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1 /*
2  * Copyright 2002-2020 The OpenSSL Project Authors. All Rights Reserved.
3  * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
4  *
5  * Licensed under the OpenSSL license (the "License").  You may not use
6  * this file except in compliance with the License.  You can obtain a copy
7  * in the file LICENSE in the source distribution or at
8  * https://www.openssl.org/source/license.html
9  */
10 
11 #include "internal/cryptlib.h"
12 #include <string.h>
13 #include "ec_local.h"
14 #include "internal/refcount.h"
15 #include <openssl/err.h>
16 #include <openssl/engine.h>
17 #include "crypto/bn.h"
18 
EC_KEY_new(void)19 EC_KEY *EC_KEY_new(void)
20 {
21     return EC_KEY_new_method(NULL);
22 }
23 
EC_KEY_new_by_curve_name(int nid)24 EC_KEY *EC_KEY_new_by_curve_name(int nid)
25 {
26     EC_KEY *ret = EC_KEY_new();
27     if (ret == NULL)
28         return NULL;
29     ret->group = EC_GROUP_new_by_curve_name(nid);
30     if (ret->group == NULL) {
31         EC_KEY_free(ret);
32         return NULL;
33     }
34     if (ret->meth->set_group != NULL
35         && ret->meth->set_group(ret, ret->group) == 0) {
36         EC_KEY_free(ret);
37         return NULL;
38     }
39     return ret;
40 }
41 
EC_KEY_free(EC_KEY * r)42 void EC_KEY_free(EC_KEY *r)
43 {
44     int i;
45 
46     if (r == NULL)
47         return;
48 
49     CRYPTO_DOWN_REF(&r->references, &i, r->lock);
50     REF_PRINT_COUNT("EC_KEY", r);
51     if (i > 0)
52         return;
53     REF_ASSERT_ISNT(i < 0);
54 
55     if (r->meth != NULL && r->meth->finish != NULL)
56         r->meth->finish(r);
57 
58 #ifndef OPENSSL_NO_ENGINE
59     ENGINE_finish(r->engine);
60 #endif
61 
62     if (r->group && r->group->meth->keyfinish)
63         r->group->meth->keyfinish(r);
64 
65     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_EC_KEY, r, &r->ex_data);
66     CRYPTO_THREAD_lock_free(r->lock);
67     EC_GROUP_free(r->group);
68     EC_POINT_free(r->pub_key);
69     BN_clear_free(r->priv_key);
70 
71     OPENSSL_clear_free((void *)r, sizeof(EC_KEY));
72 }
73 
EC_KEY_copy(EC_KEY * dest,const EC_KEY * src)74 EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src)
75 {
76     if (dest == NULL || src == NULL) {
77         ECerr(EC_F_EC_KEY_COPY, ERR_R_PASSED_NULL_PARAMETER);
78         return NULL;
79     }
80     if (src->meth != dest->meth) {
81         if (dest->meth->finish != NULL)
82             dest->meth->finish(dest);
83         if (dest->group && dest->group->meth->keyfinish)
84             dest->group->meth->keyfinish(dest);
85 #ifndef OPENSSL_NO_ENGINE
86         if (ENGINE_finish(dest->engine) == 0)
87             return 0;
88         dest->engine = NULL;
89 #endif
90     }
91     /* copy the parameters */
92     if (src->group != NULL) {
93         const EC_METHOD *meth = EC_GROUP_method_of(src->group);
94         /* clear the old group */
95         EC_GROUP_free(dest->group);
96         dest->group = EC_GROUP_new(meth);
97         if (dest->group == NULL)
98             return NULL;
99         if (!EC_GROUP_copy(dest->group, src->group))
100             return NULL;
101 
102         /*  copy the public key */
103         if (src->pub_key != NULL) {
104             EC_POINT_free(dest->pub_key);
105             dest->pub_key = EC_POINT_new(src->group);
106             if (dest->pub_key == NULL)
107                 return NULL;
108             if (!EC_POINT_copy(dest->pub_key, src->pub_key))
109                 return NULL;
110         }
111         /* copy the private key */
112         if (src->priv_key != NULL) {
113             if (dest->priv_key == NULL) {
114                 dest->priv_key = BN_new();
115                 if (dest->priv_key == NULL)
116                     return NULL;
117             }
118             if (!BN_copy(dest->priv_key, src->priv_key))
119                 return NULL;
120             if (src->group->meth->keycopy
121                 && src->group->meth->keycopy(dest, src) == 0)
122                 return NULL;
123         }
124     }
125 
126 
127     /* copy the rest */
128     dest->enc_flag = src->enc_flag;
129     dest->conv_form = src->conv_form;
130     dest->version = src->version;
131     dest->flags = src->flags;
132     if (!CRYPTO_dup_ex_data(CRYPTO_EX_INDEX_EC_KEY,
133                             &dest->ex_data, &src->ex_data))
134         return NULL;
135 
136     if (src->meth != dest->meth) {
137 #ifndef OPENSSL_NO_ENGINE
138         if (src->engine != NULL && ENGINE_init(src->engine) == 0)
139             return NULL;
140         dest->engine = src->engine;
141 #endif
142         dest->meth = src->meth;
143     }
144 
145     if (src->meth->copy != NULL && src->meth->copy(dest, src) == 0)
146         return NULL;
147 
148     return dest;
149 }
150 
EC_KEY_dup(const EC_KEY * ec_key)151 EC_KEY *EC_KEY_dup(const EC_KEY *ec_key)
152 {
153     EC_KEY *ret = EC_KEY_new_method(ec_key->engine);
154 
155     if (ret == NULL)
156         return NULL;
157 
158     if (EC_KEY_copy(ret, ec_key) == NULL) {
159         EC_KEY_free(ret);
160         return NULL;
161     }
162     return ret;
163 }
164 
EC_KEY_up_ref(EC_KEY * r)165 int EC_KEY_up_ref(EC_KEY *r)
166 {
167     int i;
168 
169     if (CRYPTO_UP_REF(&r->references, &i, r->lock) <= 0)
170         return 0;
171 
172     REF_PRINT_COUNT("EC_KEY", r);
173     REF_ASSERT_ISNT(i < 2);
174     return ((i > 1) ? 1 : 0);
175 }
176 
EC_KEY_get0_engine(const EC_KEY * eckey)177 ENGINE *EC_KEY_get0_engine(const EC_KEY *eckey)
178 {
179     return eckey->engine;
180 }
181 
EC_KEY_generate_key(EC_KEY * eckey)182 int EC_KEY_generate_key(EC_KEY *eckey)
183 {
184     if (eckey == NULL || eckey->group == NULL) {
185         ECerr(EC_F_EC_KEY_GENERATE_KEY, ERR_R_PASSED_NULL_PARAMETER);
186         return 0;
187     }
188     if (eckey->meth->keygen != NULL)
189         return eckey->meth->keygen(eckey);
190     ECerr(EC_F_EC_KEY_GENERATE_KEY, EC_R_OPERATION_NOT_SUPPORTED);
191     return 0;
192 }
193 
ossl_ec_key_gen(EC_KEY * eckey)194 int ossl_ec_key_gen(EC_KEY *eckey)
195 {
196     return eckey->group->meth->keygen(eckey);
197 }
198 
ec_key_simple_generate_key(EC_KEY * eckey)199 int ec_key_simple_generate_key(EC_KEY *eckey)
200 {
201     int ok = 0;
202     BN_CTX *ctx = NULL;
203     BIGNUM *priv_key = NULL;
204     const BIGNUM *order = NULL;
205     EC_POINT *pub_key = NULL;
206 
207     if ((ctx = BN_CTX_new()) == NULL)
208         goto err;
209 
210     if (eckey->priv_key == NULL) {
211         priv_key = BN_new();
212         if (priv_key == NULL)
213             goto err;
214     } else
215         priv_key = eckey->priv_key;
216 
217     order = EC_GROUP_get0_order(eckey->group);
218     if (order == NULL)
219         goto err;
220 
221     do
222         if (!BN_priv_rand_range(priv_key, order))
223             goto err;
224     while (BN_is_zero(priv_key)) ;
225 
226     if (eckey->pub_key == NULL) {
227         pub_key = EC_POINT_new(eckey->group);
228         if (pub_key == NULL)
229             goto err;
230     } else
231         pub_key = eckey->pub_key;
232 
233     if (!EC_POINT_mul(eckey->group, pub_key, priv_key, NULL, NULL, ctx))
234         goto err;
235 
236     eckey->priv_key = priv_key;
237     eckey->pub_key = pub_key;
238 
239     ok = 1;
240 
241  err:
242     if (eckey->pub_key == NULL)
243         EC_POINT_free(pub_key);
244     if (eckey->priv_key != priv_key)
245         BN_free(priv_key);
246     BN_CTX_free(ctx);
247     return ok;
248 }
249 
ec_key_simple_generate_public_key(EC_KEY * eckey)250 int ec_key_simple_generate_public_key(EC_KEY *eckey)
251 {
252     return EC_POINT_mul(eckey->group, eckey->pub_key, eckey->priv_key, NULL,
253                         NULL, NULL);
254 }
255 
EC_KEY_check_key(const EC_KEY * eckey)256 int EC_KEY_check_key(const EC_KEY *eckey)
257 {
258     if (eckey == NULL || eckey->group == NULL || eckey->pub_key == NULL) {
259         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
260         return 0;
261     }
262 
263     if (eckey->group->meth->keycheck == NULL) {
264         ECerr(EC_F_EC_KEY_CHECK_KEY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
265         return 0;
266     }
267 
268     return eckey->group->meth->keycheck(eckey);
269 }
270 
ec_key_simple_check_key(const EC_KEY * eckey)271 int ec_key_simple_check_key(const EC_KEY *eckey)
272 {
273     int ok = 0;
274     BN_CTX *ctx = NULL;
275     const BIGNUM *order = NULL;
276     EC_POINT *point = NULL;
277 
278     if (eckey == NULL || eckey->group == NULL || eckey->pub_key == NULL) {
279         ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_PASSED_NULL_PARAMETER);
280         return 0;
281     }
282 
283     if (EC_POINT_is_at_infinity(eckey->group, eckey->pub_key)) {
284         ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_POINT_AT_INFINITY);
285         goto err;
286     }
287 
288     if ((ctx = BN_CTX_new()) == NULL)
289         goto err;
290     if ((point = EC_POINT_new(eckey->group)) == NULL)
291         goto err;
292 
293     /* testing whether the pub_key is on the elliptic curve */
294     if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) {
295         ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
296         goto err;
297     }
298     /* testing whether pub_key * order is the point at infinity */
299     order = eckey->group->order;
300     if (BN_is_zero(order)) {
301         ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_INVALID_GROUP_ORDER);
302         goto err;
303     }
304     if (!EC_POINT_mul(eckey->group, point, NULL, eckey->pub_key, order, ctx)) {
305         ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_EC_LIB);
306         goto err;
307     }
308     if (!EC_POINT_is_at_infinity(eckey->group, point)) {
309         ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_WRONG_ORDER);
310         goto err;
311     }
312     /*
313      * in case the priv_key is present : check if generator * priv_key ==
314      * pub_key
315      */
316     if (eckey->priv_key != NULL) {
317         if (BN_cmp(eckey->priv_key, order) >= 0) {
318             ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_WRONG_ORDER);
319             goto err;
320         }
321         if (!EC_POINT_mul(eckey->group, point, eckey->priv_key,
322                           NULL, NULL, ctx)) {
323             ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, ERR_R_EC_LIB);
324             goto err;
325         }
326         if (EC_POINT_cmp(eckey->group, point, eckey->pub_key, ctx) != 0) {
327             ECerr(EC_F_EC_KEY_SIMPLE_CHECK_KEY, EC_R_INVALID_PRIVATE_KEY);
328             goto err;
329         }
330     }
331     ok = 1;
332  err:
333     BN_CTX_free(ctx);
334     EC_POINT_free(point);
335     return ok;
336 }
337 
EC_KEY_set_public_key_affine_coordinates(EC_KEY * key,BIGNUM * x,BIGNUM * y)338 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
339                                              BIGNUM *y)
340 {
341     BN_CTX *ctx = NULL;
342     BIGNUM *tx, *ty;
343     EC_POINT *point = NULL;
344     int ok = 0;
345 
346     if (key == NULL || key->group == NULL || x == NULL || y == NULL) {
347         ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
348               ERR_R_PASSED_NULL_PARAMETER);
349         return 0;
350     }
351     ctx = BN_CTX_new();
352     if (ctx == NULL)
353         return 0;
354 
355     BN_CTX_start(ctx);
356     point = EC_POINT_new(key->group);
357 
358     if (point == NULL)
359         goto err;
360 
361     tx = BN_CTX_get(ctx);
362     ty = BN_CTX_get(ctx);
363     if (ty == NULL)
364         goto err;
365 
366     if (!EC_POINT_set_affine_coordinates(key->group, point, x, y, ctx))
367         goto err;
368     if (!EC_POINT_get_affine_coordinates(key->group, point, tx, ty, ctx))
369         goto err;
370 
371     /*
372      * Check if retrieved coordinates match originals and are less than field
373      * order: if not values are out of range.
374      */
375     if (BN_cmp(x, tx) || BN_cmp(y, ty)
376         || (BN_cmp(x, key->group->field) >= 0)
377         || (BN_cmp(y, key->group->field) >= 0)) {
378         ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
379               EC_R_COORDINATES_OUT_OF_RANGE);
380         goto err;
381     }
382 
383     if (!EC_KEY_set_public_key(key, point))
384         goto err;
385 
386     if (EC_KEY_check_key(key) == 0)
387         goto err;
388 
389     ok = 1;
390 
391  err:
392     BN_CTX_end(ctx);
393     BN_CTX_free(ctx);
394     EC_POINT_free(point);
395     return ok;
396 
397 }
398 
EC_KEY_get0_group(const EC_KEY * key)399 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key)
400 {
401     return key->group;
402 }
403 
EC_KEY_set_group(EC_KEY * key,const EC_GROUP * group)404 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group)
405 {
406     if (key->meth->set_group != NULL && key->meth->set_group(key, group) == 0)
407         return 0;
408     EC_GROUP_free(key->group);
409     key->group = EC_GROUP_dup(group);
410     return (key->group == NULL) ? 0 : 1;
411 }
412 
EC_KEY_get0_private_key(const EC_KEY * key)413 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key)
414 {
415     return key->priv_key;
416 }
417 
EC_KEY_set_private_key(EC_KEY * key,const BIGNUM * priv_key)418 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key)
419 {
420     int fixed_top;
421     const BIGNUM *order = NULL;
422     BIGNUM *tmp_key = NULL;
423 
424     if (key->group == NULL || key->group->meth == NULL)
425         return 0;
426 
427     /*
428      * Not only should key->group be set, but it should also be in a valid
429      * fully initialized state.
430      *
431      * Specifically, to operate in constant time, we need that the group order
432      * is set, as we use its length as the fixed public size of any scalar used
433      * as an EC private key.
434      */
435     order = EC_GROUP_get0_order(key->group);
436     if (order == NULL || BN_is_zero(order))
437         return 0; /* This should never happen */
438 
439     if (key->group->meth->set_private != NULL
440         && key->group->meth->set_private(key, priv_key) == 0)
441         return 0;
442     if (key->meth->set_private != NULL
443         && key->meth->set_private(key, priv_key) == 0)
444         return 0;
445 
446     /*
447      * We should never leak the bit length of the secret scalar in the key,
448      * so we always set the `BN_FLG_CONSTTIME` flag on the internal `BIGNUM`
449      * holding the secret scalar.
450      *
451      * This is important also because `BN_dup()` (and `BN_copy()`) do not
452      * propagate the `BN_FLG_CONSTTIME` flag from the source `BIGNUM`, and
453      * this brings an extra risk of inadvertently losing the flag, even when
454      * the caller specifically set it.
455      *
456      * The propagation has been turned on and off a few times in the past
457      * years because in some conditions has shown unintended consequences in
458      * some code paths, so at the moment we can't fix this in the BN layer.
459      *
460      * In `EC_KEY_set_private_key()` we can work around the propagation by
461      * manually setting the flag after `BN_dup()` as we know for sure that
462      * inside the EC module the `BN_FLG_CONSTTIME` is always treated
463      * correctly and should not generate unintended consequences.
464      *
465      * Setting the BN_FLG_CONSTTIME flag alone is never enough, we also have
466      * to preallocate the BIGNUM internal buffer to a fixed public size big
467      * enough that operations performed during the processing never trigger
468      * a realloc which would leak the size of the scalar through memory
469      * accesses.
470      *
471      * Fixed Length
472      * ------------
473      *
474      * The order of the large prime subgroup of the curve is our choice for
475      * a fixed public size, as that is generally the upper bound for
476      * generating a private key in EC cryptosystems and should fit all valid
477      * secret scalars.
478      *
479      * For preallocating the BIGNUM storage we look at the number of "words"
480      * required for the internal representation of the order, and we
481      * preallocate 2 extra "words" in case any of the subsequent processing
482      * might temporarily overflow the order length.
483      */
484     tmp_key = BN_dup(priv_key);
485     if (tmp_key == NULL)
486         return 0;
487 
488     BN_set_flags(tmp_key, BN_FLG_CONSTTIME);
489 
490     fixed_top = bn_get_top(order) + 2;
491     if (bn_wexpand(tmp_key, fixed_top) == NULL) {
492         BN_clear_free(tmp_key);
493         return 0;
494     }
495 
496     BN_clear_free(key->priv_key);
497     key->priv_key = tmp_key;
498 
499     return 1;
500 }
501 
EC_KEY_get0_public_key(const EC_KEY * key)502 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key)
503 {
504     return key->pub_key;
505 }
506 
EC_KEY_set_public_key(EC_KEY * key,const EC_POINT * pub_key)507 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key)
508 {
509     if (key->meth->set_public != NULL
510         && key->meth->set_public(key, pub_key) == 0)
511         return 0;
512     EC_POINT_free(key->pub_key);
513     key->pub_key = EC_POINT_dup(pub_key, key->group);
514     return (key->pub_key == NULL) ? 0 : 1;
515 }
516 
EC_KEY_get_enc_flags(const EC_KEY * key)517 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key)
518 {
519     return key->enc_flag;
520 }
521 
EC_KEY_set_enc_flags(EC_KEY * key,unsigned int flags)522 void EC_KEY_set_enc_flags(EC_KEY *key, unsigned int flags)
523 {
524     key->enc_flag = flags;
525 }
526 
EC_KEY_get_conv_form(const EC_KEY * key)527 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key)
528 {
529     return key->conv_form;
530 }
531 
EC_KEY_set_conv_form(EC_KEY * key,point_conversion_form_t cform)532 void EC_KEY_set_conv_form(EC_KEY *key, point_conversion_form_t cform)
533 {
534     key->conv_form = cform;
535     if (key->group != NULL)
536         EC_GROUP_set_point_conversion_form(key->group, cform);
537 }
538 
EC_KEY_set_asn1_flag(EC_KEY * key,int flag)539 void EC_KEY_set_asn1_flag(EC_KEY *key, int flag)
540 {
541     if (key->group != NULL)
542         EC_GROUP_set_asn1_flag(key->group, flag);
543 }
544 
EC_KEY_precompute_mult(EC_KEY * key,BN_CTX * ctx)545 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx)
546 {
547     if (key->group == NULL)
548         return 0;
549     return EC_GROUP_precompute_mult(key->group, ctx);
550 }
551 
EC_KEY_get_flags(const EC_KEY * key)552 int EC_KEY_get_flags(const EC_KEY *key)
553 {
554     return key->flags;
555 }
556 
EC_KEY_set_flags(EC_KEY * key,int flags)557 void EC_KEY_set_flags(EC_KEY *key, int flags)
558 {
559     key->flags |= flags;
560 }
561 
EC_KEY_clear_flags(EC_KEY * key,int flags)562 void EC_KEY_clear_flags(EC_KEY *key, int flags)
563 {
564     key->flags &= ~flags;
565 }
566 
EC_KEY_decoded_from_explicit_params(const EC_KEY * key)567 int EC_KEY_decoded_from_explicit_params(const EC_KEY *key)
568 {
569     if (key == NULL || key->group == NULL)
570         return -1;
571     return key->group->decoded_from_explicit_params;
572 }
573 
EC_KEY_key2buf(const EC_KEY * key,point_conversion_form_t form,unsigned char ** pbuf,BN_CTX * ctx)574 size_t EC_KEY_key2buf(const EC_KEY *key, point_conversion_form_t form,
575                         unsigned char **pbuf, BN_CTX *ctx)
576 {
577     if (key == NULL || key->pub_key == NULL || key->group == NULL)
578         return 0;
579     return EC_POINT_point2buf(key->group, key->pub_key, form, pbuf, ctx);
580 }
581 
EC_KEY_oct2key(EC_KEY * key,const unsigned char * buf,size_t len,BN_CTX * ctx)582 int EC_KEY_oct2key(EC_KEY *key, const unsigned char *buf, size_t len,
583                    BN_CTX *ctx)
584 {
585     if (key == NULL || key->group == NULL)
586         return 0;
587     if (key->pub_key == NULL)
588         key->pub_key = EC_POINT_new(key->group);
589     if (key->pub_key == NULL)
590         return 0;
591     if (EC_POINT_oct2point(key->group, key->pub_key, buf, len, ctx) == 0)
592         return 0;
593     /*
594      * Save the point conversion form.
595      * For non-custom curves the first octet of the buffer (excluding
596      * the last significant bit) contains the point conversion form.
597      * EC_POINT_oct2point() has already performed sanity checking of
598      * the buffer so we know it is valid.
599      */
600     if ((key->group->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0)
601         key->conv_form = (point_conversion_form_t)(buf[0] & ~0x01);
602     return 1;
603 }
604 
EC_KEY_priv2oct(const EC_KEY * eckey,unsigned char * buf,size_t len)605 size_t EC_KEY_priv2oct(const EC_KEY *eckey,
606                        unsigned char *buf, size_t len)
607 {
608     if (eckey->group == NULL || eckey->group->meth == NULL)
609         return 0;
610     if (eckey->group->meth->priv2oct == NULL) {
611         ECerr(EC_F_EC_KEY_PRIV2OCT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
612         return 0;
613     }
614 
615     return eckey->group->meth->priv2oct(eckey, buf, len);
616 }
617 
ec_key_simple_priv2oct(const EC_KEY * eckey,unsigned char * buf,size_t len)618 size_t ec_key_simple_priv2oct(const EC_KEY *eckey,
619                               unsigned char *buf, size_t len)
620 {
621     size_t buf_len;
622 
623     buf_len = (EC_GROUP_order_bits(eckey->group) + 7) / 8;
624     if (eckey->priv_key == NULL)
625         return 0;
626     if (buf == NULL)
627         return buf_len;
628     else if (len < buf_len)
629         return 0;
630 
631     /* Octetstring may need leading zeros if BN is to short */
632 
633     if (BN_bn2binpad(eckey->priv_key, buf, buf_len) == -1) {
634         ECerr(EC_F_EC_KEY_SIMPLE_PRIV2OCT, EC_R_BUFFER_TOO_SMALL);
635         return 0;
636     }
637 
638     return buf_len;
639 }
640 
EC_KEY_oct2priv(EC_KEY * eckey,const unsigned char * buf,size_t len)641 int EC_KEY_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len)
642 {
643     if (eckey->group == NULL || eckey->group->meth == NULL)
644         return 0;
645     if (eckey->group->meth->oct2priv == NULL) {
646         ECerr(EC_F_EC_KEY_OCT2PRIV, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
647         return 0;
648     }
649     return eckey->group->meth->oct2priv(eckey, buf, len);
650 }
651 
ec_key_simple_oct2priv(EC_KEY * eckey,const unsigned char * buf,size_t len)652 int ec_key_simple_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len)
653 {
654     if (eckey->priv_key == NULL)
655         eckey->priv_key = BN_secure_new();
656     if (eckey->priv_key == NULL) {
657         ECerr(EC_F_EC_KEY_SIMPLE_OCT2PRIV, ERR_R_MALLOC_FAILURE);
658         return 0;
659     }
660     eckey->priv_key = BN_bin2bn(buf, len, eckey->priv_key);
661     if (eckey->priv_key == NULL) {
662         ECerr(EC_F_EC_KEY_SIMPLE_OCT2PRIV, ERR_R_BN_LIB);
663         return 0;
664     }
665     return 1;
666 }
667 
EC_KEY_priv2buf(const EC_KEY * eckey,unsigned char ** pbuf)668 size_t EC_KEY_priv2buf(const EC_KEY *eckey, unsigned char **pbuf)
669 {
670     size_t len;
671     unsigned char *buf;
672 
673     len = EC_KEY_priv2oct(eckey, NULL, 0);
674     if (len == 0)
675         return 0;
676     if ((buf = OPENSSL_malloc(len)) == NULL) {
677         ECerr(EC_F_EC_KEY_PRIV2BUF, ERR_R_MALLOC_FAILURE);
678         return 0;
679     }
680     len = EC_KEY_priv2oct(eckey, buf, len);
681     if (len == 0) {
682         OPENSSL_free(buf);
683         return 0;
684     }
685     *pbuf = buf;
686     return len;
687 }
688 
EC_KEY_can_sign(const EC_KEY * eckey)689 int EC_KEY_can_sign(const EC_KEY *eckey)
690 {
691     if (eckey->group == NULL || eckey->group->meth == NULL
692         || (eckey->group->meth->flags & EC_FLAGS_NO_SIGN))
693         return 0;
694     return 1;
695 }
696