*
*/
/* ====================================================================
- * Copyright (c) 1998-2003 The OpenSSL Project. All rights reserved.
+ * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
}
if (!BN_copy(&point->X, x)) goto err;
- BN_set_sign(&point->X, 0);
+ BN_set_negative(&point->X, 0);
if (!BN_copy(&point->Y, y)) goto err;
- BN_set_sign(&point->Y, 0);
+ BN_set_negative(&point->Y, 0);
if (!BN_copy(&point->Z, BN_value_one())) goto err;
- BN_set_sign(&point->Z, 0);
+ BN_set_negative(&point->Z, 0);
point->Z_is_one = 1;
ret = 1;
if (x != NULL)
{
if (!BN_copy(x, &point->X)) goto err;
- BN_set_sign(x, 0);
+ BN_set_negative(x, 0);
}
if (y != NULL)
{
if (!BN_copy(y, &point->Y)) goto err;
- BN_set_sign(y, 0);
+ BN_set_negative(y, 0);
}
ret = 1;
}
-/* Include patented algorithms. */
-#include "ec2_smpt.c"
+/* Calculates and sets the affine coordinates of an EC_POINT from the given
+ * compressed coordinates. Uses algorithm 2.3.4 of SEC 1.
+ * Note that the simple implementation only uses affine coordinates.
+ *
+ * The method is from the following publication:
+ *
+ * Harper, Menezes, Vanstone:
+ * "Public-Key Cryptosystems with Very Small Key Lengths",
+ * EUROCRYPT '92, Springer-Verlag LNCS 658,
+ * published February 1993
+ *
+ * US Patents 6,141,420 and 6,618,483 (Vanstone, Mullin, Agnew) describe
+ * the same method, but claim no priority date earlier than July 29, 1994
+ * (and additionally fail to cite the EUROCRYPT '92 publication as prior art).
+ */
+int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,
+ const BIGNUM *x_, int y_bit, BN_CTX *ctx)
+ {
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *tmp, *x, *y, *z;
+ int ret = 0, z0;
+
+ /* clear error queue */
+ ERR_clear_error();
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ y_bit = (y_bit != 0) ? 1 : 0;
+
+ BN_CTX_start(ctx);
+ tmp = BN_CTX_get(ctx);
+ x = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ z = BN_CTX_get(ctx);
+ if (z == NULL) goto err;
+
+ if (!BN_GF2m_mod_arr(x, x_, group->poly)) goto err;
+ if (BN_is_zero(x))
+ {
+ if (!BN_GF2m_mod_sqrt_arr(y, &group->b, group->poly, ctx)) goto err;
+ }
+ else
+ {
+ if (!group->meth->field_sqr(group, tmp, x, ctx)) goto err;
+ if (!group->meth->field_div(group, tmp, &group->b, tmp, ctx)) goto err;
+ if (!BN_GF2m_add(tmp, &group->a, tmp)) goto err;
+ if (!BN_GF2m_add(tmp, x, tmp)) goto err;
+ if (!BN_GF2m_mod_solve_quad_arr(z, tmp, group->poly, ctx))
+ {
+ unsigned long err = ERR_peek_last_error();
+
+ if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NO_SOLUTION)
+ {
+ ERR_clear_error();
+ ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
+ }
+ else
+ ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_BN_LIB);
+ goto err;
+ }
+ z0 = (BN_is_odd(z)) ? 1 : 0;
+ if (!group->meth->field_mul(group, y, x, z, ctx)) goto err;
+ if (z0 != y_bit)
+ {
+ if (!BN_GF2m_add(y, y, x)) goto err;
+ }
+ }
+
+ if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
/* Converts an EC_POINT to an octet string.
* If buf is NULL, the encoded length will be returned.
* If the length len of buf is smaller than required an error will be returned.
- *
- * The point compression section of this function is patented by Certicom Corp.
- * under US Patent 6,141,420. Point compression is disabled by default and can
- * be enabled by defining the preprocessor macro OPENSSL_EC_BIN_PT_COMP at
- * Configure-time.
*/
size_t ec_GF2m_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,
unsigned char *buf, size_t len, BN_CTX *ctx)
BIGNUM *x, *y, *yxi;
size_t field_len, i, skip;
-#ifndef OPENSSL_EC_BIN_PT_COMP
- if ((form == POINT_CONVERSION_COMPRESSED) || (form == POINT_CONVERSION_HYBRID))
- {
- ECerr(EC_F_EC_GF2M_SIMPLE_POINT2OCT, ERR_R_DISABLED);
- goto err;
- }
-#endif
-
if ((form != POINT_CONVERSION_COMPRESSED)
&& (form != POINT_CONVERSION_UNCOMPRESSED)
&& (form != POINT_CONVERSION_HYBRID))
if (!EC_POINT_get_affine_coordinates_GF2m(group, point, x, y, ctx)) goto err;
buf[0] = form;
-#ifdef OPENSSL_EC_BIN_PT_COMP
if ((form != POINT_CONVERSION_UNCOMPRESSED) && !BN_is_zero(x))
{
if (!group->meth->field_div(group, yxi, y, x, ctx)) goto err;
if (BN_is_odd(yxi)) buf[0]++;
}
-#endif
i = 1;
*/
int ec_GF2m_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx)
{
- BN_CTX *new_ctx = NULL;
- BIGNUM *rh, *lh, *tmp1;
int ret = -1;
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *lh, *y2;
+ int (*field_mul)(const EC_GROUP *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
+ int (*field_sqr)(const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
if (EC_POINT_is_at_infinity(group, point))
return 1;
-
+
+ field_mul = group->meth->field_mul;
+ field_sqr = group->meth->field_sqr;
+
/* only support affine coordinates */
if (!point->Z_is_one) goto err;
}
BN_CTX_start(ctx);
- rh = BN_CTX_get(ctx);
+ y2 = BN_CTX_get(ctx);
lh = BN_CTX_get(ctx);
- tmp1 = BN_CTX_get(ctx);
- if (tmp1 == NULL) goto err;
+ if (lh == NULL) goto err;
/* We have a curve defined by a Weierstrass equation
* y^2 + x*y = x^3 + a*x^2 + b.
- * To test this, we add up the right-hand side in 'rh'
- * and the left-hand side in 'lh'.
+ * <=> x^3 + a*x^2 + x*y + b + y^2 = 0
+ * <=> ((x + a) * x + y ) * x + b + y^2 = 0
*/
-
- /* rh := X^3 */
- if (!group->meth->field_sqr(group, tmp1, &point->X, ctx)) goto err;
- if (!group->meth->field_mul(group, rh, tmp1, &point->X, ctx)) goto err;
-
- /* rh := rh + a*X^2 */
- if (!group->meth->field_mul(group, tmp1, tmp1, &group->a, ctx)) goto err;
- if (!BN_GF2m_add(rh, rh, tmp1)) goto err;
-
- /* rh := rh + b */
- if (!BN_GF2m_add(rh, rh, &group->b)) goto err;
-
- /* lh := Y^2 */
- if (!group->meth->field_sqr(group, lh, &point->Y, ctx)) goto err;
-
- /* lh := lh + x*y */
- if (!group->meth->field_mul(group, tmp1, &point->X, &point->Y, ctx)) goto err;
- if (!BN_GF2m_add(lh, lh, tmp1)) goto err;
-
- ret = (0 == BN_GF2m_cmp(lh, rh));
-
+ if (!BN_GF2m_add(lh, &point->X, &group->a)) goto err;
+ if (!field_mul(group, lh, lh, &point->X, ctx)) goto err;
+ if (!BN_GF2m_add(lh, lh, &point->Y)) goto err;
+ if (!field_mul(group, lh, lh, &point->X, ctx)) goto err;
+ if (!BN_GF2m_add(lh, lh, &group->b)) goto err;
+ if (!field_sqr(group, y2, &point->Y, ctx)) goto err;
+ if (!BN_GF2m_add(lh, lh, y2)) goto err;
+ ret = BN_is_zero(lh);
err:
if (ctx) BN_CTX_end(ctx);
if (new_ctx) BN_CTX_free(new_ctx);
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