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/module.h>
15 #include <linux/export.h>
16 #include <linux/slab.h>
17 #include <linux/err.h>
18 #include <linux/oid_registry.h>
19 #include <crypto/public_key.h>
20 #include "pkcs7_parser.h"
21 #include "pkcs7-asn1.h"
23 MODULE_DESCRIPTION("PKCS#7 parser");
24 MODULE_AUTHOR("Red Hat, Inc.");
25 MODULE_LICENSE("GPL");
27 struct pkcs7_parse_context {
28 struct pkcs7_message *msg; /* Message being constructed */
29 struct pkcs7_signed_info *sinfo; /* SignedInfo being constructed */
30 struct pkcs7_signed_info **ppsinfo;
31 struct x509_certificate *certs; /* Certificate cache */
32 struct x509_certificate **ppcerts;
33 unsigned long data; /* Start of data */
34 enum OID last_oid; /* Last OID encountered */
37 const void *raw_serial;
38 unsigned raw_serial_size;
39 unsigned raw_issuer_size;
40 const void *raw_issuer;
42 unsigned raw_skid_size;
47 * Free a signed information block.
49 static void pkcs7_free_signed_info(struct pkcs7_signed_info *sinfo)
52 public_key_signature_free(sinfo->sig);
58 * pkcs7_free_message - Free a PKCS#7 message
59 * @pkcs7: The PKCS#7 message to free
61 void pkcs7_free_message(struct pkcs7_message *pkcs7)
63 struct x509_certificate *cert;
64 struct pkcs7_signed_info *sinfo;
67 while (pkcs7->certs) {
69 pkcs7->certs = cert->next;
70 x509_free_certificate(cert);
74 pkcs7->crl = cert->next;
75 x509_free_certificate(cert);
77 while (pkcs7->signed_infos) {
78 sinfo = pkcs7->signed_infos;
79 pkcs7->signed_infos = sinfo->next;
80 pkcs7_free_signed_info(sinfo);
85 EXPORT_SYMBOL_GPL(pkcs7_free_message);
88 * Check authenticatedAttributes are provided or not provided consistently.
90 static int pkcs7_check_authattrs(struct pkcs7_message *msg)
92 struct pkcs7_signed_info *sinfo;
95 sinfo = msg->signed_infos;
99 if (sinfo->authattrs) {
101 msg->have_authattrs = true;
104 for (sinfo = sinfo->next; sinfo; sinfo = sinfo->next)
105 if (!!sinfo->authattrs != want)
110 pr_warn("Inconsistently supplied authAttrs\n");
115 * pkcs7_parse_message - Parse a PKCS#7 message
116 * @data: The raw binary ASN.1 encoded message to be parsed
117 * @datalen: The size of the encoded message
119 struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
121 struct pkcs7_parse_context *ctx;
122 struct pkcs7_message *msg = ERR_PTR(-ENOMEM);
125 ctx = kzalloc(sizeof(struct pkcs7_parse_context), GFP_KERNEL);
128 ctx->msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
131 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
134 ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
136 if (!ctx->sinfo->sig)
139 ctx->data = (unsigned long)data;
140 ctx->ppcerts = &ctx->certs;
141 ctx->ppsinfo = &ctx->msg->signed_infos;
143 /* Attempt to decode the signature */
144 ret = asn1_ber_decoder(&pkcs7_decoder, ctx, data, datalen);
150 ret = pkcs7_check_authattrs(ctx->msg);
159 struct x509_certificate *cert = ctx->certs;
160 ctx->certs = cert->next;
161 x509_free_certificate(cert);
164 pkcs7_free_signed_info(ctx->sinfo);
166 pkcs7_free_message(ctx->msg);
172 EXPORT_SYMBOL_GPL(pkcs7_parse_message);
175 * pkcs7_get_content_data - Get access to the PKCS#7 content
176 * @pkcs7: The preparsed PKCS#7 message to access
177 * @_data: Place to return a pointer to the data
178 * @_data_len: Place to return the data length
179 * @_headerlen: Size of ASN.1 header not included in _data
181 * Get access to the data content of the PKCS#7 message. The size of the
182 * header of the ASN.1 object that contains it is also provided and can be used
183 * to adjust *_data and *_data_len to get the entire object.
185 * Returns -ENODATA if the data object was missing from the message.
187 int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
188 const void **_data, size_t *_data_len,
194 *_data = pkcs7->data;
195 *_data_len = pkcs7->data_len;
197 *_headerlen = pkcs7->data_hdrlen;
200 EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
203 * Note an OID when we find one for later processing when we know how
206 int pkcs7_note_OID(void *context, size_t hdrlen,
208 const void *value, size_t vlen)
210 struct pkcs7_parse_context *ctx = context;
212 ctx->last_oid = look_up_OID(value, vlen);
213 if (ctx->last_oid == OID__NR) {
215 sprint_oid(value, vlen, buffer, sizeof(buffer));
216 printk("PKCS7: Unknown OID: [%lu] %s\n",
217 (unsigned long)value - ctx->data, buffer);
223 * Note the digest algorithm for the signature.
225 int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
227 const void *value, size_t vlen)
229 struct pkcs7_parse_context *ctx = context;
231 switch (ctx->last_oid) {
233 ctx->sinfo->sig->hash_algo = "md4";
236 ctx->sinfo->sig->hash_algo = "md5";
239 ctx->sinfo->sig->hash_algo = "sha1";
242 ctx->sinfo->sig->hash_algo = "sha256";
245 ctx->sinfo->sig->hash_algo = "sha384";
248 ctx->sinfo->sig->hash_algo = "sha512";
251 ctx->sinfo->sig->hash_algo = "sha224";
254 printk("Unsupported digest algo: %u\n", ctx->last_oid);
261 * Note the public key algorithm for the signature.
263 int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
265 const void *value, size_t vlen)
267 struct pkcs7_parse_context *ctx = context;
269 switch (ctx->last_oid) {
270 case OID_rsaEncryption:
271 ctx->sinfo->sig->pkey_algo = "rsa";
274 printk("Unsupported pkey algo: %u\n", ctx->last_oid);
281 * We only support signed data [RFC2315 sec 9].
283 int pkcs7_check_content_type(void *context, size_t hdrlen,
285 const void *value, size_t vlen)
287 struct pkcs7_parse_context *ctx = context;
289 if (ctx->last_oid != OID_signed_data) {
290 pr_warn("Only support pkcs7_signedData type\n");
298 * Note the SignedData version
300 int pkcs7_note_signeddata_version(void *context, size_t hdrlen,
302 const void *value, size_t vlen)
304 struct pkcs7_parse_context *ctx = context;
310 ctx->msg->version = version = *(const u8 *)value;
313 /* PKCS#7 SignedData [RFC2315 sec 9.1]
314 * CMS ver 1 SignedData [RFC5652 sec 5.1]
318 /* CMS ver 3 SignedData [RFC2315 sec 5.1] */
327 pr_warn("Unsupported SignedData version\n");
332 * Note the SignerInfo version
334 int pkcs7_note_signerinfo_version(void *context, size_t hdrlen,
336 const void *value, size_t vlen)
338 struct pkcs7_parse_context *ctx = context;
344 version = *(const u8 *)value;
347 /* PKCS#7 SignerInfo [RFC2315 sec 9.2]
348 * CMS ver 1 SignerInfo [RFC5652 sec 5.3]
350 if (ctx->msg->version != 1)
351 goto version_mismatch;
352 ctx->expect_skid = false;
355 /* CMS ver 3 SignerInfo [RFC2315 sec 5.3] */
356 if (ctx->msg->version == 1)
357 goto version_mismatch;
358 ctx->expect_skid = true;
367 pr_warn("Unsupported SignerInfo version\n");
370 pr_warn("SignedData-SignerInfo version mismatch\n");
375 * Extract a certificate and store it in the context.
377 int pkcs7_extract_cert(void *context, size_t hdrlen,
379 const void *value, size_t vlen)
381 struct pkcs7_parse_context *ctx = context;
382 struct x509_certificate *x509;
384 if (tag != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | ASN1_SEQ)) {
385 pr_debug("Cert began with tag %02x at %lu\n",
386 tag, (unsigned long)ctx - ctx->data);
390 /* We have to correct for the header so that the X.509 parser can start
391 * from the beginning. Note that since X.509 stipulates DER, there
392 * probably shouldn't be an EOC trailer - but it is in PKCS#7 (which
398 if (((u8*)value)[1] == 0x80)
399 vlen += 2; /* Indefinite length - there should be an EOC */
401 x509 = x509_cert_parse(value, vlen);
403 return PTR_ERR(x509);
405 x509->index = ++ctx->x509_index;
406 pr_debug("Got cert %u for %s\n", x509->index, x509->subject);
407 pr_debug("- fingerprint %*phN\n", x509->id->len, x509->id->data);
409 *ctx->ppcerts = x509;
410 ctx->ppcerts = &x509->next;
415 * Save the certificate list
417 int pkcs7_note_certificate_list(void *context, size_t hdrlen,
419 const void *value, size_t vlen)
421 struct pkcs7_parse_context *ctx = context;
423 pr_devel("Got cert list (%02x)\n", tag);
425 *ctx->ppcerts = ctx->msg->certs;
426 ctx->msg->certs = ctx->certs;
428 ctx->ppcerts = &ctx->certs;
433 * Note the content type.
435 int pkcs7_note_content(void *context, size_t hdrlen,
437 const void *value, size_t vlen)
439 struct pkcs7_parse_context *ctx = context;
441 if (ctx->last_oid != OID_data &&
442 ctx->last_oid != OID_msIndirectData) {
443 pr_warn("Unsupported data type %d\n", ctx->last_oid);
447 ctx->msg->data_type = ctx->last_oid;
452 * Extract the data from the message and store that and its content type OID in
455 int pkcs7_note_data(void *context, size_t hdrlen,
457 const void *value, size_t vlen)
459 struct pkcs7_parse_context *ctx = context;
461 pr_debug("Got data\n");
463 ctx->msg->data = value;
464 ctx->msg->data_len = vlen;
465 ctx->msg->data_hdrlen = hdrlen;
470 * Parse authenticated attributes.
472 int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
474 const void *value, size_t vlen)
476 struct pkcs7_parse_context *ctx = context;
477 struct pkcs7_signed_info *sinfo = ctx->sinfo;
478 enum OID content_type;
480 pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
482 switch (ctx->last_oid) {
483 case OID_contentType:
484 if (__test_and_set_bit(sinfo_has_content_type, &sinfo->aa_set))
486 content_type = look_up_OID(value, vlen);
487 if (content_type != ctx->msg->data_type) {
488 pr_warn("Mismatch between global data type (%d) and sinfo %u (%d)\n",
489 ctx->msg->data_type, sinfo->index,
495 case OID_signingTime:
496 if (__test_and_set_bit(sinfo_has_signing_time, &sinfo->aa_set))
498 /* Should we check that the signing time is consistent
499 * with the signer's X.509 cert?
501 return x509_decode_time(&sinfo->signing_time,
502 hdrlen, tag, value, vlen);
504 case OID_messageDigest:
505 if (__test_and_set_bit(sinfo_has_message_digest, &sinfo->aa_set))
509 sinfo->msgdigest = value;
510 sinfo->msgdigest_len = vlen;
513 case OID_smimeCapabilites:
514 if (__test_and_set_bit(sinfo_has_smime_caps, &sinfo->aa_set))
516 if (ctx->msg->data_type != OID_msIndirectData) {
517 pr_warn("S/MIME Caps only allowed with Authenticode\n");
518 return -EKEYREJECTED;
522 /* Microsoft SpOpusInfo seems to be contain cont[0] 16-bit BE
523 * char URLs and cont[1] 8-bit char URLs.
525 * Microsoft StatementType seems to contain a list of OIDs that
526 * are also used as extendedKeyUsage types in X.509 certs.
528 case OID_msSpOpusInfo:
529 if (__test_and_set_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))
531 goto authenticode_check;
532 case OID_msStatementType:
533 if (__test_and_set_bit(sinfo_has_ms_statement_type, &sinfo->aa_set))
536 if (ctx->msg->data_type != OID_msIndirectData) {
537 pr_warn("Authenticode AuthAttrs only allowed with Authenticode\n");
538 return -EKEYREJECTED;
540 /* I'm not sure how to validate these */
547 /* We permit max one item per AuthenticatedAttribute and no repeats */
548 pr_warn("Repeated/multivalue AuthAttrs not permitted\n");
549 return -EKEYREJECTED;
553 * Note the set of auth attributes for digestion purposes [RFC2315 sec 9.3]
555 int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
557 const void *value, size_t vlen)
559 struct pkcs7_parse_context *ctx = context;
560 struct pkcs7_signed_info *sinfo = ctx->sinfo;
562 if (!test_bit(sinfo_has_content_type, &sinfo->aa_set) ||
563 !test_bit(sinfo_has_message_digest, &sinfo->aa_set)) {
564 pr_warn("Missing required AuthAttr\n");
568 if (ctx->msg->data_type != OID_msIndirectData &&
569 test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set)) {
570 pr_warn("Unexpected Authenticode AuthAttr\n");
574 /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
575 sinfo->authattrs = value - (hdrlen - 1);
576 sinfo->authattrs_len = vlen + (hdrlen - 1);
581 * Note the issuing certificate serial number
583 int pkcs7_sig_note_serial(void *context, size_t hdrlen,
585 const void *value, size_t vlen)
587 struct pkcs7_parse_context *ctx = context;
588 ctx->raw_serial = value;
589 ctx->raw_serial_size = vlen;
594 * Note the issuer's name
596 int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
598 const void *value, size_t vlen)
600 struct pkcs7_parse_context *ctx = context;
601 ctx->raw_issuer = value;
602 ctx->raw_issuer_size = vlen;
607 * Note the issuing cert's subjectKeyIdentifier
609 int pkcs7_sig_note_skid(void *context, size_t hdrlen,
611 const void *value, size_t vlen)
613 struct pkcs7_parse_context *ctx = context;
615 pr_devel("SKID: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
617 ctx->raw_skid = value;
618 ctx->raw_skid_size = vlen;
623 * Note the signature data
625 int pkcs7_sig_note_signature(void *context, size_t hdrlen,
627 const void *value, size_t vlen)
629 struct pkcs7_parse_context *ctx = context;
631 ctx->sinfo->sig->s = kmemdup(value, vlen, GFP_KERNEL);
632 if (!ctx->sinfo->sig->s)
635 ctx->sinfo->sig->s_size = vlen;
640 * Note a signature information block
642 int pkcs7_note_signed_info(void *context, size_t hdrlen,
644 const void *value, size_t vlen)
646 struct pkcs7_parse_context *ctx = context;
647 struct pkcs7_signed_info *sinfo = ctx->sinfo;
648 struct asymmetric_key_id *kid;
650 if (ctx->msg->data_type == OID_msIndirectData && !sinfo->authattrs) {
651 pr_warn("Authenticode requires AuthAttrs\n");
655 /* Generate cert issuer + serial number key ID */
656 if (!ctx->expect_skid) {
657 kid = asymmetric_key_generate_id(ctx->raw_serial,
658 ctx->raw_serial_size,
660 ctx->raw_issuer_size);
662 kid = asymmetric_key_generate_id(ctx->raw_skid,
669 pr_devel("SINFO KID: %u [%*phN]\n", kid->len, kid->len, kid->data);
671 sinfo->sig->auth_ids[0] = kid;
672 sinfo->index = ++ctx->sinfo_index;
673 *ctx->ppsinfo = sinfo;
674 ctx->ppsinfo = &sinfo->next;
675 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
678 ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
680 if (!ctx->sinfo->sig)