3 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
12 #define pr_fmt(fmt) "PKCS7: "fmt
13 #include <linux/kernel.h>
14 #include <linux/export.h>
15 #include <linux/slab.h>
16 #include <linux/err.h>
17 #include <linux/oid_registry.h>
18 #include "public_key.h"
19 #include "pkcs7_parser.h"
20 #include "pkcs7-asn1.h"
22 struct pkcs7_parse_context
{
23 struct pkcs7_message
*msg
; /* Message being constructed */
24 struct pkcs7_signed_info
*sinfo
; /* SignedInfo being constructed */
25 struct pkcs7_signed_info
**ppsinfo
;
26 struct x509_certificate
*certs
; /* Certificate cache */
27 struct x509_certificate
**ppcerts
;
28 unsigned long data
; /* Start of data */
29 enum OID last_oid
; /* Last OID encountered */
32 const void *raw_serial
;
33 unsigned raw_serial_size
;
34 unsigned raw_issuer_size
;
35 const void *raw_issuer
;
37 unsigned raw_skid_size
;
42 * Free a signed information block.
44 static void pkcs7_free_signed_info(struct pkcs7_signed_info
*sinfo
)
47 mpi_free(sinfo
->sig
.mpi
[0]);
48 kfree(sinfo
->sig
.digest
);
49 kfree(sinfo
->signing_cert_id
);
55 * pkcs7_free_message - Free a PKCS#7 message
56 * @pkcs7: The PKCS#7 message to free
58 void pkcs7_free_message(struct pkcs7_message
*pkcs7
)
60 struct x509_certificate
*cert
;
61 struct pkcs7_signed_info
*sinfo
;
64 while (pkcs7
->certs
) {
66 pkcs7
->certs
= cert
->next
;
67 x509_free_certificate(cert
);
71 pkcs7
->crl
= cert
->next
;
72 x509_free_certificate(cert
);
74 while (pkcs7
->signed_infos
) {
75 sinfo
= pkcs7
->signed_infos
;
76 pkcs7
->signed_infos
= sinfo
->next
;
77 pkcs7_free_signed_info(sinfo
);
82 EXPORT_SYMBOL_GPL(pkcs7_free_message
);
85 * Check authenticatedAttributes are provided or not provided consistently.
87 static int pkcs7_check_authattrs(struct pkcs7_message
*msg
)
89 struct pkcs7_signed_info
*sinfo
;
92 sinfo
= msg
->signed_infos
;
96 if (sinfo
->authattrs
) {
98 msg
->have_authattrs
= true;
101 for (sinfo
= sinfo
->next
; sinfo
; sinfo
= sinfo
->next
)
102 if (!!sinfo
->authattrs
!= want
)
107 pr_warn("Inconsistently supplied authAttrs\n");
112 * pkcs7_parse_message - Parse a PKCS#7 message
113 * @data: The raw binary ASN.1 encoded message to be parsed
114 * @datalen: The size of the encoded message
116 struct pkcs7_message
*pkcs7_parse_message(const void *data
, size_t datalen
)
118 struct pkcs7_parse_context
*ctx
;
119 struct pkcs7_message
*msg
= ERR_PTR(-ENOMEM
);
122 ctx
= kzalloc(sizeof(struct pkcs7_parse_context
), GFP_KERNEL
);
125 ctx
->msg
= kzalloc(sizeof(struct pkcs7_message
), GFP_KERNEL
);
128 ctx
->sinfo
= kzalloc(sizeof(struct pkcs7_signed_info
), GFP_KERNEL
);
132 ctx
->data
= (unsigned long)data
;
133 ctx
->ppcerts
= &ctx
->certs
;
134 ctx
->ppsinfo
= &ctx
->msg
->signed_infos
;
136 /* Attempt to decode the signature */
137 ret
= asn1_ber_decoder(&pkcs7_decoder
, ctx
, data
, datalen
);
143 ret
= pkcs7_check_authattrs(ctx
->msg
);
152 struct x509_certificate
*cert
= ctx
->certs
;
153 ctx
->certs
= cert
->next
;
154 x509_free_certificate(cert
);
156 pkcs7_free_signed_info(ctx
->sinfo
);
158 pkcs7_free_message(ctx
->msg
);
164 EXPORT_SYMBOL_GPL(pkcs7_parse_message
);
167 * pkcs7_get_content_data - Get access to the PKCS#7 content
168 * @pkcs7: The preparsed PKCS#7 message to access
169 * @_data: Place to return a pointer to the data
170 * @_data_len: Place to return the data length
171 * @want_wrapper: True if the ASN.1 object header should be included in the data
173 * Get access to the data content of the PKCS#7 message, including, optionally,
174 * the header of the ASN.1 object that contains it. Returns -ENODATA if the
175 * data object was missing from the message.
177 int pkcs7_get_content_data(const struct pkcs7_message
*pkcs7
,
178 const void **_data
, size_t *_data_len
,
186 wrapper
= want_wrapper
? pkcs7
->data_hdrlen
: 0;
187 *_data
= pkcs7
->data
- wrapper
;
188 *_data_len
= pkcs7
->data_len
+ wrapper
;
191 EXPORT_SYMBOL_GPL(pkcs7_get_content_data
);
194 * Note an OID when we find one for later processing when we know how
197 int pkcs7_note_OID(void *context
, size_t hdrlen
,
199 const void *value
, size_t vlen
)
201 struct pkcs7_parse_context
*ctx
= context
;
203 ctx
->last_oid
= look_up_OID(value
, vlen
);
204 if (ctx
->last_oid
== OID__NR
) {
206 sprint_oid(value
, vlen
, buffer
, sizeof(buffer
));
207 printk("PKCS7: Unknown OID: [%lu] %s\n",
208 (unsigned long)value
- ctx
->data
, buffer
);
214 * Note the digest algorithm for the signature.
216 int pkcs7_sig_note_digest_algo(void *context
, size_t hdrlen
,
218 const void *value
, size_t vlen
)
220 struct pkcs7_parse_context
*ctx
= context
;
222 switch (ctx
->last_oid
) {
224 ctx
->sinfo
->sig
.pkey_hash_algo
= HASH_ALGO_MD4
;
227 ctx
->sinfo
->sig
.pkey_hash_algo
= HASH_ALGO_MD5
;
230 ctx
->sinfo
->sig
.pkey_hash_algo
= HASH_ALGO_SHA1
;
233 ctx
->sinfo
->sig
.pkey_hash_algo
= HASH_ALGO_SHA256
;
236 ctx
->sinfo
->sig
.pkey_hash_algo
= HASH_ALGO_SHA384
;
239 ctx
->sinfo
->sig
.pkey_hash_algo
= HASH_ALGO_SHA512
;
242 ctx
->sinfo
->sig
.pkey_hash_algo
= HASH_ALGO_SHA224
;
244 printk("Unsupported digest algo: %u\n", ctx
->last_oid
);
251 * Note the public key algorithm for the signature.
253 int pkcs7_sig_note_pkey_algo(void *context
, size_t hdrlen
,
255 const void *value
, size_t vlen
)
257 struct pkcs7_parse_context
*ctx
= context
;
259 switch (ctx
->last_oid
) {
260 case OID_rsaEncryption
:
261 ctx
->sinfo
->sig
.pkey_algo
= PKEY_ALGO_RSA
;
264 printk("Unsupported pkey algo: %u\n", ctx
->last_oid
);
271 * We only support signed data [RFC2315 sec 9].
273 int pkcs7_check_content_type(void *context
, size_t hdrlen
,
275 const void *value
, size_t vlen
)
277 struct pkcs7_parse_context
*ctx
= context
;
279 if (ctx
->last_oid
!= OID_signed_data
) {
280 pr_warn("Only support pkcs7_signedData type\n");
288 * Note the SignedData version
290 int pkcs7_note_signeddata_version(void *context
, size_t hdrlen
,
292 const void *value
, size_t vlen
)
294 struct pkcs7_parse_context
*ctx
= context
;
300 ctx
->msg
->version
= version
= *(const u8
*)value
;
303 /* PKCS#7 SignedData [RFC2315 sec 9.1]
304 * CMS ver 1 SignedData [RFC5652 sec 5.1]
308 /* CMS ver 3 SignedData [RFC2315 sec 5.1] */
317 pr_warn("Unsupported SignedData version\n");
322 * Note the SignerInfo version
324 int pkcs7_note_signerinfo_version(void *context
, size_t hdrlen
,
326 const void *value
, size_t vlen
)
328 struct pkcs7_parse_context
*ctx
= context
;
334 version
= *(const u8
*)value
;
337 /* PKCS#7 SignerInfo [RFC2315 sec 9.2]
338 * CMS ver 1 SignerInfo [RFC5652 sec 5.3]
340 if (ctx
->msg
->version
!= 1)
341 goto version_mismatch
;
342 ctx
->expect_skid
= false;
345 /* CMS ver 3 SignerInfo [RFC2315 sec 5.3] */
346 if (ctx
->msg
->version
== 1)
347 goto version_mismatch
;
348 ctx
->expect_skid
= true;
357 pr_warn("Unsupported SignerInfo version\n");
360 pr_warn("SignedData-SignerInfo version mismatch\n");
365 * Extract a certificate and store it in the context.
367 int pkcs7_extract_cert(void *context
, size_t hdrlen
,
369 const void *value
, size_t vlen
)
371 struct pkcs7_parse_context
*ctx
= context
;
372 struct x509_certificate
*x509
;
374 if (tag
!= ((ASN1_UNIV
<< 6) | ASN1_CONS_BIT
| ASN1_SEQ
)) {
375 pr_debug("Cert began with tag %02x at %lu\n",
376 tag
, (unsigned long)ctx
- ctx
->data
);
380 /* We have to correct for the header so that the X.509 parser can start
381 * from the beginning. Note that since X.509 stipulates DER, there
382 * probably shouldn't be an EOC trailer - but it is in PKCS#7 (which
388 if (((u8
*)value
)[1] == 0x80)
389 vlen
+= 2; /* Indefinite length - there should be an EOC */
391 x509
= x509_cert_parse(value
, vlen
);
393 return PTR_ERR(x509
);
395 x509
->index
= ++ctx
->x509_index
;
396 pr_debug("Got cert %u for %s\n", x509
->index
, x509
->subject
);
397 pr_debug("- fingerprint %*phN\n", x509
->id
->len
, x509
->id
->data
);
399 *ctx
->ppcerts
= x509
;
400 ctx
->ppcerts
= &x509
->next
;
405 * Save the certificate list
407 int pkcs7_note_certificate_list(void *context
, size_t hdrlen
,
409 const void *value
, size_t vlen
)
411 struct pkcs7_parse_context
*ctx
= context
;
413 pr_devel("Got cert list (%02x)\n", tag
);
415 *ctx
->ppcerts
= ctx
->msg
->certs
;
416 ctx
->msg
->certs
= ctx
->certs
;
418 ctx
->ppcerts
= &ctx
->certs
;
423 * Note the content type.
425 int pkcs7_note_content(void *context
, size_t hdrlen
,
427 const void *value
, size_t vlen
)
429 struct pkcs7_parse_context
*ctx
= context
;
431 if (ctx
->last_oid
!= OID_data
&&
432 ctx
->last_oid
!= OID_msIndirectData
) {
433 pr_warn("Unsupported data type %d\n", ctx
->last_oid
);
437 ctx
->msg
->data_type
= ctx
->last_oid
;
442 * Extract the data from the message and store that and its content type OID in
445 int pkcs7_note_data(void *context
, size_t hdrlen
,
447 const void *value
, size_t vlen
)
449 struct pkcs7_parse_context
*ctx
= context
;
451 pr_debug("Got data\n");
453 ctx
->msg
->data
= value
;
454 ctx
->msg
->data_len
= vlen
;
455 ctx
->msg
->data_hdrlen
= hdrlen
;
460 * Parse authenticated attributes.
462 int pkcs7_sig_note_authenticated_attr(void *context
, size_t hdrlen
,
464 const void *value
, size_t vlen
)
466 struct pkcs7_parse_context
*ctx
= context
;
467 struct pkcs7_signed_info
*sinfo
= ctx
->sinfo
;
468 enum OID content_type
;
470 pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag
, vlen
, (unsigned)vlen
, value
);
472 switch (ctx
->last_oid
) {
473 case OID_contentType
:
474 if (__test_and_set_bit(sinfo_has_content_type
, &sinfo
->aa_set
))
476 content_type
= look_up_OID(value
, vlen
);
477 if (content_type
!= ctx
->msg
->data_type
) {
478 pr_warn("Mismatch between global data type (%d) and sinfo %u (%d)\n",
479 ctx
->msg
->data_type
, sinfo
->index
,
485 case OID_signingTime
:
486 if (__test_and_set_bit(sinfo_has_signing_time
, &sinfo
->aa_set
))
488 /* Should we check that the signing time is consistent
489 * with the signer's X.509 cert?
491 return x509_decode_time(&sinfo
->signing_time
,
492 hdrlen
, tag
, value
, vlen
);
494 case OID_messageDigest
:
495 if (__test_and_set_bit(sinfo_has_message_digest
, &sinfo
->aa_set
))
499 sinfo
->msgdigest
= value
;
500 sinfo
->msgdigest_len
= vlen
;
503 case OID_smimeCapabilites
:
504 if (__test_and_set_bit(sinfo_has_smime_caps
, &sinfo
->aa_set
))
506 if (ctx
->msg
->data_type
!= OID_msIndirectData
) {
507 pr_warn("S/MIME Caps only allowed with Authenticode\n");
508 return -EKEYREJECTED
;
512 /* Microsoft SpOpusInfo seems to be contain cont[0] 16-bit BE
513 * char URLs and cont[1] 8-bit char URLs.
515 * Microsoft StatementType seems to contain a list of OIDs that
516 * are also used as extendedKeyUsage types in X.509 certs.
518 case OID_msSpOpusInfo
:
519 if (__test_and_set_bit(sinfo_has_ms_opus_info
, &sinfo
->aa_set
))
521 goto authenticode_check
;
522 case OID_msStatementType
:
523 if (__test_and_set_bit(sinfo_has_ms_statement_type
, &sinfo
->aa_set
))
526 if (ctx
->msg
->data_type
!= OID_msIndirectData
) {
527 pr_warn("Authenticode AuthAttrs only allowed with Authenticode\n");
528 return -EKEYREJECTED
;
530 /* I'm not sure how to validate these */
537 /* We permit max one item per AuthenticatedAttribute and no repeats */
538 pr_warn("Repeated/multivalue AuthAttrs not permitted\n");
539 return -EKEYREJECTED
;
543 * Note the set of auth attributes for digestion purposes [RFC2315 sec 9.3]
545 int pkcs7_sig_note_set_of_authattrs(void *context
, size_t hdrlen
,
547 const void *value
, size_t vlen
)
549 struct pkcs7_parse_context
*ctx
= context
;
550 struct pkcs7_signed_info
*sinfo
= ctx
->sinfo
;
552 if (!test_bit(sinfo_has_content_type
, &sinfo
->aa_set
) ||
553 !test_bit(sinfo_has_message_digest
, &sinfo
->aa_set
)) {
554 pr_warn("Missing required AuthAttr\n");
558 if (ctx
->msg
->data_type
!= OID_msIndirectData
&&
559 test_bit(sinfo_has_ms_opus_info
, &sinfo
->aa_set
)) {
560 pr_warn("Unexpected Authenticode AuthAttr\n");
564 /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
565 sinfo
->authattrs
= value
- (hdrlen
- 1);
566 sinfo
->authattrs_len
= vlen
+ (hdrlen
- 1);
571 * Note the issuing certificate serial number
573 int pkcs7_sig_note_serial(void *context
, size_t hdrlen
,
575 const void *value
, size_t vlen
)
577 struct pkcs7_parse_context
*ctx
= context
;
578 ctx
->raw_serial
= value
;
579 ctx
->raw_serial_size
= vlen
;
584 * Note the issuer's name
586 int pkcs7_sig_note_issuer(void *context
, size_t hdrlen
,
588 const void *value
, size_t vlen
)
590 struct pkcs7_parse_context
*ctx
= context
;
591 ctx
->raw_issuer
= value
;
592 ctx
->raw_issuer_size
= vlen
;
597 * Note the issuing cert's subjectKeyIdentifier
599 int pkcs7_sig_note_skid(void *context
, size_t hdrlen
,
601 const void *value
, size_t vlen
)
603 struct pkcs7_parse_context
*ctx
= context
;
605 pr_devel("SKID: %02x %zu [%*ph]\n", tag
, vlen
, (unsigned)vlen
, value
);
607 ctx
->raw_skid
= value
;
608 ctx
->raw_skid_size
= vlen
;
613 * Note the signature data
615 int pkcs7_sig_note_signature(void *context
, size_t hdrlen
,
617 const void *value
, size_t vlen
)
619 struct pkcs7_parse_context
*ctx
= context
;
622 BUG_ON(ctx
->sinfo
->sig
.pkey_algo
!= PKEY_ALGO_RSA
);
624 mpi
= mpi_read_raw_data(value
, vlen
);
628 ctx
->sinfo
->sig
.mpi
[0] = mpi
;
629 ctx
->sinfo
->sig
.nr_mpi
= 1;
634 * Note a signature information block
636 int pkcs7_note_signed_info(void *context
, size_t hdrlen
,
638 const void *value
, size_t vlen
)
640 struct pkcs7_parse_context
*ctx
= context
;
641 struct pkcs7_signed_info
*sinfo
= ctx
->sinfo
;
642 struct asymmetric_key_id
*kid
;
644 if (ctx
->msg
->data_type
== OID_msIndirectData
&& !sinfo
->authattrs
) {
645 pr_warn("Authenticode requires AuthAttrs\n");
649 /* Generate cert issuer + serial number key ID */
650 if (!ctx
->expect_skid
) {
651 kid
= asymmetric_key_generate_id(ctx
->raw_serial
,
652 ctx
->raw_serial_size
,
654 ctx
->raw_issuer_size
);
656 kid
= asymmetric_key_generate_id(ctx
->raw_skid
,
663 pr_devel("SINFO KID: %u [%*phN]\n", kid
->len
, kid
->len
, kid
->data
);
665 sinfo
->signing_cert_id
= kid
;
666 sinfo
->index
= ++ctx
->sinfo_index
;
667 *ctx
->ppsinfo
= sinfo
;
668 ctx
->ppsinfo
= &sinfo
->next
;
669 ctx
->sinfo
= kzalloc(sizeof(struct pkcs7_signed_info
), GFP_KERNEL
);