/* $OpenBSD: ec_asn1.c,v 1.37 2022/05/24 20:06:32 tb Exp $ */
/*
 * Written by Nils Larsch for the OpenSSL project.
 */
/* ====================================================================
 * Copyright (c) 2000-2003 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
 *    licensing@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).
 *
 */

#include <string.h>

#include <openssl/opensslconf.h>

#include <openssl/err.h>
#include <openssl/asn1t.h>
#include <openssl/objects.h>

#include "asn1_locl.h"
#include "ec_lcl.h"

int 
EC_GROUP_get_basis_type(const EC_GROUP * group)
{
        int i = 0;

        if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
            NID_X9_62_characteristic_two_field)
                /* everything else is currently not supported */
                return 0;

        while (group->poly[i] != 0)
                i++;

        if (i == 4)
                return NID_X9_62_ppBasis;
        else if (i == 2)
                return NID_X9_62_tpBasis;
        else
                /* everything else is currently not supported */
                return 0;
}

#ifndef OPENSSL_NO_EC2M
int 
EC_GROUP_get_trinomial_basis(const EC_GROUP * group, unsigned int *k)
{
        if (group == NULL)
                return 0;

        if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
            NID_X9_62_characteristic_two_field
            || !((group->poly[0] != 0) && (group->poly[1] != 0) && (group->poly[2] == 0))) {
                ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
                return 0;
        }
        if (k)
                *k = group->poly[1];

        return 1;
}

int 
EC_GROUP_get_pentanomial_basis(const EC_GROUP * group, unsigned int *k1,
    unsigned int *k2, unsigned int *k3)
{
        if (group == NULL)
                return 0;

        if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
            NID_X9_62_characteristic_two_field
            || !((group->poly[0] != 0) && (group->poly[1] != 0) && (group->poly[2] != 0) && (group->poly[3] != 0) && (group->poly[4] == 0))) {
                ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
                return 0;
        }
        if (k1)
                *k1 = group->poly[3];
        if (k2)
                *k2 = group->poly[2];
        if (k3)
                *k3 = group->poly[1];

        return 1;
}
#endif

/* some structures needed for the asn1 encoding */
typedef struct x9_62_pentanomial_st {
        long k1;
        long k2;
        long k3;
} X9_62_PENTANOMIAL;

typedef struct x9_62_characteristic_two_st {
        long m;
        ASN1_OBJECT *type;
        union {
                char *ptr;
                /* NID_X9_62_onBasis */
                ASN1_NULL *onBasis;
                /* NID_X9_62_tpBasis */
                ASN1_INTEGER *tpBasis;
                /* NID_X9_62_ppBasis */
                X9_62_PENTANOMIAL *ppBasis;
                /* anything else */
                ASN1_TYPE *other;
        } p;
} X9_62_CHARACTERISTIC_TWO;

typedef struct x9_62_fieldid_st {
        ASN1_OBJECT *fieldType;
        union {
                char *ptr;
                /* NID_X9_62_prime_field */
                ASN1_INTEGER *prime;
                /* NID_X9_62_characteristic_two_field */
                X9_62_CHARACTERISTIC_TWO *char_two;
                /* anything else */
                ASN1_TYPE *other;
        } p;
} X9_62_FIELDID;

typedef struct x9_62_curve_st {
        ASN1_OCTET_STRING *a;
        ASN1_OCTET_STRING *b;
        ASN1_BIT_STRING *seed;
} X9_62_CURVE;

typedef struct ec_parameters_st {
        long version;
        X9_62_FIELDID *fieldID;
        X9_62_CURVE *curve;
        ASN1_OCTET_STRING *base;
        ASN1_INTEGER *order;
        ASN1_INTEGER *cofactor;
} ECPARAMETERS;

struct ecpk_parameters_st {
        int type;
        union {
                ASN1_OBJECT *named_curve;
                ECPARAMETERS *parameters;
                ASN1_NULL *implicitlyCA;
        } value;
} /* ECPKPARAMETERS */ ;

/* SEC1 ECPrivateKey */
typedef struct ec_privatekey_st {
        long version;
        ASN1_OCTET_STRING *privateKey;
        ECPKPARAMETERS *parameters;
        ASN1_BIT_STRING *publicKey;
} EC_PRIVATEKEY;

/* the OpenSSL ASN.1 definitions */
static const ASN1_TEMPLATE X9_62_PENTANOMIAL_seq_tt[] = {
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(X9_62_PENTANOMIAL, k1),
                .field_name = "k1",
                .item = &LONG_it,
        },
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(X9_62_PENTANOMIAL, k2),
                .field_name = "k2",
                .item = &LONG_it,
        },
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(X9_62_PENTANOMIAL, k3),
                .field_name = "k3",
                .item = &LONG_it,
        },
};

const ASN1_ITEM X9_62_PENTANOMIAL_it = {
        .itype = ASN1_ITYPE_SEQUENCE,
        .utype = V_ASN1_SEQUENCE,
        .templates = X9_62_PENTANOMIAL_seq_tt,
        .tcount = sizeof(X9_62_PENTANOMIAL_seq_tt) / sizeof(ASN1_TEMPLATE),
        .funcs = NULL,
        .size = sizeof(X9_62_PENTANOMIAL),
        .sname = "X9_62_PENTANOMIAL",
};

X9_62_PENTANOMIAL *X9_62_PENTANOMIAL_new(void);
void X9_62_PENTANOMIAL_free(X9_62_PENTANOMIAL *a);

X9_62_PENTANOMIAL *
X9_62_PENTANOMIAL_new(void)
{
        return (X9_62_PENTANOMIAL*)ASN1_item_new(&X9_62_PENTANOMIAL_it);
}

void
X9_62_PENTANOMIAL_free(X9_62_PENTANOMIAL *a)
{
        ASN1_item_free((ASN1_VALUE *)a, &X9_62_PENTANOMIAL_it);
}

static const ASN1_TEMPLATE char_two_def_tt = {
        .flags = 0,
        .tag = 0,
        .offset = offsetof(X9_62_CHARACTERISTIC_TWO, p.other),
        .field_name = "p.other",
        .item = &ASN1_ANY_it,
};

static const ASN1_ADB_TABLE X9_62_CHARACTERISTIC_TWO_adbtbl[] = {
        {
                .value = NID_X9_62_onBasis,
                .tt = {
                        .flags = 0,
                        .tag = 0,
                        .offset = offsetof(X9_62_CHARACTERISTIC_TWO, p.onBasis),
                        .field_name = "p.onBasis",
                        .item = &ASN1_NULL_it,
                },
        
        },
        {
                .value = NID_X9_62_tpBasis,
                .tt = {
                        .flags = 0,
                        .tag = 0,
                        .offset = offsetof(X9_62_CHARACTERISTIC_TWO, p.tpBasis),
                        .field_name = "p.tpBasis",
                        .item = &ASN1_INTEGER_it,
                },
        
        },
        {
                .value = NID_X9_62_ppBasis,
                .tt = {
                        .flags = 0,
                        .tag = 0,
                        .offset = offsetof(X9_62_CHARACTERISTIC_TWO, p.ppBasis),
                        .field_name = "p.ppBasis",
                        .item = &X9_62_PENTANOMIAL_it,
                },
        
        },
};

static const ASN1_ADB X9_62_CHARACTERISTIC_TWO_adb = {
        .flags = 0,
        .offset = offsetof(X9_62_CHARACTERISTIC_TWO, type),
        .tbl = X9_62_CHARACTERISTIC_TWO_adbtbl,
        .tblcount = sizeof(X9_62_CHARACTERISTIC_TWO_adbtbl) / sizeof(ASN1_ADB_TABLE),
        .default_tt = &char_two_def_tt,
        .null_tt = NULL,
};

static const ASN1_TEMPLATE X9_62_CHARACTERISTIC_TWO_seq_tt[] = {
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(X9_62_CHARACTERISTIC_TWO, m),
                .field_name = "m",
                .item = &LONG_it,
        },
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(X9_62_CHARACTERISTIC_TWO, type),
                .field_name = "type",
                .item = &ASN1_OBJECT_it,
        },
        {
                .flags = ASN1_TFLG_ADB_OID,
                .tag = -1,
                .offset = 0,
                .field_name = "X9_62_CHARACTERISTIC_TWO",
                .item = (const ASN1_ITEM *)&X9_62_CHARACTERISTIC_TWO_adb,
        },
};

const ASN1_ITEM X9_62_CHARACTERISTIC_TWO_it = {
        .itype = ASN1_ITYPE_SEQUENCE,
        .utype = V_ASN1_SEQUENCE,
        .templates = X9_62_CHARACTERISTIC_TWO_seq_tt,
        .tcount = sizeof(X9_62_CHARACTERISTIC_TWO_seq_tt) / sizeof(ASN1_TEMPLATE),
        .funcs = NULL,
        .size = sizeof(X9_62_CHARACTERISTIC_TWO),
        .sname = "X9_62_CHARACTERISTIC_TWO",
};

X9_62_CHARACTERISTIC_TWO *X9_62_CHARACTERISTIC_TWO_new(void);
void X9_62_CHARACTERISTIC_TWO_free(X9_62_CHARACTERISTIC_TWO *a);

X9_62_CHARACTERISTIC_TWO *
X9_62_CHARACTERISTIC_TWO_new(void)
{
        return (X9_62_CHARACTERISTIC_TWO*)ASN1_item_new(&X9_62_CHARACTERISTIC_TWO_it);
}

void
X9_62_CHARACTERISTIC_TWO_free(X9_62_CHARACTERISTIC_TWO *a)
{
        ASN1_item_free((ASN1_VALUE *)a, &X9_62_CHARACTERISTIC_TWO_it);
}

static const ASN1_TEMPLATE fieldID_def_tt = {
        .flags = 0,
        .tag = 0,
        .offset = offsetof(X9_62_FIELDID, p.other),
        .field_name = "p.other",
        .item = &ASN1_ANY_it,
};

static const ASN1_ADB_TABLE X9_62_FIELDID_adbtbl[] = {
        {
                .value = NID_X9_62_prime_field,
                .tt = {
                        .flags = 0,
                        .tag = 0,
                        .offset = offsetof(X9_62_FIELDID, p.prime),
                        .field_name = "p.prime",
                        .item = &ASN1_INTEGER_it,
                },
        
        },
        {
                .value = NID_X9_62_characteristic_two_field,
                .tt = {
                        .flags = 0,
                        .tag = 0,
                        .offset = offsetof(X9_62_FIELDID, p.char_two),
                        .field_name = "p.char_two",
                        .item = &X9_62_CHARACTERISTIC_TWO_it,
                },
        
        },
};

static const ASN1_ADB X9_62_FIELDID_adb = {
        .flags = 0,
        .offset = offsetof(X9_62_FIELDID, fieldType),
        .tbl = X9_62_FIELDID_adbtbl,
        .tblcount = sizeof(X9_62_FIELDID_adbtbl) / sizeof(ASN1_ADB_TABLE),
        .default_tt = &fieldID_def_tt,
        .null_tt = NULL,
};

static const ASN1_TEMPLATE X9_62_FIELDID_seq_tt[] = {
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(X9_62_FIELDID, fieldType),
                .field_name = "fieldType",
                .item = &ASN1_OBJECT_it,
        },
        {
                .flags = ASN1_TFLG_ADB_OID,
                .tag = -1,
                .offset = 0,
                .field_name = "X9_62_FIELDID",
                .item = (const ASN1_ITEM *)&X9_62_FIELDID_adb,
        },
};

const ASN1_ITEM X9_62_FIELDID_it = {
        .itype = ASN1_ITYPE_SEQUENCE,
        .utype = V_ASN1_SEQUENCE,
        .templates = X9_62_FIELDID_seq_tt,
        .tcount = sizeof(X9_62_FIELDID_seq_tt) / sizeof(ASN1_TEMPLATE),
        .funcs = NULL,
        .size = sizeof(X9_62_FIELDID),
        .sname = "X9_62_FIELDID",
};

static const ASN1_TEMPLATE X9_62_CURVE_seq_tt[] = {
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(X9_62_CURVE, a),
                .field_name = "a",
                .item = &ASN1_OCTET_STRING_it,
        },
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(X9_62_CURVE, b),
                .field_name = "b",
                .item = &ASN1_OCTET_STRING_it,
        },
        {
                .flags = ASN1_TFLG_OPTIONAL,
                .tag = 0,
                .offset = offsetof(X9_62_CURVE, seed),
                .field_name = "seed",
                .item = &ASN1_BIT_STRING_it,
        },
};

const ASN1_ITEM X9_62_CURVE_it = {
        .itype = ASN1_ITYPE_SEQUENCE,
        .utype = V_ASN1_SEQUENCE,
        .templates = X9_62_CURVE_seq_tt,
        .tcount = sizeof(X9_62_CURVE_seq_tt) / sizeof(ASN1_TEMPLATE),
        .funcs = NULL,
        .size = sizeof(X9_62_CURVE),
        .sname = "X9_62_CURVE",
};

static const ASN1_TEMPLATE ECPARAMETERS_seq_tt[] = {
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(ECPARAMETERS, version),
                .field_name = "version",
                .item = &LONG_it,
        },
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(ECPARAMETERS, fieldID),
                .field_name = "fieldID",
                .item = &X9_62_FIELDID_it,
        },
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(ECPARAMETERS, curve),
                .field_name = "curve",
                .item = &X9_62_CURVE_it,
        },
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(ECPARAMETERS, base),
                .field_name = "base",
                .item = &ASN1_OCTET_STRING_it,
        },
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(ECPARAMETERS, order),
                .field_name = "order",
                .item = &ASN1_INTEGER_it,
        },
        {
                .flags = ASN1_TFLG_OPTIONAL,
                .tag = 0,
                .offset = offsetof(ECPARAMETERS, cofactor),
                .field_name = "cofactor",
                .item = &ASN1_INTEGER_it,
        },
};

const ASN1_ITEM ECPARAMETERS_it = {
        .itype = ASN1_ITYPE_SEQUENCE,
        .utype = V_ASN1_SEQUENCE,
        .templates = ECPARAMETERS_seq_tt,
        .tcount = sizeof(ECPARAMETERS_seq_tt) / sizeof(ASN1_TEMPLATE),
        .funcs = NULL,
        .size = sizeof(ECPARAMETERS),
        .sname = "ECPARAMETERS",
};

ECPARAMETERS *ECPARAMETERS_new(void);
void ECPARAMETERS_free(ECPARAMETERS *a);

ECPARAMETERS *
ECPARAMETERS_new(void)
{
        return (ECPARAMETERS*)ASN1_item_new(&ECPARAMETERS_it);
}

void
ECPARAMETERS_free(ECPARAMETERS *a)
{
        ASN1_item_free((ASN1_VALUE *)a, &ECPARAMETERS_it);
}

static const ASN1_TEMPLATE ECPKPARAMETERS_ch_tt[] = {
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(ECPKPARAMETERS, value.named_curve),
                .field_name = "value.named_curve",
                .item = &ASN1_OBJECT_it,
        },
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(ECPKPARAMETERS, value.parameters),
                .field_name = "value.parameters",
                .item = &ECPARAMETERS_it,
        },
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(ECPKPARAMETERS, value.implicitlyCA),
                .field_name = "value.implicitlyCA",
                .item = &ASN1_NULL_it,
        },
};

const ASN1_ITEM ECPKPARAMETERS_it = {
        .itype = ASN1_ITYPE_CHOICE,
        .utype = offsetof(ECPKPARAMETERS, type),
        .templates = ECPKPARAMETERS_ch_tt,
        .tcount = sizeof(ECPKPARAMETERS_ch_tt) / sizeof(ASN1_TEMPLATE),
        .funcs = NULL,
        .size = sizeof(ECPKPARAMETERS),
        .sname = "ECPKPARAMETERS",
};

ECPKPARAMETERS *ECPKPARAMETERS_new(void);
void ECPKPARAMETERS_free(ECPKPARAMETERS *a);
ECPKPARAMETERS *d2i_ECPKPARAMETERS(ECPKPARAMETERS **a, const unsigned char **in, long len);
int i2d_ECPKPARAMETERS(const ECPKPARAMETERS *a, unsigned char **out);

ECPKPARAMETERS *
d2i_ECPKPARAMETERS(ECPKPARAMETERS **a, const unsigned char **in, long len)
{
        return (ECPKPARAMETERS *)ASN1_item_d2i((ASN1_VALUE **)a, in, len,
            &ECPKPARAMETERS_it);
}

int
i2d_ECPKPARAMETERS(const ECPKPARAMETERS *a, unsigned char **out)
{
        return ASN1_item_i2d((ASN1_VALUE *)a, out, &ECPKPARAMETERS_it);
}

ECPKPARAMETERS *
ECPKPARAMETERS_new(void)
{
        return (ECPKPARAMETERS *)ASN1_item_new(&ECPKPARAMETERS_it);
}

void
ECPKPARAMETERS_free(ECPKPARAMETERS *a)
{
        ASN1_item_free((ASN1_VALUE *)a, &ECPKPARAMETERS_it);
}

static const ASN1_TEMPLATE EC_PRIVATEKEY_seq_tt[] = {
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(EC_PRIVATEKEY, version),
                .field_name = "version",
                .item = &LONG_it,
        },
        {
                .flags = 0,
                .tag = 0,
                .offset = offsetof(EC_PRIVATEKEY, privateKey),
                .field_name = "privateKey",
                .item = &ASN1_OCTET_STRING_it,
        },
        {
                .flags = ASN1_TFLG_EXPLICIT | ASN1_TFLG_OPTIONAL,
                .tag = 0,
                .offset = offsetof(EC_PRIVATEKEY, parameters),
                .field_name = "parameters",
                .item = &ECPKPARAMETERS_it,
        },
        {
                .flags = ASN1_TFLG_EXPLICIT | ASN1_TFLG_OPTIONAL,
                .tag = 1,
                .offset = offsetof(EC_PRIVATEKEY, publicKey),
                .field_name = "publicKey",
                .item = &ASN1_BIT_STRING_it,
        },
};

const ASN1_ITEM EC_PRIVATEKEY_it = {
        .itype = ASN1_ITYPE_SEQUENCE,
        .utype = V_ASN1_SEQUENCE,
        .templates = EC_PRIVATEKEY_seq_tt,
        .tcount = sizeof(EC_PRIVATEKEY_seq_tt) / sizeof(ASN1_TEMPLATE),
        .funcs = NULL,
        .size = sizeof(EC_PRIVATEKEY),
        .sname = "EC_PRIVATEKEY",
};

EC_PRIVATEKEY *EC_PRIVATEKEY_new(void);
void EC_PRIVATEKEY_free(EC_PRIVATEKEY *a);
EC_PRIVATEKEY *d2i_EC_PRIVATEKEY(EC_PRIVATEKEY **a, const unsigned char **in, long len);
int i2d_EC_PRIVATEKEY(const EC_PRIVATEKEY *a, unsigned char **out);

EC_PRIVATEKEY *
d2i_EC_PRIVATEKEY(EC_PRIVATEKEY **a, const unsigned char **in, long len)
{
        return (EC_PRIVATEKEY *)ASN1_item_d2i((ASN1_VALUE **)a, in, len,
            &EC_PRIVATEKEY_it);
}

int
i2d_EC_PRIVATEKEY(const EC_PRIVATEKEY *a, unsigned char **out)
{
        return ASN1_item_i2d((ASN1_VALUE *)a, out, &EC_PRIVATEKEY_it);
}

EC_PRIVATEKEY *
EC_PRIVATEKEY_new(void)
{
        return (EC_PRIVATEKEY *)ASN1_item_new(&EC_PRIVATEKEY_it);
}

void
EC_PRIVATEKEY_free(EC_PRIVATEKEY *a)
{
        ASN1_item_free((ASN1_VALUE *)a, &EC_PRIVATEKEY_it);
}

/* some declarations of internal function */

/* ec_asn1_group2field() sets the values in a X9_62_FIELDID object */
static int ec_asn1_group2fieldid(const EC_GROUP *, X9_62_FIELDID *);
/* ec_asn1_group2curve() sets the values in a X9_62_CURVE object */
static int ec_asn1_group2curve(const EC_GROUP *, X9_62_CURVE *);
/* ec_asn1_parameters2group() creates a EC_GROUP object from a
 * ECPARAMETERS object */
static EC_GROUP *ec_asn1_parameters2group(const ECPARAMETERS *);
/* ec_asn1_group2parameters() creates a ECPARAMETERS object from a
 * EC_GROUP object */
static ECPARAMETERS *ec_asn1_group2parameters(const EC_GROUP *, ECPARAMETERS *);
/* ec_asn1_pkparameters2group() creates a EC_GROUP object from a
 * ECPKPARAMETERS object */
static EC_GROUP *ec_asn1_pkparameters2group(const ECPKPARAMETERS *);
/* ec_asn1_group2pkparameters() creates a ECPKPARAMETERS object from a
 * EC_GROUP object */
static ECPKPARAMETERS *ec_asn1_group2pkparameters(const EC_GROUP *,
    ECPKPARAMETERS *);

/* the function definitions */

static int
ec_asn1_group2fieldid(const EC_GROUP * group, X9_62_FIELDID * field)
{
        int ok = 0, nid;
        BIGNUM *tmp = NULL;

        if (group == NULL || field == NULL)
                return 0;

        /* clear the old values (if necessary) */
        if (field->fieldType != NULL)
                ASN1_OBJECT_free(field->fieldType);
        if (field->p.other != NULL)
                ASN1_TYPE_free(field->p.other);

        nid = EC_METHOD_get_field_type(EC_GROUP_method_of(group));
        /* set OID for the field */
        if ((field->fieldType = OBJ_nid2obj(nid)) == NULL) {
                ECerror(ERR_R_OBJ_LIB);
                goto err;
        }
        if (nid == NID_X9_62_prime_field) {
                if ((tmp = BN_new()) == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                /* the parameters are specified by the prime number p */
                if (!EC_GROUP_get_curve(group, tmp, NULL, NULL, NULL)) {
                        ECerror(ERR_R_EC_LIB);
                        goto err;
                }
                /* set the prime number */
                field->p.prime = BN_to_ASN1_INTEGER(tmp, NULL);
                if (field->p.prime == NULL) {
                        ECerror(ERR_R_ASN1_LIB);
                        goto err;
                }
        } else                  /* nid == NID_X9_62_characteristic_two_field */
#ifdef OPENSSL_NO_EC2M
        {
                ECerror(EC_R_GF2M_NOT_SUPPORTED);
                goto err;
        }
#else
        {
                int field_type;
                X9_62_CHARACTERISTIC_TWO *char_two;

                field->p.char_two = X9_62_CHARACTERISTIC_TWO_new();
                char_two = field->p.char_two;

                if (char_two == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                char_two->m = (long) EC_GROUP_get_degree(group);

                field_type = EC_GROUP_get_basis_type(group);

                if (field_type == 0) {
                        ECerror(ERR_R_EC_LIB);
                        goto err;
                }
                /* set base type OID */
                if ((char_two->type = OBJ_nid2obj(field_type)) == NULL) {
                        ECerror(ERR_R_OBJ_LIB);
                        goto err;
                }
                if (field_type == NID_X9_62_tpBasis) {
                        unsigned int k;

                        if (!EC_GROUP_get_trinomial_basis(group, &k))
                                goto err;

                        char_two->p.tpBasis = ASN1_INTEGER_new();
                        if (!char_two->p.tpBasis) {
                                ECerror(ERR_R_MALLOC_FAILURE);
                                goto err;
                        }
                        if (!ASN1_INTEGER_set(char_two->p.tpBasis, (long) k)) {
                                ECerror(ERR_R_ASN1_LIB);
                                goto err;
                        }
                } else if (field_type == NID_X9_62_ppBasis) {
                        unsigned int k1, k2, k3;

                        if (!EC_GROUP_get_pentanomial_basis(group, &k1, &k2, &k3))
                                goto err;

                        char_two->p.ppBasis = X9_62_PENTANOMIAL_new();
                        if (!char_two->p.ppBasis) {
                                ECerror(ERR_R_MALLOC_FAILURE);
                                goto err;
                        }
                        /* set k? values */
                        char_two->p.ppBasis->k1 = (long) k1;
                        char_two->p.ppBasis->k2 = (long) k2;
                        char_two->p.ppBasis->k3 = (long) k3;
                } else {        /* field_type == NID_X9_62_onBasis */
                        /* for ONB the parameters are (asn1) NULL */
                        char_two->p.onBasis = ASN1_NULL_new();
                        if (!char_two->p.onBasis) {
                                ECerror(ERR_R_MALLOC_FAILURE);
                                goto err;
                        }
                }
        }
#endif

        ok = 1;

 err:
        BN_free(tmp);
        return (ok);
}

static int 
ec_asn1_group2curve(const EC_GROUP * group, X9_62_CURVE * curve)
{
        BIGNUM *tmp_1 = NULL, *tmp_2 = NULL;
        unsigned char *buffer_1 = NULL, *buffer_2 = NULL, *a_buf = NULL,
        *b_buf = NULL;
        size_t len_1, len_2;
        unsigned char char_zero = 0;
        int ok = 0;

        if (!group || !curve || !curve->a || !curve->b)
                return 0;

        if ((tmp_1 = BN_new()) == NULL || (tmp_2 = BN_new()) == NULL) {
                ECerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }

        /* get a and b */
        if (!EC_GROUP_get_curve(group, NULL, tmp_1, tmp_2, NULL)) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        len_1 = (size_t) BN_num_bytes(tmp_1);
        len_2 = (size_t) BN_num_bytes(tmp_2);

        if (len_1 == 0) {
                /* len_1 == 0 => a == 0 */
                a_buf = &char_zero;
                len_1 = 1;
        } else {
                if ((buffer_1 = malloc(len_1)) == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                if ((len_1 = BN_bn2bin(tmp_1, buffer_1)) == 0) {
                        ECerror(ERR_R_BN_LIB);
                        goto err;
                }
                a_buf = buffer_1;
        }

        if (len_2 == 0) {
                /* len_2 == 0 => b == 0 */
                b_buf = &char_zero;
                len_2 = 1;
        } else {
                if ((buffer_2 = malloc(len_2)) == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                if ((len_2 = BN_bn2bin(tmp_2, buffer_2)) == 0) {
                        ECerror(ERR_R_BN_LIB);
                        goto err;
                }
                b_buf = buffer_2;
        }

        /* set a and b */
        if (!ASN1_STRING_set(curve->a, a_buf, len_1) ||
            !ASN1_STRING_set(curve->b, b_buf, len_2)) {
                ECerror(ERR_R_ASN1_LIB);
                goto err;
        }

        ASN1_BIT_STRING_free(curve->seed);
        curve->seed = NULL;

        /* set the seed (optional) */
        if (group->seed != NULL) {
                if ((curve->seed = ASN1_BIT_STRING_new()) == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                if (!ASN1_BIT_STRING_set(curve->seed, group->seed,
                        (int) group->seed_len)) {
                        ECerror(ERR_R_ASN1_LIB);
                        goto err;
                }
                if (!asn1_abs_set_unused_bits(curve->seed, 0)) {
                        ECerror(ERR_R_ASN1_LIB);
                        goto err;
                }
        }

        ok = 1;

 err:
        free(buffer_1);
        free(buffer_2);
        BN_free(tmp_1);
        BN_free(tmp_2);
        return (ok);
}

static ECPARAMETERS *
ec_asn1_group2parameters(const EC_GROUP * group, ECPARAMETERS * param)
{
        int ok = 0;
        size_t len = 0;
        ECPARAMETERS *ret = NULL;
        BIGNUM *tmp = NULL;
        unsigned char *buffer = NULL;
        const EC_POINT *point = NULL;
        point_conversion_form_t form;

        if ((tmp = BN_new()) == NULL) {
                ECerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }
        if (param == NULL) {
                if ((ret = ECPARAMETERS_new()) == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
        } else
                ret = param;

        /* set the version (always one) */
        ret->version = (long) 0x1;

        /* set the fieldID */
        if (!ec_asn1_group2fieldid(group, ret->fieldID)) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        /* set the curve */
        if (!ec_asn1_group2curve(group, ret->curve)) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        /* set the base point */
        if ((point = EC_GROUP_get0_generator(group)) == NULL) {
                ECerror(EC_R_UNDEFINED_GENERATOR);
                goto err;
        }
        form = EC_GROUP_get_point_conversion_form(group);

        len = EC_POINT_point2oct(group, point, form, NULL, len, NULL);
        if (len == 0) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        if ((buffer = malloc(len)) == NULL) {
                ECerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }
        if (!EC_POINT_point2oct(group, point, form, buffer, len, NULL)) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        if (ret->base == NULL && (ret->base = ASN1_OCTET_STRING_new()) == NULL) {
                ECerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }
        if (!ASN1_OCTET_STRING_set(ret->base, buffer, len)) {
                ECerror(ERR_R_ASN1_LIB);
                goto err;
        }
        /* set the order */
        if (!EC_GROUP_get_order(group, tmp, NULL)) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        ret->order = BN_to_ASN1_INTEGER(tmp, ret->order);
        if (ret->order == NULL) {
                ECerror(ERR_R_ASN1_LIB);
                goto err;
        }
        /* set the cofactor (optional) */
        if (EC_GROUP_get_cofactor(group, tmp, NULL)) {
                ret->cofactor = BN_to_ASN1_INTEGER(tmp, ret->cofactor);
                if (ret->cofactor == NULL) {
                        ECerror(ERR_R_ASN1_LIB);
                        goto err;
                }
        }
        ok = 1;

 err:
        if (!ok) {
                if (ret && !param)
                        ECPARAMETERS_free(ret);
                ret = NULL;
        }
        BN_free(tmp);
        free(buffer);
        return (ret);
}

ECPKPARAMETERS *
ec_asn1_group2pkparameters(const EC_GROUP * group, ECPKPARAMETERS * params)
{
        int ok = 1, tmp;
        ECPKPARAMETERS *ret = params;

        if (ret == NULL) {
                if ((ret = ECPKPARAMETERS_new()) == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        return NULL;
                }
        } else {
                if (ret->type == 0 && ret->value.named_curve)
                        ASN1_OBJECT_free(ret->value.named_curve);
                else if (ret->type == 1 && ret->value.parameters)
                        ECPARAMETERS_free(ret->value.parameters);
        }

        if (EC_GROUP_get_asn1_flag(group)) {
                /*
                 * use the asn1 OID to describe the elliptic curve
                 * parameters
                 */
                tmp = EC_GROUP_get_curve_name(group);
                if (tmp) {
                        ret->type = 0;
                        if ((ret->value.named_curve = OBJ_nid2obj(tmp)) == NULL)
                                ok = 0;
                } else
                        /* we don't know the group => ERROR */
                        ok = 0;
        } else {
                /* use the ECPARAMETERS structure */
                ret->type = 1;
                if ((ret->value.parameters = ec_asn1_group2parameters(
                            group, NULL)) == NULL)
                        ok = 0;
        }

        if (!ok) {
                ECPKPARAMETERS_free(ret);
                return NULL;
        }
        return ret;
}

static EC_GROUP *
ec_asn1_parameters2group(const ECPARAMETERS * params)
{
        int ok = 0, tmp;
        EC_GROUP *ret = NULL;
        BIGNUM *p = NULL, *a = NULL, *b = NULL;
        EC_POINT *point = NULL;
        long field_bits;

        if (!params->fieldID || !params->fieldID->fieldType ||
            !params->fieldID->p.ptr) {
                ECerror(EC_R_ASN1_ERROR);
                goto err;
        }
        /* now extract the curve parameters a and b */
        if (!params->curve || !params->curve->a ||
            !params->curve->a->data || !params->curve->b ||
            !params->curve->b->data) {
                ECerror(EC_R_ASN1_ERROR);
                goto err;
        }
        a = BN_bin2bn(params->curve->a->data, params->curve->a->length, NULL);
        if (a == NULL) {
                ECerror(ERR_R_BN_LIB);
                goto err;
        }
        b = BN_bin2bn(params->curve->b->data, params->curve->b->length, NULL);
        if (b == NULL) {
                ECerror(ERR_R_BN_LIB);
                goto err;
        }
        /* get the field parameters */
        tmp = OBJ_obj2nid(params->fieldID->fieldType);
        if (tmp == NID_X9_62_characteristic_two_field)
#ifdef OPENSSL_NO_EC2M
        {
                ECerror(EC_R_GF2M_NOT_SUPPORTED);
                goto err;
        }
#else
        {
                X9_62_CHARACTERISTIC_TWO *char_two;

                char_two = params->fieldID->p.char_two;

                field_bits = char_two->m;
                if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS) {
                        ECerror(EC_R_FIELD_TOO_LARGE);
                        goto err;
                }
                if ((p = BN_new()) == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                /* get the base type */
                tmp = OBJ_obj2nid(char_two->type);

                if (tmp == NID_X9_62_tpBasis) {
                        long tmp_long;

                        if (!char_two->p.tpBasis) {
                                ECerror(EC_R_ASN1_ERROR);
                                goto err;
                        }
                        tmp_long = ASN1_INTEGER_get(char_two->p.tpBasis);

                        if (!(char_two->m > tmp_long && tmp_long > 0)) {
                                ECerror(EC_R_INVALID_TRINOMIAL_BASIS);
                                goto err;
                        }
                        /* create the polynomial */
                        if (!BN_set_bit(p, (int) char_two->m))
                                goto err;
                        if (!BN_set_bit(p, (int) tmp_long))
                                goto err;
                        if (!BN_set_bit(p, 0))
                                goto err;
                } else if (tmp == NID_X9_62_ppBasis) {
                        X9_62_PENTANOMIAL *penta;

                        penta = char_two->p.ppBasis;
                        if (!penta) {
                                ECerror(EC_R_ASN1_ERROR);
                                goto err;
                        }
                        if (!(char_two->m > penta->k3 && penta->k3 > penta->k2 && penta->k2 > penta->k1 && penta->k1 > 0)) {
                                ECerror(EC_R_INVALID_PENTANOMIAL_BASIS);
                                goto err;
                        }
                        /* create the polynomial */
                        if (!BN_set_bit(p, (int) char_two->m))
                                goto err;
                        if (!BN_set_bit(p, (int) penta->k1))
                                goto err;
                        if (!BN_set_bit(p, (int) penta->k2))
                                goto err;
                        if (!BN_set_bit(p, (int) penta->k3))
                                goto err;
                        if (!BN_set_bit(p, 0))
                                goto err;
                } else if (tmp == NID_X9_62_onBasis) {
                        ECerror(EC_R_NOT_IMPLEMENTED);
                        goto err;
                } else {        /* error */
                        ECerror(EC_R_ASN1_ERROR);
                        goto err;
                }

                /* create the EC_GROUP structure */
                ret = EC_GROUP_new_curve_GF2m(p, a, b, NULL);
        }
#endif
        else if (tmp == NID_X9_62_prime_field) {
                /* we have a curve over a prime field */
                /* extract the prime number */
                if (!params->fieldID->p.prime) {
                        ECerror(EC_R_ASN1_ERROR);
                        goto err;
                }
                p = ASN1_INTEGER_to_BN(params->fieldID->p.prime, NULL);
                if (p == NULL) {
                        ECerror(ERR_R_ASN1_LIB);
                        goto err;
                }
                if (BN_is_negative(p) || BN_is_zero(p)) {
                        ECerror(EC_R_INVALID_FIELD);
                        goto err;
                }
                field_bits = BN_num_bits(p);
                if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS) {
                        ECerror(EC_R_FIELD_TOO_LARGE);
                        goto err;
                }
                /* create the EC_GROUP structure */
                ret = EC_GROUP_new_curve_GFp(p, a, b, NULL);
        } else {
                ECerror(EC_R_INVALID_FIELD);
                goto err;
        }

        if (ret == NULL) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        /* extract seed (optional) */
        if (params->curve->seed != NULL) {
                free(ret->seed);
                if (!(ret->seed = malloc(params->curve->seed->length))) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                memcpy(ret->seed, params->curve->seed->data,
                    params->curve->seed->length);
                ret->seed_len = params->curve->seed->length;
        }
        if (!params->order || !params->base || !params->base->data) {
                ECerror(EC_R_ASN1_ERROR);
                goto err;
        }
        if ((point = EC_POINT_new(ret)) == NULL)
                goto err;

        /* set the point conversion form */
        EC_GROUP_set_point_conversion_form(ret, (point_conversion_form_t)
            (params->base->data[0] & ~0x01));

        /* extract the ec point */
        if (!EC_POINT_oct2point(ret, point, params->base->data,
                params->base->length, NULL)) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        /* extract the order */
        if ((a = ASN1_INTEGER_to_BN(params->order, a)) == NULL) {
                ECerror(ERR_R_ASN1_LIB);
                goto err;
        }
        if (BN_is_negative(a) || BN_is_zero(a)) {
                ECerror(EC_R_INVALID_GROUP_ORDER);
                goto err;
        }
        if (BN_num_bits(a) > (int) field_bits + 1) {    /* Hasse bound */
                ECerror(EC_R_INVALID_GROUP_ORDER);
                goto err;
        }
        /* extract the cofactor (optional) */
        if (params->cofactor == NULL) {
                BN_free(b);
                b = NULL;
        } else if ((b = ASN1_INTEGER_to_BN(params->cofactor, b)) == NULL) {
                ECerror(ERR_R_ASN1_LIB);
                goto err;
        }
        /* set the generator, order and cofactor (if present) */
        if (!EC_GROUP_set_generator(ret, point, a, b)) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        ok = 1;

 err:
        if (!ok) {
                EC_GROUP_clear_free(ret);
                ret = NULL;
        }
        BN_free(p);
        BN_free(a);
        BN_free(b);
        EC_POINT_free(point);
        return (ret);
}

EC_GROUP *
ec_asn1_pkparameters2group(const ECPKPARAMETERS * params)
{
        EC_GROUP *ret = NULL;
        int tmp = 0;

        if (params == NULL) {
                ECerror(EC_R_MISSING_PARAMETERS);
                return NULL;
        }
        if (params->type == 0) {/* the curve is given by an OID */
                tmp = OBJ_obj2nid(params->value.named_curve);
                if ((ret = EC_GROUP_new_by_curve_name(tmp)) == NULL) {
                        ECerror(EC_R_EC_GROUP_NEW_BY_NAME_FAILURE);
                        return NULL;
                }
                EC_GROUP_set_asn1_flag(ret, OPENSSL_EC_NAMED_CURVE);
        } else if (params->type == 1) { /* the parameters are given by a
                                         * ECPARAMETERS structure */
                ret = ec_asn1_parameters2group(params->value.parameters);
                if (!ret) {
                        ECerror(ERR_R_EC_LIB);
                        return NULL;
                }
                EC_GROUP_set_asn1_flag(ret, 0x0);
        } else if (params->type == 2) { /* implicitlyCA */
                return NULL;
        } else {
                ECerror(EC_R_ASN1_ERROR);
                return NULL;
        }

        return ret;
}

/* EC_GROUP <-> DER encoding of ECPKPARAMETERS */

EC_GROUP *
d2i_ECPKParameters(EC_GROUP ** a, const unsigned char **in, long len)
{
        EC_GROUP *group = NULL;
        ECPKPARAMETERS *params;

        if ((params = d2i_ECPKPARAMETERS(NULL, in, len)) == NULL) {
                ECerror(EC_R_D2I_ECPKPARAMETERS_FAILURE);
                goto err;
        }
        if ((group = ec_asn1_pkparameters2group(params)) == NULL) {
                ECerror(EC_R_PKPARAMETERS2GROUP_FAILURE);
                goto err;
        }

        if (a != NULL) {
                EC_GROUP_clear_free(*a);
                *a = group;
        }

 err:
        ECPKPARAMETERS_free(params);
        return (group);
}

int 
i2d_ECPKParameters(const EC_GROUP * a, unsigned char **out)
{
        int ret = 0;
        ECPKPARAMETERS *tmp = ec_asn1_group2pkparameters(a, NULL);
        if (tmp == NULL) {
                ECerror(EC_R_GROUP2PKPARAMETERS_FAILURE);
                return 0;
        }
        if ((ret = i2d_ECPKPARAMETERS(tmp, out)) == 0) {
                ECerror(EC_R_I2D_ECPKPARAMETERS_FAILURE);
                ECPKPARAMETERS_free(tmp);
                return 0;
        }
        ECPKPARAMETERS_free(tmp);
        return (ret);
}

/* some EC_KEY functions */

EC_KEY *
d2i_ECPrivateKey(EC_KEY ** a, const unsigned char **in, long len)
{
        EC_KEY *ret = NULL;
        EC_PRIVATEKEY *priv_key = NULL;

        if ((priv_key = d2i_EC_PRIVATEKEY(NULL, in, len)) == NULL) {
                ECerror(ERR_R_EC_LIB);
                return NULL;
        }
        if (a == NULL || *a == NULL) {
                if ((ret = EC_KEY_new()) == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
        } else
                ret = *a;

        if (priv_key->parameters) {
                EC_GROUP_clear_free(ret->group);
                ret->group = ec_asn1_pkparameters2group(priv_key->parameters);
        }
        if (ret->group == NULL) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        ret->version = priv_key->version;

        if (priv_key->privateKey) {
                ret->priv_key = BN_bin2bn(
                    ASN1_STRING_data(priv_key->privateKey),
                    ASN1_STRING_length(priv_key->privateKey),
                    ret->priv_key);
                if (ret->priv_key == NULL) {
                        ECerror(ERR_R_BN_LIB);
                        goto err;
                }
        } else {
                ECerror(EC_R_MISSING_PRIVATE_KEY);
                goto err;
        }

        if (ret->pub_key)
                EC_POINT_clear_free(ret->pub_key);
        ret->pub_key = EC_POINT_new(ret->group);
        if (ret->pub_key == NULL) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }

        if (priv_key->publicKey) {
                const unsigned char *pub_oct;
                size_t pub_oct_len;

                pub_oct = ASN1_STRING_data(priv_key->publicKey);
                pub_oct_len = ASN1_STRING_length(priv_key->publicKey);
                if (pub_oct == NULL || pub_oct_len <= 0) {
                        ECerror(EC_R_BUFFER_TOO_SMALL);
                        goto err;
                }

                /* save the point conversion form */
                ret->conv_form = (point_conversion_form_t) (pub_oct[0] & ~0x01);
                if (!EC_POINT_oct2point(ret->group, ret->pub_key,
                        pub_oct, pub_oct_len, NULL)) {
                        ECerror(ERR_R_EC_LIB);
                        goto err;
                }
        } else {
                if (!EC_POINT_mul(ret->group, ret->pub_key, ret->priv_key,
                        NULL, NULL, NULL)) {
                        ECerror(ERR_R_EC_LIB);
                        goto err;
                }
                /* Remember the original private-key-only encoding. */
                ret->enc_flag |= EC_PKEY_NO_PUBKEY;
        }

        EC_PRIVATEKEY_free(priv_key);
        if (a != NULL)
                *a = ret;
        return (ret);

 err:
        if (a == NULL || *a != ret)
                EC_KEY_free(ret);
        if (priv_key)
                EC_PRIVATEKEY_free(priv_key);

        return (NULL);
}

int 
i2d_ECPrivateKey(EC_KEY * a, unsigned char **out)
{
        int ret = 0, ok = 0;
        unsigned char *buffer = NULL;
        size_t buf_len = 0, tmp_len;
        EC_PRIVATEKEY *priv_key = NULL;

        if (a == NULL || a->group == NULL || a->priv_key == NULL ||
            (!(a->enc_flag & EC_PKEY_NO_PUBKEY) && a->pub_key == NULL)) {
                ECerror(ERR_R_PASSED_NULL_PARAMETER);
                goto err;
        }
        if ((priv_key = EC_PRIVATEKEY_new()) == NULL) {
                ECerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }
        priv_key->version = a->version;

        buf_len = (size_t) BN_num_bytes(a->priv_key);
        buffer = malloc(buf_len);
        if (buffer == NULL) {
                ECerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }
        if (!BN_bn2bin(a->priv_key, buffer)) {
                ECerror(ERR_R_BN_LIB);
                goto err;
        }
        if (!ASN1_STRING_set(priv_key->privateKey, buffer, buf_len)) {
                ECerror(ERR_R_ASN1_LIB);
                goto err;
        }
        if (!(a->enc_flag & EC_PKEY_NO_PARAMETERS)) {
                if ((priv_key->parameters = ec_asn1_group2pkparameters(
                            a->group, priv_key->parameters)) == NULL) {
                        ECerror(ERR_R_EC_LIB);
                        goto err;
                }
        }
        if (!(a->enc_flag & EC_PKEY_NO_PUBKEY) && a->pub_key != NULL) {
                priv_key->publicKey = ASN1_BIT_STRING_new();
                if (priv_key->publicKey == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                tmp_len = EC_POINT_point2oct(a->group, a->pub_key,
                    a->conv_form, NULL, 0, NULL);

                if (tmp_len > buf_len) {
                        unsigned char *tmp_buffer = realloc(buffer, tmp_len);
                        if (!tmp_buffer) {
                                ECerror(ERR_R_MALLOC_FAILURE);
                                goto err;
                        }
                        buffer = tmp_buffer;
                        buf_len = tmp_len;
                }
                if (!EC_POINT_point2oct(a->group, a->pub_key,
                        a->conv_form, buffer, buf_len, NULL)) {
                        ECerror(ERR_R_EC_LIB);
                        goto err;
                }
                if (!ASN1_STRING_set(priv_key->publicKey, buffer, buf_len)) {
                        ECerror(ERR_R_ASN1_LIB);
                        goto err;
                }
                if (!asn1_abs_set_unused_bits(priv_key->publicKey, 0)) {
                        ECerror(ERR_R_ASN1_LIB);
                        goto err;
                }
        }
        if ((ret = i2d_EC_PRIVATEKEY(priv_key, out)) == 0) {
                ECerror(ERR_R_EC_LIB);
                goto err;
        }
        ok = 1;
 err:
        free(buffer);
        if (priv_key)
                EC_PRIVATEKEY_free(priv_key);
        return (ok ? ret : 0);
}

int 
i2d_ECParameters(EC_KEY * a, unsigned char **out)
{
        if (a == NULL) {
                ECerror(ERR_R_PASSED_NULL_PARAMETER);
                return 0;
        }
        return i2d_ECPKParameters(a->group, out);
}

EC_KEY *
d2i_ECParameters(EC_KEY ** a, const unsigned char **in, long len)
{
        EC_KEY *ret;

        if (in == NULL || *in == NULL) {
                ECerror(ERR_R_PASSED_NULL_PARAMETER);
                return NULL;
        }
        if (a == NULL || *a == NULL) {
                if ((ret = EC_KEY_new()) == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        return NULL;
                }
        } else
                ret = *a;

        if (!d2i_ECPKParameters(&ret->group, in, len)) {
                ECerror(ERR_R_EC_LIB);
                if (a == NULL || *a != ret)
                        EC_KEY_free(ret);
                return NULL;
        }

        if (a != NULL)
                *a = ret;
        return ret;
}

EC_KEY *
o2i_ECPublicKey(EC_KEY ** a, const unsigned char **in, long len)
{
        EC_KEY *ret = NULL;

        if (a == NULL || (*a) == NULL || (*a)->group == NULL) {
                /* An EC_GROUP structure is necessary to set the public key. */
                ECerror(ERR_R_PASSED_NULL_PARAMETER);
                return 0;
        }
        ret = *a;
        if (ret->pub_key == NULL &&
            (ret->pub_key = EC_POINT_new(ret->group)) == NULL) {
                ECerror(ERR_R_MALLOC_FAILURE);
                return 0;
        }
        if (!EC_POINT_oct2point(ret->group, ret->pub_key, *in, len, NULL)) {
                ECerror(ERR_R_EC_LIB);
                return 0;
        }
        /* save the point conversion form */
        ret->conv_form = (point_conversion_form_t) (*in[0] & ~0x01);
        *in += len;
        return ret;
}

int 
i2o_ECPublicKey(const EC_KEY * a, unsigned char **out)
{
        size_t buf_len = 0;
        int new_buffer = 0;

        if (a == NULL) {
                ECerror(ERR_R_PASSED_NULL_PARAMETER);
                return 0;
        }
        buf_len = EC_POINT_point2oct(a->group, a->pub_key,
            a->conv_form, NULL, 0, NULL);

        if (out == NULL || buf_len == 0)
                /* out == NULL => just return the length of the octet string */
                return buf_len;

        if (*out == NULL) {
                if ((*out = malloc(buf_len)) == NULL) {
                        ECerror(ERR_R_MALLOC_FAILURE);
                        return 0;
                }
                new_buffer = 1;
        }
        if (!EC_POINT_point2oct(a->group, a->pub_key, a->conv_form,
                *out, buf_len, NULL)) {
                ECerror(ERR_R_EC_LIB);
                if (new_buffer) {
                        free(*out);
                        *out = NULL;
                }
                return 0;
        }
        if (!new_buffer)
                *out += buf_len;
        return buf_len;
}