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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* X.509 certificate parser
3 *
4 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#define pr_fmt(fmt) "X.509: "fmt
9#include <linux/kernel.h>
10#include <linux/export.h>
11#include <linux/slab.h>
12#include <linux/err.h>
13#include <linux/oid_registry.h>
14#include <crypto/public_key.h>
15#include "x509_parser.h"
16#include "x509.asn1.h"
17#include "x509_akid.asn1.h"
18
19struct x509_parse_context {
20 struct x509_certificate *cert; /* Certificate being constructed */
21 unsigned long data; /* Start of data */
22 const void *key; /* Key data */
23 size_t key_size; /* Size of key data */
24 const void *params; /* Key parameters */
25 size_t params_size; /* Size of key parameters */
26 enum OID key_algo; /* Algorithm used by the cert's key */
27 enum OID last_oid; /* Last OID encountered */
28 enum OID sig_algo; /* Algorithm used to sign the cert */
29 u8 o_size; /* Size of organizationName (O) */
30 u8 cn_size; /* Size of commonName (CN) */
31 u8 email_size; /* Size of emailAddress */
32 u16 o_offset; /* Offset of organizationName (O) */
33 u16 cn_offset; /* Offset of commonName (CN) */
34 u16 email_offset; /* Offset of emailAddress */
35 unsigned raw_akid_size;
36 const void *raw_akid; /* Raw authorityKeyId in ASN.1 */
37 const void *akid_raw_issuer; /* Raw directoryName in authorityKeyId */
38 unsigned akid_raw_issuer_size;
39};
40
41/*
42 * Free an X.509 certificate
43 */
44void x509_free_certificate(struct x509_certificate *cert)
45{
46 if (cert) {
47 public_key_free(cert->pub);
48 public_key_signature_free(cert->sig);
49 kfree(cert->issuer);
50 kfree(cert->subject);
51 kfree(cert->id);
52 kfree(cert->skid);
53 kfree(cert);
54 }
55}
56EXPORT_SYMBOL_GPL(x509_free_certificate);
57
58/*
59 * Parse an X.509 certificate
60 */
61struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
62{
63 struct x509_certificate *cert;
64 struct x509_parse_context *ctx;
65 struct asymmetric_key_id *kid;
66 long ret;
67
68 ret = -ENOMEM;
69 cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
70 if (!cert)
71 goto error_no_cert;
72 cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
73 if (!cert->pub)
74 goto error_no_ctx;
75 cert->sig = kzalloc(sizeof(struct public_key_signature), GFP_KERNEL);
76 if (!cert->sig)
77 goto error_no_ctx;
78 ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
79 if (!ctx)
80 goto error_no_ctx;
81
82 ctx->cert = cert;
83 ctx->data = (unsigned long)data;
84
85 /* Attempt to decode the certificate */
86 ret = asn1_ber_decoder(&x509_decoder, ctx, data, datalen);
87 if (ret < 0)
88 goto error_decode;
89
90 /* Decode the AuthorityKeyIdentifier */
91 if (ctx->raw_akid) {
92 pr_devel("AKID: %u %*phN\n",
93 ctx->raw_akid_size, ctx->raw_akid_size, ctx->raw_akid);
94 ret = asn1_ber_decoder(&x509_akid_decoder, ctx,
95 ctx->raw_akid, ctx->raw_akid_size);
96 if (ret < 0) {
97 pr_warn("Couldn't decode AuthKeyIdentifier\n");
98 goto error_decode;
99 }
100 }
101
102 ret = -ENOMEM;
103 cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
104 if (!cert->pub->key)
105 goto error_decode;
106
107 cert->pub->keylen = ctx->key_size;
108
109 cert->pub->params = kmemdup(ctx->params, ctx->params_size, GFP_KERNEL);
110 if (!cert->pub->params)
111 goto error_decode;
112
113 cert->pub->paramlen = ctx->params_size;
114 cert->pub->algo = ctx->key_algo;
115
116 /* Grab the signature bits */
117 ret = x509_get_sig_params(cert);
118 if (ret < 0)
119 goto error_decode;
120
121 /* Generate cert issuer + serial number key ID */
122 kid = asymmetric_key_generate_id(cert->raw_serial,
123 cert->raw_serial_size,
124 cert->raw_issuer,
125 cert->raw_issuer_size);
126 if (IS_ERR(kid)) {
127 ret = PTR_ERR(kid);
128 goto error_decode;
129 }
130 cert->id = kid;
131
132 /* Detect self-signed certificates */
133 ret = x509_check_for_self_signed(cert);
134 if (ret < 0)
135 goto error_decode;
136
137 kfree(ctx);
138 return cert;
139
140error_decode:
141 kfree(ctx);
142error_no_ctx:
143 x509_free_certificate(cert);
144error_no_cert:
145 return ERR_PTR(ret);
146}
147EXPORT_SYMBOL_GPL(x509_cert_parse);
148
149/*
150 * Note an OID when we find one for later processing when we know how
151 * to interpret it.
152 */
153int x509_note_OID(void *context, size_t hdrlen,
154 unsigned char tag,
155 const void *value, size_t vlen)
156{
157 struct x509_parse_context *ctx = context;
158
159 ctx->last_oid = look_up_OID(value, vlen);
160 if (ctx->last_oid == OID__NR) {
161 char buffer[50];
162 sprint_oid(value, vlen, buffer, sizeof(buffer));
163 pr_debug("Unknown OID: [%lu] %s\n",
164 (unsigned long)value - ctx->data, buffer);
165 }
166 return 0;
167}
168
169/*
170 * Save the position of the TBS data so that we can check the signature over it
171 * later.
172 */
173int x509_note_tbs_certificate(void *context, size_t hdrlen,
174 unsigned char tag,
175 const void *value, size_t vlen)
176{
177 struct x509_parse_context *ctx = context;
178
179 pr_debug("x509_note_tbs_certificate(,%zu,%02x,%ld,%zu)!\n",
180 hdrlen, tag, (unsigned long)value - ctx->data, vlen);
181
182 ctx->cert->tbs = value - hdrlen;
183 ctx->cert->tbs_size = vlen + hdrlen;
184 return 0;
185}
186
187/*
188 * Record the algorithm that was used to sign this certificate.
189 */
190int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
191 const void *value, size_t vlen)
192{
193 struct x509_parse_context *ctx = context;
194
195 pr_debug("PubKey Algo: %u\n", ctx->last_oid);
196
197 switch (ctx->last_oid) {
198 case OID_md2WithRSAEncryption:
199 case OID_md3WithRSAEncryption:
200 default:
201 return -ENOPKG; /* Unsupported combination */
202
203 case OID_md4WithRSAEncryption:
204 ctx->cert->sig->hash_algo = "md4";
205 goto rsa_pkcs1;
206
207 case OID_sha1WithRSAEncryption:
208 ctx->cert->sig->hash_algo = "sha1";
209 goto rsa_pkcs1;
210
211 case OID_sha256WithRSAEncryption:
212 ctx->cert->sig->hash_algo = "sha256";
213 goto rsa_pkcs1;
214
215 case OID_sha384WithRSAEncryption:
216 ctx->cert->sig->hash_algo = "sha384";
217 goto rsa_pkcs1;
218
219 case OID_sha512WithRSAEncryption:
220 ctx->cert->sig->hash_algo = "sha512";
221 goto rsa_pkcs1;
222
223 case OID_sha224WithRSAEncryption:
224 ctx->cert->sig->hash_algo = "sha224";
225 goto rsa_pkcs1;
226
227 case OID_id_ecdsa_with_sha1:
228 ctx->cert->sig->hash_algo = "sha1";
229 goto ecdsa;
230
231 case OID_id_ecdsa_with_sha224:
232 ctx->cert->sig->hash_algo = "sha224";
233 goto ecdsa;
234
235 case OID_id_ecdsa_with_sha256:
236 ctx->cert->sig->hash_algo = "sha256";
237 goto ecdsa;
238
239 case OID_id_ecdsa_with_sha384:
240 ctx->cert->sig->hash_algo = "sha384";
241 goto ecdsa;
242
243 case OID_id_ecdsa_with_sha512:
244 ctx->cert->sig->hash_algo = "sha512";
245 goto ecdsa;
246
247 case OID_gost2012Signature256:
248 ctx->cert->sig->hash_algo = "streebog256";
249 goto ecrdsa;
250
251 case OID_gost2012Signature512:
252 ctx->cert->sig->hash_algo = "streebog512";
253 goto ecrdsa;
254
255 case OID_SM2_with_SM3:
256 ctx->cert->sig->hash_algo = "sm3";
257 goto sm2;
258 }
259
260rsa_pkcs1:
261 ctx->cert->sig->pkey_algo = "rsa";
262 ctx->cert->sig->encoding = "pkcs1";
263 ctx->sig_algo = ctx->last_oid;
264 return 0;
265ecrdsa:
266 ctx->cert->sig->pkey_algo = "ecrdsa";
267 ctx->cert->sig->encoding = "raw";
268 ctx->sig_algo = ctx->last_oid;
269 return 0;
270sm2:
271 ctx->cert->sig->pkey_algo = "sm2";
272 ctx->cert->sig->encoding = "raw";
273 ctx->sig_algo = ctx->last_oid;
274 return 0;
275ecdsa:
276 ctx->cert->sig->pkey_algo = "ecdsa";
277 ctx->cert->sig->encoding = "x962";
278 ctx->sig_algo = ctx->last_oid;
279 return 0;
280}
281
282/*
283 * Note the whereabouts and type of the signature.
284 */
285int x509_note_signature(void *context, size_t hdrlen,
286 unsigned char tag,
287 const void *value, size_t vlen)
288{
289 struct x509_parse_context *ctx = context;
290
291 pr_debug("Signature: alg=%u, size=%zu\n", ctx->last_oid, vlen);
292
293 /*
294 * In X.509 certificates, the signature's algorithm is stored in two
295 * places: inside the TBSCertificate (the data that is signed), and
296 * alongside the signature. These *must* match.
297 */
298 if (ctx->last_oid != ctx->sig_algo) {
299 pr_warn("signatureAlgorithm (%u) differs from tbsCertificate.signature (%u)\n",
300 ctx->last_oid, ctx->sig_algo);
301 return -EINVAL;
302 }
303
304 if (strcmp(ctx->cert->sig->pkey_algo, "rsa") == 0 ||
305 strcmp(ctx->cert->sig->pkey_algo, "ecrdsa") == 0 ||
306 strcmp(ctx->cert->sig->pkey_algo, "sm2") == 0 ||
307 strcmp(ctx->cert->sig->pkey_algo, "ecdsa") == 0) {
308 /* Discard the BIT STRING metadata */
309 if (vlen < 1 || *(const u8 *)value != 0)
310 return -EBADMSG;
311
312 value++;
313 vlen--;
314 }
315
316 ctx->cert->raw_sig = value;
317 ctx->cert->raw_sig_size = vlen;
318 return 0;
319}
320
321/*
322 * Note the certificate serial number
323 */
324int x509_note_serial(void *context, size_t hdrlen,
325 unsigned char tag,
326 const void *value, size_t vlen)
327{
328 struct x509_parse_context *ctx = context;
329 ctx->cert->raw_serial = value;
330 ctx->cert->raw_serial_size = vlen;
331 return 0;
332}
333
334/*
335 * Note some of the name segments from which we'll fabricate a name.
336 */
337int x509_extract_name_segment(void *context, size_t hdrlen,
338 unsigned char tag,
339 const void *value, size_t vlen)
340{
341 struct x509_parse_context *ctx = context;
342
343 switch (ctx->last_oid) {
344 case OID_commonName:
345 ctx->cn_size = vlen;
346 ctx->cn_offset = (unsigned long)value - ctx->data;
347 break;
348 case OID_organizationName:
349 ctx->o_size = vlen;
350 ctx->o_offset = (unsigned long)value - ctx->data;
351 break;
352 case OID_email_address:
353 ctx->email_size = vlen;
354 ctx->email_offset = (unsigned long)value - ctx->data;
355 break;
356 default:
357 break;
358 }
359
360 return 0;
361}
362
363/*
364 * Fabricate and save the issuer and subject names
365 */
366static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen,
367 unsigned char tag,
368 char **_name, size_t vlen)
369{
370 const void *name, *data = (const void *)ctx->data;
371 size_t namesize;
372 char *buffer;
373
374 if (*_name)
375 return -EINVAL;
376
377 /* Empty name string if no material */
378 if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) {
379 buffer = kmalloc(1, GFP_KERNEL);
380 if (!buffer)
381 return -ENOMEM;
382 buffer[0] = 0;
383 goto done;
384 }
385
386 if (ctx->cn_size && ctx->o_size) {
387 /* Consider combining O and CN, but use only the CN if it is
388 * prefixed by the O, or a significant portion thereof.
389 */
390 namesize = ctx->cn_size;
391 name = data + ctx->cn_offset;
392 if (ctx->cn_size >= ctx->o_size &&
393 memcmp(data + ctx->cn_offset, data + ctx->o_offset,
394 ctx->o_size) == 0)
395 goto single_component;
396 if (ctx->cn_size >= 7 &&
397 ctx->o_size >= 7 &&
398 memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0)
399 goto single_component;
400
401 buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1,
402 GFP_KERNEL);
403 if (!buffer)
404 return -ENOMEM;
405
406 memcpy(buffer,
407 data + ctx->o_offset, ctx->o_size);
408 buffer[ctx->o_size + 0] = ':';
409 buffer[ctx->o_size + 1] = ' ';
410 memcpy(buffer + ctx->o_size + 2,
411 data + ctx->cn_offset, ctx->cn_size);
412 buffer[ctx->o_size + 2 + ctx->cn_size] = 0;
413 goto done;
414
415 } else if (ctx->cn_size) {
416 namesize = ctx->cn_size;
417 name = data + ctx->cn_offset;
418 } else if (ctx->o_size) {
419 namesize = ctx->o_size;
420 name = data + ctx->o_offset;
421 } else {
422 namesize = ctx->email_size;
423 name = data + ctx->email_offset;
424 }
425
426single_component:
427 buffer = kmalloc(namesize + 1, GFP_KERNEL);
428 if (!buffer)
429 return -ENOMEM;
430 memcpy(buffer, name, namesize);
431 buffer[namesize] = 0;
432
433done:
434 *_name = buffer;
435 ctx->cn_size = 0;
436 ctx->o_size = 0;
437 ctx->email_size = 0;
438 return 0;
439}
440
441int x509_note_issuer(void *context, size_t hdrlen,
442 unsigned char tag,
443 const void *value, size_t vlen)
444{
445 struct x509_parse_context *ctx = context;
446 struct asymmetric_key_id *kid;
447
448 ctx->cert->raw_issuer = value;
449 ctx->cert->raw_issuer_size = vlen;
450
451 if (!ctx->cert->sig->auth_ids[2]) {
452 kid = asymmetric_key_generate_id(value, vlen, "", 0);
453 if (IS_ERR(kid))
454 return PTR_ERR(kid);
455 ctx->cert->sig->auth_ids[2] = kid;
456 }
457
458 return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen);
459}
460
461int x509_note_subject(void *context, size_t hdrlen,
462 unsigned char tag,
463 const void *value, size_t vlen)
464{
465 struct x509_parse_context *ctx = context;
466 ctx->cert->raw_subject = value;
467 ctx->cert->raw_subject_size = vlen;
468 return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen);
469}
470
471/*
472 * Extract the parameters for the public key
473 */
474int x509_note_params(void *context, size_t hdrlen,
475 unsigned char tag,
476 const void *value, size_t vlen)
477{
478 struct x509_parse_context *ctx = context;
479
480 /*
481 * AlgorithmIdentifier is used three times in the x509, we should skip
482 * first and ignore third, using second one which is after subject and
483 * before subjectPublicKey.
484 */
485 if (!ctx->cert->raw_subject || ctx->key)
486 return 0;
487 ctx->params = value - hdrlen;
488 ctx->params_size = vlen + hdrlen;
489 return 0;
490}
491
492/*
493 * Extract the data for the public key algorithm
494 */
495int x509_extract_key_data(void *context, size_t hdrlen,
496 unsigned char tag,
497 const void *value, size_t vlen)
498{
499 struct x509_parse_context *ctx = context;
500 enum OID oid;
501
502 ctx->key_algo = ctx->last_oid;
503 switch (ctx->last_oid) {
504 case OID_rsaEncryption:
505 ctx->cert->pub->pkey_algo = "rsa";
506 break;
507 case OID_gost2012PKey256:
508 case OID_gost2012PKey512:
509 ctx->cert->pub->pkey_algo = "ecrdsa";
510 break;
511 case OID_sm2:
512 ctx->cert->pub->pkey_algo = "sm2";
513 break;
514 case OID_id_ecPublicKey:
515 if (parse_OID(ctx->params, ctx->params_size, &oid) != 0)
516 return -EBADMSG;
517
518 switch (oid) {
519 case OID_sm2:
520 ctx->cert->pub->pkey_algo = "sm2";
521 break;
522 case OID_id_prime192v1:
523 ctx->cert->pub->pkey_algo = "ecdsa-nist-p192";
524 break;
525 case OID_id_prime256v1:
526 ctx->cert->pub->pkey_algo = "ecdsa-nist-p256";
527 break;
528 case OID_id_ansip384r1:
529 ctx->cert->pub->pkey_algo = "ecdsa-nist-p384";
530 break;
531 default:
532 return -ENOPKG;
533 }
534 break;
535 default:
536 return -ENOPKG;
537 }
538
539 /* Discard the BIT STRING metadata */
540 if (vlen < 1 || *(const u8 *)value != 0)
541 return -EBADMSG;
542 ctx->key = value + 1;
543 ctx->key_size = vlen - 1;
544 return 0;
545}
546
547/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
548#define SEQ_TAG_KEYID (ASN1_CONT << 6)
549
550/*
551 * Process certificate extensions that are used to qualify the certificate.
552 */
553int x509_process_extension(void *context, size_t hdrlen,
554 unsigned char tag,
555 const void *value, size_t vlen)
556{
557 struct x509_parse_context *ctx = context;
558 struct asymmetric_key_id *kid;
559 const unsigned char *v = value;
560
561 pr_debug("Extension: %u\n", ctx->last_oid);
562
563 if (ctx->last_oid == OID_subjectKeyIdentifier) {
564 /* Get hold of the key fingerprint */
565 if (ctx->cert->skid || vlen < 3)
566 return -EBADMSG;
567 if (v[0] != ASN1_OTS || v[1] != vlen - 2)
568 return -EBADMSG;
569 v += 2;
570 vlen -= 2;
571
572 ctx->cert->raw_skid_size = vlen;
573 ctx->cert->raw_skid = v;
574 kid = asymmetric_key_generate_id(v, vlen, "", 0);
575 if (IS_ERR(kid))
576 return PTR_ERR(kid);
577 ctx->cert->skid = kid;
578 pr_debug("subjkeyid %*phN\n", kid->len, kid->data);
579 return 0;
580 }
581
582 if (ctx->last_oid == OID_authorityKeyIdentifier) {
583 /* Get hold of the CA key fingerprint */
584 ctx->raw_akid = v;
585 ctx->raw_akid_size = vlen;
586 return 0;
587 }
588
589 return 0;
590}
591
592/**
593 * x509_decode_time - Decode an X.509 time ASN.1 object
594 * @_t: The time to fill in
595 * @hdrlen: The length of the object header
596 * @tag: The object tag
597 * @value: The object value
598 * @vlen: The size of the object value
599 *
600 * Decode an ASN.1 universal time or generalised time field into a struct the
601 * kernel can handle and check it for validity. The time is decoded thus:
602 *
603 * [RFC5280 ยง4.1.2.5]
604 * CAs conforming to this profile MUST always encode certificate validity
605 * dates through the year 2049 as UTCTime; certificate validity dates in
606 * 2050 or later MUST be encoded as GeneralizedTime. Conforming
607 * applications MUST be able to process validity dates that are encoded in
608 * either UTCTime or GeneralizedTime.
609 */
610int x509_decode_time(time64_t *_t, size_t hdrlen,
611 unsigned char tag,
612 const unsigned char *value, size_t vlen)
613{
614 static const unsigned char month_lengths[] = { 31, 28, 31, 30, 31, 30,
615 31, 31, 30, 31, 30, 31 };
616 const unsigned char *p = value;
617 unsigned year, mon, day, hour, min, sec, mon_len;
618
619#define dec2bin(X) ({ unsigned char x = (X) - '0'; if (x > 9) goto invalid_time; x; })
620#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
621
622 if (tag == ASN1_UNITIM) {
623 /* UTCTime: YYMMDDHHMMSSZ */
624 if (vlen != 13)
625 goto unsupported_time;
626 year = DD2bin(p);
627 if (year >= 50)
628 year += 1900;
629 else
630 year += 2000;
631 } else if (tag == ASN1_GENTIM) {
632 /* GenTime: YYYYMMDDHHMMSSZ */
633 if (vlen != 15)
634 goto unsupported_time;
635 year = DD2bin(p) * 100 + DD2bin(p);
636 if (year >= 1950 && year <= 2049)
637 goto invalid_time;
638 } else {
639 goto unsupported_time;
640 }
641
642 mon = DD2bin(p);
643 day = DD2bin(p);
644 hour = DD2bin(p);
645 min = DD2bin(p);
646 sec = DD2bin(p);
647
648 if (*p != 'Z')
649 goto unsupported_time;
650
651 if (year < 1970 ||
652 mon < 1 || mon > 12)
653 goto invalid_time;
654
655 mon_len = month_lengths[mon - 1];
656 if (mon == 2) {
657 if (year % 4 == 0) {
658 mon_len = 29;
659 if (year % 100 == 0) {
660 mon_len = 28;
661 if (year % 400 == 0)
662 mon_len = 29;
663 }
664 }
665 }
666
667 if (day < 1 || day > mon_len ||
668 hour > 24 || /* ISO 8601 permits 24:00:00 as midnight tomorrow */
669 min > 59 ||
670 sec > 60) /* ISO 8601 permits leap seconds [X.680 46.3] */
671 goto invalid_time;
672
673 *_t = mktime64(year, mon, day, hour, min, sec);
674 return 0;
675
676unsupported_time:
677 pr_debug("Got unsupported time [tag %02x]: '%*phN'\n",
678 tag, (int)vlen, value);
679 return -EBADMSG;
680invalid_time:
681 pr_debug("Got invalid time [tag %02x]: '%*phN'\n",
682 tag, (int)vlen, value);
683 return -EBADMSG;
684}
685EXPORT_SYMBOL_GPL(x509_decode_time);
686
687int x509_note_not_before(void *context, size_t hdrlen,
688 unsigned char tag,
689 const void *value, size_t vlen)
690{
691 struct x509_parse_context *ctx = context;
692 return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
693}
694
695int x509_note_not_after(void *context, size_t hdrlen,
696 unsigned char tag,
697 const void *value, size_t vlen)
698{
699 struct x509_parse_context *ctx = context;
700 return x509_decode_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
701}
702
703/*
704 * Note a key identifier-based AuthorityKeyIdentifier
705 */
706int x509_akid_note_kid(void *context, size_t hdrlen,
707 unsigned char tag,
708 const void *value, size_t vlen)
709{
710 struct x509_parse_context *ctx = context;
711 struct asymmetric_key_id *kid;
712
713 pr_debug("AKID: keyid: %*phN\n", (int)vlen, value);
714
715 if (ctx->cert->sig->auth_ids[1])
716 return 0;
717
718 kid = asymmetric_key_generate_id(value, vlen, "", 0);
719 if (IS_ERR(kid))
720 return PTR_ERR(kid);
721 pr_debug("authkeyid %*phN\n", kid->len, kid->data);
722 ctx->cert->sig->auth_ids[1] = kid;
723 return 0;
724}
725
726/*
727 * Note a directoryName in an AuthorityKeyIdentifier
728 */
729int x509_akid_note_name(void *context, size_t hdrlen,
730 unsigned char tag,
731 const void *value, size_t vlen)
732{
733 struct x509_parse_context *ctx = context;
734
735 pr_debug("AKID: name: %*phN\n", (int)vlen, value);
736
737 ctx->akid_raw_issuer = value;
738 ctx->akid_raw_issuer_size = vlen;
739 return 0;
740}
741
742/*
743 * Note a serial number in an AuthorityKeyIdentifier
744 */
745int x509_akid_note_serial(void *context, size_t hdrlen,
746 unsigned char tag,
747 const void *value, size_t vlen)
748{
749 struct x509_parse_context *ctx = context;
750 struct asymmetric_key_id *kid;
751
752 pr_debug("AKID: serial: %*phN\n", (int)vlen, value);
753
754 if (!ctx->akid_raw_issuer || ctx->cert->sig->auth_ids[0])
755 return 0;
756
757 kid = asymmetric_key_generate_id(value,
758 vlen,
759 ctx->akid_raw_issuer,
760 ctx->akid_raw_issuer_size);
761 if (IS_ERR(kid))
762 return PTR_ERR(kid);
763
764 pr_debug("authkeyid %*phN\n", kid->len, kid->data);
765 ctx->cert->sig->auth_ids[0] = kid;
766 return 0;
767}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* X.509 certificate parser
3 *
4 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#define pr_fmt(fmt) "X.509: "fmt
9#include <linux/kernel.h>
10#include <linux/export.h>
11#include <linux/slab.h>
12#include <linux/err.h>
13#include <linux/oid_registry.h>
14#include <crypto/public_key.h>
15#include "x509_parser.h"
16#include "x509.asn1.h"
17#include "x509_akid.asn1.h"
18
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 */
25 const void *params; /* Key parameters */
26 size_t params_size; /* Size of key parameters */
27 enum OID key_algo; /* Public key algorithm */
28 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 */
37 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;
41};
42
43/*
44 * Free an X.509 certificate
45 */
46void x509_free_certificate(struct x509_certificate *cert)
47{
48 if (cert) {
49 public_key_free(cert->pub);
50 public_key_signature_free(cert->sig);
51 kfree(cert->issuer);
52 kfree(cert->subject);
53 kfree(cert->id);
54 kfree(cert->skid);
55 kfree(cert);
56 }
57}
58EXPORT_SYMBOL_GPL(x509_free_certificate);
59
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;
67 struct asymmetric_key_id *kid;
68 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;
77 cert->sig = kzalloc(sizeof(struct public_key_signature), GFP_KERNEL);
78 if (!cert->sig)
79 goto error_no_ctx;
80 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
92 /* 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
104 ret = -ENOMEM;
105 cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
106 if (!cert->pub->key)
107 goto error_decode;
108
109 cert->pub->keylen = ctx->key_size;
110
111 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
118 /* Grab the signature bits */
119 ret = x509_get_sig_params(cert);
120 if (ret < 0)
121 goto error_decode;
122
123 /* 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
134 /* Detect self-signed certificates */
135 ret = x509_check_for_self_signed(cert);
136 if (ret < 0)
137 goto error_decode;
138
139 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}
149EXPORT_SYMBOL_GPL(x509_cert_parse);
150
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));
165 pr_debug("Unknown OID: [%lu] %s\n",
166 (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:
207 ctx->cert->sig->hash_algo = "md4";
208 goto rsa_pkcs1;
209
210 case OID_sha1WithRSAEncryption:
211 ctx->cert->sig->hash_algo = "sha1";
212 goto rsa_pkcs1;
213
214 case OID_sha256WithRSAEncryption:
215 ctx->cert->sig->hash_algo = "sha256";
216 goto rsa_pkcs1;
217
218 case OID_sha384WithRSAEncryption:
219 ctx->cert->sig->hash_algo = "sha384";
220 goto rsa_pkcs1;
221
222 case OID_sha512WithRSAEncryption:
223 ctx->cert->sig->hash_algo = "sha512";
224 goto rsa_pkcs1;
225
226 case OID_sha224WithRSAEncryption:
227 ctx->cert->sig->hash_algo = "sha224";
228 goto rsa_pkcs1;
229
230 case OID_gost2012Signature256:
231 ctx->cert->sig->hash_algo = "streebog256";
232 goto ecrdsa;
233
234 case OID_gost2012Signature512:
235 ctx->cert->sig->hash_algo = "streebog512";
236 goto ecrdsa;
237 }
238
239rsa_pkcs1:
240 ctx->cert->sig->pkey_algo = "rsa";
241 ctx->cert->sig->encoding = "pkcs1";
242 ctx->algo_oid = ctx->last_oid;
243 return 0;
244ecrdsa:
245 ctx->cert->sig->pkey_algo = "ecrdsa";
246 ctx->cert->sig->encoding = "raw";
247 ctx->algo_oid = ctx->last_oid;
248 return 0;
249}
250
251/*
252 * Note the whereabouts and type of the signature.
253 */
254int x509_note_signature(void *context, size_t hdrlen,
255 unsigned char tag,
256 const void *value, size_t vlen)
257{
258 struct x509_parse_context *ctx = context;
259
260 pr_debug("Signature type: %u size %zu\n", ctx->last_oid, vlen);
261
262 if (ctx->last_oid != ctx->algo_oid) {
263 pr_warn("Got cert with pkey (%u) and sig (%u) algorithm OIDs\n",
264 ctx->algo_oid, ctx->last_oid);
265 return -EINVAL;
266 }
267
268 if (strcmp(ctx->cert->sig->pkey_algo, "rsa") == 0 ||
269 strcmp(ctx->cert->sig->pkey_algo, "ecrdsa") == 0) {
270 /* Discard the BIT STRING metadata */
271 if (vlen < 1 || *(const u8 *)value != 0)
272 return -EBADMSG;
273
274 value++;
275 vlen--;
276 }
277
278 ctx->cert->raw_sig = value;
279 ctx->cert->raw_sig_size = vlen;
280 return 0;
281}
282
283/*
284 * Note the certificate serial number
285 */
286int x509_note_serial(void *context, size_t hdrlen,
287 unsigned char tag,
288 const void *value, size_t vlen)
289{
290 struct x509_parse_context *ctx = context;
291 ctx->cert->raw_serial = value;
292 ctx->cert->raw_serial_size = vlen;
293 return 0;
294}
295
296/*
297 * Note some of the name segments from which we'll fabricate a name.
298 */
299int x509_extract_name_segment(void *context, size_t hdrlen,
300 unsigned char tag,
301 const void *value, size_t vlen)
302{
303 struct x509_parse_context *ctx = context;
304
305 switch (ctx->last_oid) {
306 case OID_commonName:
307 ctx->cn_size = vlen;
308 ctx->cn_offset = (unsigned long)value - ctx->data;
309 break;
310 case OID_organizationName:
311 ctx->o_size = vlen;
312 ctx->o_offset = (unsigned long)value - ctx->data;
313 break;
314 case OID_email_address:
315 ctx->email_size = vlen;
316 ctx->email_offset = (unsigned long)value - ctx->data;
317 break;
318 default:
319 break;
320 }
321
322 return 0;
323}
324
325/*
326 * Fabricate and save the issuer and subject names
327 */
328static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen,
329 unsigned char tag,
330 char **_name, size_t vlen)
331{
332 const void *name, *data = (const void *)ctx->data;
333 size_t namesize;
334 char *buffer;
335
336 if (*_name)
337 return -EINVAL;
338
339 /* Empty name string if no material */
340 if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) {
341 buffer = kmalloc(1, GFP_KERNEL);
342 if (!buffer)
343 return -ENOMEM;
344 buffer[0] = 0;
345 goto done;
346 }
347
348 if (ctx->cn_size && ctx->o_size) {
349 /* Consider combining O and CN, but use only the CN if it is
350 * prefixed by the O, or a significant portion thereof.
351 */
352 namesize = ctx->cn_size;
353 name = data + ctx->cn_offset;
354 if (ctx->cn_size >= ctx->o_size &&
355 memcmp(data + ctx->cn_offset, data + ctx->o_offset,
356 ctx->o_size) == 0)
357 goto single_component;
358 if (ctx->cn_size >= 7 &&
359 ctx->o_size >= 7 &&
360 memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0)
361 goto single_component;
362
363 buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1,
364 GFP_KERNEL);
365 if (!buffer)
366 return -ENOMEM;
367
368 memcpy(buffer,
369 data + ctx->o_offset, ctx->o_size);
370 buffer[ctx->o_size + 0] = ':';
371 buffer[ctx->o_size + 1] = ' ';
372 memcpy(buffer + ctx->o_size + 2,
373 data + ctx->cn_offset, ctx->cn_size);
374 buffer[ctx->o_size + 2 + ctx->cn_size] = 0;
375 goto done;
376
377 } else if (ctx->cn_size) {
378 namesize = ctx->cn_size;
379 name = data + ctx->cn_offset;
380 } else if (ctx->o_size) {
381 namesize = ctx->o_size;
382 name = data + ctx->o_offset;
383 } else {
384 namesize = ctx->email_size;
385 name = data + ctx->email_offset;
386 }
387
388single_component:
389 buffer = kmalloc(namesize + 1, GFP_KERNEL);
390 if (!buffer)
391 return -ENOMEM;
392 memcpy(buffer, name, namesize);
393 buffer[namesize] = 0;
394
395done:
396 *_name = buffer;
397 ctx->cn_size = 0;
398 ctx->o_size = 0;
399 ctx->email_size = 0;
400 return 0;
401}
402
403int x509_note_issuer(void *context, size_t hdrlen,
404 unsigned char tag,
405 const void *value, size_t vlen)
406{
407 struct x509_parse_context *ctx = context;
408 ctx->cert->raw_issuer = value;
409 ctx->cert->raw_issuer_size = vlen;
410 return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen);
411}
412
413int x509_note_subject(void *context, size_t hdrlen,
414 unsigned char tag,
415 const void *value, size_t vlen)
416{
417 struct x509_parse_context *ctx = context;
418 ctx->cert->raw_subject = value;
419 ctx->cert->raw_subject_size = vlen;
420 return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen);
421}
422
423/*
424 * Extract the parameters for the public key
425 */
426int x509_note_params(void *context, size_t hdrlen,
427 unsigned char tag,
428 const void *value, size_t vlen)
429{
430 struct x509_parse_context *ctx = context;
431
432 /*
433 * AlgorithmIdentifier is used three times in the x509, we should skip
434 * first and ignore third, using second one which is after subject and
435 * before subjectPublicKey.
436 */
437 if (!ctx->cert->raw_subject || ctx->key)
438 return 0;
439 ctx->params = value - hdrlen;
440 ctx->params_size = vlen + hdrlen;
441 return 0;
442}
443
444/*
445 * Extract the data for the public key algorithm
446 */
447int x509_extract_key_data(void *context, size_t hdrlen,
448 unsigned char tag,
449 const void *value, size_t vlen)
450{
451 struct x509_parse_context *ctx = context;
452
453 ctx->key_algo = ctx->last_oid;
454 if (ctx->last_oid == OID_rsaEncryption)
455 ctx->cert->pub->pkey_algo = "rsa";
456 else if (ctx->last_oid == OID_gost2012PKey256 ||
457 ctx->last_oid == OID_gost2012PKey512)
458 ctx->cert->pub->pkey_algo = "ecrdsa";
459 else
460 return -ENOPKG;
461
462 /* Discard the BIT STRING metadata */
463 if (vlen < 1 || *(const u8 *)value != 0)
464 return -EBADMSG;
465 ctx->key = value + 1;
466 ctx->key_size = vlen - 1;
467 return 0;
468}
469
470/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
471#define SEQ_TAG_KEYID (ASN1_CONT << 6)
472
473/*
474 * Process certificate extensions that are used to qualify the certificate.
475 */
476int x509_process_extension(void *context, size_t hdrlen,
477 unsigned char tag,
478 const void *value, size_t vlen)
479{
480 struct x509_parse_context *ctx = context;
481 struct asymmetric_key_id *kid;
482 const unsigned char *v = value;
483
484 pr_debug("Extension: %u\n", ctx->last_oid);
485
486 if (ctx->last_oid == OID_subjectKeyIdentifier) {
487 /* Get hold of the key fingerprint */
488 if (ctx->cert->skid || vlen < 3)
489 return -EBADMSG;
490 if (v[0] != ASN1_OTS || v[1] != vlen - 2)
491 return -EBADMSG;
492 v += 2;
493 vlen -= 2;
494
495 ctx->cert->raw_skid_size = vlen;
496 ctx->cert->raw_skid = v;
497 kid = asymmetric_key_generate_id(v, vlen, "", 0);
498 if (IS_ERR(kid))
499 return PTR_ERR(kid);
500 ctx->cert->skid = kid;
501 pr_debug("subjkeyid %*phN\n", kid->len, kid->data);
502 return 0;
503 }
504
505 if (ctx->last_oid == OID_authorityKeyIdentifier) {
506 /* Get hold of the CA key fingerprint */
507 ctx->raw_akid = v;
508 ctx->raw_akid_size = vlen;
509 return 0;
510 }
511
512 return 0;
513}
514
515/**
516 * x509_decode_time - Decode an X.509 time ASN.1 object
517 * @_t: The time to fill in
518 * @hdrlen: The length of the object header
519 * @tag: The object tag
520 * @value: The object value
521 * @vlen: The size of the object value
522 *
523 * Decode an ASN.1 universal time or generalised time field into a struct the
524 * kernel can handle and check it for validity. The time is decoded thus:
525 *
526 * [RFC5280 ยง4.1.2.5]
527 * CAs conforming to this profile MUST always encode certificate validity
528 * dates through the year 2049 as UTCTime; certificate validity dates in
529 * 2050 or later MUST be encoded as GeneralizedTime. Conforming
530 * applications MUST be able to process validity dates that are encoded in
531 * either UTCTime or GeneralizedTime.
532 */
533int x509_decode_time(time64_t *_t, size_t hdrlen,
534 unsigned char tag,
535 const unsigned char *value, size_t vlen)
536{
537 static const unsigned char month_lengths[] = { 31, 28, 31, 30, 31, 30,
538 31, 31, 30, 31, 30, 31 };
539 const unsigned char *p = value;
540 unsigned year, mon, day, hour, min, sec, mon_len;
541
542#define dec2bin(X) ({ unsigned char x = (X) - '0'; if (x > 9) goto invalid_time; x; })
543#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
544
545 if (tag == ASN1_UNITIM) {
546 /* UTCTime: YYMMDDHHMMSSZ */
547 if (vlen != 13)
548 goto unsupported_time;
549 year = DD2bin(p);
550 if (year >= 50)
551 year += 1900;
552 else
553 year += 2000;
554 } else if (tag == ASN1_GENTIM) {
555 /* GenTime: YYYYMMDDHHMMSSZ */
556 if (vlen != 15)
557 goto unsupported_time;
558 year = DD2bin(p) * 100 + DD2bin(p);
559 if (year >= 1950 && year <= 2049)
560 goto invalid_time;
561 } else {
562 goto unsupported_time;
563 }
564
565 mon = DD2bin(p);
566 day = DD2bin(p);
567 hour = DD2bin(p);
568 min = DD2bin(p);
569 sec = DD2bin(p);
570
571 if (*p != 'Z')
572 goto unsupported_time;
573
574 if (year < 1970 ||
575 mon < 1 || mon > 12)
576 goto invalid_time;
577
578 mon_len = month_lengths[mon - 1];
579 if (mon == 2) {
580 if (year % 4 == 0) {
581 mon_len = 29;
582 if (year % 100 == 0) {
583 mon_len = 28;
584 if (year % 400 == 0)
585 mon_len = 29;
586 }
587 }
588 }
589
590 if (day < 1 || day > mon_len ||
591 hour > 24 || /* ISO 8601 permits 24:00:00 as midnight tomorrow */
592 min > 59 ||
593 sec > 60) /* ISO 8601 permits leap seconds [X.680 46.3] */
594 goto invalid_time;
595
596 *_t = mktime64(year, mon, day, hour, min, sec);
597 return 0;
598
599unsupported_time:
600 pr_debug("Got unsupported time [tag %02x]: '%*phN'\n",
601 tag, (int)vlen, value);
602 return -EBADMSG;
603invalid_time:
604 pr_debug("Got invalid time [tag %02x]: '%*phN'\n",
605 tag, (int)vlen, value);
606 return -EBADMSG;
607}
608EXPORT_SYMBOL_GPL(x509_decode_time);
609
610int x509_note_not_before(void *context, size_t hdrlen,
611 unsigned char tag,
612 const void *value, size_t vlen)
613{
614 struct x509_parse_context *ctx = context;
615 return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
616}
617
618int x509_note_not_after(void *context, size_t hdrlen,
619 unsigned char tag,
620 const void *value, size_t vlen)
621{
622 struct x509_parse_context *ctx = context;
623 return x509_decode_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
624}
625
626/*
627 * Note a key identifier-based AuthorityKeyIdentifier
628 */
629int x509_akid_note_kid(void *context, size_t hdrlen,
630 unsigned char tag,
631 const void *value, size_t vlen)
632{
633 struct x509_parse_context *ctx = context;
634 struct asymmetric_key_id *kid;
635
636 pr_debug("AKID: keyid: %*phN\n", (int)vlen, value);
637
638 if (ctx->cert->sig->auth_ids[1])
639 return 0;
640
641 kid = asymmetric_key_generate_id(value, vlen, "", 0);
642 if (IS_ERR(kid))
643 return PTR_ERR(kid);
644 pr_debug("authkeyid %*phN\n", kid->len, kid->data);
645 ctx->cert->sig->auth_ids[1] = kid;
646 return 0;
647}
648
649/*
650 * Note a directoryName in an AuthorityKeyIdentifier
651 */
652int x509_akid_note_name(void *context, size_t hdrlen,
653 unsigned char tag,
654 const void *value, size_t vlen)
655{
656 struct x509_parse_context *ctx = context;
657
658 pr_debug("AKID: name: %*phN\n", (int)vlen, value);
659
660 ctx->akid_raw_issuer = value;
661 ctx->akid_raw_issuer_size = vlen;
662 return 0;
663}
664
665/*
666 * Note a serial number in an AuthorityKeyIdentifier
667 */
668int x509_akid_note_serial(void *context, size_t hdrlen,
669 unsigned char tag,
670 const void *value, size_t vlen)
671{
672 struct x509_parse_context *ctx = context;
673 struct asymmetric_key_id *kid;
674
675 pr_debug("AKID: serial: %*phN\n", (int)vlen, value);
676
677 if (!ctx->akid_raw_issuer || ctx->cert->sig->auth_ids[0])
678 return 0;
679
680 kid = asymmetric_key_generate_id(value,
681 vlen,
682 ctx->akid_raw_issuer,
683 ctx->akid_raw_issuer_size);
684 if (IS_ERR(kid))
685 return PTR_ERR(kid);
686
687 pr_debug("authkeyid %*phN\n", kid->len, kid->data);
688 ctx->cert->sig->auth_ids[0] = kid;
689 return 0;
690}