx_s
 
   /* This structure is private to mpi/ec.c! */
   struct {
+    int need_sync;     /* Helper for ec_p_sync.  */
+
     int a_is_pminus3;  /* True if A = P - 3. */
 
     gcry_mpi_t two_inv_p;