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 <crypto/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)
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.hash_algo = "md4";
224 ctx->sinfo->sig.hash_algo = "md5";
227 ctx->sinfo->sig.hash_algo = "sha1";
230 ctx->sinfo->sig.hash_algo = "sha256";
233 ctx->sinfo->sig.hash_algo = "sha384";
236 ctx->sinfo->sig.hash_algo = "sha512";
239 ctx->sinfo->sig.hash_algo = "sha224";
242 printk("Unsupported digest algo: %u\n", ctx->last_oid);
249 * Note the public key algorithm for the signature.
251 int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
253 const void *value, size_t vlen)
255 struct pkcs7_parse_context *ctx = context;
257 switch (ctx->last_oid) {
258 case OID_rsaEncryption:
259 ctx->sinfo->sig.pkey_algo = "rsa";
262 printk("Unsupported pkey algo: %u\n", ctx->last_oid);
269 * We only support signed data [RFC2315 sec 9].
271 int pkcs7_check_content_type(void *context, size_t hdrlen,
273 const void *value, size_t vlen)
275 struct pkcs7_parse_context *ctx = context;
277 if (ctx->last_oid != OID_signed_data) {
278 pr_warn("Only support pkcs7_signedData type\n");
286 * Note the SignedData version
288 int pkcs7_note_signeddata_version(void *context, size_t hdrlen,
290 const void *value, size_t vlen)
292 struct pkcs7_parse_context *ctx = context;
298 ctx->msg->version = version = *(const u8 *)value;
301 /* PKCS#7 SignedData [RFC2315 sec 9.1]
302 * CMS ver 1 SignedData [RFC5652 sec 5.1]
306 /* CMS ver 3 SignedData [RFC2315 sec 5.1] */
315 pr_warn("Unsupported SignedData version\n");
320 * Note the SignerInfo version
322 int pkcs7_note_signerinfo_version(void *context, size_t hdrlen,
324 const void *value, size_t vlen)
326 struct pkcs7_parse_context *ctx = context;
332 version = *(const u8 *)value;
335 /* PKCS#7 SignerInfo [RFC2315 sec 9.2]
336 * CMS ver 1 SignerInfo [RFC5652 sec 5.3]
338 if (ctx->msg->version != 1)
339 goto version_mismatch;
340 ctx->expect_skid = false;
343 /* CMS ver 3 SignerInfo [RFC2315 sec 5.3] */
344 if (ctx->msg->version == 1)
345 goto version_mismatch;
346 ctx->expect_skid = true;
355 pr_warn("Unsupported SignerInfo version\n");
358 pr_warn("SignedData-SignerInfo version mismatch\n");
363 * Extract a certificate and store it in the context.
365 int pkcs7_extract_cert(void *context, size_t hdrlen,
367 const void *value, size_t vlen)
369 struct pkcs7_parse_context *ctx = context;
370 struct x509_certificate *x509;
372 if (tag != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | ASN1_SEQ)) {
373 pr_debug("Cert began with tag %02x at %lu\n",
374 tag, (unsigned long)ctx - ctx->data);
378 /* We have to correct for the header so that the X.509 parser can start
379 * from the beginning. Note that since X.509 stipulates DER, there
380 * probably shouldn't be an EOC trailer - but it is in PKCS#7 (which
386 if (((u8*)value)[1] == 0x80)
387 vlen += 2; /* Indefinite length - there should be an EOC */
389 x509 = x509_cert_parse(value, vlen);
391 return PTR_ERR(x509);
393 x509->index = ++ctx->x509_index;
394 pr_debug("Got cert %u for %s\n", x509->index, x509->subject);
395 pr_debug("- fingerprint %*phN\n", x509->id->len, x509->id->data);
397 *ctx->ppcerts = x509;
398 ctx->ppcerts = &x509->next;
403 * Save the certificate list
405 int pkcs7_note_certificate_list(void *context, size_t hdrlen,
407 const void *value, size_t vlen)
409 struct pkcs7_parse_context *ctx = context;
411 pr_devel("Got cert list (%02x)\n", tag);
413 *ctx->ppcerts = ctx->msg->certs;
414 ctx->msg->certs = ctx->certs;
416 ctx->ppcerts = &ctx->certs;
421 * Note the content type.
423 int pkcs7_note_content(void *context, size_t hdrlen,
425 const void *value, size_t vlen)
427 struct pkcs7_parse_context *ctx = context;
429 if (ctx->last_oid != OID_data &&
430 ctx->last_oid != OID_msIndirectData) {
431 pr_warn("Unsupported data type %d\n", ctx->last_oid);
435 ctx->msg->data_type = ctx->last_oid;
440 * Extract the data from the message and store that and its content type OID in
443 int pkcs7_note_data(void *context, size_t hdrlen,
445 const void *value, size_t vlen)
447 struct pkcs7_parse_context *ctx = context;
449 pr_debug("Got data\n");
451 ctx->msg->data = value;
452 ctx->msg->data_len = vlen;
453 ctx->msg->data_hdrlen = hdrlen;
458 * Parse authenticated attributes.
460 int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
462 const void *value, size_t vlen)
464 struct pkcs7_parse_context *ctx = context;
465 struct pkcs7_signed_info *sinfo = ctx->sinfo;
466 enum OID content_type;
468 pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
470 switch (ctx->last_oid) {
471 case OID_contentType:
472 if (__test_and_set_bit(sinfo_has_content_type, &sinfo->aa_set))
474 content_type = look_up_OID(value, vlen);
475 if (content_type != ctx->msg->data_type) {
476 pr_warn("Mismatch between global data type (%d) and sinfo %u (%d)\n",
477 ctx->msg->data_type, sinfo->index,
483 case OID_signingTime:
484 if (__test_and_set_bit(sinfo_has_signing_time, &sinfo->aa_set))
486 /* Should we check that the signing time is consistent
487 * with the signer's X.509 cert?
489 return x509_decode_time(&sinfo->signing_time,
490 hdrlen, tag, value, vlen);
492 case OID_messageDigest:
493 if (__test_and_set_bit(sinfo_has_message_digest, &sinfo->aa_set))
497 sinfo->msgdigest = value;
498 sinfo->msgdigest_len = vlen;
501 case OID_smimeCapabilites:
502 if (__test_and_set_bit(sinfo_has_smime_caps, &sinfo->aa_set))
504 if (ctx->msg->data_type != OID_msIndirectData) {
505 pr_warn("S/MIME Caps only allowed with Authenticode\n");
506 return -EKEYREJECTED;
510 /* Microsoft SpOpusInfo seems to be contain cont[0] 16-bit BE
511 * char URLs and cont[1] 8-bit char URLs.
513 * Microsoft StatementType seems to contain a list of OIDs that
514 * are also used as extendedKeyUsage types in X.509 certs.
516 case OID_msSpOpusInfo:
517 if (__test_and_set_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))
519 goto authenticode_check;
520 case OID_msStatementType:
521 if (__test_and_set_bit(sinfo_has_ms_statement_type, &sinfo->aa_set))
524 if (ctx->msg->data_type != OID_msIndirectData) {
525 pr_warn("Authenticode AuthAttrs only allowed with Authenticode\n");
526 return -EKEYREJECTED;
528 /* I'm not sure how to validate these */
535 /* We permit max one item per AuthenticatedAttribute and no repeats */
536 pr_warn("Repeated/multivalue AuthAttrs not permitted\n");
537 return -EKEYREJECTED;
541 * Note the set of auth attributes for digestion purposes [RFC2315 sec 9.3]
543 int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
545 const void *value, size_t vlen)
547 struct pkcs7_parse_context *ctx = context;
548 struct pkcs7_signed_info *sinfo = ctx->sinfo;
550 if (!test_bit(sinfo_has_content_type, &sinfo->aa_set) ||
551 !test_bit(sinfo_has_message_digest, &sinfo->aa_set)) {
552 pr_warn("Missing required AuthAttr\n");
556 if (ctx->msg->data_type != OID_msIndirectData &&
557 test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set)) {
558 pr_warn("Unexpected Authenticode AuthAttr\n");
562 /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
563 sinfo->authattrs = value - (hdrlen - 1);
564 sinfo->authattrs_len = vlen + (hdrlen - 1);
569 * Note the issuing certificate serial number
571 int pkcs7_sig_note_serial(void *context, size_t hdrlen,
573 const void *value, size_t vlen)
575 struct pkcs7_parse_context *ctx = context;
576 ctx->raw_serial = value;
577 ctx->raw_serial_size = vlen;
582 * Note the issuer's name
584 int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
586 const void *value, size_t vlen)
588 struct pkcs7_parse_context *ctx = context;
589 ctx->raw_issuer = value;
590 ctx->raw_issuer_size = vlen;
595 * Note the issuing cert's subjectKeyIdentifier
597 int pkcs7_sig_note_skid(void *context, size_t hdrlen,
599 const void *value, size_t vlen)
601 struct pkcs7_parse_context *ctx = context;
603 pr_devel("SKID: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
605 ctx->raw_skid = value;
606 ctx->raw_skid_size = vlen;
611 * Note the signature data
613 int pkcs7_sig_note_signature(void *context, size_t hdrlen,
615 const void *value, size_t vlen)
617 struct pkcs7_parse_context *ctx = context;
619 ctx->sinfo->sig.s = kmemdup(value, vlen, GFP_KERNEL);
620 if (!ctx->sinfo->sig.s)
623 ctx->sinfo->sig.s_size = vlen;
628 * Note a signature information block
630 int pkcs7_note_signed_info(void *context, size_t hdrlen,
632 const void *value, size_t vlen)
634 struct pkcs7_parse_context *ctx = context;
635 struct pkcs7_signed_info *sinfo = ctx->sinfo;
636 struct asymmetric_key_id *kid;
638 if (ctx->msg->data_type == OID_msIndirectData && !sinfo->authattrs) {
639 pr_warn("Authenticode requires AuthAttrs\n");
643 /* Generate cert issuer + serial number key ID */
644 if (!ctx->expect_skid) {
645 kid = asymmetric_key_generate_id(ctx->raw_serial,
646 ctx->raw_serial_size,
648 ctx->raw_issuer_size);
650 kid = asymmetric_key_generate_id(ctx->raw_skid,
657 pr_devel("SINFO KID: %u [%*phN]\n", kid->len, kid->len, kid->data);
659 sinfo->signing_cert_id = kid;
660 sinfo->index = ++ctx->sinfo_index;
661 *ctx->ppsinfo = sinfo;
662 ctx->ppsinfo = &sinfo->next;
663 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);