/* crypto/ec/ec2_smpt.c */
-/* This code was originally written by Douglas Stebila
+/*
+ * This code was originally written by Douglas Stebila
* <dstebila@student.math.uwaterloo.ca> for the OpenSSL project.
*/
/* ====================================================================
* are met:
*
* 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
+ * notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
*
*/
-
-/* Calaculates 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.
- *
- * This algorithm is patented by Certicom Corp. under US Patent 6,141,420
- * (for licensing information, contact licensing@certicom.com).
- * This function is disabled by default and can be enabled by defining the
- * preprocessor macro OPENSSL_EC_BIN_PT_COMP at Configure-time.
+/*
+ * Calaculates 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. This algorithm is
+ * patented by Certicom Corp. under US Patent 6,141,420 (for licensing
+ * information, contact licensing@certicom.com). This function is disabled by
+ * default and can be enabled by defining the preprocessor macro
+ * OPENSSL_EC_BIN_PT_COMP at Configure-time.
*/
-int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,
- const BIGNUM *x_, int y_bit, BN_CTX *ctx)
- {
-#ifndef OPENSSL_EC_BIN_PT_COMP
- ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_DISABLED);
- return 0;
+int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group,
+ EC_POINT *point,
+ const BIGNUM *x_, int y_bit,
+ BN_CTX *ctx)
+{
+#ifndef OPENSSL_EC_BIN_PT_COMP
+ ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_DISABLED);
+ return 0;
#else
- BN_CTX *new_ctx = NULL;
- BIGNUM *tmp, *x, *y, *z;
- int ret = 0, z0;
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *tmp, *x, *y, *z;
+ int ret = 0, z0;
+
+ /* clear error queue */
+ ERR_clear_error();
- /* clear error queue */
- ERR_clear_error();
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
+ y_bit = (y_bit != 0) ? 1 : 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;
- 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 (!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 (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;
+ if (!EC_POINT_set_affine_coordinates_GF2m(group, point, x, y, ctx))
+ goto err;
- ret = 1;
+ ret = 1;
err:
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
#endif
- }
+}
projects / openssl.git / blobdiff