/* crypto/ec/ec_curve.c */

/*

 * Written by Nils Larsch for the OpenSSL project.

 */

/* ====================================================================

 * Copyright (c) 1998-2010 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 of the attached software ("Contribution") are developed by

 * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.

 *

 * The Contribution is licensed pursuant to the OpenSSL open source

 * license provided above.

 *

 * The elliptic curve binary polynomial software is originally written by

 * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems Laboratories.

 *

 */

#include <string.h>

#include "ec_lcl.h"

#include <openssl/err.h>

#include <openssl/obj_mac.h>

#include <openssl/opensslconf.h>

#ifdef OPENSSL_FIPS

# include <openssl/fips.h>

#endif

typedef struct {

    int field_type,             /* either NID_X9_62_prime_field or

                                 * NID_X9_62_characteristic_two_field */

     seed_len, param_len;

    unsigned int cofactor;      /* promoted to BN_ULONG */

} EC_CURVE_DATA;

/* the nist prime curves */

static const struct {

    EC_CURVE_DATA h;

    unsigned char data[20 + 48 * 6];

} _EC_NIST_PRIME_384 = {

    {

        NID_X9_62_prime_field, 20, 48, 1

    },

    {

        /* seed */

        0xA3, 0x35, 0x92, 0x6A, 0xA3, 0x19, 0xA2, 0x7A, 0x1D, 0x00, 0x89, 0x6A,

        0x67, 0x73, 0xA4, 0x82, 0x7A, 0xCD, 0xAC, 0x73,

        /* p */

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xFF, 0xFF, 0xFF, 0xFF,

        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,

        /* a */

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xFF, 0xFF, 0xFF, 0xFF,

        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFC,

        /* b */

        0xB3, 0x31, 0x2F, 0xA7, 0xE2, 0x3E, 0xE7, 0xE4, 0x98, 0x8E, 0x05, 0x6B,

        0xE3, 0xF8, 0x2D, 0x19, 0x18, 0x1D, 0x9C, 0x6E, 0xFE, 0x81, 0x41, 0x12,

        0x03, 0x14, 0x08, 0x8F, 0x50, 0x13, 0x87, 0x5A, 0xC6, 0x56, 0x39, 0x8D,

        0x8A, 0x2E, 0xD1, 0x9D, 0x2A, 0x85, 0xC8, 0xED, 0xD3, 0xEC, 0x2A, 0xEF,

        /* x */

        0xAA, 0x87, 0xCA, 0x22, 0xBE, 0x8B, 0x05, 0x37, 0x8E, 0xB1, 0xC7, 0x1E,

        0xF3, 0x20, 0xAD, 0x74, 0x6E, 0x1D, 0x3B, 0x62, 0x8B, 0xA7, 0x9B, 0x98,

        0x59, 0xF7, 0x41, 0xE0, 0x82, 0x54, 0x2A, 0x38, 0x55, 0x02, 0xF2, 0x5D,

        0xBF, 0x55, 0x29, 0x6C, 0x3A, 0x54, 0x5E, 0x38, 0x72, 0x76, 0x0A, 0xB7,

        /* y */

        0x36, 0x17, 0xde, 0x4a, 0x96, 0x26, 0x2c, 0x6f, 0x5d, 0x9e, 0x98, 0xbf,

        0x92, 0x92, 0xdc, 0x29, 0xf8, 0xf4, 0x1d, 0xbd, 0x28, 0x9a, 0x14, 0x7c,

        0xe9, 0xda, 0x31, 0x13, 0xb5, 0xf0, 0xb8, 0xc0, 0x0a, 0x60, 0xb1, 0xce,

        0x1d, 0x7e, 0x81, 0x9d, 0x7a, 0x43, 0x1d, 0x7c, 0x90, 0xea, 0x0e, 0x5f,

        /* order */

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xC7, 0x63, 0x4D, 0x81, 0xF4, 0x37, 0x2D, 0xDF, 0x58, 0x1A, 0x0D, 0xB2,

        0x48, 0xB0, 0xA7, 0x7A, 0xEC, 0xEC, 0x19, 0x6A, 0xCC, 0xC5, 0x29, 0x73

    }

};

static const struct {

    EC_CURVE_DATA h;

    unsigned char data[20 + 66 * 6];

} _EC_NIST_PRIME_521 = {

    {

        NID_X9_62_prime_field, 20, 66, 1

    },

    {

        /* seed */

        0xD0, 0x9E, 0x88, 0x00, 0x29, 0x1C, 0xB8, 0x53, 0x96, 0xCC, 0x67, 0x17,

        0x39, 0x32, 0x84, 0xAA, 0xA0, 0xDA, 0x64, 0xBA,

        /* p */

        0x01, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        /* a */

        0x01, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFC,

        /* b */

        0x00, 0x51, 0x95, 0x3E, 0xB9, 0x61, 0x8E, 0x1C, 0x9A, 0x1F, 0x92, 0x9A,

        0x21, 0xA0, 0xB6, 0x85, 0x40, 0xEE, 0xA2, 0xDA, 0x72, 0x5B, 0x99, 0xB3,

        0x15, 0xF3, 0xB8, 0xB4, 0x89, 0x91, 0x8E, 0xF1, 0x09, 0xE1, 0x56, 0x19,

        0x39, 0x51, 0xEC, 0x7E, 0x93, 0x7B, 0x16, 0x52, 0xC0, 0xBD, 0x3B, 0xB1,

        0xBF, 0x07, 0x35, 0x73, 0xDF, 0x88, 0x3D, 0x2C, 0x34, 0xF1, 0xEF, 0x45,

        0x1F, 0xD4, 0x6B, 0x50, 0x3F, 0x00,

        /* x */

        0x00, 0xC6, 0x85, 0x8E, 0x06, 0xB7, 0x04, 0x04, 0xE9, 0xCD, 0x9E, 0x3E,

        0xCB, 0x66, 0x23, 0x95, 0xB4, 0x42, 0x9C, 0x64, 0x81, 0x39, 0x05, 0x3F,

        0xB5, 0x21, 0xF8, 0x28, 0xAF, 0x60, 0x6B, 0x4D, 0x3D, 0xBA, 0xA1, 0x4B,

        0x5E, 0x77, 0xEF, 0xE7, 0x59, 0x28, 0xFE, 0x1D, 0xC1, 0x27, 0xA2, 0xFF,

        0xA8, 0xDE, 0x33, 0x48, 0xB3, 0xC1, 0x85, 0x6A, 0x42, 0x9B, 0xF9, 0x7E,

        0x7E, 0x31, 0xC2, 0xE5, 0xBD, 0x66,

        /* y */

        0x01, 0x18, 0x39, 0x29, 0x6a, 0x78, 0x9a, 0x3b, 0xc0, 0x04, 0x5c, 0x8a,

        0x5f, 0xb4, 0x2c, 0x7d, 0x1b, 0xd9, 0x98, 0xf5, 0x44, 0x49, 0x57, 0x9b,

        0x44, 0x68, 0x17, 0xaf, 0xbd, 0x17, 0x27, 0x3e, 0x66, 0x2c, 0x97, 0xee,

        0x72, 0x99, 0x5e, 0xf4, 0x26, 0x40, 0xc5, 0x50, 0xb9, 0x01, 0x3f, 0xad,

        0x07, 0x61, 0x35, 0x3c, 0x70, 0x86, 0xa2, 0x72, 0xc2, 0x40, 0x88, 0xbe,

        0x94, 0x76, 0x9f, 0xd1, 0x66, 0x50,

        /* order */

        0x01, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFA, 0x51, 0x86,

        0x87, 0x83, 0xBF, 0x2F, 0x96, 0x6B, 0x7F, 0xCC, 0x01, 0x48, 0xF7, 0x09,

        0xA5, 0xD0, 0x3B, 0xB5, 0xC9, 0xB8, 0x89, 0x9C, 0x47, 0xAE, 0xBB, 0x6F,

        0xB7, 0x1E, 0x91, 0x38, 0x64, 0x09

    }

};

static const struct {

    EC_CURVE_DATA h;

    unsigned char data[20 + 32 * 6];

} _EC_X9_62_PRIME_256V1 = {

    {

        NID_X9_62_prime_field, 20, 32, 1

    },

    {

        /* seed */

        0xC4, 0x9D, 0x36, 0x08, 0x86, 0xE7, 0x04, 0x93, 0x6A, 0x66, 0x78, 0xE1,

        0x13, 0x9D, 0x26, 0xB7, 0x81, 0x9F, 0x7E, 0x90,

        /* p */

        0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,

        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

        /* a */

        0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,

        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFC,

        /* b */

        0x5A, 0xC6, 0x35, 0xD8, 0xAA, 0x3A, 0x93, 0xE7, 0xB3, 0xEB, 0xBD, 0x55,

        0x76, 0x98, 0x86, 0xBC, 0x65, 0x1D, 0x06, 0xB0, 0xCC, 0x53, 0xB0, 0xF6,

        0x3B, 0xCE, 0x3C, 0x3E, 0x27, 0xD2, 0x60, 0x4B,

        /* x */

        0x6B, 0x17, 0xD1, 0xF2, 0xE1, 0x2C, 0x42, 0x47, 0xF8, 0xBC, 0xE6, 0xE5,

        0x63, 0xA4, 0x40, 0xF2, 0x77, 0x03, 0x7D, 0x81, 0x2D, 0xEB, 0x33, 0xA0,

        0xF4, 0xA1, 0x39, 0x45, 0xD8, 0x98, 0xC2, 0x96,

        /* y */

        0x4f, 0xe3, 0x42, 0xe2, 0xfe, 0x1a, 0x7f, 0x9b, 0x8e, 0xe7, 0xeb, 0x4a,

        0x7c, 0x0f, 0x9e, 0x16, 0x2b, 0xce, 0x33, 0x57, 0x6b, 0x31, 0x5e, 0xce,

        0xcb, 0xb6, 0x40, 0x68, 0x37, 0xbf, 0x51, 0xf5,

        /* order */

        0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF,

        0xFF, 0xFF, 0xFF, 0xFF, 0xBC, 0xE6, 0xFA, 0xAD, 0xA7, 0x17, 0x9E, 0x84,

        0xF3, 0xB9, 0xCA, 0xC2, 0xFC, 0x63, 0x25, 0x51

    }

};

typedef struct _ec_list_element_st {

    int nid;

    const EC_CURVE_DATA *data;

    const EC_METHOD *(*meth) (void);

    const char *comment;

} ec_list_element;

static const ec_list_element curve_list[] = {

    /* prime field curves */

    /* secg curves */

    /* SECG secp256r1 is the same as X9.62 prime256v1 and hence omitted */

    {NID_secp384r1, &_EC_NIST_PRIME_384.h, 0,

     "NIST/SECG curve over a 384 bit prime field"},

#ifndef OPENSSL_NO_EC_NISTP_64_GCC_128

    {NID_secp521r1, &_EC_NIST_PRIME_521.h, EC_GFp_nistp521_method,

     "NIST/SECG curve over a 521 bit prime field"},

#else

    {NID_secp521r1, &_EC_NIST_PRIME_521.h, 0,

     "NIST/SECG curve over a 521 bit prime field"},

#endif

    /* X9.62 curves */

    {NID_X9_62_prime256v1, &_EC_X9_62_PRIME_256V1.h,

#if defined(ECP_NISTZ256_ASM)

     EC_GFp_nistz256_method,

#elif !defined(OPENSSL_NO_EC_NISTP_64_GCC_128)

     EC_GFp_nistp256_method,

#else

     0,

#endif

     "X9.62/SECG curve over a 256 bit prime field"},

};

#define curve_list_length (sizeof(curve_list)/sizeof(ec_list_element))

static EC_GROUP *ec_group_new_from_data(const ec_list_element curve)

{

    EC_GROUP *group = NULL;

    EC_POINT *P = NULL;

    BN_CTX *ctx = NULL;

    BIGNUM *p = NULL, *a = NULL, *b = NULL, *x = NULL, *y = NULL, *order =

        NULL;

    int ok = 0;

    int seed_len, param_len;

    const EC_METHOD *meth;

    const EC_CURVE_DATA *data;

    const unsigned char *params;

    if ((ctx = BN_CTX_new()) == NULL) {

        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    data = curve.data;

    seed_len = data->seed_len;

    param_len = data->param_len;

    params = (const unsigned char *)(data + 1); /* skip header */

    params += seed_len;         /* skip seed */

    if (!(p = BN_bin2bn(params + 0 * param_len, param_len, NULL))

        || !(a = BN_bin2bn(params + 1 * param_len, param_len, NULL))

        || !(b = BN_bin2bn(params + 2 * param_len, param_len, NULL))) {

        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_BN_LIB);

        goto err;

    }

    if (curve.meth != 0) {

        meth = curve.meth();

        if (((group = EC_GROUP_new(meth)) == NULL) ||

            (!(group->meth->group_set_curve(group, p, a, b, ctx)))) {

            ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);

            goto err;

        }

    } else if (data->field_type == NID_X9_62_prime_field) {

        if ((group = EC_GROUP_new_curve_GFp(p, a, b, ctx)) == NULL) {

            ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);

            goto err;

        }

    }

#ifndef OPENSSL_NO_EC2M

    else {                      /* field_type ==

                                 * NID_X9_62_characteristic_two_field */

        if ((group = EC_GROUP_new_curve_GF2m(p, a, b, ctx)) == NULL) {

            ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);

            goto err;

        }

    }

#endif

    if ((P = EC_POINT_new(group)) == NULL) {

        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);

        goto err;

    }

    if (!(x = BN_bin2bn(params + 3 * param_len, param_len, NULL))

        || !(y = BN_bin2bn(params + 4 * param_len, param_len, NULL))) {

        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_BN_LIB);

        goto err;

    }

    if (!EC_POINT_set_affine_coordinates_GFp(group, P, x, y, ctx)) {

        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);

        goto err;

    }

    if (!(order = BN_bin2bn(params + 5 * param_len, param_len, NULL))

        || !BN_set_word(x, (BN_ULONG)data->cofactor)) {

        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_BN_LIB);

        goto err;

    }

    if (!EC_GROUP_set_generator(group, P, order, x)) {

        ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);

        goto err;

    }

    if (seed_len) {

        if (!EC_GROUP_set_seed(group, params - seed_len, seed_len)) {

            ECerr(EC_F_EC_GROUP_NEW_FROM_DATA, ERR_R_EC_LIB);

            goto err;

        }

    }

    ok = 1;

 err:

    if (!ok) {

        EC_GROUP_free(group);

        group = NULL;

    }

    if (P)

        EC_POINT_free(P);

    if (ctx)

        BN_CTX_free(ctx);

    if (p)

        BN_free(p);

    if (a)

        BN_free(a);

    if (b)

        BN_free(b);

    if (order)

        BN_free(order);

    if (x)

        BN_free(x);

    if (y)

        BN_free(y);

    return group;

}

EC_GROUP *EC_GROUP_new_by_curve_name(int nid)

{

    size_t i;

    EC_GROUP *ret = NULL;

    if (nid <= 0)

        return NULL;

    for (i = 0; i < curve_list_length; i++)

        if (curve_list[i].nid == nid) {

            ret = ec_group_new_from_data(curve_list[i]);

            break;

        }

    if (ret == NULL) {

        ECerr(EC_F_EC_GROUP_NEW_BY_CURVE_NAME, EC_R_UNKNOWN_GROUP);

        return NULL;

    }

    EC_GROUP_set_curve_name(ret, nid);

    return ret;

}

size_t EC_get_builtin_curves(EC_builtin_curve *r, size_t nitems)

{

    size_t i, min;

    if (r == NULL || nitems == 0)

        return curve_list_length;

    min = nitems < curve_list_length ? nitems : curve_list_length;

    for (i = 0; i < min; i++) {

        r[i].nid = curve_list[i].nid;

        r[i].comment = curve_list[i].comment;

    }

    return curve_list_length;

}

/* Functions to translate between common NIST curve names and NIDs */

typedef struct {

    const char *name;           /* NIST Name of curve */

    int nid;                    /* Curve NID */

} EC_NIST_NAME;

static EC_NIST_NAME nist_curves[] = {

    {"B-163", NID_sect163r2},

    {"B-233", NID_sect233r1},

    {"B-283", NID_sect283r1},

    {"B-409", NID_sect409r1},

    {"B-571", NID_sect571r1},

    {"K-163", NID_sect163k1},

    {"K-233", NID_sect233k1},

    {"K-283", NID_sect283k1},

    {"K-409", NID_sect409k1},

    {"K-571", NID_sect571k1},

    {"P-192", NID_X9_62_prime192v1},

    {"P-224", NID_secp224r1},

    {"P-256", NID_X9_62_prime256v1},

    {"P-384", NID_secp384r1},

    {"P-521", NID_secp521r1}

};

const char *EC_curve_nid2nist(int nid)

{

    size_t i;

    for (i = 0; i < sizeof(nist_curves) / sizeof(EC_NIST_NAME); i++) {

        if (nist_curves[i].nid == nid)

            return nist_curves[i].name;

    }

    return NULL;

}

int EC_curve_nist2nid(const char *name)

{

    size_t i;

    for (i = 0; i < sizeof(nist_curves) / sizeof(EC_NIST_NAME); i++) {

        if (!strcmp(nist_curves[i].name, name))

            return nist_curves[i].nid;

    }

    return NID_undef;

}