Commit 03e759fc authored by Niels Möller's avatar Niels Möller

* dsa-sign.c (dsa_sign): Needs the public key as argument, in

addition to the private key. Use const.

Rev: src/nettle/dsa-sign.c:1.3
parent 8675a35b
......@@ -72,7 +72,8 @@ nettle_mpz_random(mpz_t x, const mpz_t n,
}
void
dsa_sign(struct dsa_private_key *key,
dsa_sign(const struct dsa_public_key *pub,
const struct dsa_private_key *key,
void *random_ctx, nettle_random_func random,
struct sha1_ctx *hash,
struct dsa_signature *signature)
......@@ -82,7 +83,7 @@ dsa_sign(struct dsa_private_key *key,
mpz_t tmp;
/* Select k, 0<k<q, randomly */
mpz_init_set(tmp, key->pub.q);
mpz_init_set(tmp, pub->q);
mpz_sub_ui(tmp, tmp, 1);
mpz_init(k);
......@@ -90,24 +91,24 @@ dsa_sign(struct dsa_private_key *key,
mpz_add_ui(k, k, 1);
/* Compute r = (g^k (mod p)) (mod q) */
mpz_powm(tmp, key->pub.g, k, key->pub.p);
mpz_fdiv_r(signature->r, tmp, key->pub.q);
mpz_powm(tmp, pub->g, k, pub->p);
mpz_fdiv_r(signature->r, tmp, pub->q);
/* Compute hash */
mpz_init(h);
_dsa_hash(h, hash);
/* Compute k^-1 (mod q) */
if (!mpz_invert(k, k, key->pub.q))
if (!mpz_invert(k, k, pub->q))
/* What do we do now? The key is invalid. */
abort();
/* Compute signature s = k^-1(h + xr) (mod q) */
mpz_mul(tmp, signature->r, key->x);
mpz_fdiv_r(tmp, tmp, key->pub.q);
mpz_fdiv_r(tmp, tmp, pub->q);
mpz_add(tmp, tmp, h);
mpz_mul(tmp, tmp, k);
mpz_fdiv_r(signature->s, tmp, key->pub.q);
mpz_fdiv_r(signature->s, tmp, pub->q);
mpz_clear(k);
mpz_clear(h);
......
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