ecc: Add Ed25519 key generation and prepare for optimizations.

* src/mpi.h (enum ecc_dialects): New.
* src/ec-context.h (mpi_ec_ctx_s): Add field DIALECT.
* cipher/ecc-common.h (elliptic_curve_t): Ditto.
* cipher/ecc-curves.c (ecc_domain_parms_t): Ditto.
(domain_parms): Add dialect values.
(_gcry_ecc_fill_in_curve): Set dialect.
(_gcry_ecc_get_curve): Ditto.
(_gcry_mpi_ec_new): Ditto.
(_gcry_ecc_get_param): Use ECC_DIALECT_STANDARD for now.
* cipher/ecc-misc.c (_gcry_ecc_curve_copy): Copy dialect.
(_gcry_ecc_dialect2str): New.
* mpi/ec.c (ec_p_init): Add arg DIALECT.
(_gcry_mpi_ec_p_internal_new): Ditto.
(_gcry_mpi_ec_p_new): Ditto.

* mpi/mpiutil.c (gcry_mpi_set_opaque): Set the secure flag.
(_gcry_mpi_set_opaque_copy): New.

* cipher/ecc-misc.c (_gcry_ecc_os2ec): Take care of an opaque MPI.
* cipher/ecc.c (eddsa_generate_key): New.
(generate_key): Rename to nist_generate_key and factor some code out
to ...
(ecc_generate_ext): here.  Divert to eddsa_generate_key if desired.
(eddsa_decodepoint): Take care of an opaque MPI.
(ecc_check_secret_key): Ditto.
(ecc_sign): Ditto.
* cipher/pubkey.c (sexp_elements_extract_ecc): Store public and secret
key as opaque MPIs.
(gcry_pk_genkey): Add the curve_name also to the private key part of
the result.

* tests/benchmark.c (ecc_bench): Support Ed25519.
(main): Add option --debug.
* tests/curves.c (sample_key_2): Make sure that P and N are positive.
* tests/keygen.c (show): New.
(check_ecc_keys): Support Ed25519.
--

There are two main purposes of this patch: Add a key generation
feature for Ed25519 and add the "dialect" thingy which will eventually
be used to add curve specific optimization.

Note that the entire way of how we interface between the public key
modules and pubkey.c is overly complex and probably also the cause for
a lot of performance overhead.  Given that we don't have the loadable
module system anymore, we should entirely get rid of the MPI-array
based internal interface and move parts of the s-expression handling
direct into the pubkey modules.  This needs to be fixed or we are
turning Libgcrypt into another software incarnation of Heathrow
Airport.

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

1 files changed, 13 insertions, 0 deletions

diff --git a/src/mpi.h b/src/mpi.h
index bd931681..f24e9681 100644
--- a/src/mpi.h
+++ b/src/mpi.h
@@ -134,6 +134,8 @@ void _gcry_mpi_m_check( gcry_mpi_t a );
 void _gcry_mpi_swap( gcry_mpi_t a, gcry_mpi_t b);
 gcry_mpi_t _gcry_mpi_new (unsigned int nbits);
 gcry_mpi_t _gcry_mpi_snew (unsigned int nbits);
+gcry_mpi_t _gcry_mpi_set_opaque_copy (gcry_mpi_t a,
+                                      void *p, unsigned int nbits);
 void *_gcry_mpi_get_opaque_copy (gcry_mpi_t a, unsigned int *nbits);
 int _gcry_mpi_is_neg (gcry_mpi_t a);
 void _gcry_mpi_neg (gcry_mpi_t w, gcry_mpi_t u);
@@ -289,6 +291,15 @@ enum gcry_mpi_ec_models
        Note that we use 'b' instead of the commonly used 'd'.  */
   };
 
+/* Dialects used with elliptic curves.  It is easier to keep the
+   definition here than in ecc-common.h. */
+enum ecc_dialects
+  {
+    ECC_DIALECT_STANDARD = 0,
+    ECC_DIALECT_ED25519
+  };
+
+
 /* Context used with elliptic curve functions.  */
 struct mpi_ec_ctx_s;
 typedef struct mpi_ec_ctx_s *mpi_ec_t;
@@ -297,9 +308,11 @@ void _gcry_mpi_point_log (const char *name, mpi_point_t point, mpi_ec_t ctx);
 #define log_printpnt(a,p,c) _gcry_mpi_point_log ((a), (p), (c))
 
 mpi_ec_t _gcry_mpi_ec_p_internal_new (enum gcry_mpi_ec_models model,
+                                      enum ecc_dialects dialect,
                                       gcry_mpi_t p, gcry_mpi_t a, gcry_mpi_t b);
 gpg_err_code_t _gcry_mpi_ec_p_new (gcry_ctx_t *r_ctx,
                                    enum gcry_mpi_ec_models model,
+                                   enum ecc_dialects dialect,
                                    gcry_mpi_t p, gcry_mpi_t a, gcry_mpi_t b);
 void _gcry_mpi_ec_free (mpi_ec_t ctx);