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-rw-r--r--crypto/ec/ecp_oct.c719
1 files changed, 357 insertions, 362 deletions
diff --git a/crypto/ec/ecp_oct.c b/crypto/ec/ecp_oct.c
index 374a0ee731ae..e5cec8be8266 100644
--- a/crypto/ec/ecp_oct.c
+++ b/crypto/ec/ecp_oct.c
@@ -1,8 +1,9 @@
/* crypto/ec/ecp_oct.c */
-/* 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.
-*/
+/*
+ * 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.
*
@@ -11,7 +12,7 @@
* 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
@@ -67,367 +68,361 @@
#include "ec_lcl.h"
-int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,
- const BIGNUM *x_, int y_bit, BN_CTX *ctx)
- {
- BN_CTX *new_ctx = NULL;
- BIGNUM *tmp1, *tmp2, *x, *y;
- int ret = 0;
-
- /* clear error queue*/
- ERR_clear_error();
-
- if (ctx == NULL)
- {
- ctx = new_ctx = BN_CTX_new();
- if (ctx == NULL)
- return 0;
- }
-
- y_bit = (y_bit != 0);
-
- 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_last_error();
-
- if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE)
- {
- ERR_clear_error();
- ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
- }
- else
- ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_BN_LIB);
- goto err;
- }
-
- 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, EC_R_INVALID_COMPRESSION_BIT);
- else
- /* BN_mod_sqrt() should have cought this error (not a square) */
- ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, 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, ERR_R_INTERNAL_ERROR);
- goto err;
- }
-
- if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
-
- ret = 1;
+int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *group,
+ EC_POINT *point,
+ const BIGNUM *x_, int y_bit,
+ BN_CTX *ctx)
+{
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *tmp1, *tmp2, *x, *y;
+ int ret = 0;
+
+ /* clear error queue */
+ ERR_clear_error();
+
+ if (ctx == NULL) {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ y_bit = (y_bit != 0);
+
+ 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_last_error();
+
+ if (ERR_GET_LIB(err) == ERR_LIB_BN
+ && ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE) {
+ ERR_clear_error();
+ ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,
+ EC_R_INVALID_COMPRESSED_POINT);
+ } else
+ ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,
+ ERR_R_BN_LIB);
+ goto err;
+ }
+
+ 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,
+ EC_R_INVALID_COMPRESSION_BIT);
+ else
+ /*
+ * BN_mod_sqrt() should have cought this error (not a square)
+ */
+ ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,
+ 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,
+ ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx))
+ goto err;
+
+ ret = 1;
err:
- BN_CTX_end(ctx);
- if (new_ctx != NULL)
- BN_CTX_free(new_ctx);
- return ret;
- }
-
-
-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;
+ 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;
- }
-
+ 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 & ~1U;
- 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;
- }
+ 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 & ~1U;
+ 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;
+ }
+
+ /* test required by X9.62 */
+ if (!EC_POINT_is_on_curve(group, point, ctx)) {
+ 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;
+}