*
*/
-#include "ecdsa.h"
+#include "ecs_locl.h"
#include <openssl/err.h>
#include <openssl/obj_mac.h>
#include <openssl/bn.h>
static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dlen,
- EC_KEY *eckey);
+ const BIGNUM *, const BIGNUM *, EC_KEY *eckey);
static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in, BIGNUM **kinvp,
BIGNUM **rp);
static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
BN_CTX *ctx = NULL;
BIGNUM *k = NULL, *r = NULL, *order = NULL, *X = NULL;
EC_POINT *tmp_point=NULL;
- EC_GROUP *group;
+ const EC_GROUP *group;
int ret = 0;
- if (!eckey || !eckey->group || !eckey->pub_key || !eckey->priv_key)
+
+ if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL)
{
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
- group = eckey->group;
if (ctx_in == NULL)
{
}
while (BN_is_zero(k));
+ /* We do not want timing information to leak the length of k,
+ * so we compute G*k using an equivalent scalar of fixed
+ * bit-length. */
+
+ if (!BN_add(k, k, order)) goto err;
+ if (BN_num_bits(k) <= BN_num_bits(order))
+ if (!BN_add(k, k, order)) goto err;
+
/* compute r the x-coordinate of generator * k */
if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx))
{
goto err;
}
}
+#ifndef OPENSSL_NO_EC2M
else /* NID_X9_62_characteristic_two_field */
{
if (!EC_POINT_get_affine_coordinates_GF2m(group,
goto err;
}
}
+#endif
if (!BN_nnmod(r, X, order, ctx))
{
ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dgst_len,
- EC_KEY *eckey)
+ const BIGNUM *in_kinv, const BIGNUM *in_r, EC_KEY *eckey)
{
- int ok = 0;
- BIGNUM *kinv=NULL, *r, *s, *m=NULL,*tmp=NULL,*order=NULL;
+ int ok = 0, i;
+ BIGNUM *kinv=NULL, *s, *m=NULL,*tmp=NULL,*order=NULL;
+ const BIGNUM *ckinv;
BN_CTX *ctx = NULL;
- EC_GROUP *group;
+ const EC_GROUP *group;
ECDSA_SIG *ret;
ECDSA_DATA *ecdsa;
+ const BIGNUM *priv_key;
- ecdsa = ecdsa_check(eckey);
-
- if (!eckey->group || !eckey->pub_key || !eckey->priv_key || !ecdsa)
+ ecdsa = ecdsa_check(eckey);
+ group = EC_KEY_get0_group(eckey);
+ priv_key = EC_KEY_get0_private_key(eckey);
+
+ if (group == NULL || priv_key == NULL || ecdsa == NULL)
{
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_PASSED_NULL_PARAMETER);
return NULL;
}
- group = eckey->group;
ret = ECDSA_SIG_new();
if (!ret)
{
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_EC_LIB);
goto err;
}
- if (dgst_len > BN_num_bytes(order))
+ i = BN_num_bits(order);
+ /* Need to truncate digest if it is too long: first truncate whole
+ * bytes.
+ */
+ if (8 * dgst_len > i)
+ dgst_len = (i + 7)/8;
+ if (!BN_bin2bn(dgst, dgst_len, m))
{
- ECDSAerr(ECDSA_F_ECDSA_DO_SIGN,
- ECDSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
goto err;
}
-
- if (!BN_bin2bn(dgst, dgst_len, m))
+ /* If still too long truncate remaining bits with a shift */
+ if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7)))
{
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
goto err;
}
do
{
- if (ecdsa->kinv == NULL || ecdsa->r == NULL)
+ if (in_kinv == NULL || in_r == NULL)
{
if (!ECDSA_sign_setup(eckey, ctx, &kinv, &ret->r))
{
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN,ERR_R_ECDSA_LIB);
goto err;
}
- r = ret->r;
+ ckinv = kinv;
}
else
{
- BN_free(ret->r);
- kinv = ecdsa->kinv;
- r = ecdsa->r;
- ret->r = r;
- ecdsa->kinv = NULL;
- ecdsa->r = NULL;
+ ckinv = in_kinv;
+ if (BN_copy(ret->r, in_r) == NULL)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
}
- if (!BN_mod_mul(tmp, eckey->priv_key, r, order, ctx))
+ if (!BN_mod_mul(tmp, priv_key, ret->r, order, ctx))
{
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
goto err;
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
goto err;
}
- if (!BN_mod_mul(s, s, kinv, order, ctx))
+ if (!BN_mod_mul(s, s, ckinv, order, ctx))
{
ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ERR_R_BN_LIB);
goto err;
}
+ if (BN_is_zero(s))
+ {
+ /* if kinv and r have been supplied by the caller
+ * don't to generate new kinv and r values */
+ if (in_kinv != NULL && in_r != NULL)
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_SIGN, ECDSA_R_NEED_NEW_SETUP_VALUES);
+ goto err;
+ }
+ }
+ else
+ /* s != 0 => we have a valid signature */
+ break;
}
- while (BN_is_zero(s));
+ while (1);
ok = 1;
err:
static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
const ECDSA_SIG *sig, EC_KEY *eckey)
{
- int ret = -1;
+ int ret = -1, i;
BN_CTX *ctx;
BIGNUM *order, *u1, *u2, *m, *X;
EC_POINT *point = NULL;
- EC_GROUP *group;
+ const EC_GROUP *group;
+ const EC_POINT *pub_key;
+
/* check input values */
- if (!eckey || !eckey->group || !eckey->pub_key || !sig)
+ if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL ||
+ (pub_key = EC_KEY_get0_public_key(eckey)) == NULL || sig == NULL)
{
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_MISSING_PARAMETERS);
return -1;
}
- group = eckey->group;
-
ctx = BN_CTX_new();
if (!ctx)
{
goto err;
}
/* digest -> m */
+ i = BN_num_bits(order);
+ /* Need to truncate digest if it is too long: first truncate whole
+ * bytes.
+ */
+ if (8 * dgst_len > i)
+ dgst_len = (i + 7)/8;
if (!BN_bin2bn(dgst, dgst_len, m))
{
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
goto err;
}
+ /* If still too long truncate remaining bits with a shift */
+ if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7)))
+ {
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
+ goto err;
+ }
/* u1 = m * tmp mod order */
if (!BN_mod_mul(u1, m, u2, order, ctx))
{
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
goto err;
}
- if (!EC_POINT_mul(group, point, u1, eckey->pub_key, u2, ctx))
+ if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx))
{
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
goto err;
if (!EC_POINT_get_affine_coordinates_GFp(group,
point, X, NULL, ctx))
{
- ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
goto err;
}
}
+#ifndef OPENSSL_NO_EC2M
else /* NID_X9_62_characteristic_two_field */
{
if (!EC_POINT_get_affine_coordinates_GF2m(group,
point, X, NULL, ctx))
{
- ECDSAerr(ECDSA_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
+ ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
goto err;
}
}
-
+#endif
if (!BN_nnmod(u1, X, order, ctx))
{
ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
projects / openssl.git / blobdiff