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      1 /* Written by Nils Larsch for the OpenSSL project. */
      2 /* ====================================================================
      3  * Copyright (c) 2000-2003 The OpenSSL Project.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  *
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  *
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in
     14  *    the documentation and/or other materials provided with the
     15  *    distribution.
     16  *
     17  * 3. All advertising materials mentioning features or use of this
     18  *    software must display the following acknowledgment:
     19  *    "This product includes software developed by the OpenSSL Project
     20  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
     21  *
     22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
     23  *    endorse or promote products derived from this software without
     24  *    prior written permission. For written permission, please contact
     25  *    licensing (at) OpenSSL.org.
     26  *
     27  * 5. Products derived from this software may not be called "OpenSSL"
     28  *    nor may "OpenSSL" appear in their names without prior written
     29  *    permission of the OpenSSL Project.
     30  *
     31  * 6. Redistributions of any form whatsoever must retain the following
     32  *    acknowledgment:
     33  *    "This product includes software developed by the OpenSSL Project
     34  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
     35  *
     36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
     37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
     40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     47  * OF THE POSSIBILITY OF SUCH DAMAGE.
     48  * ====================================================================
     49  *
     50  * This product includes cryptographic software written by Eric Young
     51  * (eay (at) cryptsoft.com).  This product includes software written by Tim
     52  * Hudson (tjh (at) cryptsoft.com). */
     53 
     54 #include <openssl/ec.h>
     55 
     56 #include <string.h>
     57 
     58 #include <openssl/asn1.h>
     59 #include <openssl/asn1t.h>
     60 #include <openssl/bn.h>
     61 #include <openssl/err.h>
     62 #include <openssl/mem.h>
     63 #include <openssl/obj.h>
     64 
     65 #include "internal.h"
     66 
     67 
     68 typedef struct x9_62_fieldid_st {
     69   ASN1_OBJECT *fieldType;
     70   union {
     71     char *ptr;
     72     /* NID_X9_62_prime_field */
     73     ASN1_INTEGER *prime;
     74     /* anything else */
     75     ASN1_TYPE *other;
     76   } p;
     77 } X9_62_FIELDID;
     78 
     79 ASN1_ADB_TEMPLATE(fieldID_def) = ASN1_SIMPLE(X9_62_FIELDID, p.other, ASN1_ANY);
     80 
     81 ASN1_ADB(X9_62_FIELDID) = {
     82   ADB_ENTRY(NID_X9_62_prime_field, ASN1_SIMPLE(X9_62_FIELDID, p.prime, ASN1_INTEGER)),
     83 } ASN1_ADB_END(X9_62_FIELDID, 0, fieldType, 0, &fieldID_def_tt, NULL);
     84 
     85 ASN1_SEQUENCE(X9_62_FIELDID) = {
     86   ASN1_SIMPLE(X9_62_FIELDID, fieldType, ASN1_OBJECT),
     87   ASN1_ADB_OBJECT(X9_62_FIELDID)
     88 } ASN1_SEQUENCE_END(X9_62_FIELDID);
     89 
     90 typedef struct x9_62_curve_st {
     91   ASN1_OCTET_STRING *a;
     92   ASN1_OCTET_STRING *b;
     93   ASN1_BIT_STRING *seed;
     94 } X9_62_CURVE;
     95 
     96 ASN1_SEQUENCE(X9_62_CURVE) = {
     97   ASN1_SIMPLE(X9_62_CURVE, a, ASN1_OCTET_STRING),
     98   ASN1_SIMPLE(X9_62_CURVE, b, ASN1_OCTET_STRING),
     99   ASN1_OPT(X9_62_CURVE, seed, ASN1_BIT_STRING)
    100 } ASN1_SEQUENCE_END(X9_62_CURVE);
    101 
    102 typedef struct ec_parameters_st {
    103   long version;
    104   X9_62_FIELDID *fieldID;
    105   X9_62_CURVE *curve;
    106   ASN1_OCTET_STRING *base;
    107   ASN1_INTEGER *order;
    108   ASN1_INTEGER *cofactor;
    109 } ECPARAMETERS;
    110 
    111 DECLARE_ASN1_ALLOC_FUNCTIONS(ECPARAMETERS);
    112 
    113 ASN1_SEQUENCE(ECPARAMETERS) = {
    114     ASN1_SIMPLE(ECPARAMETERS, version, LONG),
    115     ASN1_SIMPLE(ECPARAMETERS, fieldID, X9_62_FIELDID),
    116     ASN1_SIMPLE(ECPARAMETERS, curve, X9_62_CURVE),
    117     ASN1_SIMPLE(ECPARAMETERS, base, ASN1_OCTET_STRING),
    118     ASN1_SIMPLE(ECPARAMETERS, order, ASN1_INTEGER),
    119     ASN1_OPT(ECPARAMETERS, cofactor, ASN1_INTEGER)
    120 } ASN1_SEQUENCE_END(ECPARAMETERS);
    121 
    122 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(ECPARAMETERS);
    123 
    124 typedef struct ecpk_parameters_st {
    125   int type;
    126   union {
    127     ASN1_OBJECT *named_curve;
    128     ECPARAMETERS *parameters;
    129   } value;
    130 } ECPKPARAMETERS;
    131 
    132 /* SEC1 ECPrivateKey */
    133 typedef struct ec_privatekey_st {
    134   long version;
    135   ASN1_OCTET_STRING *privateKey;
    136   ECPKPARAMETERS *parameters;
    137   ASN1_BIT_STRING *publicKey;
    138 } EC_PRIVATEKEY;
    139 
    140 DECLARE_ASN1_FUNCTIONS_const(ECPKPARAMETERS);
    141 DECLARE_ASN1_ENCODE_FUNCTIONS_const(ECPKPARAMETERS, ECPKPARAMETERS);
    142 
    143 ASN1_CHOICE(ECPKPARAMETERS) = {
    144     ASN1_SIMPLE(ECPKPARAMETERS, value.named_curve, ASN1_OBJECT),
    145     ASN1_SIMPLE(ECPKPARAMETERS, value.parameters, ECPARAMETERS),
    146 } ASN1_CHOICE_END(ECPKPARAMETERS);
    147 
    148 IMPLEMENT_ASN1_FUNCTIONS_const(ECPKPARAMETERS);
    149 
    150 DECLARE_ASN1_FUNCTIONS_const(EC_PRIVATEKEY);
    151 DECLARE_ASN1_ENCODE_FUNCTIONS_const(EC_PRIVATEKEY, EC_PRIVATEKEY);
    152 
    153 ASN1_SEQUENCE(EC_PRIVATEKEY) = {
    154     ASN1_SIMPLE(EC_PRIVATEKEY, version, LONG),
    155     ASN1_SIMPLE(EC_PRIVATEKEY, privateKey, ASN1_OCTET_STRING),
    156     ASN1_EXP_OPT(EC_PRIVATEKEY, parameters, ECPKPARAMETERS, 0),
    157     ASN1_EXP_OPT(EC_PRIVATEKEY, publicKey, ASN1_BIT_STRING, 1),
    158 } ASN1_SEQUENCE_END(EC_PRIVATEKEY);
    159 
    160 IMPLEMENT_ASN1_FUNCTIONS_const(EC_PRIVATEKEY);
    161 
    162 
    163 ECPKPARAMETERS *ec_asn1_group2pkparameters(const EC_GROUP *group,
    164                                            ECPKPARAMETERS *params) {
    165   int ok = 0, nid;
    166   ECPKPARAMETERS *ret = params;
    167 
    168   if (ret == NULL) {
    169     ret = ECPKPARAMETERS_new();
    170     if (ret == NULL) {
    171       OPENSSL_PUT_ERROR(EC, ec_asn1_group2pkparameters, ERR_R_MALLOC_FAILURE);
    172       return NULL;
    173     }
    174   } else {
    175     ASN1_OBJECT_free(ret->value.named_curve);
    176   }
    177 
    178   /* use the ASN.1 OID to describe the the elliptic curve parameters. */
    179   nid = EC_GROUP_get_curve_name(group);
    180   if (nid) {
    181     ret->type = 0;
    182     ret->value.named_curve = (ASN1_OBJECT*) OBJ_nid2obj(nid);
    183     ok = ret->value.named_curve != NULL;
    184   }
    185 
    186   if (!ok) {
    187     ECPKPARAMETERS_free(ret);
    188     return NULL;
    189   }
    190 
    191   return ret;
    192 }
    193 
    194 EC_GROUP *ec_asn1_pkparameters2group(const ECPKPARAMETERS *params) {
    195   EC_GROUP *ret = NULL;
    196   int nid = NID_undef;
    197 
    198   if (params == NULL) {
    199     OPENSSL_PUT_ERROR(EC, ec_asn1_pkparameters2group, EC_R_MISSING_PARAMETERS);
    200     return NULL;
    201   }
    202 
    203   if (params->type == 0) {
    204     nid = OBJ_obj2nid(params->value.named_curve);
    205   } else if (params->type == 1) {
    206     /* We don't support arbitary curves so we attempt to recognise it from the
    207      * group order. */
    208     const ECPARAMETERS *ecparams = params->value.parameters;
    209     unsigned i;
    210     const struct built_in_curve *curve;
    211 
    212     for (i = 0; OPENSSL_built_in_curves[i].nid != NID_undef; i++) {
    213       curve = &OPENSSL_built_in_curves[i];
    214       const unsigned param_len = curve->data->param_len;
    215       if (ecparams->order->length == param_len &&
    216           memcmp(ecparams->order->data, &curve->data->data[param_len * 5],
    217                  param_len) == 0) {
    218         nid = curve->nid;
    219         break;
    220       }
    221     }
    222   }
    223 
    224   if (nid == NID_undef) {
    225     OPENSSL_PUT_ERROR(EC, ec_asn1_pkparameters2group, EC_R_NON_NAMED_CURVE);
    226     return NULL;
    227   }
    228 
    229   ret = EC_GROUP_new_by_curve_name(nid);
    230   if (ret == NULL) {
    231     OPENSSL_PUT_ERROR(EC, ec_asn1_pkparameters2group,
    232                       EC_R_EC_GROUP_NEW_BY_NAME_FAILURE);
    233     return NULL;
    234   }
    235 
    236   return ret;
    237 }
    238 
    239 static EC_GROUP *d2i_ECPKParameters(EC_GROUP **groupp, const uint8_t **inp,
    240                                     long len) {
    241   EC_GROUP *group = NULL;
    242   ECPKPARAMETERS *params = NULL;
    243 
    244   params = d2i_ECPKPARAMETERS(NULL, inp, len);
    245   if (params == NULL) {
    246     OPENSSL_PUT_ERROR(EC, d2i_ECPKParameters, EC_R_D2I_ECPKPARAMETERS_FAILURE);
    247     ECPKPARAMETERS_free(params);
    248     return NULL;
    249   }
    250 
    251   group = ec_asn1_pkparameters2group(params);
    252   if (group == NULL) {
    253     OPENSSL_PUT_ERROR(EC, d2i_ECPKParameters, EC_R_PKPARAMETERS2GROUP_FAILURE);
    254     ECPKPARAMETERS_free(params);
    255     return NULL;
    256   }
    257 
    258   if (groupp) {
    259     EC_GROUP_free(*groupp);
    260     *groupp = group;
    261   }
    262 
    263   ECPKPARAMETERS_free(params);
    264   return group;
    265 }
    266 
    267 static int i2d_ECPKParameters(const EC_GROUP *group, uint8_t **outp) {
    268   int ret = 0;
    269   ECPKPARAMETERS *tmp = ec_asn1_group2pkparameters(group, NULL);
    270   if (tmp == NULL) {
    271     OPENSSL_PUT_ERROR(EC, i2d_ECPKParameters, EC_R_GROUP2PKPARAMETERS_FAILURE);
    272     return 0;
    273   }
    274   ret = i2d_ECPKPARAMETERS(tmp, outp);
    275   if (ret == 0) {
    276     OPENSSL_PUT_ERROR(EC, i2d_ECPKParameters, EC_R_I2D_ECPKPARAMETERS_FAILURE);
    277     ECPKPARAMETERS_free(tmp);
    278     return 0;
    279   }
    280   ECPKPARAMETERS_free(tmp);
    281   return ret;
    282 }
    283 
    284 EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const uint8_t **in, long len) {
    285   int ok = 0;
    286   EC_KEY *ret = NULL;
    287   EC_PRIVATEKEY *priv_key = NULL;
    288 
    289   priv_key = d2i_EC_PRIVATEKEY(NULL, in, len);
    290   if (priv_key == NULL) {
    291     OPENSSL_PUT_ERROR(EC, d2i_ECPrivateKey, ERR_R_EC_LIB);
    292     return NULL;
    293   }
    294 
    295   if (a == NULL || *a == NULL) {
    296     ret = EC_KEY_new();
    297     if (ret == NULL) {
    298       OPENSSL_PUT_ERROR(EC, d2i_ECPrivateKey, ERR_R_MALLOC_FAILURE);
    299       goto err;
    300     }
    301   } else {
    302     ret = *a;
    303   }
    304 
    305   if (priv_key->parameters) {
    306     EC_GROUP_free(ret->group);
    307     ret->group = ec_asn1_pkparameters2group(priv_key->parameters);
    308   }
    309 
    310   if (ret->group == NULL) {
    311     OPENSSL_PUT_ERROR(EC, d2i_ECPrivateKey, ERR_R_EC_LIB);
    312     goto err;
    313   }
    314 
    315   ret->version = priv_key->version;
    316 
    317   if (priv_key->privateKey) {
    318     ret->priv_key =
    319         BN_bin2bn(M_ASN1_STRING_data(priv_key->privateKey),
    320                   M_ASN1_STRING_length(priv_key->privateKey), ret->priv_key);
    321     if (ret->priv_key == NULL) {
    322       OPENSSL_PUT_ERROR(EC, d2i_ECPrivateKey, ERR_R_BN_LIB);
    323       goto err;
    324     }
    325   } else {
    326     OPENSSL_PUT_ERROR(EC, d2i_ECPrivateKey, EC_R_MISSING_PRIVATE_KEY);
    327     goto err;
    328   }
    329 
    330   EC_POINT_free(ret->pub_key);
    331   ret->pub_key = EC_POINT_new(ret->group);
    332   if (ret->pub_key == NULL) {
    333     OPENSSL_PUT_ERROR(EC, d2i_ECPrivateKey, ERR_R_EC_LIB);
    334     goto err;
    335   }
    336 
    337   if (priv_key->publicKey) {
    338     const uint8_t *pub_oct;
    339     int pub_oct_len;
    340 
    341     pub_oct = M_ASN1_STRING_data(priv_key->publicKey);
    342     pub_oct_len = M_ASN1_STRING_length(priv_key->publicKey);
    343     /* The first byte (the point conversion form) must be present. */
    344     if (pub_oct_len <= 0) {
    345       OPENSSL_PUT_ERROR(EC, d2i_ECPrivateKey, EC_R_BUFFER_TOO_SMALL);
    346       goto err;
    347     }
    348     /* Save the point conversion form. */
    349     ret->conv_form = (point_conversion_form_t)(pub_oct[0] & ~0x01);
    350     if (!EC_POINT_oct2point(ret->group, ret->pub_key, pub_oct, pub_oct_len,
    351                             NULL)) {
    352       OPENSSL_PUT_ERROR(EC, d2i_ECPrivateKey, ERR_R_EC_LIB);
    353       goto err;
    354     }
    355   } else {
    356     if (!EC_POINT_mul(ret->group, ret->pub_key, ret->priv_key, NULL, NULL,
    357                       NULL)) {
    358       OPENSSL_PUT_ERROR(EC, d2i_ECPrivateKey, ERR_R_EC_LIB);
    359       goto err;
    360     }
    361     /* Remember the original private-key-only encoding. */
    362     ret->enc_flag |= EC_PKEY_NO_PUBKEY;
    363   }
    364 
    365   if (a) {
    366     *a = ret;
    367   }
    368   ok = 1;
    369 
    370 err:
    371   if (!ok) {
    372     if (a == NULL || *a != ret) {
    373       EC_KEY_free(ret);
    374     }
    375     ret = NULL;
    376   }
    377 
    378   EC_PRIVATEKEY_free(priv_key);
    379 
    380   return ret;
    381 }
    382 
    383 int i2d_ECPrivateKey(const EC_KEY *key, uint8_t **outp) {
    384   int ret = 0, ok = 0;
    385   uint8_t *buffer = NULL;
    386   size_t buf_len = 0, tmp_len;
    387   EC_PRIVATEKEY *priv_key = NULL;
    388 
    389   if (key == NULL || key->group == NULL || key->priv_key == NULL) {
    390     OPENSSL_PUT_ERROR(EC, i2d_ECPrivateKey, ERR_R_PASSED_NULL_PARAMETER);
    391     goto err;
    392   }
    393 
    394   priv_key = EC_PRIVATEKEY_new();
    395   if (priv_key == NULL) {
    396     OPENSSL_PUT_ERROR(EC, i2d_ECPrivateKey, ERR_R_MALLOC_FAILURE);
    397     goto err;
    398   }
    399 
    400   priv_key->version = key->version;
    401 
    402   buf_len = BN_num_bytes(&key->group->order);
    403   buffer = OPENSSL_malloc(buf_len);
    404   if (buffer == NULL) {
    405     OPENSSL_PUT_ERROR(EC, i2d_ECPrivateKey, ERR_R_MALLOC_FAILURE);
    406     goto err;
    407   }
    408 
    409   if (!BN_bn2bin_padded(buffer, buf_len, key->priv_key)) {
    410     OPENSSL_PUT_ERROR(EC, i2d_ECPrivateKey, ERR_R_BN_LIB);
    411     goto err;
    412   }
    413 
    414   if (!M_ASN1_OCTET_STRING_set(priv_key->privateKey, buffer, buf_len)) {
    415     OPENSSL_PUT_ERROR(EC, i2d_ECPrivateKey, ERR_R_ASN1_LIB);
    416     goto err;
    417   }
    418 
    419   /* TODO(fork): replace this flexibility with key sensible default? */
    420   if (!(key->enc_flag & EC_PKEY_NO_PARAMETERS)) {
    421     if ((priv_key->parameters = ec_asn1_group2pkparameters(
    422              key->group, priv_key->parameters)) == NULL) {
    423       OPENSSL_PUT_ERROR(EC, i2d_ECPrivateKey, ERR_R_EC_LIB);
    424       goto err;
    425     }
    426   }
    427 
    428   /* TODO(fork): replace this flexibility with key sensible default? */
    429   if (!(key->enc_flag & EC_PKEY_NO_PUBKEY) && key->pub_key != NULL) {
    430     priv_key->publicKey = M_ASN1_BIT_STRING_new();
    431     if (priv_key->publicKey == NULL) {
    432       OPENSSL_PUT_ERROR(EC, i2d_ECPrivateKey, ERR_R_MALLOC_FAILURE);
    433       goto err;
    434     }
    435 
    436     tmp_len = EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, NULL,
    437                                  0, NULL);
    438 
    439     if (tmp_len > buf_len) {
    440       uint8_t *tmp_buffer = OPENSSL_realloc(buffer, tmp_len);
    441       if (!tmp_buffer) {
    442         OPENSSL_PUT_ERROR(EC, i2d_ECPrivateKey, ERR_R_MALLOC_FAILURE);
    443         goto err;
    444       }
    445       buffer = tmp_buffer;
    446       buf_len = tmp_len;
    447     }
    448 
    449     if (!EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, buffer,
    450                             buf_len, NULL)) {
    451       OPENSSL_PUT_ERROR(EC, i2d_ECPrivateKey, ERR_R_EC_LIB);
    452       goto err;
    453     }
    454 
    455     priv_key->publicKey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
    456     priv_key->publicKey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
    457     if (!M_ASN1_BIT_STRING_set(priv_key->publicKey, buffer, buf_len)) {
    458       OPENSSL_PUT_ERROR(EC, i2d_ECPrivateKey, ERR_R_ASN1_LIB);
    459       goto err;
    460     }
    461   }
    462 
    463   ret = i2d_EC_PRIVATEKEY(priv_key, outp);
    464   if (ret == 0) {
    465     OPENSSL_PUT_ERROR(EC, i2d_ECPrivateKey, ERR_R_EC_LIB);
    466     goto err;
    467   }
    468   ok = 1;
    469 
    470 err:
    471   OPENSSL_free(buffer);
    472   EC_PRIVATEKEY_free(priv_key);
    473   return (ok ? ret : 0);
    474 }
    475 
    476 int i2d_ECParameters(const EC_KEY *key, uint8_t **outp) {
    477   if (key == NULL) {
    478     OPENSSL_PUT_ERROR(EC, i2d_ECParameters, ERR_R_PASSED_NULL_PARAMETER);
    479     return 0;
    480   }
    481   return i2d_ECPKParameters(key->group, outp);
    482 }
    483 
    484 EC_KEY *d2i_ECParameters(EC_KEY **key, const uint8_t **inp, long len) {
    485   EC_KEY *ret;
    486 
    487   if (inp == NULL || *inp == NULL) {
    488     OPENSSL_PUT_ERROR(EC, d2i_ECParameters, ERR_R_PASSED_NULL_PARAMETER);
    489     return NULL;
    490   }
    491 
    492   if (key == NULL || *key == NULL) {
    493     ret = EC_KEY_new();
    494     if (ret == NULL) {
    495       OPENSSL_PUT_ERROR(EC, d2i_ECParameters, ERR_R_MALLOC_FAILURE);
    496       return NULL;
    497     }
    498   } else {
    499     ret = *key;
    500   }
    501 
    502   if (!d2i_ECPKParameters(&ret->group, inp, len)) {
    503     OPENSSL_PUT_ERROR(EC, d2i_ECParameters, ERR_R_EC_LIB);
    504     if (key == NULL || *key == NULL) {
    505       EC_KEY_free(ret);
    506     }
    507     return NULL;
    508   }
    509 
    510   if (key) {
    511     *key = ret;
    512   }
    513   return ret;
    514 }
    515 
    516 EC_KEY *o2i_ECPublicKey(EC_KEY **keyp, const uint8_t **inp, long len) {
    517   EC_KEY *ret = NULL;
    518 
    519   if (keyp == NULL || *keyp == NULL || (*keyp)->group == NULL) {
    520     OPENSSL_PUT_ERROR(EC, o2i_ECPublicKey, ERR_R_PASSED_NULL_PARAMETER);
    521     return 0;
    522   }
    523   ret = *keyp;
    524   if (ret->pub_key == NULL &&
    525       (ret->pub_key = EC_POINT_new(ret->group)) == NULL) {
    526     OPENSSL_PUT_ERROR(EC, o2i_ECPublicKey, ERR_R_MALLOC_FAILURE);
    527     return 0;
    528   }
    529   if (!EC_POINT_oct2point(ret->group, ret->pub_key, *inp, len, NULL)) {
    530     OPENSSL_PUT_ERROR(EC, o2i_ECPublicKey, ERR_R_EC_LIB);
    531     return 0;
    532   }
    533   /* save the point conversion form */
    534   ret->conv_form = (point_conversion_form_t)(*inp[0] & ~0x01);
    535   *inp += len;
    536   return ret;
    537 }
    538 
    539 int i2o_ECPublicKey(const EC_KEY *key, uint8_t **outp) {
    540   size_t buf_len = 0;
    541   int new_buffer = 0;
    542 
    543   if (key == NULL) {
    544     OPENSSL_PUT_ERROR(EC, i2o_ECPublicKey, ERR_R_PASSED_NULL_PARAMETER);
    545     return 0;
    546   }
    547 
    548   buf_len = EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, NULL,
    549                                0, NULL);
    550 
    551   if (outp == NULL || buf_len == 0) {
    552     /* out == NULL => just return the length of the octet string */
    553     return buf_len;
    554   }
    555 
    556   if (*outp == NULL) {
    557     *outp = OPENSSL_malloc(buf_len);
    558     if (*outp == NULL) {
    559       OPENSSL_PUT_ERROR(EC, i2o_ECPublicKey, ERR_R_MALLOC_FAILURE);
    560       return 0;
    561     }
    562     new_buffer = 1;
    563   }
    564   if (!EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, *outp,
    565                           buf_len, NULL)) {
    566     OPENSSL_PUT_ERROR(EC, i2o_ECPublicKey, ERR_R_EC_LIB);
    567     if (new_buffer) {
    568       OPENSSL_free(*outp);
    569       *outp = NULL;
    570     }
    571     return 0;
    572   }
    573 
    574   if (!new_buffer) {
    575     *outp += buf_len;
    576   }
    577   return buf_len;
    578 }
    579