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 <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
70static const unsigned kParametersTag =
71 CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 0;
72static const unsigned kPublicKeyTag =
73 CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC | 1;
74
75EC_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 BIGNUM *priv_key = NULL;
90 if (CBS_peek_asn1_tag(&ec_private_key, kParametersTag)) {
91 // Per SEC 1, as an alternative to omitting it, one is allowed to specify
92 // this field and put in a NULL to mean inheriting this value. This was
93 // omitted in a previous version of this logic without problems, so leave it
94 // unimplemented.
95 CBS child;
96 if (!CBS_get_asn1(&ec_private_key, &child, kParametersTag)) {
97 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR);
98 goto err;
99 }
100 inner_group = EC_KEY_parse_parameters(&child);
101 if (inner_group == NULL) {
102 goto err;
103 }
104 if (group == NULL) {
105 group = inner_group;
106 } else if (EC_GROUP_cmp(group, inner_group, NULL) != 0) {
107 // If a group was supplied externally, it must match.
108 OPENSSL_PUT_ERROR(EC, EC_R_GROUP_MISMATCH);
109 goto err;
110 }
111 if (CBS_len(&child) != 0) {
112 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR);
113 goto err;
114 }
115 }
116
117 if (group == NULL) {
118 OPENSSL_PUT_ERROR(EC, EC_R_MISSING_PARAMETERS);
119 goto err;
120 }
121
122 ret = EC_KEY_new();
123 if (ret == NULL || !EC_KEY_set_group(ret, group)) {
124 goto err;
125 }
126
127 // Although RFC 5915 specifies the length of the key, OpenSSL historically
128 // got this wrong, so accept any length. See upstream's
129 // 30cd4ff294252c4b6a4b69cbef6a5b4117705d22.
130 priv_key = BN_bin2bn(CBS_data(&private_key), CBS_len(&private_key), NULL);
131 ret->pub_key = EC_POINT_new(group);
132 if (priv_key == NULL || ret->pub_key == NULL ||
133 !EC_KEY_set_private_key(ret, priv_key)) {
134 goto err;
135 }
136
137 if (CBS_peek_asn1_tag(&ec_private_key, kPublicKeyTag)) {
138 CBS child, public_key;
139 uint8_t padding;
140 if (!CBS_get_asn1(&ec_private_key, &child, kPublicKeyTag) ||
141 !CBS_get_asn1(&child, &public_key, CBS_ASN1_BITSTRING) ||
142 // As in a SubjectPublicKeyInfo, the byte-encoded public key is then
143 // encoded as a BIT STRING with bits ordered as in the DER encoding.
144 !CBS_get_u8(&public_key, &padding) ||
145 padding != 0 ||
146 // Explicitly check |public_key| is non-empty to save the conversion
147 // form later.
148 CBS_len(&public_key) == 0 ||
149 !EC_POINT_oct2point(group, ret->pub_key, CBS_data(&public_key),
150 CBS_len(&public_key), NULL) ||
151 CBS_len(&child) != 0) {
152 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR);
153 goto err;
154 }
155
156 // Save the point conversion form.
157 // TODO(davidben): Consider removing this.
158 ret->conv_form =
159 (point_conversion_form_t)(CBS_data(&public_key)[0] & ~0x01);
160 } else {
161 // Compute the public key instead.
162 if (!ec_point_mul_scalar_base(group, &ret->pub_key->raw,
163 &ret->priv_key->scalar)) {
164 goto err;
165 }
166 // Remember the original private-key-only encoding.
167 // TODO(davidben): Consider removing this.
168 ret->enc_flag |= EC_PKEY_NO_PUBKEY;
169 }
170
171 if (CBS_len(&ec_private_key) != 0) {
172 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR);
173 goto err;
174 }
175
176 // Ensure the resulting key is valid.
177 if (!EC_KEY_check_key(ret)) {
178 goto err;
179 }
180
181 BN_free(priv_key);
182 EC_GROUP_free(inner_group);
183 return ret;
184
185err:
186 EC_KEY_free(ret);
187 BN_free(priv_key);
188 EC_GROUP_free(inner_group);
189 return NULL;
190}
191
192int EC_KEY_marshal_private_key(CBB *cbb, const EC_KEY *key,
193 unsigned enc_flags) {
194 if (key == NULL || key->group == NULL || key->priv_key == NULL) {
195 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
196 return 0;
197 }
198
199 CBB ec_private_key, private_key;
200 if (!CBB_add_asn1(cbb, &ec_private_key, CBS_ASN1_SEQUENCE) ||
201 !CBB_add_asn1_uint64(&ec_private_key, 1 /* version */) ||
202 !CBB_add_asn1(&ec_private_key, &private_key, CBS_ASN1_OCTETSTRING) ||
203 !BN_bn2cbb_padded(&private_key,
204 BN_num_bytes(EC_GROUP_get0_order(key->group)),
205 EC_KEY_get0_private_key(key))) {
206 OPENSSL_PUT_ERROR(EC, EC_R_ENCODE_ERROR);
207 return 0;
208 }
209
210 if (!(enc_flags & EC_PKEY_NO_PARAMETERS)) {
211 CBB child;
212 if (!CBB_add_asn1(&ec_private_key, &child, kParametersTag) ||
213 !EC_KEY_marshal_curve_name(&child, key->group) ||
214 !CBB_flush(&ec_private_key)) {
215 OPENSSL_PUT_ERROR(EC, EC_R_ENCODE_ERROR);
216 return 0;
217 }
218 }
219
220 // TODO(fork): replace this flexibility with sensible default?
221 if (!(enc_flags & EC_PKEY_NO_PUBKEY) && key->pub_key != NULL) {
222 CBB child, public_key;
223 if (!CBB_add_asn1(&ec_private_key, &child, kPublicKeyTag) ||
224 !CBB_add_asn1(&child, &public_key, CBS_ASN1_BITSTRING) ||
225 // As in a SubjectPublicKeyInfo, the byte-encoded public key is then
226 // encoded as a BIT STRING with bits ordered as in the DER encoding.
227 !CBB_add_u8(&public_key, 0 /* padding */) ||
228 !EC_POINT_point2cbb(&public_key, key->group, key->pub_key,
229 key->conv_form, NULL) ||
230 !CBB_flush(&ec_private_key)) {
231 OPENSSL_PUT_ERROR(EC, EC_R_ENCODE_ERROR);
232 return 0;
233 }
234 }
235
236 if (!CBB_flush(cbb)) {
237 OPENSSL_PUT_ERROR(EC, EC_R_ENCODE_ERROR);
238 return 0;
239 }
240
241 return 1;
242}
243
244// is_unsigned_integer returns one if |cbs| is a valid unsigned DER INTEGER and
245// zero otherwise.
246static int is_unsigned_integer(const CBS *cbs) {
247 if (CBS_len(cbs) == 0) {
248 return 0;
249 }
250 uint8_t byte = CBS_data(cbs)[0];
251 if ((byte & 0x80) ||
252 (byte == 0 && CBS_len(cbs) > 1 && (CBS_data(cbs)[1] & 0x80) == 0)) {
253 // Negative or not minimally-encoded.
254 return 0;
255 }
256 return 1;
257}
258
259// kPrimeFieldOID is the encoding of 1.2.840.10045.1.1.
260static const uint8_t kPrimeField[] = {0x2a, 0x86, 0x48, 0xce, 0x3d, 0x01, 0x01};
261
262static int parse_explicit_prime_curve(CBS *in, CBS *out_prime, CBS *out_a,
263 CBS *out_b, CBS *out_base_x,
264 CBS *out_base_y, CBS *out_order) {
265 // See RFC 3279, section 2.3.5. Note that RFC 3279 calls this structure an
266 // ECParameters while RFC 5480 calls it a SpecifiedECDomain.
267 CBS params, field_id, field_type, curve, base;
268 uint64_t version;
269 if (!CBS_get_asn1(in, &params, CBS_ASN1_SEQUENCE) ||
270 !CBS_get_asn1_uint64(&params, &version) ||
271 version != 1 ||
272 !CBS_get_asn1(&params, &field_id, CBS_ASN1_SEQUENCE) ||
273 !CBS_get_asn1(&field_id, &field_type, CBS_ASN1_OBJECT) ||
274 CBS_len(&field_type) != sizeof(kPrimeField) ||
275 OPENSSL_memcmp(CBS_data(&field_type), kPrimeField, sizeof(kPrimeField)) != 0 ||
276 !CBS_get_asn1(&field_id, out_prime, CBS_ASN1_INTEGER) ||
277 !is_unsigned_integer(out_prime) ||
278 CBS_len(&field_id) != 0 ||
279 !CBS_get_asn1(&params, &curve, CBS_ASN1_SEQUENCE) ||
280 !CBS_get_asn1(&curve, out_a, CBS_ASN1_OCTETSTRING) ||
281 !CBS_get_asn1(&curve, out_b, CBS_ASN1_OCTETSTRING) ||
282 // |curve| has an optional BIT STRING seed which we ignore.
283 !CBS_get_asn1(&params, &base, CBS_ASN1_OCTETSTRING) ||
284 !CBS_get_asn1(&params, out_order, CBS_ASN1_INTEGER) ||
285 !is_unsigned_integer(out_order)) {
286 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR);
287 return 0;
288 }
289
290 // |params| has an optional cofactor which we ignore. With the optional seed
291 // in |curve|, a group already has arbitrarily many encodings. Parse enough to
292 // uniquely determine the curve.
293
294 // Require that the base point use uncompressed form.
295 uint8_t form;
296 if (!CBS_get_u8(&base, &form) || form != POINT_CONVERSION_UNCOMPRESSED) {
297 OPENSSL_PUT_ERROR(EC, EC_R_INVALID_FORM);
298 return 0;
299 }
300
301 if (CBS_len(&base) % 2 != 0) {
302 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR);
303 return 0;
304 }
305 size_t field_len = CBS_len(&base) / 2;
306 CBS_init(out_base_x, CBS_data(&base), field_len);
307 CBS_init(out_base_y, CBS_data(&base) + field_len, field_len);
308
309 return 1;
310}
311
312// integers_equal returns one if |a| and |b| are equal, up to leading zeros, and
313// zero otherwise.
314static int integers_equal(const CBS *a, const uint8_t *b, size_t b_len) {
315 // Remove leading zeros from |a| and |b|.
316 CBS a_copy = *a;
317 while (CBS_len(&a_copy) > 0 && CBS_data(&a_copy)[0] == 0) {
318 CBS_skip(&a_copy, 1);
319 }
320 while (b_len > 0 && b[0] == 0) {
321 b++;
322 b_len--;
323 }
324 return CBS_mem_equal(&a_copy, b, b_len);
325}
326
327EC_GROUP *EC_KEY_parse_curve_name(CBS *cbs) {
328 CBS named_curve;
329 if (!CBS_get_asn1(cbs, &named_curve, CBS_ASN1_OBJECT)) {
330 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR);
331 return NULL;
332 }
333
334 // Look for a matching curve.
335 const struct built_in_curves *const curves = OPENSSL_built_in_curves();
336 for (size_t i = 0; i < OPENSSL_NUM_BUILT_IN_CURVES; i++) {
337 const struct built_in_curve *curve = &curves->curves[i];
338 if (CBS_len(&named_curve) == curve->oid_len &&
339 OPENSSL_memcmp(CBS_data(&named_curve), curve->oid, curve->oid_len) ==
340 0) {
341 return EC_GROUP_new_by_curve_name(curve->nid);
342 }
343 }
344
345 OPENSSL_PUT_ERROR(EC, EC_R_UNKNOWN_GROUP);
346 return NULL;
347}
348
349int EC_KEY_marshal_curve_name(CBB *cbb, const EC_GROUP *group) {
350 int nid = EC_GROUP_get_curve_name(group);
351 if (nid == NID_undef) {
352 OPENSSL_PUT_ERROR(EC, EC_R_UNKNOWN_GROUP);
353 return 0;
354 }
355
356 const struct built_in_curves *const curves = OPENSSL_built_in_curves();
357 for (size_t i = 0; i < OPENSSL_NUM_BUILT_IN_CURVES; i++) {
358 const struct built_in_curve *curve = &curves->curves[i];
359 if (curve->nid == nid) {
360 CBB child;
361 return CBB_add_asn1(cbb, &child, CBS_ASN1_OBJECT) &&
362 CBB_add_bytes(&child, curve->oid, curve->oid_len) &&
363 CBB_flush(cbb);
364 }
365 }
366
367 OPENSSL_PUT_ERROR(EC, EC_R_UNKNOWN_GROUP);
368 return 0;
369}
370
371EC_GROUP *EC_KEY_parse_parameters(CBS *cbs) {
372 if (!CBS_peek_asn1_tag(cbs, CBS_ASN1_SEQUENCE)) {
373 return EC_KEY_parse_curve_name(cbs);
374 }
375
376 // OpenSSL sometimes produces ECPrivateKeys with explicitly-encoded versions
377 // of named curves.
378 //
379 // TODO(davidben): Remove support for this.
380 CBS prime, a, b, base_x, base_y, order;
381 if (!parse_explicit_prime_curve(cbs, &prime, &a, &b, &base_x, &base_y,
382 &order)) {
383 return NULL;
384 }
385
386 // Look for a matching prime curve.
387 const struct built_in_curves *const curves = OPENSSL_built_in_curves();
388 for (size_t i = 0; i < OPENSSL_NUM_BUILT_IN_CURVES; i++) {
389 const struct built_in_curve *curve = &curves->curves[i];
390 const unsigned param_len = curve->param_len;
391 // |curve->params| is ordered p, a, b, x, y, order, each component
392 // zero-padded up to the field length. Although SEC 1 states that the
393 // Field-Element-to-Octet-String conversion also pads, OpenSSL mis-encodes
394 // |a| and |b|, so this comparison must allow omitting leading zeros. (This
395 // is relevant for P-521 whose |b| has a leading 0.)
396 if (integers_equal(&prime, curve->params, param_len) &&
397 integers_equal(&a, curve->params + param_len, param_len) &&
398 integers_equal(&b, curve->params + param_len * 2, param_len) &&
399 integers_equal(&base_x, curve->params + param_len * 3, param_len) &&
400 integers_equal(&base_y, curve->params + param_len * 4, param_len) &&
401 integers_equal(&order, curve->params + param_len * 5, param_len)) {
402 return EC_GROUP_new_by_curve_name(curve->nid);
403 }
404 }
405
406 OPENSSL_PUT_ERROR(EC, EC_R_UNKNOWN_GROUP);
407 return NULL;
408}
409
410int EC_POINT_point2cbb(CBB *out, const EC_GROUP *group, const EC_POINT *point,
411 point_conversion_form_t form, BN_CTX *ctx) {
412 size_t len = EC_POINT_point2oct(group, point, form, NULL, 0, ctx);
413 if (len == 0) {
414 return 0;
415 }
416 uint8_t *p;
417 return CBB_add_space(out, &p, len) &&
418 EC_POINT_point2oct(group, point, form, p, len, ctx) == len;
419}
420
421EC_KEY *d2i_ECPrivateKey(EC_KEY **out, const uint8_t **inp, long len) {
422 // This function treats its |out| parameter differently from other |d2i|
423 // functions. If supplied, take the group from |*out|.
424 const EC_GROUP *group = NULL;
425 if (out != NULL && *out != NULL) {
426 group = EC_KEY_get0_group(*out);
427 }
428
429 if (len < 0) {
430 OPENSSL_PUT_ERROR(EC, EC_R_DECODE_ERROR);
431 return NULL;
432 }
433 CBS cbs;
434 CBS_init(&cbs, *inp, (size_t)len);
435 EC_KEY *ret = EC_KEY_parse_private_key(&cbs, group);
436 if (ret == NULL) {
437 return NULL;
438 }
439 if (out != NULL) {
440 EC_KEY_free(*out);
441 *out = ret;
442 }
443 *inp = CBS_data(&cbs);
444 return ret;
445}
446
447int i2d_ECPrivateKey(const EC_KEY *key, uint8_t **outp) {
448 CBB cbb;
449 if (!CBB_init(&cbb, 0) ||
450 !EC_KEY_marshal_private_key(&cbb, key, EC_KEY_get_enc_flags(key))) {
451 CBB_cleanup(&cbb);
452 return -1;
453 }
454 return CBB_finish_i2d(&cbb, outp);
455}
456
457EC_KEY *d2i_ECParameters(EC_KEY **out_key, const uint8_t **inp, long len) {
458 if (len < 0) {
459 return NULL;
460 }
461
462 CBS cbs;
463 CBS_init(&cbs, *inp, (size_t)len);
464 EC_GROUP *group = EC_KEY_parse_parameters(&cbs);
465 if (group == NULL) {
466 return NULL;
467 }
468
469 EC_KEY *ret = EC_KEY_new();
470 if (ret == NULL || !EC_KEY_set_group(ret, group)) {
471 EC_GROUP_free(group);
472 EC_KEY_free(ret);
473 return NULL;
474 }
475 EC_GROUP_free(group);
476
477 if (out_key != NULL) {
478 EC_KEY_free(*out_key);
479 *out_key = ret;
480 }
481 *inp = CBS_data(&cbs);
482 return ret;
483}
484
485int i2d_ECParameters(const EC_KEY *key, uint8_t **outp) {
486 if (key == NULL || key->group == NULL) {
487 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
488 return -1;
489 }
490
491 CBB cbb;
492 if (!CBB_init(&cbb, 0) ||
493 !EC_KEY_marshal_curve_name(&cbb, key->group)) {
494 CBB_cleanup(&cbb);
495 return -1;
496 }
497 return CBB_finish_i2d(&cbb, outp);
498}
499
500EC_KEY *o2i_ECPublicKey(EC_KEY **keyp, const uint8_t **inp, long len) {
501 EC_KEY *ret = NULL;
502
503 if (keyp == NULL || *keyp == NULL || (*keyp)->group == NULL) {
504 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
505 return NULL;
506 }
507 ret = *keyp;
508 if (ret->pub_key == NULL &&
509 (ret->pub_key = EC_POINT_new(ret->group)) == NULL) {
510 OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
511 return NULL;
512 }
513 if (!EC_POINT_oct2point(ret->group, ret->pub_key, *inp, len, NULL)) {
514 OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
515 return NULL;
516 }
517 // save the point conversion form
518 ret->conv_form = (point_conversion_form_t)(*inp[0] & ~0x01);
519 *inp += len;
520 return ret;
521}
522
523int i2o_ECPublicKey(const EC_KEY *key, uint8_t **outp) {
524 size_t buf_len = 0;
525 int new_buffer = 0;
526
527 if (key == NULL) {
528 OPENSSL_PUT_ERROR(EC, ERR_R_PASSED_NULL_PARAMETER);
529 return 0;
530 }
531
532 buf_len = EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, NULL,
533 0, NULL);
534
535 if (outp == NULL || buf_len == 0) {
536 // out == NULL => just return the length of the octet string
537 return buf_len;
538 }
539
540 if (*outp == NULL) {
541 *outp = OPENSSL_malloc(buf_len);
542 if (*outp == NULL) {
543 OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
544 return 0;
545 }
546 new_buffer = 1;
547 }
548 if (!EC_POINT_point2oct(key->group, key->pub_key, key->conv_form, *outp,
549 buf_len, NULL)) {
550 OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
551 if (new_buffer) {
552 OPENSSL_free(*outp);
553 *outp = NULL;
554 }
555 return 0;
556 }
557
558 if (!new_buffer) {
559 *outp += buf_len;
560 }
561 return buf_len;
562}
563