More method functions.
diff --git a/crypto/ec/ec.h b/crypto/ec/ec.h
index cc0dd78..93fde52 100644
--- a/crypto/ec/ec.h
+++ b/crypto/ec/ec.h
@@ -133,7 +133,7 @@
int EC_POINT_is_at_infinity(const EC_GROUP *, const EC_POINT *);
int EC_POINT_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
-int EC_POINT_make_affine(const EC_GROUP *, const EC_POINT *, BN_CTX *);
+int EC_POINT_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
@@ -150,6 +150,7 @@
/* Function codes. */
#define EC_F_EC_GFP_SIMPLE_GROUP_SET_GENERATOR 117
+#define EC_F_EC_GFP_SIMPLE_MAKE_AFFINE 118
#define EC_F_EC_GROUP_CLEAR_FREE 103
#define EC_F_EC_GROUP_COPY 102
#define EC_F_EC_GROUP_FREE 104
diff --git a/crypto/ec/ec_err.c b/crypto/ec/ec_err.c
index 770bce5..cd2d792 100644
--- a/crypto/ec/ec_err.c
+++ b/crypto/ec/ec_err.c
@@ -67,6 +67,7 @@
static ERR_STRING_DATA EC_str_functs[]=
{
{ERR_PACK(0,EC_F_EC_GFP_SIMPLE_GROUP_SET_GENERATOR,0), "EC_GFP_SIMPLE_GROUP_SET_GENERATOR"},
+{ERR_PACK(0,EC_F_EC_GFP_SIMPLE_MAKE_AFFINE,0), "EC_GFP_SIMPLE_MAKE_AFFINE"},
{ERR_PACK(0,EC_F_EC_GROUP_CLEAR_FREE,0), "EC_GROUP_clear_free"},
{ERR_PACK(0,EC_F_EC_GROUP_COPY,0), "EC_GROUP_copy"},
{ERR_PACK(0,EC_F_EC_GROUP_FREE,0), "EC_GROUP_free"},
diff --git a/crypto/ec/ec_lcl.h b/crypto/ec/ec_lcl.h
index 231e8ca..4bfcc91 100644
--- a/crypto/ec/ec_lcl.h
+++ b/crypto/ec/ec_lcl.h
@@ -99,7 +99,7 @@
/* used by EC_POINT_is_at_infinity, EC_POINT_is_on_curve, EC_POINT_make_affine */
int (*is_at_infinity)(const EC_GROUP *, const EC_POINT *);
int (*is_on_curve)(const EC_GROUP *, const EC_POINT *, BN_CTX *);
- int (*make_affine)(const EC_GROUP *, const EC_POINT *, BN_CTX *);
+ int (*make_affine)(const EC_GROUP *, EC_POINT *, BN_CTX *);
/* internal functions */
@@ -134,7 +134,7 @@
* or abused for all kinds of fields, not just GF(p).)
* For characteristic > 3, the curve is defined
* by a Weierstrass equation of the form
- * Y^2 = X^3 + a*X + b.
+ * y^2 = x^3 + a*x + b.
*/
int a_is_minus3; /* enable optimized point arithmetics for special case */
@@ -197,7 +197,7 @@
int ec_GFp_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a, BN_CTX *);
int ec_GFp_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
int ec_GFp_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
-int ec_GFp_simple_make_affine(const EC_GROUP *, const EC_POINT *, BN_CTX *);
+int ec_GFp_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
int ec_GFp_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *);
int ec_GFp_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a, BN_CTX *);
diff --git a/crypto/ec/ec_lib.c b/crypto/ec/ec_lib.c
index 2056d58..90da84e 100644
--- a/crypto/ec/ec_lib.c
+++ b/crypto/ec/ec_lib.c
@@ -421,7 +421,7 @@
}
-int EC_POINT_make_affine(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx)
+int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
{
if (group->meth->make_affine == 0)
{
diff --git a/crypto/ec/ecp_smpl.c b/crypto/ec/ecp_smpl.c
index bae7528..5306efd 100644
--- a/crypto/ec/ecp_smpl.c
+++ b/crypto/ec/ecp_smpl.c
@@ -385,8 +385,8 @@
{
/* a is the same point as b */
BN_CTX_end(ctx);
- ctx = NULL;
ret = EC_POINT_dbl(group, r, a, ctx);
+ ctx = NULL;
goto end;
}
else
@@ -491,8 +491,6 @@
n3 = BN_CTX_get(ctx);
if (n3 == NULL) goto err;
- /* TODO: optimization for group->a_is_minus3 */
-
/* n1 */
if (a->Z_is_one)
{
@@ -577,12 +575,168 @@
}
-int ec_GFp_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx);
-/* TODO */
+int ec_GFp_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx)
+ {
+ int (*field_mul)(const EC_GROUP *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
+ int (*field_sqr)(const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
+ const BIGNUM *p;
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *rh, *tmp1, *tmp2, *Z4, *Z6;
+ int ret = -1;
+
+ if (EC_POINT_is_at_infinity(group, point))
+ return 1;
+
+ field_mul = group->meth->field_mul;
+ field_sqr = group->meth->field_sqr;
+ p = &group->field;
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+ BN_CTX_start(ctx);
+
+ rh = BN_CTX_get(ctx);
+ tmp1 = BN_CTX_get(ctx);
+ tmp2 = BN_CTX_get(ctx);
+ Z4 = BN_CTX_get(ctx);
+ Z6 = BN_CTX_get(ctx);
+ if (Z6 == NULL) goto err;
+
+ /* We have a curve defined by a Weierstrass equation
+ * y^2 = x^3 + a*x + b.
+ * The point to consider is given in Jacobian projective coordinates
+ * where (X, Y, Z) represents (x, y) = (X/Z^2, Y/Z^3).
+ * Substituting this and multiplying by Z^6 transforms the above equation into
+ * Y^2 = X^3 + a*X*Z^4 + b*Z^6.
+ * To test this, we add up the right-hand side in 'rh'.
+ */
+
+ /* rh := X^3 */
+ if (!field_sqr(group, rh, &point->X, ctx)) goto err;
+ if (!field_mul(group, rh, rh, &point->X, ctx)) goto err;
+
+ if (!point->Z_is_one)
+ {
+ if (!field_sqr(group, tmp1, &point->Z, ctx)) goto err;
+ if (!field_sqr(group, Z4, tmp1, ctx)) goto err;
+ if (!field_mul(group, Z6, Z4, tmp1, ctx)) goto err;
+
+ /* rh := rh + a*X*Z^4 */
+ if (!field_mul(group, tmp1, &point->X, Z4, ctx)) goto err;
+ if (&group->a_is_minus3)
+ {
+ if (!BN_mod_lshift1_quick(tmp2, tmp1, p)) goto err;
+ if (!BN_mod_add_quick(tmp2, tmp2, tmp1, p)) goto err;
+ if (!BN_mod_sub_quick(rh, rh, tmp2, p)) goto err;
+ }
+ else
+ {
+ if (!field_mul(group, tmp2, tmp1, &group->a, ctx)) goto err;
+ if (!BN_mod_add_quick(rh, rh, tmp2, p)) goto err;
+ }
+
+ /* rh := rh + b*Z^6 */
+ if (!field_mul(group, tmp1, &group->b, Z6, ctx)) goto err;
+ if (!BN_mod_add_quick(rh, rh, tmp1, p)) goto err;
+ }
+ else
+ {
+ /* point->Z_is_one */
+
+ /* rh := rh + a*X */
+ if (&group->a_is_minus3)
+ {
+ if (!BN_mod_lshift1_quick(tmp2, &point->X, p)) goto err;
+ if (!BN_mod_add_quick(tmp2, tmp2, &point->X, p)) goto err;
+ if (!BN_mod_sub_quick(rh, rh, tmp2, p)) goto err;
+ }
+ else
+ {
+ if (!field_mul(group, tmp2, &point->X, &group->a, ctx)) goto err;
+ if (!BN_mod_add_quick(rh, rh, tmp2, p)) goto err;
+ }
+
+ /* rh := rh + b */
+ if (!BN_mod_add_quick(rh, rh, &group->b, p)) goto err;
+ }
+
+ /* 'lh' := Y^2 */
+ if (!field_sqr(group, tmp1, &point->Y, ctx)) goto err;
+
+ ret = (0 == BN_cmp(tmp1, rh));
+
+ err:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
-int ec_GFp_simple_make_affine(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx);
-/* TODO */
+int ec_GFp_simple_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
+ {
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *Z, *Z_1, *Z_2, *Z_3;
+ int ret = 0;
+
+ if (point->Z_is_one || EC_POINT_is_at_infinity(group, point))
+ return 1;
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+ BN_CTX_start(ctx);
+
+ Z = BN_CTX_get(ctx);
+ Z_1 = BN_CTX_get(ctx);
+ Z_2 = BN_CTX_get(ctx);
+ Z_3 = BN_CTX_get(ctx);
+ if (Z_3 == NULL) goto end;
+
+ /* transform (X, Y, Z) into (X/Z^2, Y/Z^3, 1) */
+
+ if (group->meth->field_decode)
+ {
+ if (!group->meth->field_decode(group, Z, &point->Z, ctx)) goto end;
+ }
+ else
+ Z = &point->Z;
+
+ if (BN_is_one(Z))
+ {
+ point->Z_is_one = 1;
+ ret = 1;
+ goto end;
+ }
+
+ if (!BN_mod_inverse(Z_1, Z, &group->field, ctx))
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_MAKE_AFFINE, ERR_R_BN_LIB);
+ goto end;
+ }
+ if (!BN_mod_sqr(Z_2, Z_1, &group->field, ctx)) goto end;
+ if (!BN_mod_mul(Z_3, Z_2, Z_1, &group->field, ctx)) goto end;
+
+ if (!BN_mod_mul(&point->X, &point->X, Z_2, &group->field, ctx)) goto end;
+ if (!BN_mod_mul(&point->Y, &point->Y, Z_2, &group->field, ctx)) goto end;
+ if (!BN_set_word(&point->Z, 1)) goto end;
+ point->Z_is_one = 1;
+
+ ret = 1;
+
+ end:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
int ec_GFp_simple_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
