Add group_order_bits to EC_METHOD.
[openssl.git] / crypto / ec / ecp_smpl.c
index 27b4472b71700eea505633f229797475f9907e30..2ba40f40b282755364bb91e9ad6d11a2ca2f44fd 100644 (file)
@@ -1,6 +1,8 @@
-/* crypto/ec/ecp_smpl.c */
-/* Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de>
- * for the OpenSSL project. */
+/*
+ * Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de>
+ * for the OpenSSL project. Includes code written by Bodo Moeller for the
+ * OpenSSL project.
+ */
 /* ====================================================================
  * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
  *
@@ -9,7 +11,7 @@
  * 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
 #include "ec_lcl.h"
 
 const EC_METHOD *EC_GFp_simple_method(void)
-       {
-       static const EC_METHOD ret = {
-               NID_X9_62_prime_field,
-               ec_GFp_simple_group_init,
-               ec_GFp_simple_group_finish,
-               ec_GFp_simple_group_clear_finish,
-               ec_GFp_simple_group_copy,
-               ec_GFp_simple_group_set_curve_GFp,
-               ec_GFp_simple_group_get_curve_GFp,
-               ec_GFp_simple_group_get_degree,
-               ec_GFp_simple_group_check_discriminant,
-               ec_GFp_simple_point_init,
-               ec_GFp_simple_point_finish,
-               ec_GFp_simple_point_clear_finish,
-               ec_GFp_simple_point_copy,
-               ec_GFp_simple_point_set_to_infinity,
-               ec_GFp_simple_set_Jprojective_coordinates_GFp,
-               ec_GFp_simple_get_Jprojective_coordinates_GFp,
-               ec_GFp_simple_point_set_affine_coordinates_GFp,
-               ec_GFp_simple_point_get_affine_coordinates_GFp,
-               ec_GFp_simple_set_compressed_coordinates_GFp,
-               ec_GFp_simple_point2oct,
-               ec_GFp_simple_oct2point,
-               ec_GFp_simple_add,
-               ec_GFp_simple_dbl,
-               ec_GFp_simple_invert,
-               0 /* mul */,
-               0 /* precompute_mult */,
-               ec_GFp_simple_is_at_infinity,
-               ec_GFp_simple_is_on_curve,
-               ec_GFp_simple_cmp,
-               ec_GFp_simple_make_affine,
-               ec_GFp_simple_points_make_affine,
-               ec_GFp_simple_field_mul,
-               ec_GFp_simple_field_sqr,
-               0 /* field_div */,
-               0 /* field_encode */,
-               0 /* field_decode */,
-               0 /* field_set_to_one */ };
-
-       return &ret;
-       }
-
+{
+    static const EC_METHOD ret = {
+        EC_FLAGS_DEFAULT_OCT,
+        NID_X9_62_prime_field,
+        ec_GFp_simple_group_init,
+        ec_GFp_simple_group_finish,
+        ec_GFp_simple_group_clear_finish,
+        ec_GFp_simple_group_copy,
+        ec_GFp_simple_group_set_curve,
+        ec_GFp_simple_group_get_curve,
+        ec_GFp_simple_group_get_degree,
+        0, /* group_order_bits */
+        ec_GFp_simple_group_check_discriminant,
+        ec_GFp_simple_point_init,
+        ec_GFp_simple_point_finish,
+        ec_GFp_simple_point_clear_finish,
+        ec_GFp_simple_point_copy,
+        ec_GFp_simple_point_set_to_infinity,
+        ec_GFp_simple_set_Jprojective_coordinates_GFp,
+        ec_GFp_simple_get_Jprojective_coordinates_GFp,
+        ec_GFp_simple_point_set_affine_coordinates,
+        ec_GFp_simple_point_get_affine_coordinates,
+        0, 0, 0,
+        ec_GFp_simple_add,
+        ec_GFp_simple_dbl,
+        ec_GFp_simple_invert,
+        ec_GFp_simple_is_at_infinity,
+        ec_GFp_simple_is_on_curve,
+        ec_GFp_simple_cmp,
+        ec_GFp_simple_make_affine,
+        ec_GFp_simple_points_make_affine,
+        0 /* mul */ ,
+        0 /* precompute_mult */ ,
+        0 /* have_precompute_mult */ ,
+        ec_GFp_simple_field_mul,
+        ec_GFp_simple_field_sqr,
+        0 /* field_div */ ,
+        0 /* field_encode */ ,
+        0 /* field_decode */ ,
+        0                       /* field_set_to_one */
+    };
+
+    return &ret;
+}
+
+/*
+ * Most method functions in this file are designed to work with
+ * non-trivial representations of field elements if necessary
+ * (see ecp_mont.c): while standard modular addition and subtraction
+ * are used, the field_mul and field_sqr methods will be used for
+ * multiplication, and field_encode and field_decode (if defined)
+ * will be used for converting between representations.
+ *
+ * Functions ec_GFp_simple_points_make_affine() and
+ * ec_GFp_simple_point_get_affine_coordinates() specifically assume
+ * that if a non-trivial representation is used, it is a Montgomery
+ * representation (i.e. 'encoding' means multiplying by some factor R).
+ */
 
 int ec_GFp_simple_group_init(EC_GROUP *group)
-       {
-       BN_init(&group->field);
-       BN_init(&group->a);
-       BN_init(&group->b);
-       group->a_is_minus3 = 0;
-       return 1;
-       }
-
+{
+    group->field = BN_new();
+    group->a = BN_new();
+    group->b = BN_new();
+    if (group->field == NULL || group->a == NULL || group->b == NULL) {
+        BN_free(group->field);
+        BN_free(group->a);
+        BN_free(group->b);
+        return 0;
+    }
+    group->a_is_minus3 = 0;
+    return 1;
+}
 
 void ec_GFp_simple_group_finish(EC_GROUP *group)
-       {
-       BN_free(&group->field);
-       BN_free(&group->a);
-       BN_free(&group->b);
-       }
-
+{
+    BN_free(group->field);
+    BN_free(group->a);
+    BN_free(group->b);
+}
 
 void ec_GFp_simple_group_clear_finish(EC_GROUP *group)
-       {
-       BN_clear_free(&group->field);
-       BN_clear_free(&group->a);
-       BN_clear_free(&group->b);
-       }
-
+{
+    BN_clear_free(group->field);
+    BN_clear_free(group->a);
+    BN_clear_free(group->b);
+}
 
 int ec_GFp_simple_group_copy(EC_GROUP *dest, const EC_GROUP *src)
-       {
-       if (!BN_copy(&dest->field, &src->field)) return 0;
-       if (!BN_copy(&dest->a, &src->a)) return 0;
-       if (!BN_copy(&dest->b, &src->b)) return 0;
-
-       dest->a_is_minus3 = src->a_is_minus3;
-
-       return 1;
-       }
-
-
-int ec_GFp_simple_group_set_curve_GFp(EC_GROUP *group,
-       const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
-       {
-       int ret = 0;
-       BN_CTX *new_ctx = NULL;
-       BIGNUM *tmp_a;
-       
-       /* p must be a prime > 3 */
-       if (BN_num_bits(p) <= 2 || !BN_is_odd(p))
-               {
-               ECerr(EC_F_EC_GFP_SIMPLE_GROUP_SET_CURVE_GFP, EC_R_INVALID_FIELD);
-               return 0;
-               }
-
-       if (ctx == NULL)
-               {
-               ctx = new_ctx = BN_CTX_new();
-               if (ctx == NULL)
-                       return 0;
-               }
-
-       BN_CTX_start(ctx);
-       tmp_a = BN_CTX_get(ctx);
-       if (tmp_a == NULL) goto err;
-
-       /* group->field */
-       if (!BN_copy(&group->field, p)) goto err;
-       group->field.neg = 0;
-
-       /* group->a */
-       if (!BN_nnmod(tmp_a, a, p, ctx)) goto err;
-       if (group->meth->field_encode)
-               { if (!group->meth->field_encode(group, &group->a, tmp_a, ctx)) goto err; }     
-       else
-               if (!BN_copy(&group->a, tmp_a)) goto err;
-       
-       /* group->b */
-       if (!BN_nnmod(&group->b, b, p, ctx)) goto err;
-       if (group->meth->field_encode)
-               if (!group->meth->field_encode(group, &group->b, &group->b, ctx)) goto err;
-       
-       /* group->a_is_minus3 */
-       if (!BN_add_word(tmp_a, 3)) goto err;
-       group->a_is_minus3 = (0 == BN_cmp(tmp_a, &group->field));
-
-       ret = 1;
+{
+    if (!BN_copy(dest->field, src->field))
+        return 0;
+    if (!BN_copy(dest->a, src->a))
+        return 0;
+    if (!BN_copy(dest->b, src->b))
+        return 0;
+
+    dest->a_is_minus3 = src->a_is_minus3;
+
+    return 1;
+}
+
+int ec_GFp_simple_group_set_curve(EC_GROUP *group,
+                                  const BIGNUM *p, const BIGNUM *a,
+                                  const BIGNUM *b, BN_CTX *ctx)
+{
+    int ret = 0;
+    BN_CTX *new_ctx = NULL;
+    BIGNUM *tmp_a;
+
+    /* p must be a prime > 3 */
+    if (BN_num_bits(p) <= 2 || !BN_is_odd(p)) {
+        ECerr(EC_F_EC_GFP_SIMPLE_GROUP_SET_CURVE, EC_R_INVALID_FIELD);
+        return 0;
+    }
+
+    if (ctx == NULL) {
+        ctx = new_ctx = BN_CTX_new();
+        if (ctx == NULL)
+            return 0;
+    }
+
+    BN_CTX_start(ctx);
+    tmp_a = BN_CTX_get(ctx);
+    if (tmp_a == NULL)
+        goto err;
+
+    /* group->field */
+    if (!BN_copy(group->field, p))
+        goto err;
+    BN_set_negative(group->field, 0);
+
+    /* group->a */
+    if (!BN_nnmod(tmp_a, a, p, ctx))
+        goto err;
+    if (group->meth->field_encode) {
+        if (!group->meth->field_encode(group, group->a, tmp_a, ctx))
+            goto err;
+    } else if (!BN_copy(group->a, tmp_a))
+        goto err;
+
+    /* group->b */
+    if (!BN_nnmod(group->b, b, p, ctx))
+        goto err;
+    if (group->meth->field_encode)
+        if (!group->meth->field_encode(group, group->b, group->b, ctx))
+            goto err;
+
+    /* group->a_is_minus3 */
+    if (!BN_add_word(tmp_a, 3))
+        goto err;
+    group->a_is_minus3 = (0 == BN_cmp(tmp_a, group->field));
+
+    ret = 1;
 
  err:
-       BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
-
-
-int ec_GFp_simple_group_get_curve_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
-       {
-       int ret = 0;
-       BN_CTX *new_ctx = NULL;
-       
-       if (p != NULL)
-               {
-               if (!BN_copy(p, &group->field)) return 0;
-               }
-
-       if (a != NULL || b != NULL)
-               {
-               if (group->meth->field_decode)
-                       {
-                       if (ctx == NULL)
-                               {
-                               ctx = new_ctx = BN_CTX_new();
-                               if (ctx == NULL)
-                                       return 0;
-                               }
-                       if (a != NULL)
-                               {
-                               if (!group->meth->field_decode(group, a, &group->a, ctx)) goto err;
-                               }
-                       if (b != NULL)
-                               {
-                               if (!group->meth->field_decode(group, b, &group->b, ctx)) goto err;
-                               }
-                       }
-               else
-                       {
-                       if (a != NULL)
-                               {
-                               if (!BN_copy(a, &group->a)) goto err;
-                               }
-                       if (b != NULL)
-                               {
-                               if (!BN_copy(b, &group->b)) goto err;
-                               }
-                       }
-               }
-       
-       ret = 1;
-       
- err:
-       if (new_ctx)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
+    BN_CTX_end(ctx);
+    BN_CTX_free(new_ctx);
+    return ret;
+}
+
+int ec_GFp_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
+                                  BIGNUM *b, BN_CTX *ctx)
+{
+    int ret = 0;
+    BN_CTX *new_ctx = NULL;
+
+    if (p != NULL) {
+        if (!BN_copy(p, group->field))
+            return 0;
+    }
+
+    if (a != NULL || b != NULL) {
+        if (group->meth->field_decode) {
+            if (ctx == NULL) {
+                ctx = new_ctx = BN_CTX_new();
+                if (ctx == NULL)
+                    return 0;
+            }
+            if (a != NULL) {
+                if (!group->meth->field_decode(group, a, group->a, ctx))
+                    goto err;
+            }
+            if (b != NULL) {
+                if (!group->meth->field_decode(group, b, group->b, ctx))
+                    goto err;
+            }
+        } else {
+            if (a != NULL) {
+                if (!BN_copy(a, group->a))
+                    goto err;
+            }
+            if (b != NULL) {
+                if (!BN_copy(b, group->b))
+                    goto err;
+            }
+        }
+    }
+
+    ret = 1;
 
+ err:
+    BN_CTX_free(new_ctx);
+    return ret;
+}
 
 int ec_GFp_simple_group_get_degree(const EC_GROUP *group)
-       {
-       return BN_num_bits(&group->field);
-       }
-
+{
+    return BN_num_bits(group->field);
+}
 
 int ec_GFp_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
-       {
-       int ret = 0;
-       BIGNUM *a,*b,*order,*tmp_1,*tmp_2;
-       const BIGNUM *p = &group->field;
-       BN_CTX *new_ctx = NULL;
-
-       if (ctx == NULL)
-               {
-               ctx = new_ctx = BN_CTX_new();
-               if (ctx == NULL)
-                       {
-                       ECerr(EC_F_EC_GFP_SIMPLE_GROUP_CHECK_DISCRIMINANT, ERR_R_MALLOC_FAILURE);
-                       goto err;
-                       }
-               }
-       BN_CTX_start(ctx);
-       a = BN_CTX_get(ctx);
-       b = BN_CTX_get(ctx);
-       tmp_1 = BN_CTX_get(ctx);
-       tmp_2 = BN_CTX_get(ctx);
-       order = BN_CTX_get(ctx);
-       if (order == NULL) goto err;
-
-       if (group->meth->field_decode)
-               {
-               if (!group->meth->field_decode(group, a, &group->a, ctx)) goto err;
-               if (!group->meth->field_decode(group, b, &group->b, ctx)) goto err;
-               }
-       else
-               {
-               if (!BN_copy(a, &group->a)) goto err;
-               if (!BN_copy(b, &group->b)) goto err;
-               }
-       
-       /* check the discriminant:
-        * y^2 = x^3 + a*x + b is an elliptic curve <=> 4*a^3 + 27*b^2 != 0 (mod p) 
-         * 0 =< a, b < p */
-       if (BN_is_zero(a))
-               {
-               if (BN_is_zero(b)) goto err;
-               }
-       else if (!BN_is_zero(b))
-               {
-               if (!BN_mod_sqr(tmp_1, a, p, ctx)) goto err;
-               if (!BN_mod_mul(tmp_2, tmp_1, a, p, ctx)) goto err;
-               if (!BN_lshift(tmp_1, tmp_2, 2)) goto err;
-               /* tmp_1 = 4*a^3 */
-
-               if (!BN_mod_sqr(tmp_2, b, p, ctx)) goto err;
-               if (!BN_mul_word(tmp_2, 27)) goto err;
-               /* tmp_2 = 27*b^2 */
-
-               if (!BN_mod_add(a, tmp_1, tmp_2, p, ctx)) goto err;
-               if (BN_is_zero(a)) goto err;
-               }
-       ret = 1;
-
-err:
-       BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
+{
+    int ret = 0;
+    BIGNUM *a, *b, *order, *tmp_1, *tmp_2;
+    const BIGNUM *p = group->field;
+    BN_CTX *new_ctx = NULL;
+
+    if (ctx == NULL) {
+        ctx = new_ctx = BN_CTX_new();
+        if (ctx == NULL) {
+            ECerr(EC_F_EC_GFP_SIMPLE_GROUP_CHECK_DISCRIMINANT,
+                  ERR_R_MALLOC_FAILURE);
+            goto err;
+        }
+    }
+    BN_CTX_start(ctx);
+    a = BN_CTX_get(ctx);
+    b = BN_CTX_get(ctx);
+    tmp_1 = BN_CTX_get(ctx);
+    tmp_2 = BN_CTX_get(ctx);
+    order = BN_CTX_get(ctx);
+    if (order == NULL)
+        goto err;
+
+    if (group->meth->field_decode) {
+        if (!group->meth->field_decode(group, a, group->a, ctx))
+            goto err;
+        if (!group->meth->field_decode(group, b, group->b, ctx))
+            goto err;
+    } else {
+        if (!BN_copy(a, group->a))
+            goto err;
+        if (!BN_copy(b, group->b))
+            goto err;
+    }
+
+    /*-
+     * check the discriminant:
+     * y^2 = x^3 + a*x + b is an elliptic curve <=> 4*a^3 + 27*b^2 != 0 (mod p)
+     * 0 =< a, b < p
+     */
+    if (BN_is_zero(a)) {
+        if (BN_is_zero(b))
+            goto err;
+    } else if (!BN_is_zero(b)) {
+        if (!BN_mod_sqr(tmp_1, a, p, ctx))
+            goto err;
+        if (!BN_mod_mul(tmp_2, tmp_1, a, p, ctx))
+            goto err;
+        if (!BN_lshift(tmp_1, tmp_2, 2))
+            goto err;
+        /* tmp_1 = 4*a^3 */
+
+        if (!BN_mod_sqr(tmp_2, b, p, ctx))
+            goto err;
+        if (!BN_mul_word(tmp_2, 27))
+            goto err;
+        /* tmp_2 = 27*b^2 */
+
+        if (!BN_mod_add(a, tmp_1, tmp_2, p, ctx))
+            goto err;
+        if (BN_is_zero(a))
+            goto err;
+    }
+    ret = 1;
 
+ err:
+    if (ctx != NULL)
+        BN_CTX_end(ctx);
+    BN_CTX_free(new_ctx);
+    return ret;
+}
 
 int ec_GFp_simple_point_init(EC_POINT *point)
-       {
-       BN_init(&point->X);
-       BN_init(&point->Y);
-       BN_init(&point->Z);
-       point->Z_is_one = 0;
-
-       return 1;
-       }
-
+{
+    point->X = BN_new();
+    point->Y = BN_new();
+    point->Z = BN_new();
+    point->Z_is_one = 0;
+
+    if (point->X == NULL || point->Y == NULL || point->Z == NULL) {
+        BN_free(point->X);
+        BN_free(point->Y);
+        BN_free(point->Z);
+        return 0;
+    }
+    return 1;
+}
 
 void ec_GFp_simple_point_finish(EC_POINT *point)
-       {
-       BN_free(&point->X);
-       BN_free(&point->Y);
-       BN_free(&point->Z);
-       }
-
+{
+    BN_free(point->X);
+    BN_free(point->Y);
+    BN_free(point->Z);
+}
 
 void ec_GFp_simple_point_clear_finish(EC_POINT *point)
-       {
-       BN_clear_free(&point->X);
-       BN_clear_free(&point->Y);
-       BN_clear_free(&point->Z);
-       point->Z_is_one = 0;
-       }
-
+{
+    BN_clear_free(point->X);
+    BN_clear_free(point->Y);
+    BN_clear_free(point->Z);
+    point->Z_is_one = 0;
+}
 
 int ec_GFp_simple_point_copy(EC_POINT *dest, const EC_POINT *src)
-       {
-       if (!BN_copy(&dest->X, &src->X)) return 0;
-       if (!BN_copy(&dest->Y, &src->Y)) return 0;
-       if (!BN_copy(&dest->Z, &src->Z)) return 0;
-       dest->Z_is_one = src->Z_is_one;
-
-       return 1;
-       }
-
-
-int ec_GFp_simple_point_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
-       {
-       point->Z_is_one = 0;
-       return (BN_zero(&point->Z));
-       }
-
-
-int ec_GFp_simple_set_Jprojective_coordinates_GFp(const EC_GROUP *group, EC_POINT *point,
-       const BIGNUM *x, const BIGNUM *y, const BIGNUM *z, BN_CTX *ctx)
-       {
-       BN_CTX *new_ctx = NULL;
-       int ret = 0;
-       
-       if (ctx == NULL)
-               {
-               ctx = new_ctx = BN_CTX_new();
-               if (ctx == NULL)
-                       return 0;
-               }
-
-       if (x != NULL)
-               {
-               if (!BN_nnmod(&point->X, x, &group->field, ctx)) goto err;
-               if (group->meth->field_encode)
-                       {
-                       if (!group->meth->field_encode(group, &point->X, &point->X, ctx)) goto err;
-                       }
-               }
-       
-       if (y != NULL)
-               {
-               if (!BN_nnmod(&point->Y, y, &group->field, ctx)) goto err;
-               if (group->meth->field_encode)
-                       {
-                       if (!group->meth->field_encode(group, &point->Y, &point->Y, ctx)) goto err;
-                       }
-               }
-       
-       if (z != NULL)
-               {
-               int Z_is_one;
-
-               if (!BN_nnmod(&point->Z, z, &group->field, ctx)) goto err;
-               Z_is_one = BN_is_one(&point->Z);
-               if (group->meth->field_encode)
-                       {
-                       if (Z_is_one && (group->meth->field_set_to_one != 0))
-                               {
-                               if (!group->meth->field_set_to_one(group, &point->Z, ctx)) goto err;
-                               }
-                       else
-                               {
-                               if (!group->meth->field_encode(group, &point->Z, &point->Z, ctx)) goto err;
-                               }
-                       }
-               point->Z_is_one = Z_is_one;
-               }
-       
-       ret = 1;
-       
- err:
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
-
-
-int ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *group, const EC_POINT *point,
-       BIGNUM *x, BIGNUM *y, BIGNUM *z, BN_CTX *ctx)
-       {
-       BN_CTX *new_ctx = NULL;
-       int ret = 0;
-       
-       if (group->meth->field_decode != 0)
-               {
-               if (ctx == NULL)
-                       {
-                       ctx = new_ctx = BN_CTX_new();
-                       if (ctx == NULL)
-                               return 0;
-                       }
-
-               if (x != NULL)
-                       {
-                       if (!group->meth->field_decode(group, x, &point->X, ctx)) goto err;
-                       }
-               if (y != NULL)
-                       {
-                       if (!group->meth->field_decode(group, y, &point->Y, ctx)) goto err;
-                       }
-               if (z != NULL)
-                       {
-                       if (!group->meth->field_decode(group, z, &point->Z, ctx)) goto err;
-                       }
-               }
-       else    
-               {
-               if (x != NULL)
-                       {
-                       if (!BN_copy(x, &point->X)) goto err;
-                       }
-               if (y != NULL)
-                       {
-                       if (!BN_copy(y, &point->Y)) goto err;
-                       }
-               if (z != NULL)
-                       {
-                       if (!BN_copy(z, &point->Z)) goto err;
-                       }
-               }
-       
-       ret = 1;
+{
+    if (!BN_copy(dest->X, src->X))
+        return 0;
+    if (!BN_copy(dest->Y, src->Y))
+        return 0;
+    if (!BN_copy(dest->Z, src->Z))
+        return 0;
+    dest->Z_is_one = src->Z_is_one;
+
+    return 1;
+}
+
+int ec_GFp_simple_point_set_to_infinity(const EC_GROUP *group,
+                                        EC_POINT *point)
+{
+    point->Z_is_one = 0;
+    BN_zero(point->Z);
+    return 1;
+}
+
+int ec_GFp_simple_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
+                                                  EC_POINT *point,
+                                                  const BIGNUM *x,
+                                                  const BIGNUM *y,
+                                                  const BIGNUM *z,
+                                                  BN_CTX *ctx)
+{
+    BN_CTX *new_ctx = NULL;
+    int ret = 0;
+
+    if (ctx == NULL) {
+        ctx = new_ctx = BN_CTX_new();
+        if (ctx == NULL)
+            return 0;
+    }
+
+    if (x != NULL) {
+        if (!BN_nnmod(point->X, x, group->field, ctx))
+            goto err;
+        if (group->meth->field_encode) {
+            if (!group->meth->field_encode(group, point->X, point->X, ctx))
+                goto err;
+        }
+    }
+
+    if (y != NULL) {
+        if (!BN_nnmod(point->Y, y, group->field, ctx))
+            goto err;
+        if (group->meth->field_encode) {
+            if (!group->meth->field_encode(group, point->Y, point->Y, ctx))
+                goto err;
+        }
+    }
+
+    if (z != NULL) {
+        int Z_is_one;
+
+        if (!BN_nnmod(point->Z, z, group->field, ctx))
+            goto err;
+        Z_is_one = BN_is_one(point->Z);
+        if (group->meth->field_encode) {
+            if (Z_is_one && (group->meth->field_set_to_one != 0)) {
+                if (!group->meth->field_set_to_one(group, point->Z, ctx))
+                    goto err;
+            } else {
+                if (!group->
+                    meth->field_encode(group, point->Z, point->Z, ctx))
+                    goto err;
+            }
+        }
+        point->Z_is_one = Z_is_one;
+    }
+
+    ret = 1;
 
  err:
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
-
-
-int ec_GFp_simple_point_set_affine_coordinates_GFp(const EC_GROUP *group, EC_POINT *point,
-       const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx)
-       {
-       if (x == NULL || y == NULL)
-               {
-               /* unlike for projective coordinates, we do not tolerate this */
-               ECerr(EC_F_EC_GFP_SIMPLE_POINT_SET_AFFINE_COORDINATES_GFP, ERR_R_PASSED_NULL_PARAMETER);
-               return 0;
-               }
-
-       return EC_POINT_set_Jprojective_coordinates_GFp(group, point, x, y, BN_value_one(), ctx);
-       }
-
-
-int ec_GFp_simple_point_get_affine_coordinates_GFp(const EC_GROUP *group, const EC_POINT *point,
-       BIGNUM *x, BIGNUM *y, BN_CTX *ctx)
-       {
-       BN_CTX *new_ctx = NULL;
-       BIGNUM *X, *Y, *Z, *Z_1, *Z_2, *Z_3;
-       const BIGNUM *X_, *Y_, *Z_;
-       int ret = 0;
-
-       if (EC_POINT_is_at_infinity(group, point))
-               {
-               ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES_GFP, EC_R_POINT_AT_INFINITY);
-               return 0;
-               }
-
-       if (ctx == NULL)
-               {
-               ctx = new_ctx = BN_CTX_new();
-               if (ctx == NULL)
-                       return 0;
-               }
-
-       BN_CTX_start(ctx);
-       X = BN_CTX_get(ctx);
-       Y = BN_CTX_get(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 err;
-
-       /* transform  (X, Y, Z)  into  (x, y) := (X/Z^2, Y/Z^3) */
-       
-       if (group->meth->field_decode)
-               {
-               if (!group->meth->field_decode(group, X, &point->X, ctx)) goto err;
-               if (!group->meth->field_decode(group, Y, &point->Y, ctx)) goto err;
-               if (!group->meth->field_decode(group, Z, &point->Z, ctx)) goto err;
-               X_ = X; Y_ = Y; Z_ = Z;
-               }
-       else
-               {
-               X_ = &point->X;
-               Y_ = &point->Y;
-               Z_ = &point->Z;
-               }
-       
-       if (BN_is_one(Z_))
-               {
-               if (x != NULL)
-                       {
-                       if (!BN_copy(x, X_)) goto err;
-                       }
-               if (y != NULL)
-                       {
-                       if (!BN_copy(y, Y_)) goto err;
-                       }
-               }
-       else
-               {
-               if (!BN_mod_inverse(Z_1, Z_, &group->field, ctx))
-                       {
-                       ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES_GFP, ERR_R_BN_LIB);
-                       goto err;
-                       }
-               
-               if (group->meth->field_encode == 0)
-                       {
-                       /* field_sqr works on standard representation */
-                       if (!group->meth->field_sqr(group, Z_2, Z_1, ctx)) goto err;
-                       }
-               else
-                       {
-                       if (!BN_mod_sqr(Z_2, Z_1, &group->field, ctx)) goto err;
-                       }
-       
-               if (x != NULL)
-                       {
-                       if (group->meth->field_encode == 0)
-                               {
-                               /* field_mul works on standard representation */
-                               if (!group->meth->field_mul(group, x, X_, Z_2, ctx)) goto err;
-                               }
-                       else
-                               {
-                               if (!BN_mod_mul(x, X_, Z_2, &group->field, ctx)) goto err;
-                               }
-                       }
-
-               if (y != NULL)
-                       {
-                       if (group->meth->field_encode == 0)
-                               {
-                               /* field_mul works on standard representation */
-                               if (!group->meth->field_mul(group, Z_3, Z_2, Z_1, ctx)) goto err;
-                               if (!group->meth->field_mul(group, y, Y_, Z_3, ctx)) goto err;
-                               
-                               }
-                       else
-                               {
-                               if (!BN_mod_mul(Z_3, Z_2, Z_1, &group->field, ctx)) goto err;
-                               if (!BN_mod_mul(y, Y_, Z_3, &group->field, ctx)) goto err;
-                               }
-                       }
-               }
-
-       ret = 1;
+    BN_CTX_free(new_ctx);
+    return ret;
+}
+
+int ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
+                                                  const EC_POINT *point,
+                                                  BIGNUM *x, BIGNUM *y,
+                                                  BIGNUM *z, BN_CTX *ctx)
+{
+    BN_CTX *new_ctx = NULL;
+    int ret = 0;
+
+    if (group->meth->field_decode != 0) {
+        if (ctx == NULL) {
+            ctx = new_ctx = BN_CTX_new();
+            if (ctx == NULL)
+                return 0;
+        }
+
+        if (x != NULL) {
+            if (!group->meth->field_decode(group, x, point->X, ctx))
+                goto err;
+        }
+        if (y != NULL) {
+            if (!group->meth->field_decode(group, y, point->Y, ctx))
+                goto err;
+        }
+        if (z != NULL) {
+            if (!group->meth->field_decode(group, z, point->Z, ctx))
+                goto err;
+        }
+    } else {
+        if (x != NULL) {
+            if (!BN_copy(x, point->X))
+                goto err;
+        }
+        if (y != NULL) {
+            if (!BN_copy(y, point->Y))
+                goto err;
+        }
+        if (z != NULL) {
+            if (!BN_copy(z, point->Z))
+                goto err;
+        }
+    }
+
+    ret = 1;
 
  err:
-       BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
-
-
-int ec_GFp_simple_set_compressed_coordinates_GFp(const EC_GROUP *group, EC_POINT *point,
-       const BIGNUM *x_, int y_bit, BN_CTX *ctx)
-       {
-       BN_CTX *new_ctx = NULL;
-       BIGNUM *tmp1, *tmp2, *x, *y;
-       int ret = 0;
-
-       if (ctx == NULL)
-               {
-               ctx = new_ctx = BN_CTX_new();
-               if (ctx == NULL)
-                       return 0;
-               }
-
-       y_bit = (y_bit != 0);
-
-       BN_CTX_start(ctx);
-       tmp1 = BN_CTX_get(ctx);
-       tmp2 = BN_CTX_get(ctx);
-       x = BN_CTX_get(ctx);
-       y = BN_CTX_get(ctx);
-       if (y == NULL) goto err;
-
-       /* Recover y.  We have a Weierstrass equation
-        *     y^2 = x^3 + a*x + b,
-        * so  y  is one of the square roots of  x^3 + a*x + b.
-        */
-
-       /* tmp1 := x^3 */
-       if (!BN_nnmod(x, x_, &group->field,ctx)) goto err;
-       if (group->meth->field_decode == 0)
-               {
-               /* field_{sqr,mul} work on standard representation */
-               if (!group->meth->field_sqr(group, tmp2, x_, ctx)) goto err;
-               if (!group->meth->field_mul(group, tmp1, tmp2, x_, ctx)) goto err;
-               }
-       else
-               {
-               if (!BN_mod_sqr(tmp2, x_, &group->field, ctx)) goto err;
-               if (!BN_mod_mul(tmp1, tmp2, x_, &group->field, ctx)) goto err;
-               }
-       
-       /* tmp1 := tmp1 + a*x */
-       if (group->a_is_minus3)
-               {
-               if (!BN_mod_lshift1_quick(tmp2, x, &group->field)) goto err;
-               if (!BN_mod_add_quick(tmp2, tmp2, x, &group->field)) goto err;
-               if (!BN_mod_sub_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
-               }
-       else
-               {
-               if (group->meth->field_decode)
-                       {
-                       if (!group->meth->field_decode(group, tmp2, &group->a, ctx)) goto err;
-                       if (!BN_mod_mul(tmp2, tmp2, x, &group->field, ctx)) goto err;
-                       }
-               else
-                       {
-                       /* field_mul works on standard representation */
-                       if (!group->meth->field_mul(group, tmp2, &group->a, x, ctx)) goto err;
-                       }
-               
-               if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
-               }
-       
-       /* tmp1 := tmp1 + b */
-       if (group->meth->field_decode)
-               {
-               if (!group->meth->field_decode(group, tmp2, &group->b, ctx)) goto err;
-               if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
-               }
-       else
-               {
-               if (!BN_mod_add_quick(tmp1, tmp1, &group->b, &group->field)) goto err;
-               }
-       
-       if (!BN_mod_sqrt(y, tmp1, &group->field, ctx))
-               {
-               unsigned long err = ERR_peek_error();
-               
-               if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE)
-                       {
-                       (void)ERR_get_error();
-                       ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES_GFP, EC_R_INVALID_COMPRESSED_POINT);
-                       }
-               else
-                       ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES_GFP, ERR_R_BN_LIB);
-               goto err;
-               }
-       /* If tmp1 is not a square (i.e. there is no point on the curve with
-        * our x), then y now is a nonsense value too */
-
-       if (y_bit != BN_is_odd(y))
-               {
-               if (BN_is_zero(y))
-                       {
-                       int kron;
-
-                       kron = BN_kronecker(x, &group->field, ctx);
-                       if (kron == -2) goto err;
-
-                       if (kron == 1)
-                               ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES_GFP, EC_R_INVALID_COMPRESSION_BIT);
-                       else
-                               ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES_GFP, EC_R_INVALID_COMPRESSED_POINT);
-                       goto err;
-                       }
-               if (!BN_usub(y, &group->field, y)) goto err;
-               }
-       if (y_bit != BN_is_odd(y))
-               {
-               ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES_GFP, ERR_R_INTERNAL_ERROR);
-               goto err;
-               }
-
-       if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
-
-       ret = 1;
+    BN_CTX_free(new_ctx);
+    return ret;
+}
+
+int ec_GFp_simple_point_set_affine_coordinates(const EC_GROUP *group,
+                                               EC_POINT *point,
+                                               const BIGNUM *x,
+                                               const BIGNUM *y, BN_CTX *ctx)
+{
+    if (x == NULL || y == NULL) {
+        /*
+         * unlike for projective coordinates, we do not tolerate this
+         */
+        ECerr(EC_F_EC_GFP_SIMPLE_POINT_SET_AFFINE_COORDINATES,
+              ERR_R_PASSED_NULL_PARAMETER);
+        return 0;
+    }
+
+    return EC_POINT_set_Jprojective_coordinates_GFp(group, point, x, y,
+                                                    BN_value_one(), ctx);
+}
+
+int ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *group,
+                                               const EC_POINT *point,
+                                               BIGNUM *x, BIGNUM *y,
+                                               BN_CTX *ctx)
+{
+    BN_CTX *new_ctx = NULL;
+    BIGNUM *Z, *Z_1, *Z_2, *Z_3;
+    const BIGNUM *Z_;
+    int ret = 0;
+
+    if (EC_POINT_is_at_infinity(group, point)) {
+        ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES,
+              EC_R_POINT_AT_INFINITY);
+        return 0;
+    }
+
+    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 err;
+
+    /* transform  (X, Y, Z)  into  (x, y) := (X/Z^2, Y/Z^3) */
+
+    if (group->meth->field_decode) {
+        if (!group->meth->field_decode(group, Z, point->Z, ctx))
+            goto err;
+        Z_ = Z;
+    } else {
+        Z_ = point->Z;
+    }
+
+    if (BN_is_one(Z_)) {
+        if (group->meth->field_decode) {
+            if (x != NULL) {
+                if (!group->meth->field_decode(group, x, point->X, ctx))
+                    goto err;
+            }
+            if (y != NULL) {
+                if (!group->meth->field_decode(group, y, point->Y, ctx))
+                    goto err;
+            }
+        } else {
+            if (x != NULL) {
+                if (!BN_copy(x, point->X))
+                    goto err;
+            }
+            if (y != NULL) {
+                if (!BN_copy(y, point->Y))
+                    goto err;
+            }
+        }
+    } else {
+        if (!BN_mod_inverse(Z_1, Z_, group->field, ctx)) {
+            ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES,
+                  ERR_R_BN_LIB);
+            goto err;
+        }
+
+        if (group->meth->field_encode == 0) {
+            /* field_sqr works on standard representation */
+            if (!group->meth->field_sqr(group, Z_2, Z_1, ctx))
+                goto err;
+        } else {
+            if (!BN_mod_sqr(Z_2, Z_1, group->field, ctx))
+                goto err;
+        }
+
+        if (x != NULL) {
+            /*
+             * in the Montgomery case, field_mul will cancel out Montgomery
+             * factor in X:
+             */
+            if (!group->meth->field_mul(group, x, point->X, Z_2, ctx))
+                goto err;
+        }
+
+        if (y != NULL) {
+            if (group->meth->field_encode == 0) {
+                /*
+                 * field_mul works on standard representation
+                 */
+                if (!group->meth->field_mul(group, Z_3, Z_2, Z_1, ctx))
+                    goto err;
+            } else {
+                if (!BN_mod_mul(Z_3, Z_2, Z_1, group->field, ctx))
+                    goto err;
+            }
+
+            /*
+             * in the Montgomery case, field_mul will cancel out Montgomery
+             * factor in Y:
+             */
+            if (!group->meth->field_mul(group, y, point->Y, Z_3, ctx))
+                goto err;
+        }
+    }
+
+    ret = 1;
 
  err:
-       BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
-
-
-size_t ec_GFp_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,
-       unsigned char *buf, size_t len, BN_CTX *ctx)
-       {
-       size_t ret;
-       BN_CTX *new_ctx = NULL;
-       int used_ctx = 0;
-       BIGNUM *x, *y;
-       size_t field_len, i, skip;
-
-       if ((form != POINT_CONVERSION_COMPRESSED)
-               && (form != POINT_CONVERSION_UNCOMPRESSED)
-               && (form != POINT_CONVERSION_HYBRID))
-               {
-               ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
-               goto err;
-               }
-
-       if (EC_POINT_is_at_infinity(group, point))
-               {
-               /* encodes to a single 0 octet */
-               if (buf != NULL)
-                       {
-                       if (len < 1)
-                               {
-                               ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
-                               return 0;
-                               }
-                       buf[0] = 0;
-                       }
-               return 1;
-               }
-
-
-       /* ret := required output buffer length */
-       field_len = BN_num_bytes(&group->field);
-       ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
-       /* if 'buf' is NULL, just return required length */
-       if (buf != NULL)
-               {
-               if (len < ret)
-                       {
-                       ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
-                       goto err;
-                       }
-
-               if (ctx == NULL)
-                       {
-                       ctx = new_ctx = BN_CTX_new();
-                       if (ctx == NULL)
-                               return 0;
-                       }
-
-               BN_CTX_start(ctx);
-               used_ctx = 1;
-               x = BN_CTX_get(ctx);
-               y = BN_CTX_get(ctx);
-               if (y == NULL) goto err;
-
-               if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
-
-               if ((form == POINT_CONVERSION_COMPRESSED || form == POINT_CONVERSION_HYBRID) && BN_is_odd(y))
-                       buf[0] = form + 1;
-               else
-                       buf[0] = form;
-       
-               i = 1;
-               
-               skip = field_len - BN_num_bytes(x);
-               if (skip > field_len)
-                       {
-                       ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-                       goto err;
-                       }
-               while (skip > 0)
-                       {
-                       buf[i++] = 0;
-                       skip--;
-                       }
-               skip = BN_bn2bin(x, buf + i);
-               i += skip;
-               if (i != 1 + field_len)
-                       {
-                       ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-                       goto err;
-                       }
-
-               if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)
-                       {
-                       skip = field_len - BN_num_bytes(y);
-                       if (skip > field_len)
-                               {
-                               ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-                               goto err;
-                               }
-                       while (skip > 0)
-                               {
-                               buf[i++] = 0;
-                               skip--;
-                               }
-                       skip = BN_bn2bin(y, buf + i);
-                       i += skip;
-                       }
-
-               if (i != ret)
-                       {
-                       ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
-                       goto err;
-                       }
-               }
-       
-       if (used_ctx)
-               BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-
- err:
-       if (used_ctx)
-               BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return 0;
-       }
-
-
-int ec_GFp_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
-       const unsigned char *buf, size_t len, BN_CTX *ctx)
-       {
-       point_conversion_form_t form;
-       int y_bit;
-       BN_CTX *new_ctx = NULL;
-       BIGNUM *x, *y;
-       size_t field_len, enc_len;
-       int ret = 0;
-
-       if (len == 0)
-               {
-               ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
-               return 0;
-               }
-       form = buf[0];
-       y_bit = form & 1;
-       form = form & ~1;
-       if ((form != 0) && (form != POINT_CONVERSION_COMPRESSED)
-               && (form != POINT_CONVERSION_UNCOMPRESSED)
-               && (form != POINT_CONVERSION_HYBRID))
-               {
-               ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-               return 0;
-               }
-       if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit)
-               {
-               ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-               return 0;
-               }
-
-       if (form == 0)
-               {
-               if (len != 1)
-                       {
-                       ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-                       return 0;
-                       }
-
-               return EC_POINT_set_to_infinity(group, point);
-               }
-       
-       field_len = BN_num_bytes(&group->field);
-       enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
-
-       if (len != enc_len)
-               {
-               ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-               return 0;
-               }
-
-       if (ctx == NULL)
-               {
-               ctx = new_ctx = BN_CTX_new();
-               if (ctx == NULL)
-                       return 0;
-               }
-
-       BN_CTX_start(ctx);
-       x = BN_CTX_get(ctx);
-       y = BN_CTX_get(ctx);
-       if (y == NULL) goto err;
-
-       if (!BN_bin2bn(buf + 1, field_len, x)) goto err;
-       if (BN_ucmp(x, &group->field) >= 0)
-               {
-               ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-               goto err;
-               }
-
-       if (form == POINT_CONVERSION_COMPRESSED)
-               {
-               if (!EC_POINT_set_compressed_coordinates_GFp(group, point, x, y_bit, ctx)) goto err;
-               }
-       else
-               {
-               if (!BN_bin2bn(buf + 1 + field_len, field_len, y)) goto err;
-               if (BN_ucmp(y, &group->field) >= 0)
-                       {
-                       ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-                       goto err;
-                       }
-               if (form == POINT_CONVERSION_HYBRID)
-                       {
-                       if (y_bit != BN_is_odd(y))
-                               {
-                               ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
-                               goto err;
-                               }
-                       }
-
-               if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
-               }
-       
-       if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62 */
-               {
-               ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
-               goto err;
-               }
-
-       ret = 1;
-       
- err:
-       BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
-
-
-int ec_GFp_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, const EC_POINT *b, 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 *n0, *n1, *n2, *n3, *n4, *n5, *n6;
-       int ret = 0;
-       
-       if (a == b)
-               return EC_POINT_dbl(group, r, a, ctx);
-       if (EC_POINT_is_at_infinity(group, a))
-               return EC_POINT_copy(r, b);
-       if (EC_POINT_is_at_infinity(group, b))
-               return EC_POINT_copy(r, a);
-       
-       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);
-       n0 = BN_CTX_get(ctx);
-       n1 = BN_CTX_get(ctx);
-       n2 = BN_CTX_get(ctx);
-       n3 = BN_CTX_get(ctx);
-       n4 = BN_CTX_get(ctx);
-       n5 = BN_CTX_get(ctx);
-       n6 = BN_CTX_get(ctx);
-       if (n6 == NULL) goto end;
-
-       /* Note that in this function we must not read components of 'a' or 'b'
-        * once we have written the corresponding components of 'r'.
-        * ('r' might be one of 'a' or 'b'.)
-        */
-
-       /* n1, n2 */
-       if (b->Z_is_one)
-               {
-               if (!BN_copy(n1, &a->X)) goto end;
-               if (!BN_copy(n2, &a->Y)) goto end;
-               /* n1 = X_a */
-               /* n2 = Y_a */
-               }
-       else
-               {
-               if (!field_sqr(group, n0, &b->Z, ctx)) goto end;
-               if (!field_mul(group, n1, &a->X, n0, ctx)) goto end;
-               /* n1 = X_a * Z_b^2 */
-
-               if (!field_mul(group, n0, n0, &b->Z, ctx)) goto end;
-               if (!field_mul(group, n2, &a->Y, n0, ctx)) goto end;
-               /* n2 = Y_a * Z_b^3 */
-               }
-
-       /* n3, n4 */
-       if (a->Z_is_one)
-               {
-               if (!BN_copy(n3, &b->X)) goto end;
-               if (!BN_copy(n4, &b->Y)) goto end;
-               /* n3 = X_b */
-               /* n4 = Y_b */
-               }
-       else
-               {
-               if (!field_sqr(group, n0, &a->Z, ctx)) goto end;
-               if (!field_mul(group, n3, &b->X, n0, ctx)) goto end;
-               /* n3 = X_b * Z_a^2 */
-
-               if (!field_mul(group, n0, n0, &a->Z, ctx)) goto end;
-               if (!field_mul(group, n4, &b->Y, n0, ctx)) goto end;
-               /* n4 = Y_b * Z_a^3 */
-               }
-
-       /* n5, n6 */
-       if (!BN_mod_sub_quick(n5, n1, n3, p)) goto end;
-       if (!BN_mod_sub_quick(n6, n2, n4, p)) goto end;
-       /* n5 = n1 - n3 */
-       /* n6 = n2 - n4 */
-
-       if (BN_is_zero(n5))
-               {
-               if (BN_is_zero(n6))
-                       {
-                       /* a is the same point as b */
-                       BN_CTX_end(ctx);
-                       ret = EC_POINT_dbl(group, r, a, ctx);
-                       ctx = NULL;
-                       goto end;
-                       }
-               else
-                       {
-                       /* a is the inverse of b */
-                       if (!BN_zero(&r->Z)) goto end;
-                       r->Z_is_one = 0;
-                       ret = 1;
-                       goto end;
-                       }
-               }
-
-       /* 'n7', 'n8' */
-       if (!BN_mod_add_quick(n1, n1, n3, p)) goto end;
-       if (!BN_mod_add_quick(n2, n2, n4, p)) goto end;
-       /* 'n7' = n1 + n3 */
-       /* 'n8' = n2 + n4 */
-
-       /* Z_r */
-       if (a->Z_is_one && b->Z_is_one)
-               {
-               if (!BN_copy(&r->Z, n5)) goto end;
-               }
-       else
-               {
-               if (a->Z_is_one)
-                       { if (!BN_copy(n0, &b->Z)) goto end; }
-               else if (b->Z_is_one)
-                       { if (!BN_copy(n0, &a->Z)) goto end; }
-               else
-                       { if (!field_mul(group, n0, &a->Z, &b->Z, ctx)) goto end; }
-               if (!field_mul(group, &r->Z, n0, n5, ctx)) goto end;
-               }
-       r->Z_is_one = 0;
-       /* Z_r = Z_a * Z_b * n5 */
-
-       /* X_r */
-       if (!field_sqr(group, n0, n6, ctx)) goto end;
-       if (!field_sqr(group, n4, n5, ctx)) goto end;
-       if (!field_mul(group, n3, n1, n4, ctx)) goto end;
-       if (!BN_mod_sub_quick(&r->X, n0, n3, p)) goto end;
-       /* X_r = n6^2 - n5^2 * 'n7' */
-       
-       /* 'n9' */
-       if (!BN_mod_lshift1_quick(n0, &r->X, p)) goto end;
-       if (!BN_mod_sub_quick(n0, n3, n0, p)) goto end;
-       /* n9 = n5^2 * 'n7' - 2 * X_r */
-
-       /* Y_r */
-       if (!field_mul(group, n0, n0, n6, ctx)) goto end;
-       if (!field_mul(group, n5, n4, n5, ctx)) goto end; /* now n5 is n5^3 */
-       if (!field_mul(group, n1, n2, n5, ctx)) goto end;
-       if (!BN_mod_sub_quick(n0, n0, n1, p)) goto end;
-       if (BN_is_odd(n0))
-               if (!BN_add(n0, n0, p)) goto end;
-       /* now  0 <= n0 < 2*p,  and n0 is even */
-       if (!BN_rshift1(&r->Y, n0)) goto end;
-       /* Y_r = (n6 * 'n9' - 'n8' * 'n5^3') / 2 */
-
-       ret = 1;
+    BN_CTX_end(ctx);
+    BN_CTX_free(new_ctx);
+    return ret;
+}
+
+int ec_GFp_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
+                      const EC_POINT *b, 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 *n0, *n1, *n2, *n3, *n4, *n5, *n6;
+    int ret = 0;
+
+    if (a == b)
+        return EC_POINT_dbl(group, r, a, ctx);
+    if (EC_POINT_is_at_infinity(group, a))
+        return EC_POINT_copy(r, b);
+    if (EC_POINT_is_at_infinity(group, b))
+        return EC_POINT_copy(r, a);
+
+    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);
+    n0 = BN_CTX_get(ctx);
+    n1 = BN_CTX_get(ctx);
+    n2 = BN_CTX_get(ctx);
+    n3 = BN_CTX_get(ctx);
+    n4 = BN_CTX_get(ctx);
+    n5 = BN_CTX_get(ctx);
+    n6 = BN_CTX_get(ctx);
+    if (n6 == NULL)
+        goto end;
+
+    /*
+     * Note that in this function we must not read components of 'a' or 'b'
+     * once we have written the corresponding components of 'r'. ('r' might
+     * be one of 'a' or 'b'.)
+     */
+
+    /* n1, n2 */
+    if (b->Z_is_one) {
+        if (!BN_copy(n1, a->X))
+            goto end;
+        if (!BN_copy(n2, a->Y))
+            goto end;
+        /* n1 = X_a */
+        /* n2 = Y_a */
+    } else {
+        if (!field_sqr(group, n0, b->Z, ctx))
+            goto end;
+        if (!field_mul(group, n1, a->X, n0, ctx))
+            goto end;
+        /* n1 = X_a * Z_b^2 */
+
+        if (!field_mul(group, n0, n0, b->Z, ctx))
+            goto end;
+        if (!field_mul(group, n2, a->Y, n0, ctx))
+            goto end;
+        /* n2 = Y_a * Z_b^3 */
+    }
+
+    /* n3, n4 */
+    if (a->Z_is_one) {
+        if (!BN_copy(n3, b->X))
+            goto end;
+        if (!BN_copy(n4, b->Y))
+            goto end;
+        /* n3 = X_b */
+        /* n4 = Y_b */
+    } else {
+        if (!field_sqr(group, n0, a->Z, ctx))
+            goto end;
+        if (!field_mul(group, n3, b->X, n0, ctx))
+            goto end;
+        /* n3 = X_b * Z_a^2 */
+
+        if (!field_mul(group, n0, n0, a->Z, ctx))
+            goto end;
+        if (!field_mul(group, n4, b->Y, n0, ctx))
+            goto end;
+        /* n4 = Y_b * Z_a^3 */
+    }
+
+    /* n5, n6 */
+    if (!BN_mod_sub_quick(n5, n1, n3, p))
+        goto end;
+    if (!BN_mod_sub_quick(n6, n2, n4, p))
+        goto end;
+    /* n5 = n1 - n3 */
+    /* n6 = n2 - n4 */
+
+    if (BN_is_zero(n5)) {
+        if (BN_is_zero(n6)) {
+            /* a is the same point as b */
+            BN_CTX_end(ctx);
+            ret = EC_POINT_dbl(group, r, a, ctx);
+            ctx = NULL;
+            goto end;
+        } else {
+            /* a is the inverse of b */
+            BN_zero(r->Z);
+            r->Z_is_one = 0;
+            ret = 1;
+            goto end;
+        }
+    }
+
+    /* 'n7', 'n8' */
+    if (!BN_mod_add_quick(n1, n1, n3, p))
+        goto end;
+    if (!BN_mod_add_quick(n2, n2, n4, p))
+        goto end;
+    /* 'n7' = n1 + n3 */
+    /* 'n8' = n2 + n4 */
+
+    /* Z_r */
+    if (a->Z_is_one && b->Z_is_one) {
+        if (!BN_copy(r->Z, n5))
+            goto end;
+    } else {
+        if (a->Z_is_one) {
+            if (!BN_copy(n0, b->Z))
+                goto end;
+        } else if (b->Z_is_one) {
+            if (!BN_copy(n0, a->Z))
+                goto end;
+        } else {
+            if (!field_mul(group, n0, a->Z, b->Z, ctx))
+                goto end;
+        }
+        if (!field_mul(group, r->Z, n0, n5, ctx))
+            goto end;
+    }
+    r->Z_is_one = 0;
+    /* Z_r = Z_a * Z_b * n5 */
+
+    /* X_r */
+    if (!field_sqr(group, n0, n6, ctx))
+        goto end;
+    if (!field_sqr(group, n4, n5, ctx))
+        goto end;
+    if (!field_mul(group, n3, n1, n4, ctx))
+        goto end;
+    if (!BN_mod_sub_quick(r->X, n0, n3, p))
+        goto end;
+    /* X_r = n6^2 - n5^2 * 'n7' */
+
+    /* 'n9' */
+    if (!BN_mod_lshift1_quick(n0, r->X, p))
+        goto end;
+    if (!BN_mod_sub_quick(n0, n3, n0, p))
+        goto end;
+    /* n9 = n5^2 * 'n7' - 2 * X_r */
+
+    /* Y_r */
+    if (!field_mul(group, n0, n0, n6, ctx))
+        goto end;
+    if (!field_mul(group, n5, n4, n5, ctx))
+        goto end;               /* now n5 is n5^3 */
+    if (!field_mul(group, n1, n2, n5, ctx))
+        goto end;
+    if (!BN_mod_sub_quick(n0, n0, n1, p))
+        goto end;
+    if (BN_is_odd(n0))
+        if (!BN_add(n0, n0, p))
+            goto end;
+    /* now  0 <= n0 < 2*p,  and n0 is even */
+    if (!BN_rshift1(r->Y, n0))
+        goto end;
+    /* Y_r = (n6 * 'n9' - 'n8' * 'n5^3') / 2 */
+
+    ret = 1;
 
  end:
-       if (ctx) /* otherwise we already called BN_CTX_end */
-               BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
-
-
-int ec_GFp_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, 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 *n0, *n1, *n2, *n3;
-       int ret = 0;
-       
-       if (EC_POINT_is_at_infinity(group, a))
-               {
-               if (!BN_zero(&r->Z)) return 0;
-               r->Z_is_one = 0;
-               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);
-       n0 = BN_CTX_get(ctx);
-       n1 = BN_CTX_get(ctx);
-       n2 = BN_CTX_get(ctx);
-       n3 = BN_CTX_get(ctx);
-       if (n3 == NULL) goto err;
-
-       /* Note that in this function we must not read components of 'a'
-        * once we have written the corresponding components of 'r'.
-        * ('r' might the same as 'a'.)
-        */
-
-       /* n1 */
-       if (a->Z_is_one)
-               {
-               if (!field_sqr(group, n0, &a->X, ctx)) goto err;
-               if (!BN_mod_lshift1_quick(n1, n0, p)) goto err;
-               if (!BN_mod_add_quick(n0, n0, n1, p)) goto err;
-               if (!BN_mod_add_quick(n1, n0, &group->a, p)) goto err;
-               /* n1 = 3 * X_a^2 + a_curve */
-               }
-       else if (group->a_is_minus3)
-               {
-               if (!field_sqr(group, n1, &a->Z, ctx)) goto err;
-               if (!BN_mod_add_quick(n0, &a->X, n1, p)) goto err;
-               if (!BN_mod_sub_quick(n2, &a->X, n1, p)) goto err;
-               if (!field_mul(group, n1, n0, n2, ctx)) goto err;
-               if (!BN_mod_lshift1_quick(n0, n1, p)) goto err;
-               if (!BN_mod_add_quick(n1, n0, n1, p)) goto err;
-               /* n1 = 3 * (X_a + Z_a^2) * (X_a - Z_a^2)
-                *    = 3 * X_a^2 - 3 * Z_a^4 */
-               }
-       else
-               {
-               if (!field_sqr(group, n0, &a->X, ctx)) goto err;
-               if (!BN_mod_lshift1_quick(n1, n0, p)) goto err;
-               if (!BN_mod_add_quick(n0, n0, n1, p)) goto err;
-               if (!field_sqr(group, n1, &a->Z, ctx)) goto err;
-               if (!field_sqr(group, n1, n1, ctx)) goto err;
-               if (!field_mul(group, n1, n1, &group->a, ctx)) goto err;
-               if (!BN_mod_add_quick(n1, n1, n0, p)) goto err;
-               /* n1 = 3 * X_a^2 + a_curve * Z_a^4 */
-               }
-
-       /* Z_r */
-       if (a->Z_is_one)
-               {
-               if (!BN_copy(n0, &a->Y)) goto err;
-               }
-       else
-               {
-               if (!field_mul(group, n0, &a->Y, &a->Z, ctx)) goto err;
-               }
-       if (!BN_mod_lshift1_quick(&r->Z, n0, p)) goto err;
-       r->Z_is_one = 0;
-       /* Z_r = 2 * Y_a * Z_a */
-
-       /* n2 */
-       if (!field_sqr(group, n3, &a->Y, ctx)) goto err;
-       if (!field_mul(group, n2, &a->X, n3, ctx)) goto err;
-       if (!BN_mod_lshift_quick(n2, n2, 2, p)) goto err;
-       /* n2 = 4 * X_a * Y_a^2 */
-
-       /* X_r */
-       if (!BN_mod_lshift1_quick(n0, n2, p)) goto err;
-       if (!field_sqr(group, &r->X, n1, ctx)) goto err;
-       if (!BN_mod_sub_quick(&r->X, &r->X, n0, p)) goto err;
-       /* X_r = n1^2 - 2 * n2 */
-       
-       /* n3 */
-       if (!field_sqr(group, n0, n3, ctx)) goto err;
-       if (!BN_mod_lshift_quick(n3, n0, 3, p)) goto err;
-       /* n3 = 8 * Y_a^4 */
-       
-       /* Y_r */
-       if (!BN_mod_sub_quick(n0, n2, &r->X, p)) goto err;
-       if (!field_mul(group, n0, n1, n0, ctx)) goto err;
-       if (!BN_mod_sub_quick(&r->Y, n0, n3, p)) goto err;
-       /* Y_r = n1 * (n2 - X_r) - n3 */
-
-       ret = 1;
+    if (ctx)                    /* otherwise we already called BN_CTX_end */
+        BN_CTX_end(ctx);
+    BN_CTX_free(new_ctx);
+    return ret;
+}
+
+int ec_GFp_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
+                      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 *n0, *n1, *n2, *n3;
+    int ret = 0;
+
+    if (EC_POINT_is_at_infinity(group, a)) {
+        BN_zero(r->Z);
+        r->Z_is_one = 0;
+        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);
+    n0 = BN_CTX_get(ctx);
+    n1 = BN_CTX_get(ctx);
+    n2 = BN_CTX_get(ctx);
+    n3 = BN_CTX_get(ctx);
+    if (n3 == NULL)
+        goto err;
+
+    /*
+     * Note that in this function we must not read components of 'a' once we
+     * have written the corresponding components of 'r'. ('r' might the same
+     * as 'a'.)
+     */
+
+    /* n1 */
+    if (a->Z_is_one) {
+        if (!field_sqr(group, n0, a->X, ctx))
+            goto err;
+        if (!BN_mod_lshift1_quick(n1, n0, p))
+            goto err;
+        if (!BN_mod_add_quick(n0, n0, n1, p))
+            goto err;
+        if (!BN_mod_add_quick(n1, n0, group->a, p))
+            goto err;
+        /* n1 = 3 * X_a^2 + a_curve */
+    } else if (group->a_is_minus3) {
+        if (!field_sqr(group, n1, a->Z, ctx))
+            goto err;
+        if (!BN_mod_add_quick(n0, a->X, n1, p))
+            goto err;
+        if (!BN_mod_sub_quick(n2, a->X, n1, p))
+            goto err;
+        if (!field_mul(group, n1, n0, n2, ctx))
+            goto err;
+        if (!BN_mod_lshift1_quick(n0, n1, p))
+            goto err;
+        if (!BN_mod_add_quick(n1, n0, n1, p))
+            goto err;
+        /*-
+         * n1 = 3 * (X_a + Z_a^2) * (X_a - Z_a^2)
+         *    = 3 * X_a^2 - 3 * Z_a^4
+         */
+    } else {
+        if (!field_sqr(group, n0, a->X, ctx))
+            goto err;
+        if (!BN_mod_lshift1_quick(n1, n0, p))
+            goto err;
+        if (!BN_mod_add_quick(n0, n0, n1, p))
+            goto err;
+        if (!field_sqr(group, n1, a->Z, ctx))
+            goto err;
+        if (!field_sqr(group, n1, n1, ctx))
+            goto err;
+        if (!field_mul(group, n1, n1, group->a, ctx))
+            goto err;
+        if (!BN_mod_add_quick(n1, n1, n0, p))
+            goto err;
+        /* n1 = 3 * X_a^2 + a_curve * Z_a^4 */
+    }
+
+    /* Z_r */
+    if (a->Z_is_one) {
+        if (!BN_copy(n0, a->Y))
+            goto err;
+    } else {
+        if (!field_mul(group, n0, a->Y, a->Z, ctx))
+            goto err;
+    }
+    if (!BN_mod_lshift1_quick(r->Z, n0, p))
+        goto err;
+    r->Z_is_one = 0;
+    /* Z_r = 2 * Y_a * Z_a */
+
+    /* n2 */
+    if (!field_sqr(group, n3, a->Y, ctx))
+        goto err;
+    if (!field_mul(group, n2, a->X, n3, ctx))
+        goto err;
+    if (!BN_mod_lshift_quick(n2, n2, 2, p))
+        goto err;
+    /* n2 = 4 * X_a * Y_a^2 */
+
+    /* X_r */
+    if (!BN_mod_lshift1_quick(n0, n2, p))
+        goto err;
+    if (!field_sqr(group, r->X, n1, ctx))
+        goto err;
+    if (!BN_mod_sub_quick(r->X, r->X, n0, p))
+        goto err;
+    /* X_r = n1^2 - 2 * n2 */
+
+    /* n3 */
+    if (!field_sqr(group, n0, n3, ctx))
+        goto err;
+    if (!BN_mod_lshift_quick(n3, n0, 3, p))
+        goto err;
+    /* n3 = 8 * Y_a^4 */
+
+    /* Y_r */
+    if (!BN_mod_sub_quick(n0, n2, r->X, p))
+        goto err;
+    if (!field_mul(group, n0, n1, n0, ctx))
+        goto err;
+    if (!BN_mod_sub_quick(r->Y, n0, n3, p))
+        goto err;
+    /* Y_r = n1 * (n2 - X_r) - n3 */
+
+    ret = 1;
 
  err:
-       BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
-
+    BN_CTX_end(ctx);
+    BN_CTX_free(new_ctx);
+    return ret;
+}
 
 int ec_GFp_simple_invert(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
-       {
-       if (EC_POINT_is_at_infinity(group, point) || BN_is_zero(&point->Y))
-               /* point is its own inverse */
-               return 1;
-       
-       return BN_usub(&point->Y, &group->field, &point->Y);
-       }
+{
+    if (EC_POINT_is_at_infinity(group, point) || BN_is_zero(point->Y))
+        /* point is its own inverse */
+        return 1;
 
+    return BN_usub(point->Y, group->field, point->Y);
+}
 
 int ec_GFp_simple_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
-       {
-       return BN_is_zero(&point->Z);
-       }
-
-
-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 -1;
-               }
-
-       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));
+{
+    return BN_is_zero(point->Z);
+}
+
+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, *tmp, *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 -1;
+    }
+
+    BN_CTX_start(ctx);
+    rh = BN_CTX_get(ctx);
+    tmp = 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^2 */
+    if (!field_sqr(group, rh, point->X, ctx))
+        goto err;
+
+    if (!point->Z_is_one) {
+        if (!field_sqr(group, tmp, point->Z, ctx))
+            goto err;
+        if (!field_sqr(group, Z4, tmp, ctx))
+            goto err;
+        if (!field_mul(group, Z6, Z4, tmp, ctx))
+            goto err;
+
+        /* rh := (rh + a*Z^4)*X */
+        if (group->a_is_minus3) {
+            if (!BN_mod_lshift1_quick(tmp, Z4, p))
+                goto err;
+            if (!BN_mod_add_quick(tmp, tmp, Z4, p))
+                goto err;
+            if (!BN_mod_sub_quick(rh, rh, tmp, p))
+                goto err;
+            if (!field_mul(group, rh, rh, point->X, ctx))
+                goto err;
+        } else {
+            if (!field_mul(group, tmp, Z4, group->a, ctx))
+                goto err;
+            if (!BN_mod_add_quick(rh, rh, tmp, p))
+                goto err;
+            if (!field_mul(group, rh, rh, point->X, ctx))
+                goto err;
+        }
+
+        /* rh := rh + b*Z^6 */
+        if (!field_mul(group, tmp, group->b, Z6, ctx))
+            goto err;
+        if (!BN_mod_add_quick(rh, rh, tmp, p))
+            goto err;
+    } else {
+        /* point->Z_is_one */
+
+        /* rh := (rh + a)*X */
+        if (!BN_mod_add_quick(rh, rh, group->a, p))
+            goto err;
+        if (!field_mul(group, rh, rh, point->X, ctx))
+            goto err;
+        /* rh := rh + b */
+        if (!BN_mod_add_quick(rh, rh, group->b, p))
+            goto err;
+    }
+
+    /* 'lh' := Y^2 */
+    if (!field_sqr(group, tmp, point->Y, ctx))
+        goto err;
+
+    ret = (0 == BN_ucmp(tmp, rh));
 
  err:
-       BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
-
-
-int ec_GFp_simple_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)
-       {
-       /* return values:
-        *  -1   error
-        *   0   equal (in affine coordinates)
-        *   1   not equal
-        */
-
-       int (*field_mul)(const EC_GROUP *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
-       int (*field_sqr)(const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
-       BN_CTX *new_ctx = NULL;
-       BIGNUM *tmp1, *tmp2, *Za23, *Zb23;
-       const BIGNUM *tmp1_, *tmp2_;
-       int ret = -1;
-       
-       if (EC_POINT_is_at_infinity(group, a))
-               {
-               return EC_POINT_is_at_infinity(group, b) ? 0 : 1;
-               }
-       
-       if (a->Z_is_one && b->Z_is_one)
-               {
-               return ((BN_cmp(&a->X, &b->X) == 0) && BN_cmp(&a->Y, &b->Y) == 0) ? 0 : 1;
-               }
-
-       field_mul = group->meth->field_mul;
-       field_sqr = group->meth->field_sqr;
-
-       if (ctx == NULL)
-               {
-               ctx = new_ctx = BN_CTX_new();
-               if (ctx == NULL)
-                       return -1;
-               }
-
-       BN_CTX_start(ctx);
-       tmp1 = BN_CTX_get(ctx);
-       tmp2 = BN_CTX_get(ctx);
-       Za23 = BN_CTX_get(ctx);
-       Zb23 = BN_CTX_get(ctx);
-       if (Zb23 == NULL) goto end;
-
-       /* We have to decide whether
-        *     (X_a/Z_a^2, Y_a/Z_a^3) = (X_b/Z_b^2, Y_b/Z_b^3),
-        * or equivalently, whether
-        *     (X_a*Z_b^2, Y_a*Z_b^3) = (X_b*Z_a^2, Y_b*Z_a^3).
-        */
-
-       if (!b->Z_is_one)
-               {
-               if (!field_sqr(group, Zb23, &b->Z, ctx)) goto end;
-               if (!field_mul(group, tmp1, &a->X, Zb23, ctx)) goto end;
-               tmp1_ = tmp1;
-               }
-       else
-               tmp1_ = &a->X;
-       if (!a->Z_is_one)
-               {
-               if (!field_sqr(group, Za23, &a->Z, ctx)) goto end;
-               if (!field_mul(group, tmp2, &b->X, Za23, ctx)) goto end;
-               tmp2_ = tmp2;
-               }
-       else
-               tmp2_ = &b->X;
-       
-       /* compare  X_a*Z_b^2  with  X_b*Z_a^2 */
-       if (BN_cmp(tmp1_, tmp2_) != 0)
-               {
-               ret = 1; /* points differ */
-               goto end;
-               }
-
-
-       if (!b->Z_is_one)
-               {
-               if (!field_mul(group, Zb23, Zb23, &b->Z, ctx)) goto end;
-               if (!field_mul(group, tmp1, &a->Y, Zb23, ctx)) goto end;
-               /* tmp1_ = tmp1 */
-               }
-       else
-               tmp1_ = &a->Y;
-       if (!a->Z_is_one)
-               {
-               if (!field_mul(group, Za23, Za23, &a->Z, ctx)) goto end;
-               if (!field_mul(group, tmp2, &b->Y, Za23, ctx)) goto end;
-               /* tmp2_ = tmp2 */
-               }
-       else
-               tmp2_ = &b->Y;
-
-       /* compare  Y_a*Z_b^3  with  Y_b*Z_a^3 */
-       if (BN_cmp(tmp1_, tmp2_) != 0)
-               {
-               ret = 1; /* points differ */
-               goto end;
-               }
-
-       /* points are equal */
-       ret = 0;
+    BN_CTX_end(ctx);
+    BN_CTX_free(new_ctx);
+    return ret;
+}
+
+int ec_GFp_simple_cmp(const EC_GROUP *group, const EC_POINT *a,
+                      const EC_POINT *b, BN_CTX *ctx)
+{
+    /*-
+     * return values:
+     *  -1   error
+     *   0   equal (in affine coordinates)
+     *   1   not equal
+     */
+
+    int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
+                      const BIGNUM *, BN_CTX *);
+    int (*field_sqr) (const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
+    BN_CTX *new_ctx = NULL;
+    BIGNUM *tmp1, *tmp2, *Za23, *Zb23;
+    const BIGNUM *tmp1_, *tmp2_;
+    int ret = -1;
+
+    if (EC_POINT_is_at_infinity(group, a)) {
+        return EC_POINT_is_at_infinity(group, b) ? 0 : 1;
+    }
+
+    if (EC_POINT_is_at_infinity(group, b))
+        return 1;
+
+    if (a->Z_is_one && b->Z_is_one) {
+        return ((BN_cmp(a->X, b->X) == 0) && BN_cmp(a->Y, b->Y) == 0) ? 0 : 1;
+    }
+
+    field_mul = group->meth->field_mul;
+    field_sqr = group->meth->field_sqr;
+
+    if (ctx == NULL) {
+        ctx = new_ctx = BN_CTX_new();
+        if (ctx == NULL)
+            return -1;
+    }
+
+    BN_CTX_start(ctx);
+    tmp1 = BN_CTX_get(ctx);
+    tmp2 = BN_CTX_get(ctx);
+    Za23 = BN_CTX_get(ctx);
+    Zb23 = BN_CTX_get(ctx);
+    if (Zb23 == NULL)
+        goto end;
+
+    /*-
+     * We have to decide whether
+     *     (X_a/Z_a^2, Y_a/Z_a^3) = (X_b/Z_b^2, Y_b/Z_b^3),
+     * or equivalently, whether
+     *     (X_a*Z_b^2, Y_a*Z_b^3) = (X_b*Z_a^2, Y_b*Z_a^3).
+     */
+
+    if (!b->Z_is_one) {
+        if (!field_sqr(group, Zb23, b->Z, ctx))
+            goto end;
+        if (!field_mul(group, tmp1, a->X, Zb23, ctx))
+            goto end;
+        tmp1_ = tmp1;
+    } else
+        tmp1_ = a->X;
+    if (!a->Z_is_one) {
+        if (!field_sqr(group, Za23, a->Z, ctx))
+            goto end;
+        if (!field_mul(group, tmp2, b->X, Za23, ctx))
+            goto end;
+        tmp2_ = tmp2;
+    } else
+        tmp2_ = b->X;
+
+    /* compare  X_a*Z_b^2  with  X_b*Z_a^2 */
+    if (BN_cmp(tmp1_, tmp2_) != 0) {
+        ret = 1;                /* points differ */
+        goto end;
+    }
+
+    if (!b->Z_is_one) {
+        if (!field_mul(group, Zb23, Zb23, b->Z, ctx))
+            goto end;
+        if (!field_mul(group, tmp1, a->Y, Zb23, ctx))
+            goto end;
+        /* tmp1_ = tmp1 */
+    } else
+        tmp1_ = a->Y;
+    if (!a->Z_is_one) {
+        if (!field_mul(group, Za23, Za23, a->Z, ctx))
+            goto end;
+        if (!field_mul(group, tmp2, b->Y, Za23, ctx))
+            goto end;
+        /* tmp2_ = tmp2 */
+    } else
+        tmp2_ = b->Y;
+
+    /* compare  Y_a*Z_b^3  with  Y_b*Z_a^3 */
+    if (BN_cmp(tmp1_, tmp2_) != 0) {
+        ret = 1;                /* points differ */
+        goto end;
+    }
+
+    /* points are equal */
+    ret = 0;
 
  end:
-       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, EC_POINT *point, BN_CTX *ctx)
-       {
-       BN_CTX *new_ctx = NULL;
-       BIGNUM *x, *y;
-       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);
-       x = BN_CTX_get(ctx);
-       y = BN_CTX_get(ctx);
-       if (y == NULL) goto err;
-
-       if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
-       if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
-       if (!point->Z_is_one)
-               {
-               ECerr(EC_F_EC_GFP_SIMPLE_MAKE_AFFINE, ERR_R_INTERNAL_ERROR);
-               goto err;
-               }
-       
-       ret = 1;
+    BN_CTX_end(ctx);
+    BN_CTX_free(new_ctx);
+    return ret;
+}
+
+int ec_GFp_simple_make_affine(const EC_GROUP *group, EC_POINT *point,
+                              BN_CTX *ctx)
+{
+    BN_CTX *new_ctx = NULL;
+    BIGNUM *x, *y;
+    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);
+    x = BN_CTX_get(ctx);
+    y = BN_CTX_get(ctx);
+    if (y == NULL)
+        goto err;
+
+    if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx))
+        goto err;
+    if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx))
+        goto err;
+    if (!point->Z_is_one) {
+        ECerr(EC_F_EC_GFP_SIMPLE_MAKE_AFFINE, ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    ret = 1;
 
  err:
-       BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       return ret;
-       }
-
-
-int ec_GFp_simple_points_make_affine(const EC_GROUP *group, size_t num, EC_POINT *points[], BN_CTX *ctx)
-       {
-       BN_CTX *new_ctx = NULL;
-       BIGNUM *tmp0, *tmp1;
-       size_t pow2 = 0;
-       BIGNUM **heap = NULL;
-       size_t i;
-       int ret = 0;
-
-       if (num == 0)
-               return 1;
-
-       if (ctx == NULL)
-               {
-               ctx = new_ctx = BN_CTX_new();
-               if (ctx == NULL)
-                       return 0;
-               }
-
-       BN_CTX_start(ctx);
-       tmp0 = BN_CTX_get(ctx);
-       tmp1 = BN_CTX_get(ctx);
-       if (tmp0  == NULL || tmp1 == NULL) goto err;
-
-       /* Before converting the individual points, compute inverses of all Z values.
-        * Modular inversion is rather slow, but luckily we can do with a single
-        * explicit inversion, plus about 3 multiplications per input value.
-        */
-
-       pow2 = 1;
-       while (num > pow2)
-               pow2 <<= 1;
-       /* Now pow2 is the smallest power of 2 satifsying pow2 >= num.
-        * We need twice that. */
-       pow2 <<= 1;
-
-       heap = OPENSSL_malloc(pow2 * sizeof heap[0]);
-       if (heap == NULL) goto err;
-       
-       /* The array is used as a binary tree, exactly as in heapsort:
-        *
-        *                               heap[1]
-        *                 heap[2]                     heap[3]
-        *          heap[4]       heap[5]       heap[6]       heap[7]
-        *   heap[8]heap[9] heap[10]heap[11] heap[12]heap[13] heap[14] heap[15]
-        *
-        * We put the Z's in the last line;
-        * then we set each other node to the product of its two child-nodes (where
-        * empty or 0 entries are treated as ones);
-        * then we invert heap[1];
-        * then we invert each other node by replacing it by the product of its
-        * parent (after inversion) and its sibling (before inversion).
-        */
-       heap[0] = NULL;
-       for (i = pow2/2 - 1; i > 0; i--)
-               heap[i] = NULL;
-       for (i = 0; i < num; i++)
-               heap[pow2/2 + i] = &points[i]->Z;
-       for (i = pow2/2 + num; i < pow2; i++)
-               heap[i] = NULL;
-       
-       /* set each node to the product of its children */
-       for (i = pow2/2 - 1; i > 0; i--)
-               {
-               heap[i] = BN_new();
-               if (heap[i] == NULL) goto err;
-               
-               if (heap[2*i] != NULL)
-                       {
-                       if ((heap[2*i + 1] == NULL) || BN_is_zero(heap[2*i + 1]))
-                               {
-                               if (!BN_copy(heap[i], heap[2*i])) goto err;
-                               }
-                       else
-                               {
-                               if (BN_is_zero(heap[2*i]))
-                                       {
-                                       if (!BN_copy(heap[i], heap[2*i + 1])) goto err;
-                                       }
-                               else
-                                       {
-                                       if (!group->meth->field_mul(group, heap[i],
-                                               heap[2*i], heap[2*i + 1], ctx)) goto err;
-                                       }
-                               }
-                       }
-               }
-
-       /* invert heap[1] */
-       if (!BN_is_zero(heap[1]))
-               {
-               if (!BN_mod_inverse(heap[1], heap[1], &group->field, ctx))
-                       {
-                       ECerr(EC_F_EC_GFP_SIMPLE_POINTS_MAKE_AFFINE, ERR_R_BN_LIB);
-                       goto err;
-                       }
-               }
-       if (group->meth->field_encode != 0)
-               {
-               /* in the Montgomery case, we just turned  R*H  (representing H)
-                * into  1/(R*H),  but we need  R*(1/H)  (representing 1/H);
-                * i.e. we have need to multiply by the Montgomery factor twice */
-               if (!group->meth->field_encode(group, heap[1], heap[1], ctx)) goto err;
-               if (!group->meth->field_encode(group, heap[1], heap[1], ctx)) goto err;
-               }
-
-       /* set other heap[i]'s to their inverses */
-       for (i = 2; i < pow2/2 + num; i += 2)
-               {
-               /* i is even */
-               if ((heap[i + 1] != NULL) && !BN_is_zero(heap[i + 1]))
-                       {
-                       if (!group->meth->field_mul(group, tmp0, heap[i/2], heap[i + 1], ctx)) goto err;
-                       if (!group->meth->field_mul(group, tmp1, heap[i/2], heap[i], ctx)) goto err;
-                       if (!BN_copy(heap[i], tmp0)) goto err;
-                       if (!BN_copy(heap[i + 1], tmp1)) goto err;
-                       }
-               else
-                       {
-                       if (!BN_copy(heap[i], heap[i/2])) goto err;
-                       }
-               }
-
-       /* we have replaced all non-zero Z's by their inverses, now fix up all the points */
-       for (i = 0; i < num; i++)
-               {
-               EC_POINT *p = points[i];
-               
-               if (!BN_is_zero(&p->Z))
-                       {
-                       /* turn  (X, Y, 1/Z)  into  (X/Z^2, Y/Z^3, 1) */
-
-                       if (!group->meth->field_sqr(group, tmp1, &p->Z, ctx)) goto err;
-                       if (!group->meth->field_mul(group, &p->X, &p->X, tmp1, ctx)) goto err;
-
-                       if (!group->meth->field_mul(group, tmp1, tmp1, &p->Z, ctx)) goto err;
-                       if (!group->meth->field_mul(group, &p->Y, &p->Y, tmp1, ctx)) goto err;
-               
-                       if (group->meth->field_set_to_one != 0)
-                               {
-                               if (!group->meth->field_set_to_one(group, &p->Z, ctx)) goto err;
-                               }
-                       else
-                               {
-                               if (!BN_one(&p->Z)) goto err;
-                               }
-                       p->Z_is_one = 1;
-                       }
-               }
-
-       ret = 1;
-               
+    BN_CTX_end(ctx);
+    BN_CTX_free(new_ctx);
+    return ret;
+}
+
+int ec_GFp_simple_points_make_affine(const EC_GROUP *group, size_t num,
+                                     EC_POINT *points[], BN_CTX *ctx)
+{
+    BN_CTX *new_ctx = NULL;
+    BIGNUM *tmp, *tmp_Z;
+    BIGNUM **prod_Z = NULL;
+    size_t i;
+    int ret = 0;
+
+    if (num == 0)
+        return 1;
+
+    if (ctx == NULL) {
+        ctx = new_ctx = BN_CTX_new();
+        if (ctx == NULL)
+            return 0;
+    }
+
+    BN_CTX_start(ctx);
+    tmp = BN_CTX_get(ctx);
+    tmp_Z = BN_CTX_get(ctx);
+    if (tmp == NULL || tmp_Z == NULL)
+        goto err;
+
+    prod_Z = OPENSSL_malloc(num * sizeof prod_Z[0]);
+    if (prod_Z == NULL)
+        goto err;
+    for (i = 0; i < num; i++) {
+        prod_Z[i] = BN_new();
+        if (prod_Z[i] == NULL)
+            goto err;
+    }
+
+    /*
+     * Set each prod_Z[i] to the product of points[0]->Z .. points[i]->Z,
+     * skipping any zero-valued inputs (pretend that they're 1).
+     */
+
+    if (!BN_is_zero(points[0]->Z)) {
+        if (!BN_copy(prod_Z[0], points[0]->Z))
+            goto err;
+    } else {
+        if (group->meth->field_set_to_one != 0) {
+            if (!group->meth->field_set_to_one(group, prod_Z[0], ctx))
+                goto err;
+        } else {
+            if (!BN_one(prod_Z[0]))
+                goto err;
+        }
+    }
+
+    for (i = 1; i < num; i++) {
+        if (!BN_is_zero(points[i]->Z)) {
+            if (!group->
+                meth->field_mul(group, prod_Z[i], prod_Z[i - 1], points[i]->Z,
+                                ctx))
+                goto err;
+        } else {
+            if (!BN_copy(prod_Z[i], prod_Z[i - 1]))
+                goto err;
+        }
+    }
+
+    /*
+     * Now use a single explicit inversion to replace every non-zero
+     * points[i]->Z by its inverse.
+     */
+
+    if (!BN_mod_inverse(tmp, prod_Z[num - 1], group->field, ctx)) {
+        ECerr(EC_F_EC_GFP_SIMPLE_POINTS_MAKE_AFFINE, ERR_R_BN_LIB);
+        goto err;
+    }
+    if (group->meth->field_encode != 0) {
+        /*
+         * In the Montgomery case, we just turned R*H (representing H) into
+         * 1/(R*H), but we need R*(1/H) (representing 1/H); i.e. we need to
+         * multiply by the Montgomery factor twice.
+         */
+        if (!group->meth->field_encode(group, tmp, tmp, ctx))
+            goto err;
+        if (!group->meth->field_encode(group, tmp, tmp, ctx))
+            goto err;
+    }
+
+    for (i = num - 1; i > 0; --i) {
+        /*
+         * Loop invariant: tmp is the product of the inverses of points[0]->Z
+         * .. points[i]->Z (zero-valued inputs skipped).
+         */
+        if (!BN_is_zero(points[i]->Z)) {
+            /*
+             * Set tmp_Z to the inverse of points[i]->Z (as product of Z
+             * inverses 0 .. i, Z values 0 .. i - 1).
+             */
+            if (!group->
+                meth->field_mul(group, tmp_Z, prod_Z[i - 1], tmp, ctx))
+                goto err;
+            /*
+             * Update tmp to satisfy the loop invariant for i - 1.
+             */
+            if (!group->meth->field_mul(group, tmp, tmp, points[i]->Z, ctx))
+                goto err;
+            /* Replace points[i]->Z by its inverse. */
+            if (!BN_copy(points[i]->Z, tmp_Z))
+                goto err;
+        }
+    }
+
+    if (!BN_is_zero(points[0]->Z)) {
+        /* Replace points[0]->Z by its inverse. */
+        if (!BN_copy(points[0]->Z, tmp))
+            goto err;
+    }
+
+    /* Finally, fix up the X and Y coordinates for all points. */
+
+    for (i = 0; i < num; i++) {
+        EC_POINT *p = points[i];
+
+        if (!BN_is_zero(p->Z)) {
+            /* turn  (X, Y, 1/Z)  into  (X/Z^2, Y/Z^3, 1) */
+
+            if (!group->meth->field_sqr(group, tmp, p->Z, ctx))
+                goto err;
+            if (!group->meth->field_mul(group, p->X, p->X, tmp, ctx))
+                goto err;
+
+            if (!group->meth->field_mul(group, tmp, tmp, p->Z, ctx))
+                goto err;
+            if (!group->meth->field_mul(group, p->Y, p->Y, tmp, ctx))
+                goto err;
+
+            if (group->meth->field_set_to_one != 0) {
+                if (!group->meth->field_set_to_one(group, p->Z, ctx))
+                    goto err;
+            } else {
+                if (!BN_one(p->Z))
+                    goto err;
+            }
+            p->Z_is_one = 1;
+        }
+    }
+
+    ret = 1;
+
  err:
-       BN_CTX_end(ctx);
-       if (new_ctx != NULL)
-               BN_CTX_free(new_ctx);
-       if (heap != NULL)
-               {
-               /* heap[pow2/2] .. heap[pow2-1] have not been allocated locally! */
-               for (i = pow2/2 - 1; i > 0; i--)
-                       {
-                       if (heap[i] != NULL)
-                               BN_clear_free(heap[i]);
-                       }
-               OPENSSL_free(heap);
-               }
-       return ret;
-       }
-
-
-int ec_GFp_simple_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
-       {
-       return BN_mod_mul(r, a, b, &group->field, ctx);
-       }
-
-
-int ec_GFp_simple_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
-       {
-       return BN_mod_sqr(r, a, &group->field, ctx);
-       }
+    BN_CTX_end(ctx);
+    BN_CTX_free(new_ctx);
+    if (prod_Z != NULL) {
+        for (i = 0; i < num; i++) {
+            if (prod_Z[i] == NULL)
+                break;
+            BN_clear_free(prod_Z[i]);
+        }
+        OPENSSL_free(prod_Z);
+    }
+    return ret;
+}
+
+int ec_GFp_simple_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
+                            const BIGNUM *b, BN_CTX *ctx)
+{
+    return BN_mod_mul(r, a, b, group->field, ctx);
+}
+
+int ec_GFp_simple_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a,
+                            BN_CTX *ctx)
+{
+    return BN_mod_sqr(r, a, group->field, ctx);
+}