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@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@cryptsoft.com).  This product includes software written by Tim
52  * Hudson (tjh@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 
ec_asn1_group2pkparameters(const EC_GROUP * group,ECPKPARAMETERS * params)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, 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 
ec_asn1_pkparameters2group(const ECPKPARAMETERS * params)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_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 ((unsigned) 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_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_R_EC_GROUP_NEW_BY_NAME_FAILURE);
232     return NULL;
233   }
234 
235   return ret;
236 }
237 
d2i_ECPKParameters(EC_GROUP ** groupp,const uint8_t ** inp,long len)238 static EC_GROUP *d2i_ECPKParameters(EC_GROUP **groupp, const uint8_t **inp,
239                                     long len) {
240   EC_GROUP *group = NULL;
241   ECPKPARAMETERS *params = NULL;
242   const uint8_t *in = *inp;
243 
244   params = d2i_ECPKPARAMETERS(NULL, &in, len);
245   if (params == NULL) {
246     OPENSSL_PUT_ERROR(EC, 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, 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   *inp = in;
265   return group;
266 }
267 
i2d_ECPKParameters(const EC_GROUP * group,uint8_t ** outp)268 static int i2d_ECPKParameters(const EC_GROUP *group, uint8_t **outp) {
269   int ret = 0;
270   ECPKPARAMETERS *tmp = ec_asn1_group2pkparameters(group, NULL);
271   if (tmp == NULL) {
272     OPENSSL_PUT_ERROR(EC, EC_R_GROUP2PKPARAMETERS_FAILURE);
273     return 0;
274   }
275   ret = i2d_ECPKPARAMETERS(tmp, outp);
276   if (ret == 0) {
277     OPENSSL_PUT_ERROR(EC, EC_R_I2D_ECPKPARAMETERS_FAILURE);
278     ECPKPARAMETERS_free(tmp);
279     return 0;
280   }
281   ECPKPARAMETERS_free(tmp);
282   return ret;
283 }
284 
d2i_ECPrivateKey(EC_KEY ** a,const uint8_t ** inp,long len)285 EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const uint8_t **inp, long len) {
286   int ok = 0;
287   EC_KEY *ret = NULL;
288   EC_PRIVATEKEY *priv_key = NULL;
289 
290   const uint8_t *in = *inp;
291   priv_key = d2i_EC_PRIVATEKEY(NULL, &in, len);
292   if (priv_key == NULL) {
293     OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
294     return NULL;
295   }
296 
297   if (a == NULL || *a == NULL) {
298     ret = EC_KEY_new();
299     if (ret == NULL) {
300       OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
301       goto err;
302     }
303   } else {
304     ret = *a;
305   }
306 
307   if (priv_key->parameters) {
308     EC_GROUP_free(ret->group);
309     ret->group = ec_asn1_pkparameters2group(priv_key->parameters);
310   }
311 
312   if (ret->group == NULL) {
313     OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
314     goto err;
315   }
316 
317   ret->version = priv_key->version;
318 
319   if (priv_key->privateKey) {
320     ret->priv_key =
321         BN_bin2bn(M_ASN1_STRING_data(priv_key->privateKey),
322                   M_ASN1_STRING_length(priv_key->privateKey), ret->priv_key);
323     if (ret->priv_key == NULL) {
324       OPENSSL_PUT_ERROR(EC, ERR_R_BN_LIB);
325       goto err;
326     }
327   } else {
328     OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PRIVATE_KEY);
329     goto err;
330   }
331 
332   if (BN_cmp(ret->priv_key, EC_GROUP_get0_order(ret->group)) >= 0) {
333     OPENSSL_PUT_ERROR(EC, EC_R_WRONG_ORDER);
334     goto err;
335   }
336 
337   EC_POINT_free(ret->pub_key);
338   ret->pub_key = EC_POINT_new(ret->group);
339   if (ret->pub_key == NULL) {
340     OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
341     goto err;
342   }
343 
344   if (priv_key->publicKey) {
345     const uint8_t *pub_oct;
346     int pub_oct_len;
347 
348     pub_oct = M_ASN1_STRING_data(priv_key->publicKey);
349     pub_oct_len = M_ASN1_STRING_length(priv_key->publicKey);
350     /* The first byte (the point conversion form) must be present. */
351     if (pub_oct_len <= 0) {
352       OPENSSL_PUT_ERROR(EC, EC_R_BUFFER_TOO_SMALL);
353       goto err;
354     }
355     /* Save the point conversion form. */
356     ret->conv_form = (point_conversion_form_t)(pub_oct[0] & ~0x01);
357     if (!EC_POINT_oct2point(ret->group, ret->pub_key, pub_oct, pub_oct_len,
358                             NULL)) {
359       OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
360       goto err;
361     }
362   } else {
363     if (!EC_POINT_mul(ret->group, ret->pub_key, ret->priv_key, NULL, NULL,
364                       NULL)) {
365       OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
366       goto err;
367     }
368     /* Remember the original private-key-only encoding. */
369     ret->enc_flag |= EC_PKEY_NO_PUBKEY;
370   }
371 
372   if (a) {
373     *a = ret;
374   }
375   *inp = in;
376   ok = 1;
377 
378 err:
379   if (!ok) {
380     if (a == NULL || *a != ret) {
381       EC_KEY_free(ret);
382     }
383     ret = NULL;
384   }
385 
386   EC_PRIVATEKEY_free(priv_key);
387 
388   return ret;
389 }
390 
i2d_ECPrivateKey(const EC_KEY * key,uint8_t ** outp)391 int i2d_ECPrivateKey(const EC_KEY *key, uint8_t **outp) {
392   int ret = 0, ok = 0;
393   uint8_t *buffer = NULL;
394   size_t buf_len = 0, tmp_len;
395   EC_PRIVATEKEY *priv_key = NULL;
396 
397   if (key == NULL || key->group == NULL || key->priv_key == NULL) {
398     OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
399     goto err;
400   }
401 
402   priv_key = EC_PRIVATEKEY_new();
403   if (priv_key == NULL) {
404     OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
405     goto err;
406   }
407 
408   priv_key->version = key->version;
409 
410   buf_len = BN_num_bytes(&key->group->order);
411   buffer = OPENSSL_malloc(buf_len);
412   if (buffer == NULL) {
413     OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
414     goto err;
415   }
416 
417   if (!BN_bn2bin_padded(buffer, buf_len, key->priv_key)) {
418     OPENSSL_PUT_ERROR(EC, ERR_R_BN_LIB);
419     goto err;
420   }
421 
422   if (!M_ASN1_OCTET_STRING_set(priv_key->privateKey, buffer, buf_len)) {
423     OPENSSL_PUT_ERROR(EC, ERR_R_ASN1_LIB);
424     goto err;
425   }
426 
427   /* TODO(fork): replace this flexibility with key sensible default? */
428   if (!(key->enc_flag & EC_PKEY_NO_PARAMETERS)) {
429     if ((priv_key->parameters = ec_asn1_group2pkparameters(
430              key->group, priv_key->parameters)) == NULL) {
431       OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
432       goto err;
433     }
434   }
435 
436   /* TODO(fork): replace this flexibility with key sensible default? */
437   if (!(key->enc_flag & EC_PKEY_NO_PUBKEY) && key->pub_key != NULL) {
438     priv_key->publicKey = M_ASN1_BIT_STRING_new();
439     if (priv_key->publicKey == NULL) {
440       OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
441       goto err;
442     }
443 
444     tmp_len = EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, NULL,
445                                  0, NULL);
446 
447     if (tmp_len > buf_len) {
448       uint8_t *tmp_buffer = OPENSSL_realloc(buffer, tmp_len);
449       if (!tmp_buffer) {
450         OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
451         goto err;
452       }
453       buffer = tmp_buffer;
454       buf_len = tmp_len;
455     }
456 
457     if (!EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, buffer,
458                             buf_len, NULL)) {
459       OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
460       goto err;
461     }
462 
463     priv_key->publicKey->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
464     priv_key->publicKey->flags |= ASN1_STRING_FLAG_BITS_LEFT;
465     if (!M_ASN1_BIT_STRING_set(priv_key->publicKey, buffer, buf_len)) {
466       OPENSSL_PUT_ERROR(EC, ERR_R_ASN1_LIB);
467       goto err;
468     }
469   }
470 
471   ret = i2d_EC_PRIVATEKEY(priv_key, outp);
472   if (ret == 0) {
473     OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
474     goto err;
475   }
476   ok = 1;
477 
478 err:
479   OPENSSL_free(buffer);
480   EC_PRIVATEKEY_free(priv_key);
481   return (ok ? ret : 0);
482 }
483 
i2d_ECParameters(const EC_KEY * key,uint8_t ** outp)484 int i2d_ECParameters(const EC_KEY *key, uint8_t **outp) {
485   if (key == NULL) {
486     OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
487     return 0;
488   }
489   return i2d_ECPKParameters(key->group, outp);
490 }
491 
d2i_ECParameters(EC_KEY ** key,const uint8_t ** inp,long len)492 EC_KEY *d2i_ECParameters(EC_KEY **key, const uint8_t **inp, long len) {
493   EC_KEY *ret;
494 
495   if (inp == NULL || *inp == NULL) {
496     OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
497     return NULL;
498   }
499 
500   if (key == NULL || *key == NULL) {
501     ret = EC_KEY_new();
502     if (ret == NULL) {
503       OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
504       return NULL;
505     }
506   } else {
507     ret = *key;
508   }
509 
510   if (!d2i_ECPKParameters(&ret->group, inp, len)) {
511     OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
512     if (key == NULL || *key == NULL) {
513       EC_KEY_free(ret);
514     }
515     return NULL;
516   }
517 
518   if (key) {
519     *key = ret;
520   }
521   return ret;
522 }
523 
o2i_ECPublicKey(EC_KEY ** keyp,const uint8_t ** inp,long len)524 EC_KEY *o2i_ECPublicKey(EC_KEY **keyp, const uint8_t **inp, long len) {
525   EC_KEY *ret = NULL;
526 
527   if (keyp == NULL || *keyp == NULL || (*keyp)->group == NULL) {
528     OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
529     return 0;
530   }
531   ret = *keyp;
532   if (ret->pub_key == NULL &&
533       (ret->pub_key = EC_POINT_new(ret->group)) == NULL) {
534     OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
535     return 0;
536   }
537   if (!EC_POINT_oct2point(ret->group, ret->pub_key, *inp, len, NULL)) {
538     OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
539     return 0;
540   }
541   /* save the point conversion form */
542   ret->conv_form = (point_conversion_form_t)(*inp[0] & ~0x01);
543   *inp += len;
544   return ret;
545 }
546 
i2o_ECPublicKey(const EC_KEY * key,uint8_t ** outp)547 int i2o_ECPublicKey(const EC_KEY *key, uint8_t **outp) {
548   size_t buf_len = 0;
549   int new_buffer = 0;
550 
551   if (key == NULL) {
552     OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
553     return 0;
554   }
555 
556   buf_len = EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, NULL,
557                                0, NULL);
558 
559   if (outp == NULL || buf_len == 0) {
560     /* out == NULL => just return the length of the octet string */
561     return buf_len;
562   }
563 
564   if (*outp == NULL) {
565     *outp = OPENSSL_malloc(buf_len);
566     if (*outp == NULL) {
567       OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
568       return 0;
569     }
570     new_buffer = 1;
571   }
572   if (!EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, *outp,
573                           buf_len, NULL)) {
574     OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
575     if (new_buffer) {
576       OPENSSL_free(*outp);
577       *outp = NULL;
578     }
579     return 0;
580   }
581 
582   if (!new_buffer) {
583     *outp += buf_len;
584   }
585   return buf_len;
586 }
587