generic-library/openssl
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avoid shifting input

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This commit is contained in:
Nils Larsch 2007-02-11 19:33:21 +00:00
parent 15780a1ea0
commit b900a6b42f
1 changed files with 10 additions and 17 deletions
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27
crypto/dsa/dsa_ossl.c
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@ -134,7 +134,7 @@ static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
BIGNUM m;
BIGNUM xr;
BN_CTX *ctx=NULL;
int i, reason=ERR_R_BN_LIB;
int reason=ERR_R_BN_LIB;
DSA_SIG *ret=NULL;
BN_init(&m);
@ -172,17 +172,14 @@ static DSA_SIG *dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
dsa->r=NULL;
}
if (BN_bin2bn(dgst,dlen,&m) == NULL)
goto err;
i = BN_num_bytes(dsa->q);
if (dlen > i)
{
if (dlen > BN_num_bytes(dsa->q))
/* if the digest length is greater than the size of q use the
* BN_num_bits(dsa->q) leftmost bits of the digest, see
* fips 186-3, 4.2 */
if (!BN_rshift(&m, &m, (dlen - i) << 3))
goto err;
}
dlen = BN_num_bytes(dsa->q);
if (BN_bin2bn(dgst,dlen,&m) == NULL)
goto err;
/* Compute s = inv(k) (m + xr) mod q */
if (!BN_mod_mul(&xr,dsa->priv_key,r,dsa->q,ctx)) goto err;/* s = xr */
@ -308,7 +305,7 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
BN_CTX *ctx;
BIGNUM u1,u2,t1;
BN_MONT_CTX *mont=NULL;
int ret = -1, i, j;
int ret = -1, i;
if (!dsa->p || !dsa->q || !dsa->g)
{
DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_MISSING_PARAMETERS);
@ -361,16 +358,12 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
if ((BN_mod_inverse(&u2,sig->s,dsa->q,ctx)) == NULL) goto err;
/* save M in u1 */
if (BN_bin2bn(dgst,dgst_len,&u1) == NULL) goto err;
j = dgst_len << 3;
if (j > i)
{
if (dgst_len > (i >> 3))
/* if the digest length is greater than the size of q use the
* BN_num_bits(dsa->q) leftmost bits of the digest, see
* fips 186-3, 4.2 */
if (!BN_rshift(&u1, &u1, j - i))
goto err;
}
dgst_len = (i >> 3);
if (BN_bin2bn(dgst,dgst_len,&u1) == NULL) goto err;
/* u1 = M * w mod q */
if (!BN_mod_mul(&u1,&u1,&u2,dsa->q,ctx)) goto err;