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Fixed ECDSA checking.

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This commit is contained in:
Sorvigolova 2015-04-06 14:16:39 +03:00
parent 5a46f2f1b3
commit bd746e9e3a
2 changed files with 39 additions and 6 deletions
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41
src/ec.cpp
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@ -73,7 +73,7 @@ static void elt_square(u8 *d, u8 *a)
elt_mul(d, a, a); elt_mul(d, a, a);
} }
static void elt_inv(u8 *d, u8 *a) void elt_inv(u8 *d, u8 *a)
{ {
u8 s[20]; u8 s[20];
elt_copy(s, a); elt_copy(s, a);
@ -314,12 +314,16 @@ static int check_ecdsa(struct point *Q, u8 *R, u8 *S, u8 *hash)
return (bn_compare(rr, R, 21) == 0); return (bn_compare(rr, R, 21) == 0);
} }
#if 0
static void ec_priv_to_pub(u8 *k, u8 *Q) void ec_priv_to_pub(u8 *k, u8 *Q)
{ {
point_mul(Q, k, ec_G); struct point mQ;
point_mul(&mQ, k, &ec_G);
point_from_mon(&mQ);
elt_copy(Q, mQ.x);
elt_copy(Q+20, mQ.y);
} }
#endif
int ecdsa_set_curve(u32 type) int ecdsa_set_curve(u32 type)
{ {
@ -355,3 +359,30 @@ void ecdsa_sign(u8 *hash, u8 *R, u8 *S)
{ {
generate_ecdsa(R, S, ec_k, hash); generate_ecdsa(R, S, ec_k, hash);
} }
void get_m (u8 *r, u8 *s, u8 *e, u8 *k, u8 *m)
{
u8 tmp_r[21], tmp_s[21], tmp_e[21], tmp_k[21];
u8 tmp_mul[21], tmp_sum[21], tmp_inv[21];
tmp_r[0] = tmp_s[0] = tmp_e[0] = 0;
bn_copy(tmp_r, r, 21);
bn_copy(tmp_s, s, 21);
bn_copy(tmp_e + 1, e, 20);
bn_reduce(tmp_e, ec_N, 21);
bn_to_mon(tmp_r, ec_N, 21);
bn_to_mon(tmp_s, ec_N, 21);
bn_to_mon(tmp_e, ec_N, 21);
tmp_k[0] = 0;
bn_copy(tmp_k, k, 21);
bn_reduce(tmp_k, ec_N, 21);
bn_to_mon(tmp_k, ec_N, 21);
bn_mon_mul(tmp_mul, tmp_r, tmp_k, ec_N, 21);
bn_add(tmp_sum, tmp_mul, tmp_e, ec_N, 21);
bn_mon_inv(tmp_inv, tmp_s, ec_N, 21);
bn_mon_mul(tmp_mul, tmp_inv, tmp_sum, ec_N, 21);
bn_from_mon(tmp_mul, ec_N, 21);
memcpy (m, tmp_mul + 1, 20);
}

4
src/ecdsa.h
View file

@ -6,5 +6,7 @@ void ecdsa_set_pub(u8 *Q);
void ecdsa_set_priv(u8 *k); void ecdsa_set_priv(u8 *k);
int ecdsa_verify(u8 *hash, u8 *R, u8 *S); int ecdsa_verify(u8 *hash, u8 *R, u8 *S);
void ecdsa_sign(u8 *hash, u8 *R, u8 *S); void ecdsa_sign(u8 *hash, u8 *R, u8 *S);
void ec_priv_to_pub(u8 *k, u8 *Q);
void elt_inv(u8 *d, u8 *a);
void get_m (u8 *r, u8 *s, u8 *e, u8 *k, u8 *m);
#endif #endif