blob: a53bada240b15a57c881f851cdd5ce3853b92bf2 [file] [log] [blame]
Paul Bakkerc7bb02b2013-09-15 14:54:56 +02001/*
2 * Public Key layer for writing key files and structures
3 *
Bence Szépkúti1e148272020-08-07 13:07:28 +02004 * Copyright The Mbed TLS Contributors
Manuel Pégourié-Gonnard37ff1402015-09-04 14:21:07 +02005 * SPDX-License-Identifier: Apache-2.0
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
8 * not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
Paul Bakkerc7bb02b2013-09-15 14:54:56 +020018 */
19
Gilles Peskinedb09ef62020-06-03 01:43:33 +020020#include "common.h"
Paul Bakkerc7bb02b2013-09-15 14:54:56 +020021
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020022#if defined(MBEDTLS_PK_WRITE_C)
Paul Bakkerc7bb02b2013-09-15 14:54:56 +020023
Manuel Pégourié-Gonnard7f809972015-03-09 17:05:11 +000024#include "mbedtls/pk.h"
25#include "mbedtls/asn1write.h"
26#include "mbedtls/oid.h"
Andrzej Kurekc470b6b2019-01-31 08:20:20 -050027#include "mbedtls/platform_util.h"
Janos Follath24eed8d2019-11-22 13:21:35 +000028#include "mbedtls/error.h"
Valerio Setti77a75682023-05-15 11:18:46 +020029#include "pk_internal.h"
Paul Bakkerc7bb02b2013-09-15 14:54:56 +020030
Rich Evans00ab4702015-02-06 13:43:58 +000031#include <string.h>
32
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020033#if defined(MBEDTLS_RSA_C)
Manuel Pégourié-Gonnard7f809972015-03-09 17:05:11 +000034#include "mbedtls/rsa.h"
Paul Bakkerc7bb02b2013-09-15 14:54:56 +020035#endif
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020036#if defined(MBEDTLS_ECP_C)
Gilles Peskine2700cfb2018-08-11 00:48:44 +020037#include "mbedtls/bignum.h"
Manuel Pégourié-Gonnard7f809972015-03-09 17:05:11 +000038#include "mbedtls/ecp.h"
Gilles Peskine2700cfb2018-08-11 00:48:44 +020039#include "mbedtls/platform_util.h"
Paul Bakkerc7bb02b2013-09-15 14:54:56 +020040#endif
Valerio Setti4064dbb2023-05-17 15:33:07 +020041#if defined(MBEDTLS_ECP_LIGHT)
42#include "pk_internal.h"
43#endif
44#if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECP_LIGHT)
Neil Armstronge0326a62022-02-25 08:57:19 +010045#include "pkwrite.h"
46#endif
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020047#if defined(MBEDTLS_ECDSA_C)
Manuel Pégourié-Gonnard7f809972015-03-09 17:05:11 +000048#include "mbedtls/ecdsa.h"
Paul Bakkerc7bb02b2013-09-15 14:54:56 +020049#endif
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +020050#if defined(MBEDTLS_PEM_WRITE_C)
Manuel Pégourié-Gonnard7f809972015-03-09 17:05:11 +000051#include "mbedtls/pem.h"
Paul Bakkerc7bb02b2013-09-15 14:54:56 +020052#endif
53
Andrzej Kurek5fec0862018-11-19 10:07:36 -050054#if defined(MBEDTLS_USE_PSA_CRYPTO)
55#include "psa/crypto.h"
Hanno Becker65935d92019-02-01 11:55:03 +000056#include "mbedtls/psa_util.h"
Andrzej Kurek5fec0862018-11-19 10:07:36 -050057#endif
Manuel Pégourié-Gonnard7f809972015-03-09 17:05:11 +000058#include "mbedtls/platform.h"
Paul Bakkerc7bb02b2013-09-15 14:54:56 +020059
Valerio Settie0e63112023-05-18 18:48:07 +020060/* Helper for Montgomery curves */
valeriob7273142023-05-31 12:07:18 +020061#if defined(MBEDTLS_ECP_LIGHT)
62#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
Valerio Settie0e63112023-05-18 18:48:07 +020063static inline int mbedtls_pk_is_rfc8410(const mbedtls_pk_context *pk)
64{
65 mbedtls_ecp_group_id id = mbedtls_pk_get_group_id(pk);
66
67#if defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED)
68 if (id == MBEDTLS_ECP_DP_CURVE25519) {
69 return 1;
70 }
71#endif
72#if defined(MBEDTLS_ECP_DP_CURVE448_ENABLED)
73 if (id == MBEDTLS_ECP_DP_CURVE448) {
74 return 1;
75 }
76#endif
77 return 0;
78}
valeriob7273142023-05-31 12:07:18 +020079#endif /* MBEDTLS_PK_HAVE_RFC8410_CURVES */
80#if defined(MBEDTLS_USE_PSA_CRYPTO)
81/* It is assumed that the input key is opaque */
82static psa_ecc_family_t pk_get_opaque_ec_family(const mbedtls_pk_context *pk)
83{
84 psa_ecc_family_t ec_family = 0;
85 psa_key_attributes_t key_attrs = PSA_KEY_ATTRIBUTES_INIT;
86
87 if (psa_get_key_attributes(pk->priv_id, &key_attrs) != PSA_SUCCESS) {
88 return 0;
89 }
90 ec_family = PSA_KEY_TYPE_ECC_GET_FAMILY(psa_get_key_type(&key_attrs));
91 psa_reset_key_attributes(&key_attrs);
92
93 return ec_family;
94}
95#endif /* MBETLS_USE_PSA_CRYPTO */
96#endif /* MBEDTLS_ECP_LIGHT */
97
98#if defined(MBEDTLS_USE_PSA_CRYPTO)
99/* It is assumed that the input key is opaque */
100static psa_key_type_t pk_get_opaque_key_type(const mbedtls_pk_context *pk)
101{
102 psa_key_attributes_t opaque_attrs = PSA_KEY_ATTRIBUTES_INIT;
103 psa_key_type_t opaque_key_type;
104
105 if (psa_get_key_attributes(pk->priv_id, &opaque_attrs) != PSA_SUCCESS) {
106 return 0;
107 }
108 opaque_key_type = psa_get_key_type(&opaque_attrs);
109 psa_reset_key_attributes(&opaque_attrs);
110
111 return opaque_key_type;
112}
113#endif /* MBETLS_USE_PSA_CRYPTO */
Valerio Settie0e63112023-05-18 18:48:07 +0200114
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200115#if defined(MBEDTLS_RSA_C)
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200116/*
117 * RSAPublicKey ::= SEQUENCE {
118 * modulus INTEGER, -- n
119 * publicExponent INTEGER -- e
120 * }
121 */
Gilles Peskine449bd832023-01-11 14:50:10 +0100122static int pk_write_rsa_pubkey(unsigned char **p, unsigned char *start,
valerio9ea26172023-05-31 12:10:23 +0200123 const mbedtls_pk_context *pk)
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200124{
Janos Follath24eed8d2019-11-22 13:21:35 +0000125 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200126 size_t len = 0;
Hanno Becker15f81fa2017-08-23 12:38:27 +0100127 mbedtls_mpi T;
valerio9ea26172023-05-31 12:10:23 +0200128 mbedtls_rsa_context *rsa = mbedtls_pk_rsa(*pk);
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200129
Gilles Peskine449bd832023-01-11 14:50:10 +0100130 mbedtls_mpi_init(&T);
Hanno Becker15f81fa2017-08-23 12:38:27 +0100131
132 /* Export E */
Gilles Peskine449bd832023-01-11 14:50:10 +0100133 if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
134 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
Hanno Becker15f81fa2017-08-23 12:38:27 +0100135 goto end_of_export;
Gilles Peskine449bd832023-01-11 14:50:10 +0100136 }
Hanno Becker15f81fa2017-08-23 12:38:27 +0100137 len += ret;
138
139 /* Export N */
Gilles Peskine449bd832023-01-11 14:50:10 +0100140 if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
141 (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
Hanno Becker15f81fa2017-08-23 12:38:27 +0100142 goto end_of_export;
Gilles Peskine449bd832023-01-11 14:50:10 +0100143 }
Hanno Becker15f81fa2017-08-23 12:38:27 +0100144 len += ret;
145
146end_of_export:
147
Gilles Peskine449bd832023-01-11 14:50:10 +0100148 mbedtls_mpi_free(&T);
149 if (ret < 0) {
150 return ret;
151 }
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200152
Gilles Peskine449bd832023-01-11 14:50:10 +0100153 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
154 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED |
155 MBEDTLS_ASN1_SEQUENCE));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200156
Gilles Peskine449bd832023-01-11 14:50:10 +0100157 return (int) len;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200158}
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200159#endif /* MBEDTLS_RSA_C */
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200160
Valerio Setti0d2980f2023-04-05 18:17:13 +0200161#if defined(MBEDTLS_ECP_LIGHT)
valerio9ea26172023-05-31 12:10:23 +0200162#if defined(MBEDTLS_PK_USE_PSA_EC_DATA)
Gilles Peskine449bd832023-01-11 14:50:10 +0100163static int pk_write_ec_pubkey(unsigned char **p, unsigned char *start,
Valerio Setti4064dbb2023-05-17 15:33:07 +0200164 const mbedtls_pk_context *pk)
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200165{
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200166 size_t len = 0;
valerio9ea26172023-05-31 12:10:23 +0200167 uint8_t buf[PSA_EXPORT_KEY_PAIR_MAX_SIZE];
Valerio Setti4064dbb2023-05-17 15:33:07 +0200168
valerio9ea26172023-05-31 12:10:23 +0200169 if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_OPAQUE) {
170 if (psa_export_public_key(pk->priv_id, buf, sizeof(buf), &len) != PSA_SUCCESS) {
171 return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
172 }
173 } else {
174 len = pk->pub_raw_len;
Valerio Setti4064dbb2023-05-17 15:33:07 +0200175
valerio9ea26172023-05-31 12:10:23 +0200176 if (*p < start || (size_t) (*p - start) < len) {
177 return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
178 }
Valerio Setti4064dbb2023-05-17 15:33:07 +0200179
valerio9ea26172023-05-31 12:10:23 +0200180 memcpy(*p - len, pk->pub_raw, len);
181 *p -= len;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200182 }
183
Gilles Peskine449bd832023-01-11 14:50:10 +0100184 if (*p < start || (size_t) (*p - start) < len) {
185 return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
186 }
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200187
188 *p -= len;
Gilles Peskine449bd832023-01-11 14:50:10 +0100189 memcpy(*p, buf, len);
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200190
Gilles Peskine449bd832023-01-11 14:50:10 +0100191 return (int) len;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200192}
valerio9ea26172023-05-31 12:10:23 +0200193#else /* MBEDTLS_PK_USE_PSA_EC_DATA */
194static int pk_write_ec_pubkey(unsigned char **p, unsigned char *start,
195 const mbedtls_pk_context *pk)
196{
197 size_t len = 0;
198#if defined(MBEDTLS_USE_PSA_CRYPTO)
199 uint8_t buf[PSA_EXPORT_PUBLIC_KEY_MAX_SIZE];
200#else
201 unsigned char buf[MBEDTLS_ECP_MAX_PT_LEN];
202#endif /* MBEDTLS_USE_PSA_CRYPTO */
203 mbedtls_ecp_keypair *ec = mbedtls_pk_ec(*pk);
204 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
205
206#if defined(MBEDTLS_USE_PSA_CRYPTO)
207 if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_OPAQUE) {
208 if (psa_export_public_key(pk->priv_id, buf, sizeof(buf), &len) != PSA_SUCCESS) {
209 return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
210 }
211 *p -= len;
212 memcpy(*p, buf, len);
213 return (int) len;
214 } else
215#endif /* MBEDTLS_USE_PSA_CRYPTO */
216 {
217 if ((ret = mbedtls_ecp_point_write_binary(&ec->grp, &ec->Q,
218 MBEDTLS_ECP_PF_UNCOMPRESSED,
219 &len, buf, sizeof(buf))) != 0) {
220 return ret;
221 }
222 }
223
224 if (*p < start || (size_t) (*p - start) < len) {
225 return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
226 }
227
228 *p -= len;
229 memcpy(*p, buf, len);
230
231 return (int) len;
232}
233#endif /* MBEDTLS_PK_USE_PSA_EC_DATA */
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200234
235/*
236 * ECParameters ::= CHOICE {
237 * namedCurve OBJECT IDENTIFIER
238 * }
239 */
Gilles Peskine449bd832023-01-11 14:50:10 +0100240static int pk_write_ec_param(unsigned char **p, unsigned char *start,
Jethro Beekman8e59ebb2023-05-03 13:05:33 +0200241 mbedtls_ecp_group_id grp_id)
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200242{
Janos Follath24eed8d2019-11-22 13:21:35 +0000243 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200244 size_t len = 0;
245 const char *oid;
246 size_t oid_len;
247
Jethro Beekman8e59ebb2023-05-03 13:05:33 +0200248 if ((ret = mbedtls_oid_get_oid_by_ec_grp(grp_id, &oid, &oid_len)) != 0) {
Gilles Peskine449bd832023-01-11 14:50:10 +0100249 return ret;
250 }
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200251
Gilles Peskine449bd832023-01-11 14:50:10 +0100252 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200253
Gilles Peskine449bd832023-01-11 14:50:10 +0100254 return (int) len;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200255}
Gilles Peskine2700cfb2018-08-11 00:48:44 +0200256
257/*
258 * privateKey OCTET STRING -- always of length ceil(log2(n)/8)
259 */
valerio52b675f2023-05-31 12:14:37 +0200260#if defined(MBEDTLS_PK_USE_PSA_EC_DATA)
Gilles Peskine449bd832023-01-11 14:50:10 +0100261static int pk_write_ec_private(unsigned char **p, unsigned char *start,
Valerio Setti00e8dd12023-05-18 18:56:59 +0200262 const mbedtls_pk_context *pk)
Gilles Peskine2700cfb2018-08-11 00:48:44 +0200263{
Valerio Setti00e8dd12023-05-18 18:56:59 +0200264 size_t byte_length;
Janos Follath24eed8d2019-11-22 13:21:35 +0000265 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
Valerio Setti00e8dd12023-05-18 18:56:59 +0200266 unsigned char tmp[MBEDTLS_PSA_MAX_EC_KEY_PAIR_LENGTH];
267 psa_status_t status;
268
valerio52b675f2023-05-31 12:14:37 +0200269 if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_OPAQUE) {
270 status = psa_export_key(pk->priv_id, tmp, sizeof(tmp), &byte_length);
271 if (status != PSA_SUCCESS) {
272 ret = PSA_PK_ECDSA_TO_MBEDTLS_ERR(status);
273 return ret;
274 }
275 } else {
276 status = psa_export_key(pk->priv_id, tmp, sizeof(tmp), &byte_length);
277 if (status != PSA_SUCCESS) {
278 ret = PSA_PK_ECDSA_TO_MBEDTLS_ERR(status);
279 goto exit;
280 }
Valerio Setti00e8dd12023-05-18 18:56:59 +0200281 }
Gilles Peskine2700cfb2018-08-11 00:48:44 +0200282
Gilles Peskine449bd832023-01-11 14:50:10 +0100283 ret = mbedtls_asn1_write_octet_string(p, start, tmp, byte_length);
Gilles Peskine2700cfb2018-08-11 00:48:44 +0200284exit:
Valerio Setti00e8dd12023-05-18 18:56:59 +0200285 mbedtls_platform_zeroize(tmp, sizeof(tmp));
Gilles Peskine449bd832023-01-11 14:50:10 +0100286 return ret;
Gilles Peskine2700cfb2018-08-11 00:48:44 +0200287}
valerio52b675f2023-05-31 12:14:37 +0200288#else /* MBEDTLS_PK_USE_PSA_EC_DATA */
289static int pk_write_ec_private(unsigned char **p, unsigned char *start,
290 const mbedtls_pk_context *pk)
291{
292 size_t byte_length;
293 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
294#if defined(MBEDTLS_USE_PSA_CRYPTO)
295 unsigned char tmp[MBEDTLS_PSA_MAX_EC_KEY_PAIR_LENGTH];
296 psa_status_t status;
297#else
298 unsigned char tmp[MBEDTLS_ECP_MAX_BYTES];
299#endif /* MBEDTLS_USE_PSA_CRYPTO */
300
301#if defined(MBEDTLS_USE_PSA_CRYPTO)
302 if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_OPAQUE) {
303 status = psa_export_key(pk->priv_id, tmp, sizeof(tmp), &byte_length);
304 if (status != PSA_SUCCESS) {
305 ret = PSA_PK_ECDSA_TO_MBEDTLS_ERR(status);
306 return ret;
307 }
308 } else
309#endif /* MBEDTLS_USE_PSA_CRYPTO */
310 {
311 mbedtls_ecp_keypair *ec = mbedtls_pk_ec_rw(*pk);
312 byte_length = (ec->grp.pbits + 7) / 8;
313
314 ret = mbedtls_ecp_write_key(ec, tmp, byte_length);
315 if (ret != 0) {
316 goto exit;
317 }
318 }
319 ret = mbedtls_asn1_write_octet_string(p, start, tmp, byte_length);
320exit:
321 mbedtls_platform_zeroize(tmp, sizeof(tmp));
322 return ret;
323}
324#endif /* MBEDTLS_PK_USE_PSA_EC_DATA */
Valerio Setti0d2980f2023-04-05 18:17:13 +0200325#endif /* MBEDTLS_ECP_LIGHT */
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200326
valerio9ea26172023-05-31 12:10:23 +0200327#if defined(MBEDTLS_USE_PSA_CRYPTO)
328static int pk_write_opaque_pubkey(unsigned char **p, unsigned char *start,
329 const mbedtls_pk_context *pk)
330{
331 size_t buffer_size;
332 size_t len = 0;
333
334 if (*p < start) {
335 return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
336 }
337
338 buffer_size = (size_t) (*p - start);
339 if (psa_export_public_key(pk->priv_id, start, buffer_size,
340 &len) != PSA_SUCCESS) {
341 return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
342 }
343
344 *p -= len;
345 memmove(*p, start, len);
346
347 return (int) len;
348}
349#endif /* MBEDTLS_USE_PSA_CRYPTO */
350
Gilles Peskine449bd832023-01-11 14:50:10 +0100351int mbedtls_pk_write_pubkey(unsigned char **p, unsigned char *start,
352 const mbedtls_pk_context *key)
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200353{
Janos Follath24eed8d2019-11-22 13:21:35 +0000354 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200355 size_t len = 0;
356
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200357#if defined(MBEDTLS_RSA_C)
Gilles Peskine449bd832023-01-11 14:50:10 +0100358 if (mbedtls_pk_get_type(key) == MBEDTLS_PK_RSA) {
valerio9ea26172023-05-31 12:10:23 +0200359 MBEDTLS_ASN1_CHK_ADD(len, pk_write_rsa_pubkey(p, start, key));
Gilles Peskine449bd832023-01-11 14:50:10 +0100360 } else
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200361#endif
Valerio Setti0d2980f2023-04-05 18:17:13 +0200362#if defined(MBEDTLS_ECP_LIGHT)
Gilles Peskine449bd832023-01-11 14:50:10 +0100363 if (mbedtls_pk_get_type(key) == MBEDTLS_PK_ECKEY) {
Valerio Setti4064dbb2023-05-17 15:33:07 +0200364 MBEDTLS_ASN1_CHK_ADD(len, pk_write_ec_pubkey(p, start, key));
Gilles Peskine449bd832023-01-11 14:50:10 +0100365 } else
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200366#endif
Andrzej Kurek5fec0862018-11-19 10:07:36 -0500367#if defined(MBEDTLS_USE_PSA_CRYPTO)
Gilles Peskine449bd832023-01-11 14:50:10 +0100368 if (mbedtls_pk_get_type(key) == MBEDTLS_PK_OPAQUE) {
valerio9ea26172023-05-31 12:10:23 +0200369 MBEDTLS_ASN1_CHK_ADD(len, pk_write_opaque_pubkey(p, start, key));
Gilles Peskine449bd832023-01-11 14:50:10 +0100370 } else
Andrzej Kurek5fec0862018-11-19 10:07:36 -0500371#endif /* MBEDTLS_USE_PSA_CRYPTO */
Gilles Peskine449bd832023-01-11 14:50:10 +0100372 return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200373
Gilles Peskine449bd832023-01-11 14:50:10 +0100374 return (int) len;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200375}
376
Gilles Peskine449bd832023-01-11 14:50:10 +0100377int mbedtls_pk_write_pubkey_der(const mbedtls_pk_context *key, unsigned char *buf, size_t size)
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200378{
Janos Follath24eed8d2019-11-22 13:21:35 +0000379 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200380 unsigned char *c;
Jethro Beekman01672442023-04-19 14:08:14 +0200381 int has_par = 1;
382 size_t len = 0, par_len = 0, oid_len = 0;
Hanno Becker493c1712019-02-01 10:07:07 +0000383 mbedtls_pk_type_t pk_type;
Jethro Beekman13d415c2023-05-04 10:11:58 +0200384#if defined(MBEDTLS_ECP_LIGHT)
Jethro Beekmancb706ea2023-05-04 12:28:49 +0200385 mbedtls_ecp_group_id ec_grp_id = MBEDTLS_ECP_DP_NONE;
Jethro Beekman13d415c2023-05-04 10:11:58 +0200386#endif
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200387 const char *oid;
388
Gilles Peskine449bd832023-01-11 14:50:10 +0100389 if (size == 0) {
390 return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
391 }
Andrzej Kurekc470b6b2019-01-31 08:20:20 -0500392
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200393 c = buf + size;
394
Gilles Peskine449bd832023-01-11 14:50:10 +0100395 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_pk_write_pubkey(&c, buf, key));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200396
Gilles Peskine449bd832023-01-11 14:50:10 +0100397 if (c - buf < 1) {
398 return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
399 }
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200400
401 /*
402 * SubjectPublicKeyInfo ::= SEQUENCE {
403 * algorithm AlgorithmIdentifier,
404 * subjectPublicKey BIT STRING }
405 */
406 *--c = 0;
407 len += 1;
408
Gilles Peskine449bd832023-01-11 14:50:10 +0100409 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
410 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_BIT_STRING));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200411
Gilles Peskine449bd832023-01-11 14:50:10 +0100412 pk_type = mbedtls_pk_get_type(key);
Valerio Setti0d2980f2023-04-05 18:17:13 +0200413#if defined(MBEDTLS_ECP_LIGHT)
Gilles Peskine449bd832023-01-11 14:50:10 +0100414 if (pk_type == MBEDTLS_PK_ECKEY) {
valerioba1fd322023-05-31 12:13:17 +0200415 ec_grp_id = mbedtls_pk_get_group_id(key);
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200416 }
Valerio Setti0d2980f2023-04-05 18:17:13 +0200417#endif /* MBEDTLS_ECP_LIGHT */
Hanno Becker493c1712019-02-01 10:07:07 +0000418#if defined(MBEDTLS_USE_PSA_CRYPTO)
Gilles Peskine449bd832023-01-11 14:50:10 +0100419 if (pk_type == MBEDTLS_PK_OPAQUE) {
valerioba1fd322023-05-31 12:13:17 +0200420 psa_key_type_t opaque_key_type = pk_get_opaque_key_type(key);
Jethro Beekman13d415c2023-05-04 10:11:58 +0200421#if defined(MBEDTLS_ECP_LIGHT)
valerioba1fd322023-05-31 12:13:17 +0200422 if (PSA_KEY_TYPE_IS_ECC(opaque_key_type)) {
valerio52b675f2023-05-31 12:14:37 +0200423 pk_type = MBEDTLS_PK_ECKEY;
valerioba1fd322023-05-31 12:13:17 +0200424 ec_grp_id = mbedtls_pk_get_group_id(key);
425 } else
Jethro Beekman13d415c2023-05-04 10:11:58 +0200426#endif /* MBEDTLS_ECP_LIGHT */
valerioba1fd322023-05-31 12:13:17 +0200427 if (PSA_KEY_TYPE_IS_RSA(opaque_key_type)) {
Neil Armstrong295aeb12022-03-15 16:25:41 +0100428 /* The rest of the function works as for legacy RSA contexts. */
429 pk_type = MBEDTLS_PK_RSA;
Neil Armstrong295aeb12022-03-15 16:25:41 +0100430 }
Jethro Beekmancf4545e2023-05-04 12:05:55 +0200431 }
432 /* `pk_type` will have been changed to non-opaque by here if this function can handle it */
433 if (pk_type == MBEDTLS_PK_OPAQUE) {
434 return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
Hanno Becker493c1712019-02-01 10:07:07 +0000435 }
436#endif /* MBEDTLS_USE_PSA_CRYPTO */
437
Jethro Beekman8e59ebb2023-05-03 13:05:33 +0200438#if defined(MBEDTLS_ECP_LIGHT)
439 if (pk_type == MBEDTLS_PK_ECKEY) {
valerioba1fd322023-05-31 12:13:17 +0200440 /* Some groups have their own AlgorithmIdentifier OID, others are handled
441 * by mbedtls_oid_get_oid_by_pk_alg() below */
Jethro Beekman8e59ebb2023-05-03 13:05:33 +0200442 ret = mbedtls_oid_get_oid_by_ec_grp_algid(ec_grp_id, &oid, &oid_len);
443
444 if (ret == 0) {
valerioba1fd322023-05-31 12:13:17 +0200445 /* Currently, none of the supported algorithms that have their own
446 * AlgorithmIdentifier OID have any parameters */
Jethro Beekman8e59ebb2023-05-03 13:05:33 +0200447 has_par = 0;
448 } else if (ret == MBEDTLS_ERR_OID_NOT_FOUND) {
449 MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, ec_grp_id));
450 } else {
451 return ret;
452 }
453 }
454#endif /* MBEDTLS_ECP_LIGHT */
455
Jethro Beekman01672442023-04-19 14:08:14 +0200456 if (oid_len == 0) {
457 if ((ret = mbedtls_oid_get_oid_by_pk_alg(pk_type, &oid,
458 &oid_len)) != 0) {
459 return ret;
460 }
Hanno Becker493c1712019-02-01 10:07:07 +0000461 }
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200462
Jethro Beekman01672442023-04-19 14:08:14 +0200463 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_algorithm_identifier_ext(&c, buf, oid, oid_len,
464 par_len, has_par));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200465
Gilles Peskine449bd832023-01-11 14:50:10 +0100466 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
467 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_CONSTRUCTED |
468 MBEDTLS_ASN1_SEQUENCE));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200469
Gilles Peskine449bd832023-01-11 14:50:10 +0100470 return (int) len;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200471}
472
Jethro Beekman01672442023-04-19 14:08:14 +0200473#if defined(MBEDTLS_ECP_LIGHT)
474#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
475/*
Valerio Setti4064dbb2023-05-17 15:33:07 +0200476 * RFC8410 section 7
Jethro Beekman01672442023-04-19 14:08:14 +0200477 *
478 * OneAsymmetricKey ::= SEQUENCE {
479 * version Version,
480 * privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
481 * privateKey PrivateKey,
482 * attributes [0] IMPLICIT Attributes OPTIONAL,
483 * ...,
484 * [[2: publicKey [1] IMPLICIT PublicKey OPTIONAL ]],
485 * ...
486 * }
Valerio Setti4064dbb2023-05-17 15:33:07 +0200487 * ...
Jethro Beekman01672442023-04-19 14:08:14 +0200488 * CurvePrivateKey ::= OCTET STRING
489 */
490static int pk_write_ec_rfc8410_der(unsigned char **p, unsigned char *buf,
Valerio Setti00e8dd12023-05-18 18:56:59 +0200491 const mbedtls_pk_context *pk)
Jethro Beekman01672442023-04-19 14:08:14 +0200492{
493 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
494 size_t len = 0;
495 size_t oid_len = 0;
496 const char *oid;
Valerio Setti1194ffa2023-05-24 13:15:58 +0200497 mbedtls_ecp_group_id grp_id;
Jethro Beekman01672442023-04-19 14:08:14 +0200498
499 /* privateKey */
Valerio Setti00e8dd12023-05-18 18:56:59 +0200500 MBEDTLS_ASN1_CHK_ADD(len, pk_write_ec_private(p, buf, pk));
Jethro Beekman01672442023-04-19 14:08:14 +0200501 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, buf, len));
502 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, buf, MBEDTLS_ASN1_OCTET_STRING));
503
Valerio Setti1194ffa2023-05-24 13:15:58 +0200504 grp_id = mbedtls_pk_get_group_id(pk);
Jethro Beekman01672442023-04-19 14:08:14 +0200505 /* privateKeyAlgorithm */
Valerio Setti00e8dd12023-05-18 18:56:59 +0200506 if ((ret = mbedtls_oid_get_oid_by_ec_grp_algid(grp_id, &oid, &oid_len)) != 0) {
507 return ret;
508 }
Jethro Beekman01672442023-04-19 14:08:14 +0200509 MBEDTLS_ASN1_CHK_ADD(len,
510 mbedtls_asn1_write_algorithm_identifier_ext(p, buf, oid, oid_len, 0, 0));
511
512 /* version */
513 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, buf, 0));
514
515 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, buf, len));
516 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, buf, MBEDTLS_ASN1_CONSTRUCTED |
517 MBEDTLS_ASN1_SEQUENCE));
518
519 return (int) len;
520}
521#endif /* MBEDTLS_PK_HAVE_RFC8410_CURVES */
522#endif /* MBEDTLS_ECP_LIGHT */
523
Gilles Peskine449bd832023-01-11 14:50:10 +0100524int mbedtls_pk_write_key_der(const mbedtls_pk_context *key, unsigned char *buf, size_t size)
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200525{
Janos Follath24eed8d2019-11-22 13:21:35 +0000526 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
Andrzej Kurekc470b6b2019-01-31 08:20:20 -0500527 unsigned char *c;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200528 size_t len = 0;
Valerio Setti00e8dd12023-05-18 18:56:59 +0200529#if defined(MBEDTLS_ECP_LIGHT)
530 mbedtls_ecp_group_id grp_id;
531#endif
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200532
Gilles Peskine449bd832023-01-11 14:50:10 +0100533 if (size == 0) {
534 return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
535 }
Andrzej Kurekc470b6b2019-01-31 08:20:20 -0500536
537 c = buf + size;
538
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200539#if defined(MBEDTLS_RSA_C)
Gilles Peskine449bd832023-01-11 14:50:10 +0100540 if (mbedtls_pk_get_type(key) == MBEDTLS_PK_RSA) {
Hanno Becker15f81fa2017-08-23 12:38:27 +0100541 mbedtls_mpi T; /* Temporary holding the exported parameters */
Gilles Peskine449bd832023-01-11 14:50:10 +0100542 mbedtls_rsa_context *rsa = mbedtls_pk_rsa(*key);
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200543
Hanno Becker15f81fa2017-08-23 12:38:27 +0100544 /*
545 * Export the parameters one after another to avoid simultaneous copies.
546 */
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200547
Gilles Peskine449bd832023-01-11 14:50:10 +0100548 mbedtls_mpi_init(&T);
Hanno Becker15f81fa2017-08-23 12:38:27 +0100549
550 /* Export QP */
Gilles Peskine449bd832023-01-11 14:50:10 +0100551 if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 ||
552 (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
Hanno Becker15f81fa2017-08-23 12:38:27 +0100553 goto end_of_export;
Gilles Peskine449bd832023-01-11 14:50:10 +0100554 }
Hanno Becker15f81fa2017-08-23 12:38:27 +0100555 len += ret;
556
557 /* Export DQ */
Gilles Peskine449bd832023-01-11 14:50:10 +0100558 if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 ||
559 (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
Hanno Becker15f81fa2017-08-23 12:38:27 +0100560 goto end_of_export;
Gilles Peskine449bd832023-01-11 14:50:10 +0100561 }
Hanno Becker15f81fa2017-08-23 12:38:27 +0100562 len += ret;
563
564 /* Export DP */
Gilles Peskine449bd832023-01-11 14:50:10 +0100565 if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 ||
566 (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
Hanno Becker15f81fa2017-08-23 12:38:27 +0100567 goto end_of_export;
Gilles Peskine449bd832023-01-11 14:50:10 +0100568 }
Hanno Becker15f81fa2017-08-23 12:38:27 +0100569 len += ret;
570
571 /* Export Q */
Gilles Peskine449bd832023-01-11 14:50:10 +0100572 if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
573 &T, NULL, NULL)) != 0 ||
574 (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
Hanno Becker15f81fa2017-08-23 12:38:27 +0100575 goto end_of_export;
Gilles Peskine449bd832023-01-11 14:50:10 +0100576 }
Hanno Becker15f81fa2017-08-23 12:38:27 +0100577 len += ret;
578
579 /* Export P */
Gilles Peskine449bd832023-01-11 14:50:10 +0100580 if ((ret = mbedtls_rsa_export(rsa, NULL, &T,
581 NULL, NULL, NULL)) != 0 ||
582 (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
Hanno Becker15f81fa2017-08-23 12:38:27 +0100583 goto end_of_export;
Gilles Peskine449bd832023-01-11 14:50:10 +0100584 }
Hanno Becker15f81fa2017-08-23 12:38:27 +0100585 len += ret;
586
587 /* Export D */
Gilles Peskine449bd832023-01-11 14:50:10 +0100588 if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
589 NULL, &T, NULL)) != 0 ||
590 (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
Hanno Becker15f81fa2017-08-23 12:38:27 +0100591 goto end_of_export;
Gilles Peskine449bd832023-01-11 14:50:10 +0100592 }
Hanno Becker15f81fa2017-08-23 12:38:27 +0100593 len += ret;
594
595 /* Export E */
Gilles Peskine449bd832023-01-11 14:50:10 +0100596 if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
597 NULL, NULL, &T)) != 0 ||
598 (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
Hanno Becker15f81fa2017-08-23 12:38:27 +0100599 goto end_of_export;
Gilles Peskine449bd832023-01-11 14:50:10 +0100600 }
Hanno Becker15f81fa2017-08-23 12:38:27 +0100601 len += ret;
602
603 /* Export N */
Gilles Peskine449bd832023-01-11 14:50:10 +0100604 if ((ret = mbedtls_rsa_export(rsa, &T, NULL,
605 NULL, NULL, NULL)) != 0 ||
606 (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
Hanno Becker15f81fa2017-08-23 12:38:27 +0100607 goto end_of_export;
Gilles Peskine449bd832023-01-11 14:50:10 +0100608 }
Hanno Becker15f81fa2017-08-23 12:38:27 +0100609 len += ret;
610
Gilles Peskine449bd832023-01-11 14:50:10 +0100611end_of_export:
Hanno Becker15f81fa2017-08-23 12:38:27 +0100612
Gilles Peskine449bd832023-01-11 14:50:10 +0100613 mbedtls_mpi_free(&T);
614 if (ret < 0) {
615 return ret;
616 }
Hanno Becker15f81fa2017-08-23 12:38:27 +0100617
Gilles Peskine449bd832023-01-11 14:50:10 +0100618 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(&c, buf, 0));
619 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
620 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c,
621 buf, MBEDTLS_ASN1_CONSTRUCTED |
622 MBEDTLS_ASN1_SEQUENCE));
623 } else
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200624#endif /* MBEDTLS_RSA_C */
Valerio Setti0d2980f2023-04-05 18:17:13 +0200625#if defined(MBEDTLS_ECP_LIGHT)
Gilles Peskine449bd832023-01-11 14:50:10 +0100626 if (mbedtls_pk_get_type(key) == MBEDTLS_PK_ECKEY) {
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200627 size_t pub_len = 0, par_len = 0;
628
Jethro Beekman01672442023-04-19 14:08:14 +0200629#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
Valerio Setti00e8dd12023-05-18 18:56:59 +0200630 if (mbedtls_pk_is_rfc8410(key)) {
631 return pk_write_ec_rfc8410_der(&c, buf, key);
Jethro Beekman01672442023-04-19 14:08:14 +0200632 }
633#endif
634
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200635 /*
636 * RFC 5915, or SEC1 Appendix C.4
637 *
638 * ECPrivateKey ::= SEQUENCE {
639 * version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
640 * privateKey OCTET STRING,
641 * parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
642 * publicKey [1] BIT STRING OPTIONAL
643 * }
644 */
645
646 /* publicKey */
Valerio Setti4064dbb2023-05-17 15:33:07 +0200647 MBEDTLS_ASN1_CHK_ADD(pub_len, pk_write_ec_pubkey(&c, buf, key));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200648
Gilles Peskine449bd832023-01-11 14:50:10 +0100649 if (c - buf < 1) {
650 return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
651 }
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200652 *--c = 0;
653 pub_len += 1;
654
Gilles Peskine449bd832023-01-11 14:50:10 +0100655 MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_len(&c, buf, pub_len));
656 MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_BIT_STRING));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200657
Gilles Peskine449bd832023-01-11 14:50:10 +0100658 MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_len(&c, buf, pub_len));
659 MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_tag(&c, buf,
660 MBEDTLS_ASN1_CONTEXT_SPECIFIC |
661 MBEDTLS_ASN1_CONSTRUCTED | 1));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200662 len += pub_len;
663
664 /* parameters */
Valerio Setti00e8dd12023-05-18 18:56:59 +0200665 grp_id = mbedtls_pk_get_group_id(key);
666 MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, grp_id));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200667
Gilles Peskine449bd832023-01-11 14:50:10 +0100668 MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_len(&c, buf, par_len));
669 MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_tag(&c, buf,
670 MBEDTLS_ASN1_CONTEXT_SPECIFIC |
671 MBEDTLS_ASN1_CONSTRUCTED | 0));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200672 len += par_len;
673
Gilles Peskine2700cfb2018-08-11 00:48:44 +0200674 /* privateKey */
Valerio Setti00e8dd12023-05-18 18:56:59 +0200675 MBEDTLS_ASN1_CHK_ADD(len, pk_write_ec_private(&c, buf, key));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200676
677 /* version */
Gilles Peskine449bd832023-01-11 14:50:10 +0100678 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(&c, buf, 1));
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200679
Gilles Peskine449bd832023-01-11 14:50:10 +0100680 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
681 MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_CONSTRUCTED |
682 MBEDTLS_ASN1_SEQUENCE));
683 } else
Valerio Setti4064dbb2023-05-17 15:33:07 +0200684#endif /* MBEDTLS_ECP_LIGHT */
Gilles Peskine449bd832023-01-11 14:50:10 +0100685 return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200686
Gilles Peskine449bd832023-01-11 14:50:10 +0100687 return (int) len;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200688}
689
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200690#if defined(MBEDTLS_PEM_WRITE_C)
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200691
692#define PEM_BEGIN_PUBLIC_KEY "-----BEGIN PUBLIC KEY-----\n"
693#define PEM_END_PUBLIC_KEY "-----END PUBLIC KEY-----\n"
694
695#define PEM_BEGIN_PRIVATE_KEY_RSA "-----BEGIN RSA PRIVATE KEY-----\n"
696#define PEM_END_PRIVATE_KEY_RSA "-----END RSA PRIVATE KEY-----\n"
697#define PEM_BEGIN_PRIVATE_KEY_EC "-----BEGIN EC PRIVATE KEY-----\n"
698#define PEM_END_PRIVATE_KEY_EC "-----END EC PRIVATE KEY-----\n"
Jethro Beekman01672442023-04-19 14:08:14 +0200699#define PEM_BEGIN_PRIVATE_KEY_PKCS8 "-----BEGIN PRIVATE KEY-----\n"
700#define PEM_END_PRIVATE_KEY_PKCS8 "-----END PRIVATE KEY-----\n"
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200701
Neil Armstronge9ecd272022-03-01 10:03:21 +0100702#define PUB_DER_MAX_BYTES \
Gilles Peskine449bd832023-01-11 14:50:10 +0100703 (MBEDTLS_PK_RSA_PUB_DER_MAX_BYTES > MBEDTLS_PK_ECP_PUB_DER_MAX_BYTES ? \
704 MBEDTLS_PK_RSA_PUB_DER_MAX_BYTES : MBEDTLS_PK_ECP_PUB_DER_MAX_BYTES)
Neil Armstronge9ecd272022-03-01 10:03:21 +0100705#define PRV_DER_MAX_BYTES \
Gilles Peskine449bd832023-01-11 14:50:10 +0100706 (MBEDTLS_PK_RSA_PRV_DER_MAX_BYTES > MBEDTLS_PK_ECP_PRV_DER_MAX_BYTES ? \
707 MBEDTLS_PK_RSA_PRV_DER_MAX_BYTES : MBEDTLS_PK_ECP_PRV_DER_MAX_BYTES)
Manuel Pégourié-Gonnard192253a2014-07-21 16:37:15 +0200708
Gilles Peskine449bd832023-01-11 14:50:10 +0100709int mbedtls_pk_write_pubkey_pem(const mbedtls_pk_context *key, unsigned char *buf, size_t size)
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200710{
Janos Follath24eed8d2019-11-22 13:21:35 +0000711 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
Manuel Pégourié-Gonnard192253a2014-07-21 16:37:15 +0200712 unsigned char output_buf[PUB_DER_MAX_BYTES];
Paul Bakker77e23fb2013-09-15 20:03:26 +0200713 size_t olen = 0;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200714
Gilles Peskine449bd832023-01-11 14:50:10 +0100715 if ((ret = mbedtls_pk_write_pubkey_der(key, output_buf,
716 sizeof(output_buf))) < 0) {
717 return ret;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200718 }
719
Gilles Peskine449bd832023-01-11 14:50:10 +0100720 if ((ret = mbedtls_pem_write_buffer(PEM_BEGIN_PUBLIC_KEY, PEM_END_PUBLIC_KEY,
721 output_buf + sizeof(output_buf) - ret,
722 ret, buf, size, &olen)) != 0) {
723 return ret;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200724 }
725
Gilles Peskine449bd832023-01-11 14:50:10 +0100726 return 0;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200727}
728
Gilles Peskine449bd832023-01-11 14:50:10 +0100729int mbedtls_pk_write_key_pem(const mbedtls_pk_context *key, unsigned char *buf, size_t size)
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200730{
Janos Follath24eed8d2019-11-22 13:21:35 +0000731 int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
Manuel Pégourié-Gonnard192253a2014-07-21 16:37:15 +0200732 unsigned char output_buf[PRV_DER_MAX_BYTES];
Paul Bakkerfcc17212013-10-11 09:36:52 +0200733 const char *begin, *end;
Paul Bakker77e23fb2013-09-15 20:03:26 +0200734 size_t olen = 0;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200735
Gilles Peskine449bd832023-01-11 14:50:10 +0100736 if ((ret = mbedtls_pk_write_key_der(key, output_buf, sizeof(output_buf))) < 0) {
737 return ret;
738 }
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200739
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200740#if defined(MBEDTLS_RSA_C)
Gilles Peskine449bd832023-01-11 14:50:10 +0100741 if (mbedtls_pk_get_type(key) == MBEDTLS_PK_RSA) {
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200742 begin = PEM_BEGIN_PRIVATE_KEY_RSA;
743 end = PEM_END_PRIVATE_KEY_RSA;
Gilles Peskine449bd832023-01-11 14:50:10 +0100744 } else
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200745#endif
Valerio Setti6c496a12023-04-07 15:53:51 +0200746#if defined(MBEDTLS_ECP_LIGHT)
Gilles Peskine449bd832023-01-11 14:50:10 +0100747 if (mbedtls_pk_get_type(key) == MBEDTLS_PK_ECKEY) {
Jethro Beekman01672442023-04-19 14:08:14 +0200748#if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
Valerio Setti00e8dd12023-05-18 18:56:59 +0200749 if (mbedtls_pk_is_rfc8410(key)) {
Jethro Beekman01672442023-04-19 14:08:14 +0200750 begin = PEM_BEGIN_PRIVATE_KEY_PKCS8;
751 end = PEM_END_PRIVATE_KEY_PKCS8;
752 } else
753#endif
754 {
755 begin = PEM_BEGIN_PRIVATE_KEY_EC;
756 end = PEM_END_PRIVATE_KEY_EC;
757 }
Gilles Peskine449bd832023-01-11 14:50:10 +0100758 } else
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200759#endif
Gilles Peskine449bd832023-01-11 14:50:10 +0100760 return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200761
Gilles Peskine449bd832023-01-11 14:50:10 +0100762 if ((ret = mbedtls_pem_write_buffer(begin, end,
763 output_buf + sizeof(output_buf) - ret,
764 ret, buf, size, &olen)) != 0) {
765 return ret;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200766 }
767
Gilles Peskine449bd832023-01-11 14:50:10 +0100768 return 0;
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200769}
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200770#endif /* MBEDTLS_PEM_WRITE_C */
Paul Bakkerc7bb02b2013-09-15 14:54:56 +0200771
Manuel Pégourié-Gonnard2cf5a7c2015-04-08 12:49:31 +0200772#endif /* MBEDTLS_PK_WRITE_C */