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v5.4
  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}
v6.13.7
  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 __free(x509_free_certificate);
 64	struct x509_parse_context *ctx __free(kfree) = NULL;
 65	struct asymmetric_key_id *kid;
 66	long ret;
 67
 
 68	cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
 69	if (!cert)
 70		return ERR_PTR(-ENOMEM);
 71	cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
 72	if (!cert->pub)
 73		return ERR_PTR(-ENOMEM);
 74	cert->sig = kzalloc(sizeof(struct public_key_signature), GFP_KERNEL);
 75	if (!cert->sig)
 76		return ERR_PTR(-ENOMEM);
 77	ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
 78	if (!ctx)
 79		return ERR_PTR(-ENOMEM);
 80
 81	ctx->cert = cert;
 82	ctx->data = (unsigned long)data;
 83
 84	/* Attempt to decode the certificate */
 85	ret = asn1_ber_decoder(&x509_decoder, ctx, data, datalen);
 86	if (ret < 0)
 87		return ERR_PTR(ret);
 88
 89	/* Decode the AuthorityKeyIdentifier */
 90	if (ctx->raw_akid) {
 91		pr_devel("AKID: %u %*phN\n",
 92			 ctx->raw_akid_size, ctx->raw_akid_size, ctx->raw_akid);
 93		ret = asn1_ber_decoder(&x509_akid_decoder, ctx,
 94				       ctx->raw_akid, ctx->raw_akid_size);
 95		if (ret < 0) {
 96			pr_warn("Couldn't decode AuthKeyIdentifier\n");
 97			return ERR_PTR(ret);
 98		}
 99	}
100
 
101	cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
102	if (!cert->pub->key)
103		return ERR_PTR(-ENOMEM);
104
105	cert->pub->keylen = ctx->key_size;
106
107	cert->pub->params = kmemdup(ctx->params, ctx->params_size, GFP_KERNEL);
108	if (!cert->pub->params)
109		return ERR_PTR(-ENOMEM);
110
111	cert->pub->paramlen = ctx->params_size;
112	cert->pub->algo = ctx->key_algo;
113
114	/* Grab the signature bits */
115	ret = x509_get_sig_params(cert);
116	if (ret < 0)
117		return ERR_PTR(ret);
118
119	/* Generate cert issuer + serial number key ID */
120	kid = asymmetric_key_generate_id(cert->raw_serial,
121					 cert->raw_serial_size,
122					 cert->raw_issuer,
123					 cert->raw_issuer_size);
124	if (IS_ERR(kid))
125		return ERR_CAST(kid);
 
 
126	cert->id = kid;
127
128	/* Detect self-signed certificates */
129	ret = x509_check_for_self_signed(cert);
130	if (ret < 0)
131		return ERR_PTR(ret);
 
 
 
132
133	return_ptr(cert);
 
 
 
 
 
134}
135EXPORT_SYMBOL_GPL(x509_cert_parse);
136
137/*
138 * Note an OID when we find one for later processing when we know how
139 * to interpret it.
140 */
141int x509_note_OID(void *context, size_t hdrlen,
142	     unsigned char tag,
143	     const void *value, size_t vlen)
144{
145	struct x509_parse_context *ctx = context;
146
147	ctx->last_oid = look_up_OID(value, vlen);
148	if (ctx->last_oid == OID__NR) {
149		char buffer[50];
150		sprint_oid(value, vlen, buffer, sizeof(buffer));
151		pr_debug("Unknown OID: [%lu] %s\n",
152			 (unsigned long)value - ctx->data, buffer);
153	}
154	return 0;
155}
156
157/*
158 * Save the position of the TBS data so that we can check the signature over it
159 * later.
160 */
161int x509_note_tbs_certificate(void *context, size_t hdrlen,
162			      unsigned char tag,
163			      const void *value, size_t vlen)
164{
165	struct x509_parse_context *ctx = context;
166
167	pr_debug("x509_note_tbs_certificate(,%zu,%02x,%ld,%zu)!\n",
168		 hdrlen, tag, (unsigned long)value - ctx->data, vlen);
169
170	ctx->cert->tbs = value - hdrlen;
171	ctx->cert->tbs_size = vlen + hdrlen;
172	return 0;
173}
174
175/*
176 * Record the algorithm that was used to sign this certificate.
177 */
178int x509_note_sig_algo(void *context, size_t hdrlen, unsigned char tag,
179		       const void *value, size_t vlen)
 
180{
181	struct x509_parse_context *ctx = context;
182
183	pr_debug("PubKey Algo: %u\n", ctx->last_oid);
184
185	switch (ctx->last_oid) {
 
 
186	default:
187		return -ENOPKG; /* Unsupported combination */
188
 
 
 
 
189	case OID_sha1WithRSAEncryption:
190		ctx->cert->sig->hash_algo = "sha1";
191		goto rsa_pkcs1;
192
193	case OID_sha256WithRSAEncryption:
194		ctx->cert->sig->hash_algo = "sha256";
195		goto rsa_pkcs1;
196
197	case OID_sha384WithRSAEncryption:
198		ctx->cert->sig->hash_algo = "sha384";
199		goto rsa_pkcs1;
200
201	case OID_sha512WithRSAEncryption:
202		ctx->cert->sig->hash_algo = "sha512";
203		goto rsa_pkcs1;
204
205	case OID_sha224WithRSAEncryption:
206		ctx->cert->sig->hash_algo = "sha224";
207		goto rsa_pkcs1;
208
209	case OID_id_ecdsa_with_sha1:
210		ctx->cert->sig->hash_algo = "sha1";
211		goto ecdsa;
212
213	case OID_id_rsassa_pkcs1_v1_5_with_sha3_256:
214		ctx->cert->sig->hash_algo = "sha3-256";
215		goto rsa_pkcs1;
216
217	case OID_id_rsassa_pkcs1_v1_5_with_sha3_384:
218		ctx->cert->sig->hash_algo = "sha3-384";
219		goto rsa_pkcs1;
220
221	case OID_id_rsassa_pkcs1_v1_5_with_sha3_512:
222		ctx->cert->sig->hash_algo = "sha3-512";
223		goto rsa_pkcs1;
224
225	case OID_id_ecdsa_with_sha224:
226		ctx->cert->sig->hash_algo = "sha224";
227		goto ecdsa;
228
229	case OID_id_ecdsa_with_sha256:
230		ctx->cert->sig->hash_algo = "sha256";
231		goto ecdsa;
232
233	case OID_id_ecdsa_with_sha384:
234		ctx->cert->sig->hash_algo = "sha384";
235		goto ecdsa;
236
237	case OID_id_ecdsa_with_sha512:
238		ctx->cert->sig->hash_algo = "sha512";
239		goto ecdsa;
240
241	case OID_id_ecdsa_with_sha3_256:
242		ctx->cert->sig->hash_algo = "sha3-256";
243		goto ecdsa;
244
245	case OID_id_ecdsa_with_sha3_384:
246		ctx->cert->sig->hash_algo = "sha3-384";
247		goto ecdsa;
248
249	case OID_id_ecdsa_with_sha3_512:
250		ctx->cert->sig->hash_algo = "sha3-512";
251		goto ecdsa;
252
253	case OID_gost2012Signature256:
254		ctx->cert->sig->hash_algo = "streebog256";
255		goto ecrdsa;
256
257	case OID_gost2012Signature512:
258		ctx->cert->sig->hash_algo = "streebog512";
259		goto ecrdsa;
260	}
261
262rsa_pkcs1:
263	ctx->cert->sig->pkey_algo = "rsa";
264	ctx->cert->sig->encoding = "pkcs1";
265	ctx->sig_algo = ctx->last_oid;
266	return 0;
267ecrdsa:
268	ctx->cert->sig->pkey_algo = "ecrdsa";
269	ctx->cert->sig->encoding = "raw";
270	ctx->sig_algo = ctx->last_oid;
271	return 0;
272ecdsa:
273	ctx->cert->sig->pkey_algo = "ecdsa";
274	ctx->cert->sig->encoding = "x962";
275	ctx->sig_algo = ctx->last_oid;
276	return 0;
277}
278
279/*
280 * Note the whereabouts and type of the signature.
281 */
282int x509_note_signature(void *context, size_t hdrlen,
283			unsigned char tag,
284			const void *value, size_t vlen)
285{
286	struct x509_parse_context *ctx = context;
287
288	pr_debug("Signature: alg=%u, size=%zu\n", ctx->last_oid, vlen);
289
290	/*
291	 * In X.509 certificates, the signature's algorithm is stored in two
292	 * places: inside the TBSCertificate (the data that is signed), and
293	 * alongside the signature.  These *must* match.
294	 */
295	if (ctx->last_oid != ctx->sig_algo) {
296		pr_warn("signatureAlgorithm (%u) differs from tbsCertificate.signature (%u)\n",
297			ctx->last_oid, ctx->sig_algo);
298		return -EINVAL;
299	}
300
301	if (strcmp(ctx->cert->sig->pkey_algo, "rsa") == 0 ||
302	    strcmp(ctx->cert->sig->pkey_algo, "ecrdsa") == 0 ||
303	    strcmp(ctx->cert->sig->pkey_algo, "ecdsa") == 0) {
304		/* Discard the BIT STRING metadata */
305		if (vlen < 1 || *(const u8 *)value != 0)
306			return -EBADMSG;
307
308		value++;
309		vlen--;
310	}
311
312	ctx->cert->raw_sig = value;
313	ctx->cert->raw_sig_size = vlen;
314	return 0;
315}
316
317/*
318 * Note the certificate serial number
319 */
320int x509_note_serial(void *context, size_t hdrlen,
321		     unsigned char tag,
322		     const void *value, size_t vlen)
323{
324	struct x509_parse_context *ctx = context;
325	ctx->cert->raw_serial = value;
326	ctx->cert->raw_serial_size = vlen;
327	return 0;
328}
329
330/*
331 * Note some of the name segments from which we'll fabricate a name.
332 */
333int x509_extract_name_segment(void *context, size_t hdrlen,
334			      unsigned char tag,
335			      const void *value, size_t vlen)
336{
337	struct x509_parse_context *ctx = context;
338
339	switch (ctx->last_oid) {
340	case OID_commonName:
341		ctx->cn_size = vlen;
342		ctx->cn_offset = (unsigned long)value - ctx->data;
343		break;
344	case OID_organizationName:
345		ctx->o_size = vlen;
346		ctx->o_offset = (unsigned long)value - ctx->data;
347		break;
348	case OID_email_address:
349		ctx->email_size = vlen;
350		ctx->email_offset = (unsigned long)value - ctx->data;
351		break;
352	default:
353		break;
354	}
355
356	return 0;
357}
358
359/*
360 * Fabricate and save the issuer and subject names
361 */
362static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen,
363			       unsigned char tag,
364			       char **_name, size_t vlen)
365{
366	const void *name, *data = (const void *)ctx->data;
367	size_t namesize;
368	char *buffer;
369
370	if (*_name)
371		return -EINVAL;
372
373	/* Empty name string if no material */
374	if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) {
375		buffer = kmalloc(1, GFP_KERNEL);
376		if (!buffer)
377			return -ENOMEM;
378		buffer[0] = 0;
379		goto done;
380	}
381
382	if (ctx->cn_size && ctx->o_size) {
383		/* Consider combining O and CN, but use only the CN if it is
384		 * prefixed by the O, or a significant portion thereof.
385		 */
386		namesize = ctx->cn_size;
387		name = data + ctx->cn_offset;
388		if (ctx->cn_size >= ctx->o_size &&
389		    memcmp(data + ctx->cn_offset, data + ctx->o_offset,
390			   ctx->o_size) == 0)
391			goto single_component;
392		if (ctx->cn_size >= 7 &&
393		    ctx->o_size >= 7 &&
394		    memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0)
395			goto single_component;
396
397		buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1,
398				 GFP_KERNEL);
399		if (!buffer)
400			return -ENOMEM;
401
402		memcpy(buffer,
403		       data + ctx->o_offset, ctx->o_size);
404		buffer[ctx->o_size + 0] = ':';
405		buffer[ctx->o_size + 1] = ' ';
406		memcpy(buffer + ctx->o_size + 2,
407		       data + ctx->cn_offset, ctx->cn_size);
408		buffer[ctx->o_size + 2 + ctx->cn_size] = 0;
409		goto done;
410
411	} else if (ctx->cn_size) {
412		namesize = ctx->cn_size;
413		name = data + ctx->cn_offset;
414	} else if (ctx->o_size) {
415		namesize = ctx->o_size;
416		name = data + ctx->o_offset;
417	} else {
418		namesize = ctx->email_size;
419		name = data + ctx->email_offset;
420	}
421
422single_component:
423	buffer = kmalloc(namesize + 1, GFP_KERNEL);
424	if (!buffer)
425		return -ENOMEM;
426	memcpy(buffer, name, namesize);
427	buffer[namesize] = 0;
428
429done:
430	*_name = buffer;
431	ctx->cn_size = 0;
432	ctx->o_size = 0;
433	ctx->email_size = 0;
434	return 0;
435}
436
437int x509_note_issuer(void *context, size_t hdrlen,
438		     unsigned char tag,
439		     const void *value, size_t vlen)
440{
441	struct x509_parse_context *ctx = context;
442	struct asymmetric_key_id *kid;
443
444	ctx->cert->raw_issuer = value;
445	ctx->cert->raw_issuer_size = vlen;
446
447	if (!ctx->cert->sig->auth_ids[2]) {
448		kid = asymmetric_key_generate_id(value, vlen, "", 0);
449		if (IS_ERR(kid))
450			return PTR_ERR(kid);
451		ctx->cert->sig->auth_ids[2] = kid;
452	}
453
454	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen);
455}
456
457int x509_note_subject(void *context, size_t hdrlen,
458		      unsigned char tag,
459		      const void *value, size_t vlen)
460{
461	struct x509_parse_context *ctx = context;
462	ctx->cert->raw_subject = value;
463	ctx->cert->raw_subject_size = vlen;
464	return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen);
465}
466
467/*
468 * Extract the parameters for the public key
469 */
470int x509_note_params(void *context, size_t hdrlen,
471		     unsigned char tag,
472		     const void *value, size_t vlen)
473{
474	struct x509_parse_context *ctx = context;
475
476	/*
477	 * AlgorithmIdentifier is used three times in the x509, we should skip
478	 * first and ignore third, using second one which is after subject and
479	 * before subjectPublicKey.
480	 */
481	if (!ctx->cert->raw_subject || ctx->key)
482		return 0;
483	ctx->params = value - hdrlen;
484	ctx->params_size = vlen + hdrlen;
485	return 0;
486}
487
488/*
489 * Extract the data for the public key algorithm
490 */
491int x509_extract_key_data(void *context, size_t hdrlen,
492			  unsigned char tag,
493			  const void *value, size_t vlen)
494{
495	struct x509_parse_context *ctx = context;
496	enum OID oid;
497
498	ctx->key_algo = ctx->last_oid;
499	switch (ctx->last_oid) {
500	case OID_rsaEncryption:
501		ctx->cert->pub->pkey_algo = "rsa";
502		break;
503	case OID_gost2012PKey256:
504	case OID_gost2012PKey512:
505		ctx->cert->pub->pkey_algo = "ecrdsa";
506		break;
507	case OID_id_ecPublicKey:
508		if (parse_OID(ctx->params, ctx->params_size, &oid) != 0)
509			return -EBADMSG;
510
511		switch (oid) {
512		case OID_id_prime192v1:
513			ctx->cert->pub->pkey_algo = "ecdsa-nist-p192";
514			break;
515		case OID_id_prime256v1:
516			ctx->cert->pub->pkey_algo = "ecdsa-nist-p256";
517			break;
518		case OID_id_ansip384r1:
519			ctx->cert->pub->pkey_algo = "ecdsa-nist-p384";
520			break;
521		case OID_id_ansip521r1:
522			ctx->cert->pub->pkey_algo = "ecdsa-nist-p521";
523			break;
524		default:
525			return -ENOPKG;
526		}
527		break;
528	default:
529		return -ENOPKG;
530	}
531
532	/* Discard the BIT STRING metadata */
533	if (vlen < 1 || *(const u8 *)value != 0)
534		return -EBADMSG;
535	ctx->key = value + 1;
536	ctx->key_size = vlen - 1;
537	return 0;
538}
539
540/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
541#define SEQ_TAG_KEYID (ASN1_CONT << 6)
542
543/*
544 * Process certificate extensions that are used to qualify the certificate.
545 */
546int x509_process_extension(void *context, size_t hdrlen,
547			   unsigned char tag,
548			   const void *value, size_t vlen)
549{
550	struct x509_parse_context *ctx = context;
551	struct asymmetric_key_id *kid;
552	const unsigned char *v = value;
553
554	pr_debug("Extension: %u\n", ctx->last_oid);
555
556	if (ctx->last_oid == OID_subjectKeyIdentifier) {
557		/* Get hold of the key fingerprint */
558		if (ctx->cert->skid || vlen < 3)
559			return -EBADMSG;
560		if (v[0] != ASN1_OTS || v[1] != vlen - 2)
561			return -EBADMSG;
562		v += 2;
563		vlen -= 2;
564
565		ctx->cert->raw_skid_size = vlen;
566		ctx->cert->raw_skid = v;
567		kid = asymmetric_key_generate_id(v, vlen, "", 0);
568		if (IS_ERR(kid))
569			return PTR_ERR(kid);
570		ctx->cert->skid = kid;
571		pr_debug("subjkeyid %*phN\n", kid->len, kid->data);
572		return 0;
573	}
574
575	if (ctx->last_oid == OID_keyUsage) {
576		/*
577		 * Get hold of the keyUsage bit string
578		 * v[1] is the encoding size
579		 *       (Expect either 0x02 or 0x03, making it 1 or 2 bytes)
580		 * v[2] is the number of unused bits in the bit string
581		 *       (If >= 3 keyCertSign is missing when v[1] = 0x02)
582		 * v[3] and possibly v[4] contain the bit string
583		 *
584		 * From RFC 5280 4.2.1.3:
585		 *   0x04 is where keyCertSign lands in this bit string
586		 *   0x80 is where digitalSignature lands in this bit string
587		 */
588		if (v[0] != ASN1_BTS)
589			return -EBADMSG;
590		if (vlen < 4)
591			return -EBADMSG;
592		if (v[2] >= 8)
593			return -EBADMSG;
594		if (v[3] & 0x80)
595			ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_DIGITALSIG;
596		if (v[1] == 0x02 && v[2] <= 2 && (v[3] & 0x04))
597			ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_KEYCERTSIGN;
598		else if (vlen > 4 && v[1] == 0x03 && (v[3] & 0x04))
599			ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_KEYCERTSIGN;
600		return 0;
601	}
602
603	if (ctx->last_oid == OID_authorityKeyIdentifier) {
604		/* Get hold of the CA key fingerprint */
605		ctx->raw_akid = v;
606		ctx->raw_akid_size = vlen;
607		return 0;
608	}
609
610	if (ctx->last_oid == OID_basicConstraints) {
611		/*
612		 * Get hold of the basicConstraints
613		 * v[1] is the encoding size
614		 *	(Expect 0x2 or greater, making it 1 or more bytes)
615		 * v[2] is the encoding type
616		 *	(Expect an ASN1_BOOL for the CA)
617		 * v[3] is the contents of the ASN1_BOOL
618		 *      (Expect 1 if the CA is TRUE)
619		 * vlen should match the entire extension size
620		 */
621		if (v[0] != (ASN1_CONS_BIT | ASN1_SEQ))
622			return -EBADMSG;
623		if (vlen < 2)
624			return -EBADMSG;
625		if (v[1] != vlen - 2)
626			return -EBADMSG;
627		if (vlen >= 4 && v[1] != 0 && v[2] == ASN1_BOOL && v[3] == 1)
628			ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_CA;
629		return 0;
630	}
631
632	return 0;
633}
634
635/**
636 * x509_decode_time - Decode an X.509 time ASN.1 object
637 * @_t: The time to fill in
638 * @hdrlen: The length of the object header
639 * @tag: The object tag
640 * @value: The object value
641 * @vlen: The size of the object value
642 *
643 * Decode an ASN.1 universal time or generalised time field into a struct the
644 * kernel can handle and check it for validity.  The time is decoded thus:
645 *
646 *	[RFC5280 ยง4.1.2.5]
647 *	CAs conforming to this profile MUST always encode certificate validity
648 *	dates through the year 2049 as UTCTime; certificate validity dates in
649 *	2050 or later MUST be encoded as GeneralizedTime.  Conforming
650 *	applications MUST be able to process validity dates that are encoded in
651 *	either UTCTime or GeneralizedTime.
652 */
653int x509_decode_time(time64_t *_t,  size_t hdrlen,
654		     unsigned char tag,
655		     const unsigned char *value, size_t vlen)
656{
657	static const unsigned char month_lengths[] = { 31, 28, 31, 30, 31, 30,
658						       31, 31, 30, 31, 30, 31 };
659	const unsigned char *p = value;
660	unsigned year, mon, day, hour, min, sec, mon_len;
661
662#define dec2bin(X) ({ unsigned char x = (X) - '0'; if (x > 9) goto invalid_time; x; })
663#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
664
665	if (tag == ASN1_UNITIM) {
666		/* UTCTime: YYMMDDHHMMSSZ */
667		if (vlen != 13)
668			goto unsupported_time;
669		year = DD2bin(p);
670		if (year >= 50)
671			year += 1900;
672		else
673			year += 2000;
674	} else if (tag == ASN1_GENTIM) {
675		/* GenTime: YYYYMMDDHHMMSSZ */
676		if (vlen != 15)
677			goto unsupported_time;
678		year = DD2bin(p) * 100 + DD2bin(p);
679		if (year >= 1950 && year <= 2049)
680			goto invalid_time;
681	} else {
682		goto unsupported_time;
683	}
684
685	mon  = DD2bin(p);
686	day = DD2bin(p);
687	hour = DD2bin(p);
688	min  = DD2bin(p);
689	sec  = DD2bin(p);
690
691	if (*p != 'Z')
692		goto unsupported_time;
693
694	if (year < 1970 ||
695	    mon < 1 || mon > 12)
696		goto invalid_time;
697
698	mon_len = month_lengths[mon - 1];
699	if (mon == 2) {
700		if (year % 4 == 0) {
701			mon_len = 29;
702			if (year % 100 == 0) {
703				mon_len = 28;
704				if (year % 400 == 0)
705					mon_len = 29;
706			}
707		}
708	}
709
710	if (day < 1 || day > mon_len ||
711	    hour > 24 || /* ISO 8601 permits 24:00:00 as midnight tomorrow */
712	    min > 59 ||
713	    sec > 60) /* ISO 8601 permits leap seconds [X.680 46.3] */
714		goto invalid_time;
715
716	*_t = mktime64(year, mon, day, hour, min, sec);
717	return 0;
718
719unsupported_time:
720	pr_debug("Got unsupported time [tag %02x]: '%*phN'\n",
721		 tag, (int)vlen, value);
722	return -EBADMSG;
723invalid_time:
724	pr_debug("Got invalid time [tag %02x]: '%*phN'\n",
725		 tag, (int)vlen, value);
726	return -EBADMSG;
727}
728EXPORT_SYMBOL_GPL(x509_decode_time);
729
730int x509_note_not_before(void *context, size_t hdrlen,
731			 unsigned char tag,
732			 const void *value, size_t vlen)
733{
734	struct x509_parse_context *ctx = context;
735	return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
736}
737
738int x509_note_not_after(void *context, size_t hdrlen,
739			unsigned char tag,
740			const void *value, size_t vlen)
741{
742	struct x509_parse_context *ctx = context;
743	return x509_decode_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
744}
745
746/*
747 * Note a key identifier-based AuthorityKeyIdentifier
748 */
749int x509_akid_note_kid(void *context, size_t hdrlen,
750		       unsigned char tag,
751		       const void *value, size_t vlen)
752{
753	struct x509_parse_context *ctx = context;
754	struct asymmetric_key_id *kid;
755
756	pr_debug("AKID: keyid: %*phN\n", (int)vlen, value);
757
758	if (ctx->cert->sig->auth_ids[1])
759		return 0;
760
761	kid = asymmetric_key_generate_id(value, vlen, "", 0);
762	if (IS_ERR(kid))
763		return PTR_ERR(kid);
764	pr_debug("authkeyid %*phN\n", kid->len, kid->data);
765	ctx->cert->sig->auth_ids[1] = kid;
766	return 0;
767}
768
769/*
770 * Note a directoryName in an AuthorityKeyIdentifier
771 */
772int x509_akid_note_name(void *context, size_t hdrlen,
773			unsigned char tag,
774			const void *value, size_t vlen)
775{
776	struct x509_parse_context *ctx = context;
777
778	pr_debug("AKID: name: %*phN\n", (int)vlen, value);
779
780	ctx->akid_raw_issuer = value;
781	ctx->akid_raw_issuer_size = vlen;
782	return 0;
783}
784
785/*
786 * Note a serial number in an AuthorityKeyIdentifier
787 */
788int x509_akid_note_serial(void *context, size_t hdrlen,
789			  unsigned char tag,
790			  const void *value, size_t vlen)
791{
792	struct x509_parse_context *ctx = context;
793	struct asymmetric_key_id *kid;
794
795	pr_debug("AKID: serial: %*phN\n", (int)vlen, value);
796
797	if (!ctx->akid_raw_issuer || ctx->cert->sig->auth_ids[0])
798		return 0;
799
800	kid = asymmetric_key_generate_id(value,
801					 vlen,
802					 ctx->akid_raw_issuer,
803					 ctx->akid_raw_issuer_size);
804	if (IS_ERR(kid))
805		return PTR_ERR(kid);
806
807	pr_debug("authkeyid %*phN\n", kid->len, kid->data);
808	ctx->cert->sig->auth_ids[0] = kid;
809	return 0;
810}