1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #define pr_fmt(fmt) "PKCS7: "fmt
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/export.h>
12 #include <linux/slab.h>
13 #include <linux/err.h>
14 #include <linux/oid_registry.h>
15 #include <crypto/public_key.h>
16 #include "pkcs7_parser.h"
17 #include "pkcs7.asn1.h"
19 MODULE_DESCRIPTION("PKCS#7 parser");
20 MODULE_AUTHOR("Red Hat, Inc.");
21 MODULE_LICENSE("GPL");
23 struct pkcs7_parse_context {
24 struct pkcs7_message *msg; /* Message being constructed */
25 struct pkcs7_signed_info *sinfo; /* SignedInfo being constructed */
26 struct pkcs7_signed_info **ppsinfo;
27 struct x509_certificate *certs; /* Certificate cache */
28 struct x509_certificate **ppcerts;
29 unsigned long data; /* Start of data */
30 enum OID last_oid; /* Last OID encountered */
33 const void *raw_serial;
34 unsigned raw_serial_size;
35 unsigned raw_issuer_size;
36 const void *raw_issuer;
38 unsigned raw_skid_size;
43 * Free a signed information block.
45 static void pkcs7_free_signed_info(struct pkcs7_signed_info *sinfo)
48 public_key_signature_free(sinfo->sig);
54 * pkcs7_free_message - Free a PKCS#7 message
55 * @pkcs7: The PKCS#7 message to free
57 void pkcs7_free_message(struct pkcs7_message *pkcs7)
59 struct x509_certificate *cert;
60 struct pkcs7_signed_info *sinfo;
63 while (pkcs7->certs) {
65 pkcs7->certs = cert->next;
66 x509_free_certificate(cert);
70 pkcs7->crl = cert->next;
71 x509_free_certificate(cert);
73 while (pkcs7->signed_infos) {
74 sinfo = pkcs7->signed_infos;
75 pkcs7->signed_infos = sinfo->next;
76 pkcs7_free_signed_info(sinfo);
81 EXPORT_SYMBOL_GPL(pkcs7_free_message);
84 * Check authenticatedAttributes are provided or not provided consistently.
86 static int pkcs7_check_authattrs(struct pkcs7_message *msg)
88 struct pkcs7_signed_info *sinfo;
91 sinfo = msg->signed_infos;
95 if (sinfo->authattrs) {
97 msg->have_authattrs = true;
100 for (sinfo = sinfo->next; sinfo; sinfo = sinfo->next)
101 if (!!sinfo->authattrs != want)
106 pr_warn("Inconsistently supplied authAttrs\n");
111 * pkcs7_parse_message - Parse a PKCS#7 message
112 * @data: The raw binary ASN.1 encoded message to be parsed
113 * @datalen: The size of the encoded message
115 struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
117 struct pkcs7_parse_context *ctx;
118 struct pkcs7_message *msg = ERR_PTR(-ENOMEM);
121 ctx = kzalloc(sizeof(struct pkcs7_parse_context), GFP_KERNEL);
124 ctx->msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
127 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
130 ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
132 if (!ctx->sinfo->sig)
135 ctx->data = (unsigned long)data;
136 ctx->ppcerts = &ctx->certs;
137 ctx->ppsinfo = &ctx->msg->signed_infos;
139 /* Attempt to decode the signature */
140 ret = asn1_ber_decoder(&pkcs7_decoder, ctx, data, datalen);
146 ret = pkcs7_check_authattrs(ctx->msg);
157 struct x509_certificate *cert = ctx->certs;
158 ctx->certs = cert->next;
159 x509_free_certificate(cert);
162 pkcs7_free_signed_info(ctx->sinfo);
164 pkcs7_free_message(ctx->msg);
170 EXPORT_SYMBOL_GPL(pkcs7_parse_message);
173 * pkcs7_get_content_data - Get access to the PKCS#7 content
174 * @pkcs7: The preparsed PKCS#7 message to access
175 * @_data: Place to return a pointer to the data
176 * @_data_len: Place to return the data length
177 * @_headerlen: Size of ASN.1 header not included in _data
179 * Get access to the data content of the PKCS#7 message. The size of the
180 * header of the ASN.1 object that contains it is also provided and can be used
181 * to adjust *_data and *_data_len to get the entire object.
183 * Returns -ENODATA if the data object was missing from the message.
185 int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
186 const void **_data, size_t *_data_len,
192 *_data = pkcs7->data;
193 *_data_len = pkcs7->data_len;
195 *_headerlen = pkcs7->data_hdrlen;
198 EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
201 * Note an OID when we find one for later processing when we know how
204 int pkcs7_note_OID(void *context, size_t hdrlen,
206 const void *value, size_t vlen)
208 struct pkcs7_parse_context *ctx = context;
210 ctx->last_oid = look_up_OID(value, vlen);
211 if (ctx->last_oid == OID__NR) {
213 sprint_oid(value, vlen, buffer, sizeof(buffer));
214 printk("PKCS7: Unknown OID: [%lu] %s\n",
215 (unsigned long)value - ctx->data, buffer);
221 * Note the digest algorithm for the signature.
223 int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
225 const void *value, size_t vlen)
227 struct pkcs7_parse_context *ctx = context;
229 switch (ctx->last_oid) {
231 ctx->sinfo->sig->hash_algo = "md4";
234 ctx->sinfo->sig->hash_algo = "md5";
237 ctx->sinfo->sig->hash_algo = "sha1";
240 ctx->sinfo->sig->hash_algo = "sha256";
243 ctx->sinfo->sig->hash_algo = "sha384";
246 ctx->sinfo->sig->hash_algo = "sha512";
249 ctx->sinfo->sig->hash_algo = "sha224";
252 printk("Unsupported digest algo: %u\n", ctx->last_oid);
259 * Note the public key algorithm for the signature.
261 int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
263 const void *value, size_t vlen)
265 struct pkcs7_parse_context *ctx = context;
267 switch (ctx->last_oid) {
268 case OID_rsaEncryption:
269 ctx->sinfo->sig->pkey_algo = "rsa";
270 ctx->sinfo->sig->encoding = "pkcs1";
272 case OID_id_ecdsa_with_sha1:
273 case OID_id_ecdsa_with_sha224:
274 case OID_id_ecdsa_with_sha256:
275 case OID_id_ecdsa_with_sha384:
276 case OID_id_ecdsa_with_sha512:
277 ctx->sinfo->sig->pkey_algo = "ecdsa";
278 ctx->sinfo->sig->encoding = "x962";
281 printk("Unsupported pkey algo: %u\n", ctx->last_oid);
288 * We only support signed data [RFC2315 sec 9].
290 int pkcs7_check_content_type(void *context, size_t hdrlen,
292 const void *value, size_t vlen)
294 struct pkcs7_parse_context *ctx = context;
296 if (ctx->last_oid != OID_signed_data) {
297 pr_warn("Only support pkcs7_signedData type\n");
305 * Note the SignedData version
307 int pkcs7_note_signeddata_version(void *context, size_t hdrlen,
309 const void *value, size_t vlen)
311 struct pkcs7_parse_context *ctx = context;
317 ctx->msg->version = version = *(const u8 *)value;
320 /* PKCS#7 SignedData [RFC2315 sec 9.1]
321 * CMS ver 1 SignedData [RFC5652 sec 5.1]
325 /* CMS ver 3 SignedData [RFC2315 sec 5.1] */
334 pr_warn("Unsupported SignedData version\n");
339 * Note the SignerInfo version
341 int pkcs7_note_signerinfo_version(void *context, size_t hdrlen,
343 const void *value, size_t vlen)
345 struct pkcs7_parse_context *ctx = context;
351 version = *(const u8 *)value;
354 /* PKCS#7 SignerInfo [RFC2315 sec 9.2]
355 * CMS ver 1 SignerInfo [RFC5652 sec 5.3]
357 if (ctx->msg->version != 1)
358 goto version_mismatch;
359 ctx->expect_skid = false;
362 /* CMS ver 3 SignerInfo [RFC2315 sec 5.3] */
363 if (ctx->msg->version == 1)
364 goto version_mismatch;
365 ctx->expect_skid = true;
374 pr_warn("Unsupported SignerInfo version\n");
377 pr_warn("SignedData-SignerInfo version mismatch\n");
382 * Extract a certificate and store it in the context.
384 int pkcs7_extract_cert(void *context, size_t hdrlen,
386 const void *value, size_t vlen)
388 struct pkcs7_parse_context *ctx = context;
389 struct x509_certificate *x509;
391 if (tag != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | ASN1_SEQ)) {
392 pr_debug("Cert began with tag %02x at %lu\n",
393 tag, (unsigned long)ctx - ctx->data);
397 /* We have to correct for the header so that the X.509 parser can start
398 * from the beginning. Note that since X.509 stipulates DER, there
399 * probably shouldn't be an EOC trailer - but it is in PKCS#7 (which
405 if (((u8*)value)[1] == 0x80)
406 vlen += 2; /* Indefinite length - there should be an EOC */
408 x509 = x509_cert_parse(value, vlen);
410 return PTR_ERR(x509);
412 x509->index = ++ctx->x509_index;
413 pr_debug("Got cert %u for %s\n", x509->index, x509->subject);
414 pr_debug("- fingerprint %*phN\n", x509->id->len, x509->id->data);
416 *ctx->ppcerts = x509;
417 ctx->ppcerts = &x509->next;
422 * Save the certificate list
424 int pkcs7_note_certificate_list(void *context, size_t hdrlen,
426 const void *value, size_t vlen)
428 struct pkcs7_parse_context *ctx = context;
430 pr_devel("Got cert list (%02x)\n", tag);
432 *ctx->ppcerts = ctx->msg->certs;
433 ctx->msg->certs = ctx->certs;
435 ctx->ppcerts = &ctx->certs;
440 * Note the content type.
442 int pkcs7_note_content(void *context, size_t hdrlen,
444 const void *value, size_t vlen)
446 struct pkcs7_parse_context *ctx = context;
448 if (ctx->last_oid != OID_data &&
449 ctx->last_oid != OID_msIndirectData) {
450 pr_warn("Unsupported data type %d\n", ctx->last_oid);
454 ctx->msg->data_type = ctx->last_oid;
459 * Extract the data from the message and store that and its content type OID in
462 int pkcs7_note_data(void *context, size_t hdrlen,
464 const void *value, size_t vlen)
466 struct pkcs7_parse_context *ctx = context;
468 pr_debug("Got data\n");
470 ctx->msg->data = value;
471 ctx->msg->data_len = vlen;
472 ctx->msg->data_hdrlen = hdrlen;
477 * Parse authenticated attributes.
479 int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
481 const void *value, size_t vlen)
483 struct pkcs7_parse_context *ctx = context;
484 struct pkcs7_signed_info *sinfo = ctx->sinfo;
485 enum OID content_type;
487 pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
489 switch (ctx->last_oid) {
490 case OID_contentType:
491 if (__test_and_set_bit(sinfo_has_content_type, &sinfo->aa_set))
493 content_type = look_up_OID(value, vlen);
494 if (content_type != ctx->msg->data_type) {
495 pr_warn("Mismatch between global data type (%d) and sinfo %u (%d)\n",
496 ctx->msg->data_type, sinfo->index,
502 case OID_signingTime:
503 if (__test_and_set_bit(sinfo_has_signing_time, &sinfo->aa_set))
505 /* Should we check that the signing time is consistent
506 * with the signer's X.509 cert?
508 return x509_decode_time(&sinfo->signing_time,
509 hdrlen, tag, value, vlen);
511 case OID_messageDigest:
512 if (__test_and_set_bit(sinfo_has_message_digest, &sinfo->aa_set))
516 sinfo->msgdigest = value;
517 sinfo->msgdigest_len = vlen;
520 case OID_smimeCapabilites:
521 if (__test_and_set_bit(sinfo_has_smime_caps, &sinfo->aa_set))
523 if (ctx->msg->data_type != OID_msIndirectData) {
524 pr_warn("S/MIME Caps only allowed with Authenticode\n");
525 return -EKEYREJECTED;
529 /* Microsoft SpOpusInfo seems to be contain cont[0] 16-bit BE
530 * char URLs and cont[1] 8-bit char URLs.
532 * Microsoft StatementType seems to contain a list of OIDs that
533 * are also used as extendedKeyUsage types in X.509 certs.
535 case OID_msSpOpusInfo:
536 if (__test_and_set_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))
538 goto authenticode_check;
539 case OID_msStatementType:
540 if (__test_and_set_bit(sinfo_has_ms_statement_type, &sinfo->aa_set))
543 if (ctx->msg->data_type != OID_msIndirectData) {
544 pr_warn("Authenticode AuthAttrs only allowed with Authenticode\n");
545 return -EKEYREJECTED;
547 /* I'm not sure how to validate these */
554 /* We permit max one item per AuthenticatedAttribute and no repeats */
555 pr_warn("Repeated/multivalue AuthAttrs not permitted\n");
556 return -EKEYREJECTED;
560 * Note the set of auth attributes for digestion purposes [RFC2315 sec 9.3]
562 int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
564 const void *value, size_t vlen)
566 struct pkcs7_parse_context *ctx = context;
567 struct pkcs7_signed_info *sinfo = ctx->sinfo;
569 if (!test_bit(sinfo_has_content_type, &sinfo->aa_set) ||
570 !test_bit(sinfo_has_message_digest, &sinfo->aa_set)) {
571 pr_warn("Missing required AuthAttr\n");
575 if (ctx->msg->data_type != OID_msIndirectData &&
576 test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set)) {
577 pr_warn("Unexpected Authenticode AuthAttr\n");
581 /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
582 sinfo->authattrs = value - (hdrlen - 1);
583 sinfo->authattrs_len = vlen + (hdrlen - 1);
588 * Note the issuing certificate serial number
590 int pkcs7_sig_note_serial(void *context, size_t hdrlen,
592 const void *value, size_t vlen)
594 struct pkcs7_parse_context *ctx = context;
595 ctx->raw_serial = value;
596 ctx->raw_serial_size = vlen;
601 * Note the issuer's name
603 int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
605 const void *value, size_t vlen)
607 struct pkcs7_parse_context *ctx = context;
608 ctx->raw_issuer = value;
609 ctx->raw_issuer_size = vlen;
614 * Note the issuing cert's subjectKeyIdentifier
616 int pkcs7_sig_note_skid(void *context, size_t hdrlen,
618 const void *value, size_t vlen)
620 struct pkcs7_parse_context *ctx = context;
622 pr_devel("SKID: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
624 ctx->raw_skid = value;
625 ctx->raw_skid_size = vlen;
630 * Note the signature data
632 int pkcs7_sig_note_signature(void *context, size_t hdrlen,
634 const void *value, size_t vlen)
636 struct pkcs7_parse_context *ctx = context;
638 ctx->sinfo->sig->s = kmemdup(value, vlen, GFP_KERNEL);
639 if (!ctx->sinfo->sig->s)
642 ctx->sinfo->sig->s_size = vlen;
647 * Note a signature information block
649 int pkcs7_note_signed_info(void *context, size_t hdrlen,
651 const void *value, size_t vlen)
653 struct pkcs7_parse_context *ctx = context;
654 struct pkcs7_signed_info *sinfo = ctx->sinfo;
655 struct asymmetric_key_id *kid;
657 if (ctx->msg->data_type == OID_msIndirectData && !sinfo->authattrs) {
658 pr_warn("Authenticode requires AuthAttrs\n");
662 /* Generate cert issuer + serial number key ID */
663 if (!ctx->expect_skid) {
664 kid = asymmetric_key_generate_id(ctx->raw_serial,
665 ctx->raw_serial_size,
667 ctx->raw_issuer_size);
669 kid = asymmetric_key_generate_id(ctx->raw_skid,
676 pr_devel("SINFO KID: %u [%*phN]\n", kid->len, kid->len, kid->data);
678 sinfo->sig->auth_ids[0] = kid;
679 sinfo->index = ++ctx->sinfo_index;
680 *ctx->ppsinfo = sinfo;
681 ctx->ppsinfo = &sinfo->next;
682 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
685 ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
687 if (!ctx->sinfo->sig)