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authormarha <marha@users.sourceforge.net>2010-03-29 17:08:02 +0000
committermarha <marha@users.sourceforge.net>2010-03-29 17:08:02 +0000
commit15272ab4ed1e6250412fccd48200ed9eae59608f (patch)
treea5996ea67966a778a16565f19dfc2e7c7f49b376 /openssl/crypto/ec/ec2_mult.c
parent3827301b2ea5a45ac009c3bf9f08586ff40b8506 (diff)
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Updated to openssl 1.0.0
Diffstat (limited to 'openssl/crypto/ec/ec2_mult.c')
-rw-r--r--openssl/crypto/ec/ec2_mult.c33
1 files changed, 17 insertions, 16 deletions
diff --git a/openssl/crypto/ec/ec2_mult.c b/openssl/crypto/ec/ec2_mult.c
index ff368fd7d..ab631a50a 100644
--- a/openssl/crypto/ec/ec2_mult.c
+++ b/openssl/crypto/ec/ec2_mult.c
@@ -76,7 +76,7 @@
* coordinates.
* Uses algorithm Mdouble in appendix of
* Lopez, J. and Dahab, R. "Fast multiplication on elliptic curves over
- * GF(2^m) without precomputation".
+ * GF(2^m) without precomputation" (CHES '99, LNCS 1717).
* modified to not require precomputation of c=b^{2^{m-1}}.
*/
static int gf2m_Mdouble(const EC_GROUP *group, BIGNUM *x, BIGNUM *z, BN_CTX *ctx)
@@ -107,8 +107,8 @@ static int gf2m_Mdouble(const EC_GROUP *group, BIGNUM *x, BIGNUM *z, BN_CTX *ctx
/* Compute the x-coordinate x1/z1 for the point (x1/z1)+(x2/x2) in Montgomery
* projective coordinates.
* Uses algorithm Madd in appendix of
- * Lopex, J. and Dahab, R. "Fast multiplication on elliptic curves over
- * GF(2^m) without precomputation".
+ * Lopez, J. and Dahab, R. "Fast multiplication on elliptic curves over
+ * GF(2^m) without precomputation" (CHES '99, LNCS 1717).
*/
static int gf2m_Madd(const EC_GROUP *group, const BIGNUM *x, BIGNUM *x1, BIGNUM *z1,
const BIGNUM *x2, const BIGNUM *z2, BN_CTX *ctx)
@@ -140,8 +140,8 @@ static int gf2m_Madd(const EC_GROUP *group, const BIGNUM *x, BIGNUM *x1, BIGNUM
/* Compute the x, y affine coordinates from the point (x1, z1) (x2, z2)
* using Montgomery point multiplication algorithm Mxy() in appendix of
- * Lopex, J. and Dahab, R. "Fast multiplication on elliptic curves over
- * GF(2^m) without precomputation".
+ * Lopez, J. and Dahab, R. "Fast multiplication on elliptic curves over
+ * GF(2^m) without precomputation" (CHES '99, LNCS 1717).
* Returns:
* 0 on error
* 1 if return value should be the point at infinity
@@ -209,15 +209,15 @@ static int gf2m_Mxy(const EC_GROUP *group, const BIGNUM *x, const BIGNUM *y, BIG
/* Computes scalar*point and stores the result in r.
* point can not equal r.
* Uses algorithm 2P of
- * Lopex, J. and Dahab, R. "Fast multiplication on elliptic curves over
- * GF(2^m) without precomputation".
+ * Lopez, J. and Dahab, R. "Fast multiplication on elliptic curves over
+ * GF(2^m) without precomputation" (CHES '99, LNCS 1717).
*/
static int ec_GF2m_montgomery_point_multiply(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
const EC_POINT *point, BN_CTX *ctx)
{
BIGNUM *x1, *x2, *z1, *z2;
- int ret = 0, i, j;
- BN_ULONG mask;
+ int ret = 0, i;
+ BN_ULONG mask,word;
if (r == point)
{
@@ -251,22 +251,24 @@ static int ec_GF2m_montgomery_point_multiply(const EC_GROUP *group, EC_POINT *r,
if (!BN_GF2m_add(x2, x2, &group->b)) goto err; /* x2 = x^4 + b */
/* find top most bit and go one past it */
- i = scalar->top - 1; j = BN_BITS2 - 1;
+ i = scalar->top - 1;
mask = BN_TBIT;
- while (!(scalar->d[i] & mask)) { mask >>= 1; j--; }
- mask >>= 1; j--;
+ word = scalar->d[i];
+ while (!(word & mask)) mask >>= 1;
+ mask >>= 1;
/* if top most bit was at word break, go to next word */
if (!mask)
{
- i--; j = BN_BITS2 - 1;
+ i--;
mask = BN_TBIT;
}
for (; i >= 0; i--)
{
- for (; j >= 0; j--)
+ word = scalar->d[i];
+ while (mask)
{
- if (scalar->d[i] & mask)
+ if (word & mask)
{
if (!gf2m_Madd(group, &point->X, x1, z1, x2, z2, ctx)) goto err;
if (!gf2m_Mdouble(group, x2, z2, ctx)) goto err;
@@ -278,7 +280,6 @@ static int ec_GF2m_montgomery_point_multiply(const EC_GROUP *group, EC_POINT *r,
}
mask >>= 1;
}
- j = BN_BITS2 - 1;
mask = BN_TBIT;
}