update libressl to 2.8.2

[unleashed.git] / lib / libcrypto / ec / ec_key.c

/* $OpenBSD: ec_key.c,v 1.17 2018/07/15 16:27:39 tb Exp $ */
/*
 * Written by Nils Larsch for the OpenSSL project.
 */
/* ====================================================================
 * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    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
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 * Portions originally developed by SUN MICROSYSTEMS, INC., and
 * contributed to the OpenSSL project.
 */

#include <string.h>

#include <openssl/opensslconf.h>

#include "ec_lcl.h"
#include <openssl/err.h>

EC_KEY *
EC_KEY_new(void)
{
        EC_KEY *ret;

        ret = malloc(sizeof(EC_KEY));
        if (ret == NULL) {
                ECerror(ERR_R_MALLOC_FAILURE);
                return (NULL);
        }
        ret->version = 1;
        ret->flags = 0;
        ret->group = NULL;
        ret->pub_key = NULL;
        ret->priv_key = NULL;
        ret->enc_flag = 0;
        ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;
        ret->references = 1;
        ret->method_data = NULL;
        return (ret);
}

EC_KEY *
EC_KEY_new_by_curve_name(int nid)
{
        EC_KEY *ret = EC_KEY_new();
        if (ret == NULL)
                return NULL;
        ret->group = EC_GROUP_new_by_curve_name(nid);
        if (ret->group == NULL) {
                EC_KEY_free(ret);
                return NULL;
        }
        return ret;
}

void 
EC_KEY_free(EC_KEY * r)
{
        int i;

        if (r == NULL)
                return;

        i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_EC);
        if (i > 0)
                return;

        EC_GROUP_free(r->group);
        EC_POINT_free(r->pub_key);
        BN_clear_free(r->priv_key);

        EC_EX_DATA_free_all_data(&r->method_data);

        freezero(r, sizeof(EC_KEY));
}

EC_KEY *
EC_KEY_copy(EC_KEY * dest, const EC_KEY * src)
{
        EC_EXTRA_DATA *d;

        if (dest == NULL || src == NULL) {
                ECerror(ERR_R_PASSED_NULL_PARAMETER);
                return NULL;
        }
        /* copy the parameters */
        if (src->group) {
                const EC_METHOD *meth = EC_GROUP_method_of(src->group);
                /* clear the old group */
                EC_GROUP_free(dest->group);
                dest->group = EC_GROUP_new(meth);
                if (dest->group == NULL)
                        return NULL;
                if (!EC_GROUP_copy(dest->group, src->group))
                        return NULL;
        }
        /* copy the public key */
        if (src->pub_key && src->group) {
                EC_POINT_free(dest->pub_key);
                dest->pub_key = EC_POINT_new(src->group);
                if (dest->pub_key == NULL)
                        return NULL;
                if (!EC_POINT_copy(dest->pub_key, src->pub_key))
                        return NULL;
        }
        /* copy the private key */
        if (src->priv_key) {
                if (dest->priv_key == NULL) {
                        dest->priv_key = BN_new();
                        if (dest->priv_key == NULL)
                                return NULL;
                }
                if (!BN_copy(dest->priv_key, src->priv_key))
                        return NULL;
        }
        /* copy method/extra data */
        EC_EX_DATA_free_all_data(&dest->method_data);

        for (d = src->method_data; d != NULL; d = d->next) {
                void *t = d->dup_func(d->data);

                if (t == NULL)
                        return 0;
                if (!EC_EX_DATA_set_data(&dest->method_data, t, d->dup_func,
                    d->free_func, d->clear_free_func))
                        return 0;
        }

        /* copy the rest */
        dest->enc_flag = src->enc_flag;
        dest->conv_form = src->conv_form;
        dest->version = src->version;
        dest->flags = src->flags;

        return dest;
}

EC_KEY *
EC_KEY_dup(const EC_KEY * ec_key)
{
        EC_KEY *ret = EC_KEY_new();
        if (ret == NULL)
                return NULL;
        if (EC_KEY_copy(ret, ec_key) == NULL) {
                EC_KEY_free(ret);
                return NULL;
        }
        return ret;
}

int 
EC_KEY_up_ref(EC_KEY * r)
{
        int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_EC);
        return ((i > 1) ? 1 : 0);
}

int 
EC_KEY_generate_key(EC_KEY * eckey)
{
        int ok = 0;
        BN_CTX *ctx = NULL;
        BIGNUM *priv_key = NULL, *order = NULL;
        EC_POINT *pub_key = NULL;

        if (!eckey || !eckey->group) {
                ECerror(ERR_R_PASSED_NULL_PARAMETER);
                return 0;
        }
        if ((order = BN_new()) == NULL)
                goto err;
        if ((ctx = BN_CTX_new()) == NULL)
                goto err;

        if (eckey->priv_key == NULL) {
                priv_key = BN_new();
                if (priv_key == NULL)
                        goto err;
        } else
                priv_key = eckey->priv_key;

        if (!EC_GROUP_get_order(eckey->group, order, ctx))
                goto err;

        do
                if (!BN_rand_range(priv_key, order))
                        goto err;
        while (BN_is_zero(priv_key));

        if (eckey->pub_key == NULL) {
                pub_key = EC_POINT_new(eckey->group);
                if (pub_key == NULL)
                        goto err;
        } else
                pub_key = eckey->pub_key;

        if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
                goto err;

        eckey->priv_key = priv_key;
        eckey->pub_key = pub_key;

        ok = 1;

 err:
        BN_free(order);
        if (pub_key != NULL && eckey->pub_key == NULL)
                EC_POINT_free(pub_key);
        if (priv_key != NULL && eckey->priv_key == NULL)
                BN_free(priv_key);
        BN_CTX_free(ctx);
        return (ok);
}

int 
EC_KEY_check_key(const EC_KEY * eckey)
{
        int ok = 0;
        BN_CTX *ctx = NULL;
        const BIGNUM *order = NULL;
        EC_POINT *point = NULL;

        if (!eckey || !eckey->group || !eckey->pub_key) {
                ECerror(ERR_R_PASSED_NULL_PARAMETER);
                return 0;
        }
        if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key) > 0) {
                ECerror(EC_R_POINT_AT_INFINITY);
                goto err;
        }
        if ((ctx = BN_CTX_new()) == NULL)
                goto err;
        if ((point = EC_POINT_new(eckey->group)) == NULL)
                goto err;

        /* testing whether the pub_key is on the elliptic curve */
        if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) {
                ECerror(EC_R_POINT_IS_NOT_ON_CURVE);
                goto err;
        }
        /* testing whether pub_key * order is the point at infinity */
        order = &eckey->group->order;
        if (BN_is_zero(order)) {
                ECerror(EC_R_INVALID_GROUP_ORDER);
                goto err;
        }
        if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        if (EC_POINT_is_at_infinity(eckey->group, point) <= 0) {
                ECerror(EC_R_WRONG_ORDER);
                goto err;
        }
        /*
         * in case the priv_key is present : check if generator * priv_key ==
         * pub_key
         */
        if (eckey->priv_key) {
                if (BN_cmp(eckey->priv_key, order) >= 0) {
                        ECerror(EC_R_WRONG_ORDER);
                        goto err;
                }
                if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
                        NULL, NULL, ctx)) {
                        ECerror(ERR_R_EC_LIB);
                        goto err;
                }
                if (EC_POINT_cmp(eckey->group, point, eckey->pub_key,
                        ctx) != 0) {
                        ECerror(EC_R_INVALID_PRIVATE_KEY);
                        goto err;
                }
        }
        ok = 1;
 err:
        BN_CTX_free(ctx);
        EC_POINT_free(point);
        return (ok);
}

int 
EC_KEY_set_public_key_affine_coordinates(EC_KEY * key, BIGNUM * x, BIGNUM * y)
{
        BN_CTX *ctx = NULL;
        BIGNUM *tx, *ty;
        EC_POINT *point = NULL;
        int ok = 0, tmp_nid, is_char_two = 0;

        if (!key || !key->group || !x || !y) {
                ECerror(ERR_R_PASSED_NULL_PARAMETER);
                return 0;
        }
        ctx = BN_CTX_new();
        if (!ctx)
                goto err;

        point = EC_POINT_new(key->group);

        if (!point)
                goto err;

        tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group));

        if (tmp_nid == NID_X9_62_characteristic_two_field)
                is_char_two = 1;

        if ((tx = BN_CTX_get(ctx)) == NULL)
                goto err;
        if ((ty = BN_CTX_get(ctx)) == NULL)
                goto err;

#ifndef OPENSSL_NO_EC2M
        if (is_char_two) {
                if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point,
                        x, y, ctx))
                        goto err;
                if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point,
                        tx, ty, ctx))
                        goto err;
        } else
#endif
        {
                if (!EC_POINT_set_affine_coordinates_GFp(key->group, point,
                        x, y, ctx))
                        goto err;
                if (!EC_POINT_get_affine_coordinates_GFp(key->group, point,
                        tx, ty, ctx))
                        goto err;
        }
        /*
         * Check if retrieved coordinates match originals: if not values are
         * out of range.
         */
        if (BN_cmp(x, tx) || BN_cmp(y, ty)) {
                ECerror(EC_R_COORDINATES_OUT_OF_RANGE);
                goto err;
        }
        if (!EC_KEY_set_public_key(key, point))
                goto err;

        if (EC_KEY_check_key(key) == 0)
                goto err;

        ok = 1;

 err:
        BN_CTX_free(ctx);
        EC_POINT_free(point);
        return ok;

}

const EC_GROUP *
EC_KEY_get0_group(const EC_KEY * key)
{
        return key->group;
}

int 
EC_KEY_set_group(EC_KEY * key, const EC_GROUP * group)
{
        EC_GROUP_free(key->group);
        key->group = EC_GROUP_dup(group);
        return (key->group == NULL) ? 0 : 1;
}

const BIGNUM *
EC_KEY_get0_private_key(const EC_KEY * key)
{
        return key->priv_key;
}

int 
EC_KEY_set_private_key(EC_KEY * key, const BIGNUM * priv_key)
{
        BN_clear_free(key->priv_key);
        key->priv_key = BN_dup(priv_key);
        return (key->priv_key == NULL) ? 0 : 1;
}

const EC_POINT *
EC_KEY_get0_public_key(const EC_KEY * key)
{
        return key->pub_key;
}

int 
EC_KEY_set_public_key(EC_KEY * key, const EC_POINT * pub_key)
{
        EC_POINT_free(key->pub_key);
        key->pub_key = EC_POINT_dup(pub_key, key->group);
        return (key->pub_key == NULL) ? 0 : 1;
}

unsigned int 
EC_KEY_get_enc_flags(const EC_KEY * key)
{
        return key->enc_flag;
}

void 
EC_KEY_set_enc_flags(EC_KEY * key, unsigned int flags)
{
        key->enc_flag = flags;
}

point_conversion_form_t 
EC_KEY_get_conv_form(const EC_KEY * key)
{
        return key->conv_form;
}

void 
EC_KEY_set_conv_form(EC_KEY * key, point_conversion_form_t cform)
{
        key->conv_form = cform;
        if (key->group != NULL)
                EC_GROUP_set_point_conversion_form(key->group, cform);
}

void *
EC_KEY_get_key_method_data(EC_KEY *key,
    void *(*dup_func) (void *),
    void (*free_func) (void *),
    void (*clear_free_func) (void *))
{
        void *ret;

        CRYPTO_r_lock(CRYPTO_LOCK_EC);
        ret = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
        CRYPTO_r_unlock(CRYPTO_LOCK_EC);

        return ret;
}

void *
EC_KEY_insert_key_method_data(EC_KEY * key, void *data,
    void *(*dup_func) (void *),
    void (*free_func) (void *),
    void (*clear_free_func) (void *))
{
        EC_EXTRA_DATA *ex_data;

        CRYPTO_w_lock(CRYPTO_LOCK_EC);
        ex_data = EC_EX_DATA_get_data(key->method_data, dup_func, free_func, clear_free_func);
        if (ex_data == NULL)
                EC_EX_DATA_set_data(&key->method_data, data, dup_func, free_func, clear_free_func);
        CRYPTO_w_unlock(CRYPTO_LOCK_EC);

        return ex_data;
}

void 
EC_KEY_set_asn1_flag(EC_KEY * key, int flag)
{
        if (key->group != NULL)
                EC_GROUP_set_asn1_flag(key->group, flag);
}

int 
EC_KEY_precompute_mult(EC_KEY * key, BN_CTX * ctx)
{
        if (key->group == NULL)
                return 0;
        return EC_GROUP_precompute_mult(key->group, ctx);
}

int 
EC_KEY_get_flags(const EC_KEY * key)
{
        return key->flags;
}

void 
EC_KEY_set_flags(EC_KEY * key, int flags)
{
        key->flags |= flags;
}

void 
EC_KEY_clear_flags(EC_KEY * key, int flags)
{
        key->flags &= ~flags;
}