ecc: Allow the name "q@eddsa" to get/set the public key.

* cipher/ecc-curves.c (_gcry_ecc_get_mpi): Support "q@eddsa".
(_gcry_ecc_set_mpi): Support "q".
* cipher/ecc.c (eddsa_encodepoint): Rename to ...
(_gcry_ecc_eddsa_encodepoint): this and make global.  Remove arg
MINLEN and take from context.
(eddsa_decodepoint): Rename to
(_gcry_ecc_eddsa_decodepoint): this and make global. Remove arg LEN
and take from context.
(sign_eddsa, verify_eddsa): Take B from context.
(ecc_sign, ecc_verify): Add hack to set DIALECT.
(_gcry_pk_ecc_get_sexp): Use _gcry_ecc_compute_public.  Handle EdDSA.
* src/ec-context.h (mpi_ec_ctx_s): Add field NBITS.
* mpi/ec.c (ec_p_init): Init NBITS.
* tests/t-mpi-point.c (test_curve): Add Ed25519.
(sample_ed25519_q): New.
(context_param): Check new sample key.
(hex2buffer, hex2mpiopa): New.
(cmp_mpihex): Take care of opaque MPIs.

Signed-off-by: Werner Koch <wk@gnupg.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/mpi/ec.c b/mpi/ec.c
index 883d8f61..c6d0fc8c 100644
--- a/mpi/ec.c
+++ b/mpi/ec.c
@@ -436,6 +436,10 @@ ec_p_init (mpi_ec_t ctx, enum gcry_mpi_ec_models model,
 
   ctx->model = model;
   ctx->dialect = dialect;
+  if (dialect == ECC_DIALECT_ED25519)
+    ctx->nbits = 256;
+  else
+    ctx->nbits = mpi_get_nbits (p);
   ctx->p = mpi_copy (p);
   ctx->a = mpi_copy (a);
   if (b && model == MPI_EC_TWISTEDEDWARDS)