blob: 083405eb80c32a2b13173d7d3a8a737c946feb20 [file] [log] [blame]
Thomas Gleixnerb4d0d232019-05-20 19:08:01 +02001// SPDX-License-Identifier: GPL-2.0-or-later
David Howellsc26fd692012-09-24 17:11:48 +01002/* X.509 certificate parser
3 *
4 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
David Howellsc26fd692012-09-24 17:11:48 +01006 */
7
8#define pr_fmt(fmt) "X.509: "fmt
9#include <linux/kernel.h>
David Howellsace01072014-07-01 16:40:19 +010010#include <linux/export.h>
David Howellsc26fd692012-09-24 17:11:48 +010011#include <linux/slab.h>
12#include <linux/err.h>
13#include <linux/oid_registry.h>
Tadeusz Strukdb6c43b2016-02-02 10:08:53 -080014#include <crypto/public_key.h>
David Howellsc26fd692012-09-24 17:11:48 +010015#include "x509_parser.h"
Masahiro Yamada4fa8bc92018-03-23 22:04:37 +090016#include "x509.asn1.h"
17#include "x509_akid.asn1.h"
David Howellsc26fd692012-09-24 17:11:48 +010018
19struct x509_parse_context {
20 struct x509_certificate *cert; /* Certificate being constructed */
21 unsigned long data; /* Start of data */
22 const void *cert_start; /* Start of cert content */
23 const void *key; /* Key data */
24 size_t key_size; /* Size of key data */
Vitaly Chikunovf1774cb2019-04-11 18:51:17 +030025 const void *params; /* Key parameters */
26 size_t params_size; /* Size of key parameters */
27 enum OID key_algo; /* Public key algorithm */
David Howellsc26fd692012-09-24 17:11:48 +010028 enum OID last_oid; /* Last OID encountered */
29 enum OID algo_oid; /* Algorithm OID */
30 unsigned char nr_mpi; /* Number of MPIs stored */
31 u8 o_size; /* Size of organizationName (O) */
32 u8 cn_size; /* Size of commonName (CN) */
33 u8 email_size; /* Size of emailAddress */
34 u16 o_offset; /* Offset of organizationName (O) */
35 u16 cn_offset; /* Offset of commonName (CN) */
36 u16 email_offset; /* Offset of emailAddress */
David Howellsb92e6572015-07-20 21:16:26 +010037 unsigned raw_akid_size;
38 const void *raw_akid; /* Raw authorityKeyId in ASN.1 */
39 const void *akid_raw_issuer; /* Raw directoryName in authorityKeyId */
40 unsigned akid_raw_issuer_size;
David Howellsc26fd692012-09-24 17:11:48 +010041};
42
43/*
44 * Free an X.509 certificate
45 */
46void x509_free_certificate(struct x509_certificate *cert)
47{
48 if (cert) {
David Howells3b764562016-04-06 16:13:33 +010049 public_key_free(cert->pub);
David Howells77d09102016-04-06 16:13:33 +010050 public_key_signature_free(cert->sig);
David Howellsc26fd692012-09-24 17:11:48 +010051 kfree(cert->issuer);
52 kfree(cert->subject);
David Howells46963b72014-09-16 17:36:13 +010053 kfree(cert->id);
54 kfree(cert->skid);
David Howellsc26fd692012-09-24 17:11:48 +010055 kfree(cert);
56 }
57}
David Howellsace01072014-07-01 16:40:19 +010058EXPORT_SYMBOL_GPL(x509_free_certificate);
David Howellsc26fd692012-09-24 17:11:48 +010059
60/*
61 * Parse an X.509 certificate
62 */
63struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
64{
65 struct x509_certificate *cert;
66 struct x509_parse_context *ctx;
David Howells46963b72014-09-16 17:36:13 +010067 struct asymmetric_key_id *kid;
David Howellsc26fd692012-09-24 17:11:48 +010068 long ret;
69
70 ret = -ENOMEM;
71 cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
72 if (!cert)
73 goto error_no_cert;
74 cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
75 if (!cert->pub)
76 goto error_no_ctx;
David Howells77d09102016-04-06 16:13:33 +010077 cert->sig = kzalloc(sizeof(struct public_key_signature), GFP_KERNEL);
78 if (!cert->sig)
79 goto error_no_ctx;
David Howellsc26fd692012-09-24 17:11:48 +010080 ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
81 if (!ctx)
82 goto error_no_ctx;
83
84 ctx->cert = cert;
85 ctx->data = (unsigned long)data;
86
87 /* Attempt to decode the certificate */
88 ret = asn1_ber_decoder(&x509_decoder, ctx, data, datalen);
89 if (ret < 0)
90 goto error_decode;
91
David Howellsb92e6572015-07-20 21:16:26 +010092 /* Decode the AuthorityKeyIdentifier */
93 if (ctx->raw_akid) {
94 pr_devel("AKID: %u %*phN\n",
95 ctx->raw_akid_size, ctx->raw_akid_size, ctx->raw_akid);
96 ret = asn1_ber_decoder(&x509_akid_decoder, ctx,
97 ctx->raw_akid, ctx->raw_akid_size);
98 if (ret < 0) {
99 pr_warn("Couldn't decode AuthKeyIdentifier\n");
100 goto error_decode;
101 }
102 }
103
Dan Carpenter4e880162017-06-08 14:47:49 +0100104 ret = -ENOMEM;
Tadeusz Strukdb6c43b2016-02-02 10:08:53 -0800105 cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
106 if (!cert->pub->key)
David Howellsc26fd692012-09-24 17:11:48 +0100107 goto error_decode;
108
Tadeusz Strukdb6c43b2016-02-02 10:08:53 -0800109 cert->pub->keylen = ctx->key_size;
110
Vitaly Chikunovf1774cb2019-04-11 18:51:17 +0300111 cert->pub->params = kmemdup(ctx->params, ctx->params_size, GFP_KERNEL);
112 if (!cert->pub->params)
113 goto error_decode;
114
115 cert->pub->paramlen = ctx->params_size;
116 cert->pub->algo = ctx->key_algo;
117
David Howells6c2dc5a2016-04-06 16:13:34 +0100118 /* Grab the signature bits */
119 ret = x509_get_sig_params(cert);
120 if (ret < 0)
121 goto error_decode;
122
David Howells46963b72014-09-16 17:36:13 +0100123 /* Generate cert issuer + serial number key ID */
124 kid = asymmetric_key_generate_id(cert->raw_serial,
125 cert->raw_serial_size,
126 cert->raw_issuer,
127 cert->raw_issuer_size);
128 if (IS_ERR(kid)) {
129 ret = PTR_ERR(kid);
130 goto error_decode;
131 }
132 cert->id = kid;
133
David Howells6c2dc5a2016-04-06 16:13:34 +0100134 /* Detect self-signed certificates */
135 ret = x509_check_for_self_signed(cert);
136 if (ret < 0)
137 goto error_decode;
138
David Howellsc26fd692012-09-24 17:11:48 +0100139 kfree(ctx);
140 return cert;
141
142error_decode:
143 kfree(ctx);
144error_no_ctx:
145 x509_free_certificate(cert);
146error_no_cert:
147 return ERR_PTR(ret);
148}
David Howellsace01072014-07-01 16:40:19 +0100149EXPORT_SYMBOL_GPL(x509_cert_parse);
David Howellsc26fd692012-09-24 17:11:48 +0100150
151/*
152 * Note an OID when we find one for later processing when we know how
153 * to interpret it.
154 */
155int x509_note_OID(void *context, size_t hdrlen,
156 unsigned char tag,
157 const void *value, size_t vlen)
158{
159 struct x509_parse_context *ctx = context;
160
161 ctx->last_oid = look_up_OID(value, vlen);
162 if (ctx->last_oid == OID__NR) {
163 char buffer[50];
164 sprint_oid(value, vlen, buffer, sizeof(buffer));
Randy Dunlapcf754462012-10-03 16:04:46 -0700165 pr_debug("Unknown OID: [%lu] %s\n",
David Howellsc26fd692012-09-24 17:11:48 +0100166 (unsigned long)value - ctx->data, buffer);
167 }
168 return 0;
169}
170
171/*
172 * Save the position of the TBS data so that we can check the signature over it
173 * later.
174 */
175int x509_note_tbs_certificate(void *context, size_t hdrlen,
176 unsigned char tag,
177 const void *value, size_t vlen)
178{
179 struct x509_parse_context *ctx = context;
180
181 pr_debug("x509_note_tbs_certificate(,%zu,%02x,%ld,%zu)!\n",
182 hdrlen, tag, (unsigned long)value - ctx->data, vlen);
183
184 ctx->cert->tbs = value - hdrlen;
185 ctx->cert->tbs_size = vlen + hdrlen;
186 return 0;
187}
188
189/*
190 * Record the public key algorithm
191 */
192int x509_note_pkey_algo(void *context, size_t hdrlen,
193 unsigned char tag,
194 const void *value, size_t vlen)
195{
196 struct x509_parse_context *ctx = context;
197
198 pr_debug("PubKey Algo: %u\n", ctx->last_oid);
199
200 switch (ctx->last_oid) {
201 case OID_md2WithRSAEncryption:
202 case OID_md3WithRSAEncryption:
203 default:
204 return -ENOPKG; /* Unsupported combination */
205
206 case OID_md4WithRSAEncryption:
David Howells77d09102016-04-06 16:13:33 +0100207 ctx->cert->sig->hash_algo = "md4";
David Howells03988492018-10-09 17:47:15 +0100208 goto rsa_pkcs1;
David Howellsc26fd692012-09-24 17:11:48 +0100209
210 case OID_sha1WithRSAEncryption:
David Howells77d09102016-04-06 16:13:33 +0100211 ctx->cert->sig->hash_algo = "sha1";
David Howells03988492018-10-09 17:47:15 +0100212 goto rsa_pkcs1;
David Howellsc26fd692012-09-24 17:11:48 +0100213
214 case OID_sha256WithRSAEncryption:
David Howells77d09102016-04-06 16:13:33 +0100215 ctx->cert->sig->hash_algo = "sha256";
David Howells03988492018-10-09 17:47:15 +0100216 goto rsa_pkcs1;
David Howellsc26fd692012-09-24 17:11:48 +0100217
218 case OID_sha384WithRSAEncryption:
David Howells77d09102016-04-06 16:13:33 +0100219 ctx->cert->sig->hash_algo = "sha384";
David Howells03988492018-10-09 17:47:15 +0100220 goto rsa_pkcs1;
David Howellsc26fd692012-09-24 17:11:48 +0100221
222 case OID_sha512WithRSAEncryption:
David Howells77d09102016-04-06 16:13:33 +0100223 ctx->cert->sig->hash_algo = "sha512";
David Howells03988492018-10-09 17:47:15 +0100224 goto rsa_pkcs1;
David Howellsc26fd692012-09-24 17:11:48 +0100225
226 case OID_sha224WithRSAEncryption:
David Howells77d09102016-04-06 16:13:33 +0100227 ctx->cert->sig->hash_algo = "sha224";
David Howells03988492018-10-09 17:47:15 +0100228 goto rsa_pkcs1;
Vitaly Chikunov0d7a7862019-04-11 18:51:20 +0300229
Stefan Berger299f5612021-03-16 17:07:37 -0400230 case OID_id_ecdsa_with_sha1:
231 ctx->cert->sig->hash_algo = "sha1";
232 goto ecdsa;
233
234 case OID_id_ecdsa_with_sha224:
235 ctx->cert->sig->hash_algo = "sha224";
236 goto ecdsa;
237
238 case OID_id_ecdsa_with_sha256:
239 ctx->cert->sig->hash_algo = "sha256";
240 goto ecdsa;
241
242 case OID_id_ecdsa_with_sha384:
243 ctx->cert->sig->hash_algo = "sha384";
244 goto ecdsa;
245
246 case OID_id_ecdsa_with_sha512:
247 ctx->cert->sig->hash_algo = "sha512";
248 goto ecdsa;
249
Vitaly Chikunov0d7a7862019-04-11 18:51:20 +0300250 case OID_gost2012Signature256:
251 ctx->cert->sig->hash_algo = "streebog256";
252 goto ecrdsa;
253
254 case OID_gost2012Signature512:
255 ctx->cert->sig->hash_algo = "streebog512";
256 goto ecrdsa;
Tianjia Zhang254f84f2020-09-21 00:21:01 +0800257
258 case OID_SM2_with_SM3:
259 ctx->cert->sig->hash_algo = "sm3";
260 goto sm2;
David Howellsc26fd692012-09-24 17:11:48 +0100261 }
262
David Howells03988492018-10-09 17:47:15 +0100263rsa_pkcs1:
264 ctx->cert->sig->pkey_algo = "rsa";
265 ctx->cert->sig->encoding = "pkcs1";
David Howellsc26fd692012-09-24 17:11:48 +0100266 ctx->algo_oid = ctx->last_oid;
267 return 0;
Vitaly Chikunov0d7a7862019-04-11 18:51:20 +0300268ecrdsa:
269 ctx->cert->sig->pkey_algo = "ecrdsa";
270 ctx->cert->sig->encoding = "raw";
271 ctx->algo_oid = ctx->last_oid;
272 return 0;
Tianjia Zhang254f84f2020-09-21 00:21:01 +0800273sm2:
274 ctx->cert->sig->pkey_algo = "sm2";
275 ctx->cert->sig->encoding = "raw";
276 ctx->algo_oid = ctx->last_oid;
277 return 0;
Stefan Berger299f5612021-03-16 17:07:37 -0400278ecdsa:
279 ctx->cert->sig->pkey_algo = "ecdsa";
280 ctx->cert->sig->encoding = "x962";
281 ctx->algo_oid = ctx->last_oid;
282 return 0;
David Howellsc26fd692012-09-24 17:11:48 +0100283}
284
285/*
286 * Note the whereabouts and type of the signature.
287 */
288int x509_note_signature(void *context, size_t hdrlen,
289 unsigned char tag,
290 const void *value, size_t vlen)
291{
292 struct x509_parse_context *ctx = context;
293
294 pr_debug("Signature type: %u size %zu\n", ctx->last_oid, vlen);
295
296 if (ctx->last_oid != ctx->algo_oid) {
297 pr_warn("Got cert with pkey (%u) and sig (%u) algorithm OIDs\n",
298 ctx->algo_oid, ctx->last_oid);
299 return -EINVAL;
300 }
301
Vitaly Chikunov0d7a7862019-04-11 18:51:20 +0300302 if (strcmp(ctx->cert->sig->pkey_algo, "rsa") == 0 ||
Tianjia Zhang254f84f2020-09-21 00:21:01 +0800303 strcmp(ctx->cert->sig->pkey_algo, "ecrdsa") == 0 ||
Stefan Berger299f5612021-03-16 17:07:37 -0400304 strcmp(ctx->cert->sig->pkey_algo, "sm2") == 0 ||
305 strcmp(ctx->cert->sig->pkey_algo, "ecdsa") == 0) {
Maciej S. Szmigierob65c32e2018-05-19 14:23:54 +0200306 /* Discard the BIT STRING metadata */
307 if (vlen < 1 || *(const u8 *)value != 0)
308 return -EBADMSG;
309
310 value++;
311 vlen--;
312 }
313
David Howellsb426beb2013-08-30 16:18:02 +0100314 ctx->cert->raw_sig = value;
315 ctx->cert->raw_sig_size = vlen;
David Howellsc26fd692012-09-24 17:11:48 +0100316 return 0;
317}
318
319/*
David Howells84aabd42014-07-01 16:40:19 +0100320 * Note the certificate serial number
321 */
322int x509_note_serial(void *context, size_t hdrlen,
323 unsigned char tag,
324 const void *value, size_t vlen)
325{
326 struct x509_parse_context *ctx = context;
327 ctx->cert->raw_serial = value;
328 ctx->cert->raw_serial_size = vlen;
329 return 0;
330}
331
332/*
David Howellsc26fd692012-09-24 17:11:48 +0100333 * Note some of the name segments from which we'll fabricate a name.
334 */
335int x509_extract_name_segment(void *context, size_t hdrlen,
336 unsigned char tag,
337 const void *value, size_t vlen)
338{
339 struct x509_parse_context *ctx = context;
340
341 switch (ctx->last_oid) {
342 case OID_commonName:
343 ctx->cn_size = vlen;
344 ctx->cn_offset = (unsigned long)value - ctx->data;
345 break;
346 case OID_organizationName:
347 ctx->o_size = vlen;
348 ctx->o_offset = (unsigned long)value - ctx->data;
349 break;
350 case OID_email_address:
351 ctx->email_size = vlen;
352 ctx->email_offset = (unsigned long)value - ctx->data;
353 break;
354 default:
355 break;
356 }
357
358 return 0;
359}
360
361/*
362 * Fabricate and save the issuer and subject names
363 */
364static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen,
365 unsigned char tag,
366 char **_name, size_t vlen)
367{
368 const void *name, *data = (const void *)ctx->data;
369 size_t namesize;
370 char *buffer;
371
372 if (*_name)
373 return -EINVAL;
374
375 /* Empty name string if no material */
376 if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) {
377 buffer = kmalloc(1, GFP_KERNEL);
378 if (!buffer)
379 return -ENOMEM;
380 buffer[0] = 0;
381 goto done;
382 }
383
384 if (ctx->cn_size && ctx->o_size) {
385 /* Consider combining O and CN, but use only the CN if it is
386 * prefixed by the O, or a significant portion thereof.
387 */
388 namesize = ctx->cn_size;
389 name = data + ctx->cn_offset;
390 if (ctx->cn_size >= ctx->o_size &&
391 memcmp(data + ctx->cn_offset, data + ctx->o_offset,
392 ctx->o_size) == 0)
393 goto single_component;
394 if (ctx->cn_size >= 7 &&
395 ctx->o_size >= 7 &&
396 memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0)
397 goto single_component;
398
399 buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1,
400 GFP_KERNEL);
401 if (!buffer)
402 return -ENOMEM;
403
404 memcpy(buffer,
405 data + ctx->o_offset, ctx->o_size);
406 buffer[ctx->o_size + 0] = ':';
407 buffer[ctx->o_size + 1] = ' ';
408 memcpy(buffer + ctx->o_size + 2,
409 data + ctx->cn_offset, ctx->cn_size);
410 buffer[ctx->o_size + 2 + ctx->cn_size] = 0;
411 goto done;
412
413 } else if (ctx->cn_size) {
414 namesize = ctx->cn_size;
415 name = data + ctx->cn_offset;
416 } else if (ctx->o_size) {
417 namesize = ctx->o_size;
418 name = data + ctx->o_offset;
419 } else {
420 namesize = ctx->email_size;
421 name = data + ctx->email_offset;
422 }
423
424single_component:
425 buffer = kmalloc(namesize + 1, GFP_KERNEL);
426 if (!buffer)
427 return -ENOMEM;
428 memcpy(buffer, name, namesize);
429 buffer[namesize] = 0;
430
431done:
432 *_name = buffer;
433 ctx->cn_size = 0;
434 ctx->o_size = 0;
435 ctx->email_size = 0;
436 return 0;
437}
438
439int x509_note_issuer(void *context, size_t hdrlen,
440 unsigned char tag,
441 const void *value, size_t vlen)
442{
443 struct x509_parse_context *ctx = context;
Andrew Zaborowski7d301982021-11-09 16:16:49 +0100444 struct asymmetric_key_id *kid;
445
David Howells84aabd42014-07-01 16:40:19 +0100446 ctx->cert->raw_issuer = value;
447 ctx->cert->raw_issuer_size = vlen;
Andrew Zaborowski7d301982021-11-09 16:16:49 +0100448
449 if (!ctx->cert->sig->auth_ids[2]) {
450 kid = asymmetric_key_generate_id(value, vlen, "", 0);
451 if (IS_ERR(kid))
452 return PTR_ERR(kid);
453 ctx->cert->sig->auth_ids[2] = kid;
454 }
455
David Howellsc26fd692012-09-24 17:11:48 +0100456 return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen);
457}
458
459int x509_note_subject(void *context, size_t hdrlen,
460 unsigned char tag,
461 const void *value, size_t vlen)
462{
463 struct x509_parse_context *ctx = context;
David Howells84aabd42014-07-01 16:40:19 +0100464 ctx->cert->raw_subject = value;
465 ctx->cert->raw_subject_size = vlen;
David Howellsc26fd692012-09-24 17:11:48 +0100466 return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen);
467}
468
469/*
Vitaly Chikunovf1774cb2019-04-11 18:51:17 +0300470 * Extract the parameters for the public key
471 */
472int x509_note_params(void *context, size_t hdrlen,
473 unsigned char tag,
474 const void *value, size_t vlen)
475{
476 struct x509_parse_context *ctx = context;
477
478 /*
479 * AlgorithmIdentifier is used three times in the x509, we should skip
480 * first and ignore third, using second one which is after subject and
481 * before subjectPublicKey.
482 */
483 if (!ctx->cert->raw_subject || ctx->key)
484 return 0;
485 ctx->params = value - hdrlen;
486 ctx->params_size = vlen + hdrlen;
487 return 0;
488}
489
490/*
David Howellsc26fd692012-09-24 17:11:48 +0100491 * Extract the data for the public key algorithm
492 */
493int x509_extract_key_data(void *context, size_t hdrlen,
494 unsigned char tag,
495 const void *value, size_t vlen)
496{
497 struct x509_parse_context *ctx = context;
Stefan Bergerd1a303e2021-03-16 17:07:36 -0400498 enum OID oid;
David Howellsc26fd692012-09-24 17:11:48 +0100499
Vitaly Chikunov0d7a7862019-04-11 18:51:20 +0300500 ctx->key_algo = ctx->last_oid;
Tianjia Zhang254f84f2020-09-21 00:21:01 +0800501 switch (ctx->last_oid) {
502 case OID_rsaEncryption:
Vitaly Chikunov0d7a7862019-04-11 18:51:20 +0300503 ctx->cert->pub->pkey_algo = "rsa";
Tianjia Zhang254f84f2020-09-21 00:21:01 +0800504 break;
505 case OID_gost2012PKey256:
506 case OID_gost2012PKey512:
Vitaly Chikunov0d7a7862019-04-11 18:51:20 +0300507 ctx->cert->pub->pkey_algo = "ecrdsa";
Tianjia Zhang254f84f2020-09-21 00:21:01 +0800508 break;
509 case OID_id_ecPublicKey:
Stefan Bergerd1a303e2021-03-16 17:07:36 -0400510 if (parse_OID(ctx->params, ctx->params_size, &oid) != 0)
511 return -EBADMSG;
512
513 switch (oid) {
514 case OID_sm2:
515 ctx->cert->pub->pkey_algo = "sm2";
516 break;
Stefan Berger299f5612021-03-16 17:07:37 -0400517 case OID_id_prime192v1:
518 ctx->cert->pub->pkey_algo = "ecdsa-nist-p192";
519 break;
520 case OID_id_prime256v1:
521 ctx->cert->pub->pkey_algo = "ecdsa-nist-p256";
522 break;
Saulo Alessandre2a8e6152021-03-16 17:07:39 -0400523 case OID_id_ansip384r1:
524 ctx->cert->pub->pkey_algo = "ecdsa-nist-p384";
525 break;
Stefan Bergerd1a303e2021-03-16 17:07:36 -0400526 default:
527 return -ENOPKG;
528 }
Tianjia Zhang254f84f2020-09-21 00:21:01 +0800529 break;
530 default:
David Howellsc26fd692012-09-24 17:11:48 +0100531 return -ENOPKG;
Tianjia Zhang254f84f2020-09-21 00:21:01 +0800532 }
David Howellsc26fd692012-09-24 17:11:48 +0100533
David Howells67f7d60b2013-08-30 16:15:24 +0100534 /* Discard the BIT STRING metadata */
Eric Biggers0f30cbea2017-12-08 15:13:27 +0000535 if (vlen < 1 || *(const u8 *)value != 0)
536 return -EBADMSG;
David Howellsc26fd692012-09-24 17:11:48 +0100537 ctx->key = value + 1;
538 ctx->key_size = vlen - 1;
539 return 0;
540}
541
Chun-Yi Lee04b00bd2013-04-22 10:56:55 +0930542/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
543#define SEQ_TAG_KEYID (ASN1_CONT << 6)
544
David Howellsc26fd692012-09-24 17:11:48 +0100545/*
546 * Process certificate extensions that are used to qualify the certificate.
547 */
548int x509_process_extension(void *context, size_t hdrlen,
549 unsigned char tag,
550 const void *value, size_t vlen)
551{
552 struct x509_parse_context *ctx = context;
David Howells46963b72014-09-16 17:36:13 +0100553 struct asymmetric_key_id *kid;
David Howellsc26fd692012-09-24 17:11:48 +0100554 const unsigned char *v = value;
David Howellsc26fd692012-09-24 17:11:48 +0100555
556 pr_debug("Extension: %u\n", ctx->last_oid);
557
558 if (ctx->last_oid == OID_subjectKeyIdentifier) {
559 /* Get hold of the key fingerprint */
David Howells46963b72014-09-16 17:36:13 +0100560 if (ctx->cert->skid || vlen < 3)
David Howellsc26fd692012-09-24 17:11:48 +0100561 return -EBADMSG;
562 if (v[0] != ASN1_OTS || v[1] != vlen - 2)
563 return -EBADMSG;
564 v += 2;
565 vlen -= 2;
566
David Howellsdd2f6c42014-10-03 16:17:02 +0100567 ctx->cert->raw_skid_size = vlen;
568 ctx->cert->raw_skid = v;
David Howellsa4c6e572015-07-20 21:16:32 +0100569 kid = asymmetric_key_generate_id(v, vlen, "", 0);
David Howells46963b72014-09-16 17:36:13 +0100570 if (IS_ERR(kid))
571 return PTR_ERR(kid);
572 ctx->cert->skid = kid;
573 pr_debug("subjkeyid %*phN\n", kid->len, kid->data);
David Howellsc26fd692012-09-24 17:11:48 +0100574 return 0;
575 }
576
577 if (ctx->last_oid == OID_authorityKeyIdentifier) {
578 /* Get hold of the CA key fingerprint */
David Howellsb92e6572015-07-20 21:16:26 +0100579 ctx->raw_akid = v;
580 ctx->raw_akid_size = vlen;
David Howellsc26fd692012-09-24 17:11:48 +0100581 return 0;
582 }
583
584 return 0;
585}
586
David Howellsfd19a3d2015-07-29 16:58:32 +0100587/**
588 * x509_decode_time - Decode an X.509 time ASN.1 object
589 * @_t: The time to fill in
590 * @hdrlen: The length of the object header
591 * @tag: The object tag
592 * @value: The object value
593 * @vlen: The size of the object value
594 *
595 * Decode an ASN.1 universal time or generalised time field into a struct the
596 * kernel can handle and check it for validity. The time is decoded thus:
597 *
598 * [RFC5280 §4.1.2.5]
599 * CAs conforming to this profile MUST always encode certificate validity
600 * dates through the year 2049 as UTCTime; certificate validity dates in
601 * 2050 or later MUST be encoded as GeneralizedTime. Conforming
602 * applications MUST be able to process validity dates that are encoded in
603 * either UTCTime or GeneralizedTime.
David Howellsc26fd692012-09-24 17:11:48 +0100604 */
David Howellsfd19a3d2015-07-29 16:58:32 +0100605int x509_decode_time(time64_t *_t, size_t hdrlen,
606 unsigned char tag,
607 const unsigned char *value, size_t vlen)
David Howellsc26fd692012-09-24 17:11:48 +0100608{
David Howellsac4cbed2016-02-24 14:37:15 +0000609 static const unsigned char month_lengths[] = { 31, 28, 31, 30, 31, 30,
David Howellsfd19a3d2015-07-29 16:58:32 +0100610 31, 31, 30, 31, 30, 31 };
David Howellsc26fd692012-09-24 17:11:48 +0100611 const unsigned char *p = value;
David Howellsfd19a3d2015-07-29 16:58:32 +0100612 unsigned year, mon, day, hour, min, sec, mon_len;
David Howellsc26fd692012-09-24 17:11:48 +0100613
David Howellsfd19a3d2015-07-29 16:58:32 +0100614#define dec2bin(X) ({ unsigned char x = (X) - '0'; if (x > 9) goto invalid_time; x; })
David Howellsc26fd692012-09-24 17:11:48 +0100615#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
616
617 if (tag == ASN1_UNITIM) {
618 /* UTCTime: YYMMDDHHMMSSZ */
619 if (vlen != 13)
620 goto unsupported_time;
David Howellsfd19a3d2015-07-29 16:58:32 +0100621 year = DD2bin(p);
622 if (year >= 50)
623 year += 1900;
David Howellsc26fd692012-09-24 17:11:48 +0100624 else
David Howellsfd19a3d2015-07-29 16:58:32 +0100625 year += 2000;
David Howellsc26fd692012-09-24 17:11:48 +0100626 } else if (tag == ASN1_GENTIM) {
627 /* GenTime: YYYYMMDDHHMMSSZ */
628 if (vlen != 15)
629 goto unsupported_time;
David Howellsfd19a3d2015-07-29 16:58:32 +0100630 year = DD2bin(p) * 100 + DD2bin(p);
631 if (year >= 1950 && year <= 2049)
632 goto invalid_time;
David Howellsc26fd692012-09-24 17:11:48 +0100633 } else {
634 goto unsupported_time;
635 }
636
David Howellsfd19a3d2015-07-29 16:58:32 +0100637 mon = DD2bin(p);
638 day = DD2bin(p);
639 hour = DD2bin(p);
640 min = DD2bin(p);
641 sec = DD2bin(p);
David Howellsc26fd692012-09-24 17:11:48 +0100642
643 if (*p != 'Z')
644 goto unsupported_time;
645
David Howellscc25b992015-11-12 09:36:40 +0000646 if (year < 1970 ||
647 mon < 1 || mon > 12)
648 goto invalid_time;
649
650 mon_len = month_lengths[mon - 1];
David Howellsfd19a3d2015-07-29 16:58:32 +0100651 if (mon == 2) {
652 if (year % 4 == 0) {
653 mon_len = 29;
654 if (year % 100 == 0) {
David Howellsac4cbed2016-02-24 14:37:15 +0000655 mon_len = 28;
656 if (year % 400 == 0)
657 mon_len = 29;
David Howellsfd19a3d2015-07-29 16:58:32 +0100658 }
659 }
660 }
661
David Howellscc25b992015-11-12 09:36:40 +0000662 if (day < 1 || day > mon_len ||
David Howells7650cb82016-02-24 14:37:54 +0000663 hour > 24 || /* ISO 8601 permits 24:00:00 as midnight tomorrow */
sudip4dd17c92015-09-17 13:12:51 +0530664 min > 59 ||
David Howellsda025592016-02-24 14:37:53 +0000665 sec > 60) /* ISO 8601 permits leap seconds [X.680 46.3] */
David Howellsfd19a3d2015-07-29 16:58:32 +0100666 goto invalid_time;
David Howellscc25b992015-11-12 09:36:40 +0000667
David Howellsfd19a3d2015-07-29 16:58:32 +0100668 *_t = mktime64(year, mon, day, hour, min, sec);
David Howellsc26fd692012-09-24 17:11:48 +0100669 return 0;
670
671unsupported_time:
David Howellsfd19a3d2015-07-29 16:58:32 +0100672 pr_debug("Got unsupported time [tag %02x]: '%*phN'\n",
673 tag, (int)vlen, value);
674 return -EBADMSG;
675invalid_time:
676 pr_debug("Got invalid time [tag %02x]: '%*phN'\n",
677 tag, (int)vlen, value);
David Howellsc26fd692012-09-24 17:11:48 +0100678 return -EBADMSG;
679}
David Howellsfd19a3d2015-07-29 16:58:32 +0100680EXPORT_SYMBOL_GPL(x509_decode_time);
David Howellsc26fd692012-09-24 17:11:48 +0100681
682int x509_note_not_before(void *context, size_t hdrlen,
683 unsigned char tag,
684 const void *value, size_t vlen)
685{
686 struct x509_parse_context *ctx = context;
David Howellsfd19a3d2015-07-29 16:58:32 +0100687 return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
David Howellsc26fd692012-09-24 17:11:48 +0100688}
689
690int x509_note_not_after(void *context, size_t hdrlen,
691 unsigned char tag,
692 const void *value, size_t vlen)
693{
694 struct x509_parse_context *ctx = context;
David Howellsfd19a3d2015-07-29 16:58:32 +0100695 return x509_decode_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
David Howellsc26fd692012-09-24 17:11:48 +0100696}
David Howellsb92e6572015-07-20 21:16:26 +0100697
698/*
699 * Note a key identifier-based AuthorityKeyIdentifier
700 */
701int x509_akid_note_kid(void *context, size_t hdrlen,
702 unsigned char tag,
703 const void *value, size_t vlen)
704{
705 struct x509_parse_context *ctx = context;
706 struct asymmetric_key_id *kid;
707
708 pr_debug("AKID: keyid: %*phN\n", (int)vlen, value);
709
David Howells77d09102016-04-06 16:13:33 +0100710 if (ctx->cert->sig->auth_ids[1])
David Howellsb92e6572015-07-20 21:16:26 +0100711 return 0;
712
David Howellsa4c6e572015-07-20 21:16:32 +0100713 kid = asymmetric_key_generate_id(value, vlen, "", 0);
David Howellsb92e6572015-07-20 21:16:26 +0100714 if (IS_ERR(kid))
715 return PTR_ERR(kid);
716 pr_debug("authkeyid %*phN\n", kid->len, kid->data);
David Howells77d09102016-04-06 16:13:33 +0100717 ctx->cert->sig->auth_ids[1] = kid;
David Howellsb92e6572015-07-20 21:16:26 +0100718 return 0;
719}
720
721/*
722 * Note a directoryName in an AuthorityKeyIdentifier
723 */
724int x509_akid_note_name(void *context, size_t hdrlen,
725 unsigned char tag,
726 const void *value, size_t vlen)
727{
728 struct x509_parse_context *ctx = context;
729
730 pr_debug("AKID: name: %*phN\n", (int)vlen, value);
731
732 ctx->akid_raw_issuer = value;
733 ctx->akid_raw_issuer_size = vlen;
734 return 0;
735}
736
737/*
738 * Note a serial number in an AuthorityKeyIdentifier
739 */
740int x509_akid_note_serial(void *context, size_t hdrlen,
741 unsigned char tag,
742 const void *value, size_t vlen)
743{
744 struct x509_parse_context *ctx = context;
745 struct asymmetric_key_id *kid;
746
747 pr_debug("AKID: serial: %*phN\n", (int)vlen, value);
748
David Howells77d09102016-04-06 16:13:33 +0100749 if (!ctx->akid_raw_issuer || ctx->cert->sig->auth_ids[0])
David Howellsb92e6572015-07-20 21:16:26 +0100750 return 0;
751
752 kid = asymmetric_key_generate_id(value,
753 vlen,
754 ctx->akid_raw_issuer,
755 ctx->akid_raw_issuer_size);
756 if (IS_ERR(kid))
757 return PTR_ERR(kid);
758
759 pr_debug("authkeyid %*phN\n", kid->len, kid->data);
David Howells77d09102016-04-06 16:13:33 +0100760 ctx->cert->sig->auth_ids[0] = kid;
David Howellsb92e6572015-07-20 21:16:26 +0100761 return 0;
762}