add first ZKP including test case

1 files changed, 42 insertions, 49 deletions

diff --git a/smc.c b/smc.c
index 399f031..52afa35 100644
--- a/smc.c
+++ b/smc.c
@@ -19,17 +19,55 @@
  * @brief Implementation of the smc primitives.
  */
 
+#include <gcrypt.h>
+
+#include "crypto.h"
 #include "util.h"
+#include "smc.h"
+
+extern gcry_ctx_t ec_ctx;
+
+void
+smc_zkp_dl (gcry_mpi_point_t v, gcry_mpi_point_t g, gcry_mpi_t x, gcry_mpi_point_t *a, gcry_mpi_t *c, gcry_mpi_t *r)
+{
+	gcry_mpi_t z = gcry_mpi_new(0);
+
+	brandt_ec_keypair_create_base(a, &z, g);
+	/**TODO: generate c from HASH(g,v,a) and don't output it */
+	brandt_ec_skey_create(c);
+	*r = gcry_mpi_new(0);
+	gcry_mpi_mul(*r, *c, x);
+	gcry_mpi_add(*r, *r, z);
+
+	gcry_mpi_release(z);
+}
+
+int
+smc_zkp_dl_check (gcry_mpi_point_t v, gcry_mpi_point_t g, gcry_mpi_point_t a, gcry_mpi_t c, gcry_mpi_t r)
+{
+	int ret;
+	gcry_mpi_point_t left = gcry_mpi_point_new(0);
+	gcry_mpi_point_t right = gcry_mpi_point_new(0);
+
+	gcry_mpi_ec_mul(left, r, g, ec_ctx);
+	gcry_mpi_ec_mul(right, c, v, ec_ctx);
+	gcry_mpi_ec_add(right, a, right, ec_ctx);
 
-#include <pari/pari.h>
+	ret = brandt_ec_point_cmp(left, right);
+	gcry_mpi_point_release(left);
+	gcry_mpi_point_release(right);
 
+	return ret;
+}
+
+/*
 GEN
-smc_hextodec (const char *s)                      /* int */
+smc_hextodec (const char *s)
 {
 	size_t i;
 	char c;
 	pari_sp ltop = avma;
-	GEN ret = gen_0;                        /* int */
+	GEN ret = gen_0;
 
 	for (i = 0; i < strlen (s); i++)
 	{
@@ -43,49 +81,4 @@ smc_hextodec (const char *s)                      /* int */
 	}
 	return gerepilecopy (ltop, ret);
 }
-
-
-void
-smc_genbid (struct AuctionData *ad, uint16_t bid)
-{
-	uint16_t j;
-	pari_sp ltop = avma;
-	GEN ret = cgetg (itos (ad->k)+1, t_VEC);         /* vec */
-
-	for (j = 1; j <= ad->k; j++)
-	{
-		gel (ret, j) = gpowgs (ad->g, bid == j);
-	}
-	ad->b = gerepilecopy (ltop, ret);
-}
-
-
-void
-smc_genalpha (struct AuctionData *ad)
-{
-	uint16_t j;
-	pari_sp ltop = avma;
-	GEN ret = cgetg (ad->k+1, t_VEC);
-
-	for (j = 1; j <= ad->k; ++j)
-	{
-		gel (ret, j) = gmul (gel (ad->b, j), gpowgi (ad->y, gel (ad->r, j)));
-	}
-	ad->alpha = gerepilecopy (ltop, ret);
-}
-
-
-void
-smc_genbeta (struct AuctionData *ad)
-{
-	uint16_t j;
-	pari_sp ltop = avma;
-	GEN ret = cgetg (ad->k+1, t_VEC);
-
-	for (j = 1; j <= ad->k; ++j)
-	{
-		gel (ret, j) = gpowgi (ad->g, gel (ad->r, j));
-	}
-	ad->beta = gerepilecopy (ltop, ret);
-}
-
+*/