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;
93 if (sinfo->authattrs) {
95 msg->have_authattrs = true;
98 for (sinfo = sinfo->next; sinfo; sinfo = sinfo->next)
99 if (!!sinfo->authattrs != want)
104 pr_warn("Inconsistently supplied authAttrs\n");
109 * pkcs7_parse_message - Parse a PKCS#7 message
110 * @data: The raw binary ASN.1 encoded message to be parsed
111 * @datalen: The size of the encoded message
113 struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
115 struct pkcs7_parse_context *ctx;
116 struct pkcs7_message *msg = ERR_PTR(-ENOMEM);
119 ctx = kzalloc(sizeof(struct pkcs7_parse_context), GFP_KERNEL);
122 ctx->msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
125 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
129 ctx->data = (unsigned long)data;
130 ctx->ppcerts = &ctx->certs;
131 ctx->ppsinfo = &ctx->msg->signed_infos;
133 /* Attempt to decode the signature */
134 ret = asn1_ber_decoder(&pkcs7_decoder, ctx, data, datalen);
140 ret = pkcs7_check_authattrs(ctx->msg);
149 struct x509_certificate *cert = ctx->certs;
150 ctx->certs = cert->next;
151 x509_free_certificate(cert);
153 pkcs7_free_signed_info(ctx->sinfo);
155 pkcs7_free_message(ctx->msg);
161 EXPORT_SYMBOL_GPL(pkcs7_parse_message);
164 * pkcs7_get_content_data - Get access to the PKCS#7 content
165 * @pkcs7: The preparsed PKCS#7 message to access
166 * @_data: Place to return a pointer to the data
167 * @_data_len: Place to return the data length
168 * @want_wrapper: True if the ASN.1 object header should be included in the data
170 * Get access to the data content of the PKCS#7 message, including, optionally,
171 * the header of the ASN.1 object that contains it. Returns -ENODATA if the
172 * data object was missing from the message.
174 int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
175 const void **_data, size_t *_data_len,
183 wrapper = want_wrapper ? pkcs7->data_hdrlen : 0;
184 *_data = pkcs7->data - wrapper;
185 *_data_len = pkcs7->data_len + wrapper;
188 EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
191 * Note an OID when we find one for later processing when we know how
194 int pkcs7_note_OID(void *context, size_t hdrlen,
196 const void *value, size_t vlen)
198 struct pkcs7_parse_context *ctx = context;
200 ctx->last_oid = look_up_OID(value, vlen);
201 if (ctx->last_oid == OID__NR) {
203 sprint_oid(value, vlen, buffer, sizeof(buffer));
204 printk("PKCS7: Unknown OID: [%lu] %s\n",
205 (unsigned long)value - ctx->data, buffer);
211 * Note the digest algorithm for the signature.
213 int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
215 const void *value, size_t vlen)
217 struct pkcs7_parse_context *ctx = context;
219 switch (ctx->last_oid) {
221 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_MD4;
224 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_MD5;
227 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_SHA1;
230 ctx->sinfo->sig.pkey_hash_algo = HASH_ALGO_SHA256;
233 printk("Unsupported digest algo: %u\n", ctx->last_oid);
240 * Note the public key algorithm for the signature.
242 int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
244 const void *value, size_t vlen)
246 struct pkcs7_parse_context *ctx = context;
248 switch (ctx->last_oid) {
249 case OID_rsaEncryption:
250 ctx->sinfo->sig.pkey_algo = PKEY_ALGO_RSA;
253 printk("Unsupported pkey algo: %u\n", ctx->last_oid);
260 * We only support signed data [RFC2315 sec 9].
262 int pkcs7_check_content_type(void *context, size_t hdrlen,
264 const void *value, size_t vlen)
266 struct pkcs7_parse_context *ctx = context;
268 if (ctx->last_oid != OID_signed_data) {
269 pr_warn("Only support pkcs7_signedData type\n");
277 * Note the SignedData version
279 int pkcs7_note_signeddata_version(void *context, size_t hdrlen,
281 const void *value, size_t vlen)
283 struct pkcs7_parse_context *ctx = context;
289 ctx->msg->version = version = *(const u8 *)value;
292 /* PKCS#7 SignedData [RFC2315 sec 9.1]
293 * CMS ver 1 SignedData [RFC5652 sec 5.1]
297 /* CMS ver 3 SignedData [RFC2315 sec 5.1] */
306 pr_warn("Unsupported SignedData version\n");
311 * Note the SignerInfo version
313 int pkcs7_note_signerinfo_version(void *context, size_t hdrlen,
315 const void *value, size_t vlen)
317 struct pkcs7_parse_context *ctx = context;
323 version = *(const u8 *)value;
326 /* PKCS#7 SignerInfo [RFC2315 sec 9.2]
327 * CMS ver 1 SignerInfo [RFC5652 sec 5.3]
329 if (ctx->msg->version != 1)
330 goto version_mismatch;
331 ctx->expect_skid = false;
334 /* CMS ver 3 SignerInfo [RFC2315 sec 5.3] */
335 if (ctx->msg->version == 1)
336 goto version_mismatch;
337 ctx->expect_skid = true;
346 pr_warn("Unsupported SignerInfo version\n");
349 pr_warn("SignedData-SignerInfo version mismatch\n");
354 * Extract a certificate and store it in the context.
356 int pkcs7_extract_cert(void *context, size_t hdrlen,
358 const void *value, size_t vlen)
360 struct pkcs7_parse_context *ctx = context;
361 struct x509_certificate *x509;
363 if (tag != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | ASN1_SEQ)) {
364 pr_debug("Cert began with tag %02x at %lu\n",
365 tag, (unsigned long)ctx - ctx->data);
369 /* We have to correct for the header so that the X.509 parser can start
370 * from the beginning. Note that since X.509 stipulates DER, there
371 * probably shouldn't be an EOC trailer - but it is in PKCS#7 (which
377 if (((u8*)value)[1] == 0x80)
378 vlen += 2; /* Indefinite length - there should be an EOC */
380 x509 = x509_cert_parse(value, vlen);
382 return PTR_ERR(x509);
384 x509->index = ++ctx->x509_index;
385 pr_debug("Got cert %u for %s\n", x509->index, x509->subject);
386 pr_debug("- fingerprint %*phN\n", x509->id->len, x509->id->data);
388 *ctx->ppcerts = x509;
389 ctx->ppcerts = &x509->next;
394 * Save the certificate list
396 int pkcs7_note_certificate_list(void *context, size_t hdrlen,
398 const void *value, size_t vlen)
400 struct pkcs7_parse_context *ctx = context;
402 pr_devel("Got cert list (%02x)\n", tag);
404 *ctx->ppcerts = ctx->msg->certs;
405 ctx->msg->certs = ctx->certs;
407 ctx->ppcerts = &ctx->certs;
412 * Note the content type.
414 int pkcs7_note_content(void *context, size_t hdrlen,
416 const void *value, size_t vlen)
418 struct pkcs7_parse_context *ctx = context;
420 if (ctx->last_oid != OID_data &&
421 ctx->last_oid != OID_msIndirectData) {
422 pr_warn("Unsupported data type %d\n", ctx->last_oid);
426 ctx->msg->data_type = ctx->last_oid;
431 * Extract the data from the message and store that and its content type OID in
434 int pkcs7_note_data(void *context, size_t hdrlen,
436 const void *value, size_t vlen)
438 struct pkcs7_parse_context *ctx = context;
440 pr_debug("Got data\n");
442 ctx->msg->data = value;
443 ctx->msg->data_len = vlen;
444 ctx->msg->data_hdrlen = hdrlen;
449 * Parse authenticated attributes.
451 int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
453 const void *value, size_t vlen)
455 struct pkcs7_parse_context *ctx = context;
456 struct pkcs7_signed_info *sinfo = ctx->sinfo;
457 enum OID content_type;
459 pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
461 switch (ctx->last_oid) {
462 case OID_contentType:
463 if (__test_and_set_bit(sinfo_has_content_type, &sinfo->aa_set))
465 content_type = look_up_OID(value, vlen);
466 if (content_type != ctx->msg->data_type) {
467 pr_warn("Mismatch between global data type (%d) and sinfo %u (%d)\n",
468 ctx->msg->data_type, sinfo->index,
474 case OID_signingTime:
475 if (__test_and_set_bit(sinfo_has_signing_time, &sinfo->aa_set))
477 /* Should we check that the signing time is consistent
478 * with the signer's X.509 cert?
480 return x509_decode_time(&sinfo->signing_time,
481 hdrlen, tag, value, vlen);
483 case OID_messageDigest:
484 if (__test_and_set_bit(sinfo_has_message_digest, &sinfo->aa_set))
488 sinfo->msgdigest = value;
489 sinfo->msgdigest_len = vlen;
492 case OID_smimeCapabilites:
493 if (__test_and_set_bit(sinfo_has_smime_caps, &sinfo->aa_set))
495 if (ctx->msg->data_type != OID_msIndirectData) {
496 pr_warn("S/MIME Caps only allowed with Authenticode\n");
497 return -EKEYREJECTED;
501 /* Microsoft SpOpusInfo seems to be contain cont[0] 16-bit BE
502 * char URLs and cont[1] 8-bit char URLs.
504 * Microsoft StatementType seems to contain a list of OIDs that
505 * are also used as extendedKeyUsage types in X.509 certs.
507 case OID_msSpOpusInfo:
508 if (__test_and_set_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))
510 goto authenticode_check;
511 case OID_msStatementType:
512 if (__test_and_set_bit(sinfo_has_ms_statement_type, &sinfo->aa_set))
515 if (ctx->msg->data_type != OID_msIndirectData) {
516 pr_warn("Authenticode AuthAttrs only allowed with Authenticode\n");
517 return -EKEYREJECTED;
519 /* I'm not sure how to validate these */
526 /* We permit max one item per AuthenticatedAttribute and no repeats */
527 pr_warn("Repeated/multivalue AuthAttrs not permitted\n");
528 return -EKEYREJECTED;
532 * Note the set of auth attributes for digestion purposes [RFC2315 sec 9.3]
534 int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
536 const void *value, size_t vlen)
538 struct pkcs7_parse_context *ctx = context;
539 struct pkcs7_signed_info *sinfo = ctx->sinfo;
541 if (!test_bit(sinfo_has_content_type, &sinfo->aa_set) ||
542 !test_bit(sinfo_has_message_digest, &sinfo->aa_set) ||
543 (ctx->msg->data_type == OID_msIndirectData &&
544 !test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))) {
545 pr_warn("Missing required AuthAttr\n");
549 if (ctx->msg->data_type != OID_msIndirectData &&
550 test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set)) {
551 pr_warn("Unexpected Authenticode AuthAttr\n");
555 /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
556 sinfo->authattrs = value - (hdrlen - 1);
557 sinfo->authattrs_len = vlen + (hdrlen - 1);
562 * Note the issuing certificate serial number
564 int pkcs7_sig_note_serial(void *context, size_t hdrlen,
566 const void *value, size_t vlen)
568 struct pkcs7_parse_context *ctx = context;
569 ctx->raw_serial = value;
570 ctx->raw_serial_size = vlen;
575 * Note the issuer's name
577 int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
579 const void *value, size_t vlen)
581 struct pkcs7_parse_context *ctx = context;
582 ctx->raw_issuer = value;
583 ctx->raw_issuer_size = vlen;
588 * Note the issuing cert's subjectKeyIdentifier
590 int pkcs7_sig_note_skid(void *context, size_t hdrlen,
592 const void *value, size_t vlen)
594 struct pkcs7_parse_context *ctx = context;
596 pr_devel("SKID: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
598 ctx->raw_skid = value;
599 ctx->raw_skid_size = vlen;
604 * Note the signature data
606 int pkcs7_sig_note_signature(void *context, size_t hdrlen,
608 const void *value, size_t vlen)
610 struct pkcs7_parse_context *ctx = context;
613 BUG_ON(ctx->sinfo->sig.pkey_algo != PKEY_ALGO_RSA);
615 mpi = mpi_read_raw_data(value, vlen);
619 ctx->sinfo->sig.mpi[0] = mpi;
620 ctx->sinfo->sig.nr_mpi = 1;
625 * Note a signature information block
627 int pkcs7_note_signed_info(void *context, size_t hdrlen,
629 const void *value, size_t vlen)
631 struct pkcs7_parse_context *ctx = context;
632 struct pkcs7_signed_info *sinfo = ctx->sinfo;
633 struct asymmetric_key_id *kid;
635 if (ctx->msg->data_type == OID_msIndirectData && !sinfo->authattrs) {
636 pr_warn("Authenticode requires AuthAttrs\n");
640 /* Generate cert issuer + serial number key ID */
641 if (!ctx->expect_skid) {
642 kid = asymmetric_key_generate_id(ctx->raw_serial,
643 ctx->raw_serial_size,
645 ctx->raw_issuer_size);
647 kid = asymmetric_key_generate_id(ctx->raw_skid,
654 pr_devel("SINFO KID: %u [%*phN]\n", kid->len, kid->len, kid->data);
656 sinfo->signing_cert_id = kid;
657 sinfo->index = ++ctx->sinfo_index;
658 *ctx->ppsinfo = sinfo;
659 ctx->ppsinfo = &sinfo->next;
660 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);