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_keyUsage) {
583		/*
584		 * Get hold of the keyUsage bit string
585		 * v[1] is the encoding size
586		 *       (Expect either 0x02 or 0x03, making it 1 or 2 bytes)
587		 * v[2] is the number of unused bits in the bit string
588		 *       (If >= 3 keyCertSign is missing when v[1] = 0x02)
589		 * v[3] and possibly v[4] contain the bit string
590		 *
591		 * From RFC 5280 4.2.1.3:
592		 *   0x04 is where keyCertSign lands in this bit string
593		 *   0x80 is where digitalSignature lands in this bit string
594		 */
595		if (v[0] != ASN1_BTS)
596			return -EBADMSG;
597		if (vlen < 4)
598			return -EBADMSG;
599		if (v[2] >= 8)
600			return -EBADMSG;
601		if (v[3] & 0x80)
602			ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_DIGITALSIG;
603		if (v[1] == 0x02 && v[2] <= 2 && (v[3] & 0x04))
604			ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_KEYCERTSIGN;
605		else if (vlen > 4 && v[1] == 0x03 && (v[3] & 0x04))
606			ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_KEYCERTSIGN;
607		return 0;
608	}
609
610	if (ctx->last_oid == OID_authorityKeyIdentifier) {
611		/* Get hold of the CA key fingerprint */
612		ctx->raw_akid = v;
613		ctx->raw_akid_size = vlen;
614		return 0;
615	}
616
617	if (ctx->last_oid == OID_basicConstraints) {
618		/*
619		 * Get hold of the basicConstraints
620		 * v[1] is the encoding size
621		 *	(Expect 0x2 or greater, making it 1 or more bytes)
622		 * v[2] is the encoding type
623		 *	(Expect an ASN1_BOOL for the CA)
624		 * v[3] is the contents of the ASN1_BOOL
625		 *      (Expect 1 if the CA is TRUE)
626		 * vlen should match the entire extension size
627		 */
628		if (v[0] != (ASN1_CONS_BIT | ASN1_SEQ))
629			return -EBADMSG;
630		if (vlen < 2)
631			return -EBADMSG;
632		if (v[1] != vlen - 2)
633			return -EBADMSG;
634		if (vlen >= 4 && v[1] != 0 && v[2] == ASN1_BOOL && v[3] == 1)
635			ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_CA;
636		return 0;
637	}
638
639	return 0;
640}
641
642/**
643 * x509_decode_time - Decode an X.509 time ASN.1 object
644 * @_t: The time to fill in
645 * @hdrlen: The length of the object header
646 * @tag: The object tag
647 * @value: The object value
648 * @vlen: The size of the object value
649 *
650 * Decode an ASN.1 universal time or generalised time field into a struct the
651 * kernel can handle and check it for validity.  The time is decoded thus:
652 *
653 *	[RFC5280 §4.1.2.5]
654 *	CAs conforming to this profile MUST always encode certificate validity
655 *	dates through the year 2049 as UTCTime; certificate validity dates in
656 *	2050 or later MUST be encoded as GeneralizedTime.  Conforming
657 *	applications MUST be able to process validity dates that are encoded in
658 *	either UTCTime or GeneralizedTime.
659 */
660int x509_decode_time(time64_t *_t,  size_t hdrlen,
661		     unsigned char tag,
662		     const unsigned char *value, size_t vlen)
663{
664	static const unsigned char month_lengths[] = { 31, 28, 31, 30, 31, 30,
665						       31, 31, 30, 31, 30, 31 };
666	const unsigned char *p = value;
667	unsigned year, mon, day, hour, min, sec, mon_len;
668
669#define dec2bin(X) ({ unsigned char x = (X) - '0'; if (x > 9) goto invalid_time; x; })
670#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
671
672	if (tag == ASN1_UNITIM) {
673		/* UTCTime: YYMMDDHHMMSSZ */
674		if (vlen != 13)
675			goto unsupported_time;
676		year = DD2bin(p);
677		if (year >= 50)
678			year += 1900;
679		else
680			year += 2000;
681	} else if (tag == ASN1_GENTIM) {
682		/* GenTime: YYYYMMDDHHMMSSZ */
683		if (vlen != 15)
684			goto unsupported_time;
685		year = DD2bin(p) * 100 + DD2bin(p);
686		if (year >= 1950 && year <= 2049)
687			goto invalid_time;
688	} else {
689		goto unsupported_time;
690	}
691
692	mon  = DD2bin(p);
693	day = DD2bin(p);
694	hour = DD2bin(p);
695	min  = DD2bin(p);
696	sec  = DD2bin(p);
697
698	if (*p != 'Z')
699		goto unsupported_time;
700
701	if (year < 1970 ||
702	    mon < 1 || mon > 12)
703		goto invalid_time;
704
705	mon_len = month_lengths[mon - 1];
706	if (mon == 2) {
707		if (year % 4 == 0) {
708			mon_len = 29;
709			if (year % 100 == 0) {
710				mon_len = 28;
711				if (year % 400 == 0)
712					mon_len = 29;
713			}
714		}
715	}
716
717	if (day < 1 || day > mon_len ||
718	    hour > 24 || /* ISO 8601 permits 24:00:00 as midnight tomorrow */
719	    min > 59 ||
720	    sec > 60) /* ISO 8601 permits leap seconds [X.680 46.3] */
721		goto invalid_time;
722
723	*_t = mktime64(year, mon, day, hour, min, sec);
724	return 0;
725
726unsupported_time:
727	pr_debug("Got unsupported time [tag %02x]: '%*phN'\n",
728		 tag, (int)vlen, value);
729	return -EBADMSG;
730invalid_time:
731	pr_debug("Got invalid time [tag %02x]: '%*phN'\n",
732		 tag, (int)vlen, value);
733	return -EBADMSG;
734}
735EXPORT_SYMBOL_GPL(x509_decode_time);
736
737int x509_note_not_before(void *context, size_t hdrlen,
738			 unsigned char tag,
739			 const void *value, size_t vlen)
740{
741	struct x509_parse_context *ctx = context;
742	return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
743}
744
745int x509_note_not_after(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	return x509_decode_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
751}
752
753/*
754 * Note a key identifier-based AuthorityKeyIdentifier
755 */
756int x509_akid_note_kid(void *context, size_t hdrlen,
757		       unsigned char tag,
758		       const void *value, size_t vlen)
759{
760	struct x509_parse_context *ctx = context;
761	struct asymmetric_key_id *kid;
762
763	pr_debug("AKID: keyid: %*phN\n", (int)vlen, value);
764
765	if (ctx->cert->sig->auth_ids[1])
766		return 0;
767
768	kid = asymmetric_key_generate_id(value, vlen, "", 0);
769	if (IS_ERR(kid))
770		return PTR_ERR(kid);
771	pr_debug("authkeyid %*phN\n", kid->len, kid->data);
772	ctx->cert->sig->auth_ids[1] = kid;
773	return 0;
774}
775
776/*
777 * Note a directoryName in an AuthorityKeyIdentifier
778 */
779int x509_akid_note_name(void *context, size_t hdrlen,
780			unsigned char tag,
781			const void *value, size_t vlen)
782{
783	struct x509_parse_context *ctx = context;
784
785	pr_debug("AKID: name: %*phN\n", (int)vlen, value);
786
787	ctx->akid_raw_issuer = value;
788	ctx->akid_raw_issuer_size = vlen;
789	return 0;
790}
791
792/*
793 * Note a serial number in an AuthorityKeyIdentifier
794 */
795int x509_akid_note_serial(void *context, size_t hdrlen,
796			  unsigned char tag,
797			  const void *value, size_t vlen)
798{
799	struct x509_parse_context *ctx = context;
800	struct asymmetric_key_id *kid;
801
802	pr_debug("AKID: serial: %*phN\n", (int)vlen, value);
803
804	if (!ctx->akid_raw_issuer || ctx->cert->sig->auth_ids[0])
805		return 0;
806
807	kid = asymmetric_key_generate_id(value,
808					 vlen,
809					 ctx->akid_raw_issuer,
810					 ctx->akid_raw_issuer_size);
811	if (IS_ERR(kid))
812		return PTR_ERR(kid);
813
814	pr_debug("authkeyid %*phN\n", kid->len, kid->data);
815	ctx->cert->sig->auth_ids[0] = kid;
816	return 0;
817}
818