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 ctx->sinfo->sig->hash_algo = "sm3";
254 case OID_gost2012Digest256:
255 ctx->sinfo->sig->hash_algo = "streebog256";
257 case OID_gost2012Digest512:
258 ctx->sinfo->sig->hash_algo = "streebog512";
261 printk("Unsupported digest algo: %u\n", ctx->last_oid);
268 * Note the public key algorithm for the signature.
270 int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
272 const void *value, size_t vlen)
274 struct pkcs7_parse_context *ctx = context;
276 switch (ctx->last_oid) {
277 case OID_rsaEncryption:
278 ctx->sinfo->sig->pkey_algo = "rsa";
279 ctx->sinfo->sig->encoding = "pkcs1";
281 case OID_id_ecdsa_with_sha1:
282 case OID_id_ecdsa_with_sha224:
283 case OID_id_ecdsa_with_sha256:
284 case OID_id_ecdsa_with_sha384:
285 case OID_id_ecdsa_with_sha512:
286 ctx->sinfo->sig->pkey_algo = "ecdsa";
287 ctx->sinfo->sig->encoding = "x962";
289 case OID_SM2_with_SM3:
290 ctx->sinfo->sig->pkey_algo = "sm2";
291 ctx->sinfo->sig->encoding = "raw";
293 case OID_gost2012PKey256:
294 case OID_gost2012PKey512:
295 ctx->sinfo->sig->pkey_algo = "ecrdsa";
296 ctx->sinfo->sig->encoding = "raw";
299 printk("Unsupported pkey algo: %u\n", ctx->last_oid);
306 * We only support signed data [RFC2315 sec 9].
308 int pkcs7_check_content_type(void *context, size_t hdrlen,
310 const void *value, size_t vlen)
312 struct pkcs7_parse_context *ctx = context;
314 if (ctx->last_oid != OID_signed_data) {
315 pr_warn("Only support pkcs7_signedData type\n");
323 * Note the SignedData version
325 int pkcs7_note_signeddata_version(void *context, size_t hdrlen,
327 const void *value, size_t vlen)
329 struct pkcs7_parse_context *ctx = context;
335 ctx->msg->version = version = *(const u8 *)value;
338 /* PKCS#7 SignedData [RFC2315 sec 9.1]
339 * CMS ver 1 SignedData [RFC5652 sec 5.1]
343 /* CMS ver 3 SignedData [RFC2315 sec 5.1] */
352 pr_warn("Unsupported SignedData version\n");
357 * Note the SignerInfo version
359 int pkcs7_note_signerinfo_version(void *context, size_t hdrlen,
361 const void *value, size_t vlen)
363 struct pkcs7_parse_context *ctx = context;
369 version = *(const u8 *)value;
372 /* PKCS#7 SignerInfo [RFC2315 sec 9.2]
373 * CMS ver 1 SignerInfo [RFC5652 sec 5.3]
375 if (ctx->msg->version != 1)
376 goto version_mismatch;
377 ctx->expect_skid = false;
380 /* CMS ver 3 SignerInfo [RFC2315 sec 5.3] */
381 if (ctx->msg->version == 1)
382 goto version_mismatch;
383 ctx->expect_skid = true;
392 pr_warn("Unsupported SignerInfo version\n");
395 pr_warn("SignedData-SignerInfo version mismatch\n");
400 * Extract a certificate and store it in the context.
402 int pkcs7_extract_cert(void *context, size_t hdrlen,
404 const void *value, size_t vlen)
406 struct pkcs7_parse_context *ctx = context;
407 struct x509_certificate *x509;
409 if (tag != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | ASN1_SEQ)) {
410 pr_debug("Cert began with tag %02x at %lu\n",
411 tag, (unsigned long)ctx - ctx->data);
415 /* We have to correct for the header so that the X.509 parser can start
416 * from the beginning. Note that since X.509 stipulates DER, there
417 * probably shouldn't be an EOC trailer - but it is in PKCS#7 (which
423 if (((u8*)value)[1] == 0x80)
424 vlen += 2; /* Indefinite length - there should be an EOC */
426 x509 = x509_cert_parse(value, vlen);
428 return PTR_ERR(x509);
430 x509->index = ++ctx->x509_index;
431 pr_debug("Got cert %u for %s\n", x509->index, x509->subject);
432 pr_debug("- fingerprint %*phN\n", x509->id->len, x509->id->data);
434 *ctx->ppcerts = x509;
435 ctx->ppcerts = &x509->next;
440 * Save the certificate list
442 int pkcs7_note_certificate_list(void *context, size_t hdrlen,
444 const void *value, size_t vlen)
446 struct pkcs7_parse_context *ctx = context;
448 pr_devel("Got cert list (%02x)\n", tag);
450 *ctx->ppcerts = ctx->msg->certs;
451 ctx->msg->certs = ctx->certs;
453 ctx->ppcerts = &ctx->certs;
458 * Note the content type.
460 int pkcs7_note_content(void *context, size_t hdrlen,
462 const void *value, size_t vlen)
464 struct pkcs7_parse_context *ctx = context;
466 if (ctx->last_oid != OID_data &&
467 ctx->last_oid != OID_msIndirectData) {
468 pr_warn("Unsupported data type %d\n", ctx->last_oid);
472 ctx->msg->data_type = ctx->last_oid;
477 * Extract the data from the message and store that and its content type OID in
480 int pkcs7_note_data(void *context, size_t hdrlen,
482 const void *value, size_t vlen)
484 struct pkcs7_parse_context *ctx = context;
486 pr_debug("Got data\n");
488 ctx->msg->data = value;
489 ctx->msg->data_len = vlen;
490 ctx->msg->data_hdrlen = hdrlen;
495 * Parse authenticated attributes.
497 int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
499 const void *value, size_t vlen)
501 struct pkcs7_parse_context *ctx = context;
502 struct pkcs7_signed_info *sinfo = ctx->sinfo;
503 enum OID content_type;
505 pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
507 switch (ctx->last_oid) {
508 case OID_contentType:
509 if (__test_and_set_bit(sinfo_has_content_type, &sinfo->aa_set))
511 content_type = look_up_OID(value, vlen);
512 if (content_type != ctx->msg->data_type) {
513 pr_warn("Mismatch between global data type (%d) and sinfo %u (%d)\n",
514 ctx->msg->data_type, sinfo->index,
520 case OID_signingTime:
521 if (__test_and_set_bit(sinfo_has_signing_time, &sinfo->aa_set))
523 /* Should we check that the signing time is consistent
524 * with the signer's X.509 cert?
526 return x509_decode_time(&sinfo->signing_time,
527 hdrlen, tag, value, vlen);
529 case OID_messageDigest:
530 if (__test_and_set_bit(sinfo_has_message_digest, &sinfo->aa_set))
534 sinfo->msgdigest = value;
535 sinfo->msgdigest_len = vlen;
538 case OID_smimeCapabilites:
539 if (__test_and_set_bit(sinfo_has_smime_caps, &sinfo->aa_set))
541 if (ctx->msg->data_type != OID_msIndirectData) {
542 pr_warn("S/MIME Caps only allowed with Authenticode\n");
543 return -EKEYREJECTED;
547 /* Microsoft SpOpusInfo seems to be contain cont[0] 16-bit BE
548 * char URLs and cont[1] 8-bit char URLs.
550 * Microsoft StatementType seems to contain a list of OIDs that
551 * are also used as extendedKeyUsage types in X.509 certs.
553 case OID_msSpOpusInfo:
554 if (__test_and_set_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))
556 goto authenticode_check;
557 case OID_msStatementType:
558 if (__test_and_set_bit(sinfo_has_ms_statement_type, &sinfo->aa_set))
561 if (ctx->msg->data_type != OID_msIndirectData) {
562 pr_warn("Authenticode AuthAttrs only allowed with Authenticode\n");
563 return -EKEYREJECTED;
565 /* I'm not sure how to validate these */
572 /* We permit max one item per AuthenticatedAttribute and no repeats */
573 pr_warn("Repeated/multivalue AuthAttrs not permitted\n");
574 return -EKEYREJECTED;
578 * Note the set of auth attributes for digestion purposes [RFC2315 sec 9.3]
580 int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
582 const void *value, size_t vlen)
584 struct pkcs7_parse_context *ctx = context;
585 struct pkcs7_signed_info *sinfo = ctx->sinfo;
587 if (!test_bit(sinfo_has_content_type, &sinfo->aa_set) ||
588 !test_bit(sinfo_has_message_digest, &sinfo->aa_set)) {
589 pr_warn("Missing required AuthAttr\n");
593 if (ctx->msg->data_type != OID_msIndirectData &&
594 test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set)) {
595 pr_warn("Unexpected Authenticode AuthAttr\n");
599 /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
600 sinfo->authattrs = value - (hdrlen - 1);
601 sinfo->authattrs_len = vlen + (hdrlen - 1);
606 * Note the issuing certificate serial number
608 int pkcs7_sig_note_serial(void *context, size_t hdrlen,
610 const void *value, size_t vlen)
612 struct pkcs7_parse_context *ctx = context;
613 ctx->raw_serial = value;
614 ctx->raw_serial_size = vlen;
619 * Note the issuer's name
621 int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
623 const void *value, size_t vlen)
625 struct pkcs7_parse_context *ctx = context;
626 ctx->raw_issuer = value;
627 ctx->raw_issuer_size = vlen;
632 * Note the issuing cert's subjectKeyIdentifier
634 int pkcs7_sig_note_skid(void *context, size_t hdrlen,
636 const void *value, size_t vlen)
638 struct pkcs7_parse_context *ctx = context;
640 pr_devel("SKID: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
642 ctx->raw_skid = value;
643 ctx->raw_skid_size = vlen;
648 * Note the signature data
650 int pkcs7_sig_note_signature(void *context, size_t hdrlen,
652 const void *value, size_t vlen)
654 struct pkcs7_parse_context *ctx = context;
656 ctx->sinfo->sig->s = kmemdup(value, vlen, GFP_KERNEL);
657 if (!ctx->sinfo->sig->s)
660 ctx->sinfo->sig->s_size = vlen;
665 * Note a signature information block
667 int pkcs7_note_signed_info(void *context, size_t hdrlen,
669 const void *value, size_t vlen)
671 struct pkcs7_parse_context *ctx = context;
672 struct pkcs7_signed_info *sinfo = ctx->sinfo;
673 struct asymmetric_key_id *kid;
675 if (ctx->msg->data_type == OID_msIndirectData && !sinfo->authattrs) {
676 pr_warn("Authenticode requires AuthAttrs\n");
680 /* Generate cert issuer + serial number key ID */
681 if (!ctx->expect_skid) {
682 kid = asymmetric_key_generate_id(ctx->raw_serial,
683 ctx->raw_serial_size,
685 ctx->raw_issuer_size);
687 kid = asymmetric_key_generate_id(ctx->raw_skid,
694 pr_devel("SINFO KID: %u [%*phN]\n", kid->len, kid->len, kid->data);
696 sinfo->sig->auth_ids[0] = kid;
697 sinfo->index = ++ctx->sinfo_index;
698 *ctx->ppsinfo = sinfo;
699 ctx->ppsinfo = &sinfo->next;
700 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
703 ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
705 if (!ctx->sinfo->sig)