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 <limits.h> 57 #include <string.h> 58 59 #include <openssl/bytestring.h> 60 #include <openssl/bn.h> 61 #include <openssl/err.h> 62 #include <openssl/mem.h> 63 #include <openssl/nid.h> 64 65 #include "../fipsmodule/ec/internal.h" 66 #include "../bytestring/internal.h" 67 #include "../internal.h" 68 69 70 static const unsigned kParametersTag = 71 CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 0; 72 static const unsigned kPublicKeyTag = 73 CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 1; 74 75 EC_KEY *EC_KEY_parse_private_key(CBS *cbs, const EC_GROUP *group) { 76 CBS ec_private_key, private_key; 77 uint64_t version; 78 if (!CBS_get_asn1(cbs, &ec_private_key, CBS_ASN1_SEQUENCE) || 79 !CBS_get_asn1_uint64(&ec_private_key, &version) || 80 version != 1 || 81 !CBS_get_asn1(&ec_private_key, &private_key, CBS_ASN1_OCTETSTRING)) { 82 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR); 83 return NULL; 84 } 85 86 // Parse the optional parameters field. 87 EC_GROUP *inner_group = NULL; 88 EC_KEY *ret = NULL; 89 if (CBS_peek_asn1_tag(&ec_private_key, kParametersTag)) { 90 // Per SEC 1, as an alternative to omitting it, one is allowed to specify 91 // this field and put in a NULL to mean inheriting this value. This was 92 // omitted in a previous version of this logic without problems, so leave it 93 // unimplemented. 94 CBS child; 95 if (!CBS_get_asn1(&ec_private_key, &child, kParametersTag)) { 96 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR); 97 goto err; 98 } 99 inner_group = EC_KEY_parse_parameters(&child); 100 if (inner_group == NULL) { 101 goto err; 102 } 103 if (group == NULL) { 104 group = inner_group; 105 } else if (EC_GROUP_cmp(group, inner_group, NULL) != 0) { 106 // If a group was supplied externally, it must match. 107 OPENSSL_PUT_ERROR(EC, EC_R_GROUP_MISMATCH); 108 goto err; 109 } 110 if (CBS_len(&child) != 0) { 111 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR); 112 goto err; 113 } 114 } 115 116 if (group == NULL) { 117 OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS); 118 goto err; 119 } 120 121 ret = EC_KEY_new(); 122 if (ret == NULL || !EC_KEY_set_group(ret, group)) { 123 goto err; 124 } 125 126 // Although RFC 5915 specifies the length of the key, OpenSSL historically 127 // got this wrong, so accept any length. See upstream's 128 // 30cd4ff294252c4b6a4b69cbef6a5b4117705d22. 129 ret->priv_key = 130 BN_bin2bn(CBS_data(&private_key), CBS_len(&private_key), NULL); 131 ret->pub_key = EC_POINT_new(group); 132 if (ret->priv_key == NULL || ret->pub_key == NULL) { 133 goto err; 134 } 135 136 if (BN_cmp(ret->priv_key, EC_GROUP_get0_order(group)) >= 0) { 137 OPENSSL_PUT_ERROR(EC, EC_R_WRONG_ORDER); 138 goto err; 139 } 140 141 if (CBS_peek_asn1_tag(&ec_private_key, kPublicKeyTag)) { 142 CBS child, public_key; 143 uint8_t padding; 144 if (!CBS_get_asn1(&ec_private_key, &child, kPublicKeyTag) || 145 !CBS_get_asn1(&child, &public_key, CBS_ASN1_BITSTRING) || 146 // As in a SubjectPublicKeyInfo, the byte-encoded public key is then 147 // encoded as a BIT STRING with bits ordered as in the DER encoding. 148 !CBS_get_u8(&public_key, &padding) || 149 padding != 0 || 150 // Explicitly check |public_key| is non-empty to save the conversion 151 // form later. 152 CBS_len(&public_key) == 0 || 153 !EC_POINT_oct2point(group, ret->pub_key, CBS_data(&public_key), 154 CBS_len(&public_key), NULL) || 155 CBS_len(&child) != 0) { 156 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR); 157 goto err; 158 } 159 160 // Save the point conversion form. 161 // TODO(davidben): Consider removing this. 162 ret->conv_form = 163 (point_conversion_form_t)(CBS_data(&public_key)[0] & ~0x01); 164 } else { 165 // Compute the public key instead. 166 if (!EC_POINT_mul(group, ret->pub_key, ret->priv_key, NULL, NULL, NULL)) { 167 goto err; 168 } 169 // Remember the original private-key-only encoding. 170 // TODO(davidben): Consider removing this. 171 ret->enc_flag |= EC_PKEY_NO_PUBKEY; 172 } 173 174 if (CBS_len(&ec_private_key) != 0) { 175 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR); 176 goto err; 177 } 178 179 // Ensure the resulting key is valid. 180 if (!EC_KEY_check_key(ret)) { 181 goto err; 182 } 183 184 EC_GROUP_free(inner_group); 185 return ret; 186 187 err: 188 EC_KEY_free(ret); 189 EC_GROUP_free(inner_group); 190 return NULL; 191 } 192 193 int EC_KEY_marshal_private_key(CBB *cbb, const EC_KEY *key, 194 unsigned enc_flags) { 195 if (key == NULL || key->group == NULL || key->priv_key == NULL) { 196 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER); 197 return 0; 198 } 199 200 CBB ec_private_key, private_key; 201 if (!CBB_add_asn1(cbb, &ec_private_key, CBS_ASN1_SEQUENCE) || 202 !CBB_add_asn1_uint64(&ec_private_key, 1 /* version */) || 203 !CBB_add_asn1(&ec_private_key, &private_key, CBS_ASN1_OCTETSTRING) || 204 !BN_bn2cbb_padded(&private_key, 205 BN_num_bytes(EC_GROUP_get0_order(key->group)), 206 key->priv_key)) { 207 OPENSSL_PUT_ERROR(EC, EC_R_ENCODE_ERROR); 208 return 0; 209 } 210 211 if (!(enc_flags & EC_PKEY_NO_PARAMETERS)) { 212 CBB child; 213 if (!CBB_add_asn1(&ec_private_key, &child, kParametersTag) || 214 !EC_KEY_marshal_curve_name(&child, key->group) || 215 !CBB_flush(&ec_private_key)) { 216 OPENSSL_PUT_ERROR(EC, EC_R_ENCODE_ERROR); 217 return 0; 218 } 219 } 220 221 // TODO(fork): replace this flexibility with sensible default? 222 if (!(enc_flags & EC_PKEY_NO_PUBKEY) && key->pub_key != NULL) { 223 CBB child, public_key; 224 if (!CBB_add_asn1(&ec_private_key, &child, kPublicKeyTag) || 225 !CBB_add_asn1(&child, &public_key, CBS_ASN1_BITSTRING) || 226 // As in a SubjectPublicKeyInfo, the byte-encoded public key is then 227 // encoded as a BIT STRING with bits ordered as in the DER encoding. 228 !CBB_add_u8(&public_key, 0 /* padding */) || 229 !EC_POINT_point2cbb(&public_key, key->group, key->pub_key, 230 key->conv_form, NULL) || 231 !CBB_flush(&ec_private_key)) { 232 OPENSSL_PUT_ERROR(EC, EC_R_ENCODE_ERROR); 233 return 0; 234 } 235 } 236 237 if (!CBB_flush(cbb)) { 238 OPENSSL_PUT_ERROR(EC, EC_R_ENCODE_ERROR); 239 return 0; 240 } 241 242 return 1; 243 } 244 245 // is_unsigned_integer returns one if |cbs| is a valid unsigned DER INTEGER and 246 // zero otherwise. 247 static int is_unsigned_integer(const CBS *cbs) { 248 if (CBS_len(cbs) == 0) { 249 return 0; 250 } 251 uint8_t byte = CBS_data(cbs)[0]; 252 if ((byte & 0x80) || 253 (byte == 0 && CBS_len(cbs) > 1 && (CBS_data(cbs)[1] & 0x80) == 0)) { 254 // Negative or not minimally-encoded. 255 return 0; 256 } 257 return 1; 258 } 259 260 // kPrimeFieldOID is the encoding of 1.2.840.10045.1.1. 261 static const uint8_t kPrimeField[] = {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x01, 0x01}; 262 263 static int parse_explicit_prime_curve(CBS *in, CBS *out_prime, CBS *out_a, 264 CBS *out_b, CBS *out_base_x, 265 CBS *out_base_y, CBS *out_order) { 266 // See RFC 3279, section 2.3.5. Note that RFC 3279 calls this structure an 267 // ECParameters while RFC 5480 calls it a SpecifiedECDomain. 268 CBS params, field_id, field_type, curve, base; 269 uint64_t version; 270 if (!CBS_get_asn1(in, ¶ms, CBS_ASN1_SEQUENCE) || 271 !CBS_get_asn1_uint64(¶ms, &version) || 272 version != 1 || 273 !CBS_get_asn1(¶ms, &field_id, CBS_ASN1_SEQUENCE) || 274 !CBS_get_asn1(&field_id, &field_type, CBS_ASN1_OBJECT) || 275 CBS_len(&field_type) != sizeof(kPrimeField) || 276 OPENSSL_memcmp(CBS_data(&field_type), kPrimeField, sizeof(kPrimeField)) != 0 || 277 !CBS_get_asn1(&field_id, out_prime, CBS_ASN1_INTEGER) || 278 !is_unsigned_integer(out_prime) || 279 CBS_len(&field_id) != 0 || 280 !CBS_get_asn1(¶ms, &curve, CBS_ASN1_SEQUENCE) || 281 !CBS_get_asn1(&curve, out_a, CBS_ASN1_OCTETSTRING) || 282 !CBS_get_asn1(&curve, out_b, CBS_ASN1_OCTETSTRING) || 283 // |curve| has an optional BIT STRING seed which we ignore. 284 !CBS_get_asn1(¶ms, &base, CBS_ASN1_OCTETSTRING) || 285 !CBS_get_asn1(¶ms, out_order, CBS_ASN1_INTEGER) || 286 !is_unsigned_integer(out_order)) { 287 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR); 288 return 0; 289 } 290 291 // |params| has an optional cofactor which we ignore. With the optional seed 292 // in |curve|, a group already has arbitrarily many encodings. Parse enough to 293 // uniquely determine the curve. 294 295 // Require that the base point use uncompressed form. 296 uint8_t form; 297 if (!CBS_get_u8(&base, &form) || form != POINT_CONVERSION_UNCOMPRESSED) { 298 OPENSSL_PUT_ERROR(EC, EC_R_INVALID_FORM); 299 return 0; 300 } 301 302 if (CBS_len(&base) % 2 != 0) { 303 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR); 304 return 0; 305 } 306 size_t field_len = CBS_len(&base) / 2; 307 CBS_init(out_base_x, CBS_data(&base), field_len); 308 CBS_init(out_base_y, CBS_data(&base) + field_len, field_len); 309 310 return 1; 311 } 312 313 // integers_equal returns one if |a| and |b| are equal, up to leading zeros, and 314 // zero otherwise. 315 static int integers_equal(const CBS *a, const uint8_t *b, size_t b_len) { 316 // Remove leading zeros from |a| and |b|. 317 CBS a_copy = *a; 318 while (CBS_len(&a_copy) > 0 && CBS_data(&a_copy)[0] == 0) { 319 CBS_skip(&a_copy, 1); 320 } 321 while (b_len > 0 && b[0] == 0) { 322 b++; 323 b_len--; 324 } 325 return CBS_mem_equal(&a_copy, b, b_len); 326 } 327 328 EC_GROUP *EC_KEY_parse_curve_name(CBS *cbs) { 329 CBS named_curve; 330 if (!CBS_get_asn1(cbs, &named_curve, CBS_ASN1_OBJECT)) { 331 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR); 332 return NULL; 333 } 334 335 // Look for a matching curve. 336 const struct built_in_curves *const curves = OPENSSL_built_in_curves(); 337 for (size_t i = 0; i < OPENSSL_NUM_BUILT_IN_CURVES; i++) { 338 const struct built_in_curve *curve = &curves->curves[i]; 339 if (CBS_len(&named_curve) == curve->oid_len && 340 OPENSSL_memcmp(CBS_data(&named_curve), curve->oid, curve->oid_len) == 341 0) { 342 return EC_GROUP_new_by_curve_name(curve->nid); 343 } 344 } 345 346 OPENSSL_PUT_ERROR(EC, EC_R_UNKNOWN_GROUP); 347 return NULL; 348 } 349 350 int EC_KEY_marshal_curve_name(CBB *cbb, const EC_GROUP *group) { 351 int nid = EC_GROUP_get_curve_name(group); 352 if (nid == NID_undef) { 353 OPENSSL_PUT_ERROR(EC, EC_R_UNKNOWN_GROUP); 354 return 0; 355 } 356 357 const struct built_in_curves *const curves = OPENSSL_built_in_curves(); 358 for (size_t i = 0; i < OPENSSL_NUM_BUILT_IN_CURVES; i++) { 359 const struct built_in_curve *curve = &curves->curves[i]; 360 if (curve->nid == nid) { 361 CBB child; 362 return CBB_add_asn1(cbb, &child, CBS_ASN1_OBJECT) && 363 CBB_add_bytes(&child, curve->oid, curve->oid_len) && 364 CBB_flush(cbb); 365 } 366 } 367 368 OPENSSL_PUT_ERROR(EC, EC_R_UNKNOWN_GROUP); 369 return 0; 370 } 371 372 EC_GROUP *EC_KEY_parse_parameters(CBS *cbs) { 373 if (!CBS_peek_asn1_tag(cbs, CBS_ASN1_SEQUENCE)) { 374 return EC_KEY_parse_curve_name(cbs); 375 } 376 377 // OpenSSL sometimes produces ECPrivateKeys with explicitly-encoded versions 378 // of named curves. 379 // 380 // TODO(davidben): Remove support for this. 381 CBS prime, a, b, base_x, base_y, order; 382 if (!parse_explicit_prime_curve(cbs, &prime, &a, &b, &base_x, &base_y, 383 &order)) { 384 return NULL; 385 } 386 387 // Look for a matching prime curve. 388 const struct built_in_curves *const curves = OPENSSL_built_in_curves(); 389 for (size_t i = 0; i < OPENSSL_NUM_BUILT_IN_CURVES; i++) { 390 const struct built_in_curve *curve = &curves->curves[i]; 391 const unsigned param_len = curve->param_len; 392 // |curve->params| is ordered p, a, b, x, y, order, each component 393 // zero-padded up to the field length. Although SEC 1 states that the 394 // Field-Element-to-Octet-String conversion also pads, OpenSSL mis-encodes 395 // |a| and |b|, so this comparison must allow omitting leading zeros. (This 396 // is relevant for P-521 whose |b| has a leading 0.) 397 if (integers_equal(&prime, curve->params, param_len) && 398 integers_equal(&a, curve->params + param_len, param_len) && 399 integers_equal(&b, curve->params + param_len * 2, param_len) && 400 integers_equal(&base_x, curve->params + param_len * 3, param_len) && 401 integers_equal(&base_y, curve->params + param_len * 4, param_len) && 402 integers_equal(&order, curve->params + param_len * 5, param_len)) { 403 return EC_GROUP_new_by_curve_name(curve->nid); 404 } 405 } 406 407 OPENSSL_PUT_ERROR(EC, EC_R_UNKNOWN_GROUP); 408 return NULL; 409 } 410 411 int EC_POINT_point2cbb(CBB *out, const EC_GROUP *group, const EC_POINT *point, 412 point_conversion_form_t form, BN_CTX *ctx) { 413 size_t len = EC_POINT_point2oct(group, point, form, NULL, 0, ctx); 414 if (len == 0) { 415 return 0; 416 } 417 uint8_t *p; 418 return CBB_add_space(out, &p, len) && 419 EC_POINT_point2oct(group, point, form, p, len, ctx) == len; 420 } 421 422 EC_KEY *d2i_ECPrivateKey(EC_KEY **out, const uint8_t **inp, long len) { 423 // This function treats its |out| parameter differently from other |d2i| 424 // functions. If supplied, take the group from |*out|. 425 const EC_GROUP *group = NULL; 426 if (out != NULL && *out != NULL) { 427 group = EC_KEY_get0_group(*out); 428 } 429 430 if (len < 0) { 431 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR); 432 return NULL; 433 } 434 CBS cbs; 435 CBS_init(&cbs, *inp, (size_t)len); 436 EC_KEY *ret = EC_KEY_parse_private_key(&cbs, group); 437 if (ret == NULL) { 438 return NULL; 439 } 440 if (out != NULL) { 441 EC_KEY_free(*out); 442 *out = ret; 443 } 444 *inp = CBS_data(&cbs); 445 return ret; 446 } 447 448 int i2d_ECPrivateKey(const EC_KEY *key, uint8_t **outp) { 449 CBB cbb; 450 if (!CBB_init(&cbb, 0) || 451 !EC_KEY_marshal_private_key(&cbb, key, EC_KEY_get_enc_flags(key))) { 452 CBB_cleanup(&cbb); 453 return -1; 454 } 455 return CBB_finish_i2d(&cbb, outp); 456 } 457 458 EC_KEY *d2i_ECParameters(EC_KEY **out_key, const uint8_t **inp, long len) { 459 if (len < 0) { 460 return NULL; 461 } 462 463 CBS cbs; 464 CBS_init(&cbs, *inp, (size_t)len); 465 EC_GROUP *group = EC_KEY_parse_parameters(&cbs); 466 if (group == NULL) { 467 return NULL; 468 } 469 470 EC_KEY *ret = EC_KEY_new(); 471 if (ret == NULL || !EC_KEY_set_group(ret, group)) { 472 EC_GROUP_free(group); 473 EC_KEY_free(ret); 474 return NULL; 475 } 476 EC_GROUP_free(group); 477 478 if (out_key != NULL) { 479 EC_KEY_free(*out_key); 480 *out_key = ret; 481 } 482 *inp = CBS_data(&cbs); 483 return ret; 484 } 485 486 int i2d_ECParameters(const EC_KEY *key, uint8_t **outp) { 487 if (key == NULL || key->group == NULL) { 488 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER); 489 return -1; 490 } 491 492 CBB cbb; 493 if (!CBB_init(&cbb, 0) || 494 !EC_KEY_marshal_curve_name(&cbb, key->group)) { 495 CBB_cleanup(&cbb); 496 return -1; 497 } 498 return CBB_finish_i2d(&cbb, outp); 499 } 500 501 EC_KEY *o2i_ECPublicKey(EC_KEY **keyp, const uint8_t **inp, long len) { 502 EC_KEY *ret = NULL; 503 504 if (keyp == NULL || *keyp == NULL || (*keyp)->group == NULL) { 505 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER); 506 return NULL; 507 } 508 ret = *keyp; 509 if (ret->pub_key == NULL && 510 (ret->pub_key = EC_POINT_new(ret->group)) == NULL) { 511 OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE); 512 return NULL; 513 } 514 if (!EC_POINT_oct2point(ret->group, ret->pub_key, *inp, len, NULL)) { 515 OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB); 516 return NULL; 517 } 518 // save the point conversion form 519 ret->conv_form = (point_conversion_form_t)(*inp[0] & ~0x01); 520 *inp += len; 521 return ret; 522 } 523 524 int i2o_ECPublicKey(const EC_KEY *key, uint8_t **outp) { 525 size_t buf_len = 0; 526 int new_buffer = 0; 527 528 if (key == NULL) { 529 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER); 530 return 0; 531 } 532 533 buf_len = EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, NULL, 534 0, NULL); 535 536 if (outp == NULL || buf_len == 0) { 537 // out == NULL => just return the length of the octet string 538 return buf_len; 539 } 540 541 if (*outp == NULL) { 542 *outp = OPENSSL_malloc(buf_len); 543 if (*outp == NULL) { 544 OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE); 545 return 0; 546 } 547 new_buffer = 1; 548 } 549 if (!EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, *outp, 550 buf_len, NULL)) { 551 OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB); 552 if (new_buffer) { 553 OPENSSL_free(*outp); 554 *outp = NULL; 555 } 556 return 0; 557 } 558 559 if (!new_buffer) { 560 *outp += buf_len; 561 } 562 return buf_len; 563 } 564