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add second ZKP (equality of two EC DLs) with test case

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This commit is contained in:
Markus Teich 2016-06-15 00:52:18 +02:00
parent 338c95de41
commit 8035afa583
3 changed files with 104 additions and 0 deletions
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49
smc.c
View File

@ -45,8 +45,11 @@ smc_zkp_dl (gcry_mpi_point_t v, gcry_mpi_point_t g, gcry_mpi_t x,
gcry_mpi_t z = gcry_mpi_new (0);
brandt_ec_keypair_create_base (a, &z, g);
/* compute challange c */
/**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);
@ -54,6 +57,7 @@ smc_zkp_dl (gcry_mpi_point_t v, gcry_mpi_point_t g, gcry_mpi_t x,
gcry_mpi_release (z);
}
/**
* smc_zkp_dl_check
*
@ -84,6 +88,51 @@ smc_zkp_dl_check (gcry_mpi_point_t v, gcry_mpi_point_t g, gcry_mpi_point_t a,
return ret;
}
void
smc_zkp_2dle (gcry_mpi_point_t v, gcry_mpi_point_t w, gcry_mpi_point_t g1, gcry_mpi_point_t g2, gcry_mpi_t x, gcry_mpi_point_t *a, gcry_mpi_point_t *b, gcry_mpi_t *c, gcry_mpi_t *r)
{
gcry_mpi_t z = gcry_mpi_new (0);
brandt_ec_keypair_create_base (a, &z, g1);
*b = gcry_mpi_point_new(0);
gcry_mpi_ec_mul(*b, z, g2, ec_ctx);
/* compute challange c */
/**TODO: generate c from HASH(g1,g2,v,w,a,b) 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_2dle_check (gcry_mpi_point_t v, gcry_mpi_point_t w, gcry_mpi_point_t g1, gcry_mpi_point_t g2, gcry_mpi_point_t a, gcry_mpi_point_t b, 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, g1, ec_ctx);
gcry_mpi_ec_mul (right, c, v, ec_ctx);
gcry_mpi_ec_add (right, a, right, ec_ctx);
ret = brandt_ec_point_cmp (left, right);
gcry_mpi_ec_mul (left, r, g2, ec_ctx);
gcry_mpi_ec_mul (right, c, w, ec_ctx);
gcry_mpi_ec_add (right, b, right, ec_ctx);
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)
//{

3
smc.h
View File

@ -27,4 +27,7 @@
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);
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);
void smc_zkp_2dle (gcry_mpi_point_t v, gcry_mpi_point_t w, gcry_mpi_point_t g1, gcry_mpi_point_t g2, gcry_mpi_t x, gcry_mpi_point_t *a, gcry_mpi_point_t *b, gcry_mpi_t *c, gcry_mpi_t *r);
int smc_zkp_2dle_check (gcry_mpi_point_t v, gcry_mpi_point_t w, gcry_mpi_point_t g1, gcry_mpi_point_t g2, gcry_mpi_point_t a, gcry_mpi_point_t b, gcry_mpi_t c, gcry_mpi_t r);
#endif // ifndef _BRANDT_SMC_H

52
test_crypto.c
View File

@ -85,6 +85,58 @@ test_smc_zkp_dl ()
gcry_mpi_point_release (v);
}
int
test_smc_zkp_2dle ()
{
static int first = 1;
gcry_mpi_t c;
gcry_mpi_t r;
gcry_mpi_t s;
gcry_mpi_t x;
gcry_mpi_point_t a;
gcry_mpi_point_t b;
gcry_mpi_point_t g1;
gcry_mpi_point_t g2;
gcry_mpi_point_t v = gcry_mpi_point_new (0);
gcry_mpi_point_t w = gcry_mpi_point_new (0);
check (v, "no pub1 key initialized");
check (w, "no pub2 key initialized");
brandt_ec_keypair_create (&g1, &s);
gcry_mpi_release (s);
brandt_ec_keypair_create (&g2, &s);
check (g1, "no gen1 created");
check (g2, "no gen2 created");
if (first)
{
gcry_mpi_ec_mul (g1, GCRYMPI_CONST_ONE, ec_gen, ec_ctx);
gcry_mpi_ec_mul (g2, GCRYMPI_CONST_ONE, ec_gen, ec_ctx);
first = 0;
}
brandt_ec_skey_create (&x);
check (x, "no sec key created");
gcry_mpi_ec_mul (v, x, g1, ec_ctx);
check (v, "no pub1 key created");
gcry_mpi_ec_mul (w, x, g2, ec_ctx);
check (w, "no pub2 key created");
smc_zkp_2dle (v, w, g1, g2, x, &a, &b, &c, &r);
check (!smc_zkp_2dle_check (v, w, g1, g2, a, b, c, r), "zkp was false, should be true");
gcry_mpi_release (c);
gcry_mpi_release (r);
gcry_mpi_release (s);
gcry_mpi_release (x);
gcry_mpi_point_release (a);
gcry_mpi_point_release (b);
gcry_mpi_point_release (g1);
gcry_mpi_point_release (g2);
gcry_mpi_point_release (v);
gcry_mpi_point_release (w);
}
int
main (int argc, char *argv[])
{