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)
47 public_key_signature_free(sinfo->sig);
53 * pkcs7_free_message - Free a PKCS#7 message
54 * @pkcs7: The PKCS#7 message to free
56 void pkcs7_free_message(struct pkcs7_message *pkcs7)
58 struct x509_certificate *cert;
59 struct pkcs7_signed_info *sinfo;
62 while (pkcs7->certs) {
64 pkcs7->certs = cert->next;
65 x509_free_certificate(cert);
69 pkcs7->crl = cert->next;
70 x509_free_certificate(cert);
72 while (pkcs7->signed_infos) {
73 sinfo = pkcs7->signed_infos;
74 pkcs7->signed_infos = sinfo->next;
75 pkcs7_free_signed_info(sinfo);
80 EXPORT_SYMBOL_GPL(pkcs7_free_message);
83 * Check authenticatedAttributes are provided or not provided consistently.
85 static int pkcs7_check_authattrs(struct pkcs7_message *msg)
87 struct pkcs7_signed_info *sinfo;
90 sinfo = msg->signed_infos;
94 if (sinfo->authattrs) {
96 msg->have_authattrs = true;
99 for (sinfo = sinfo->next; sinfo; sinfo = sinfo->next)
100 if (!!sinfo->authattrs != want)
105 pr_warn("Inconsistently supplied authAttrs\n");
110 * pkcs7_parse_message - Parse a PKCS#7 message
111 * @data: The raw binary ASN.1 encoded message to be parsed
112 * @datalen: The size of the encoded message
114 struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
116 struct pkcs7_parse_context *ctx;
117 struct pkcs7_message *msg = ERR_PTR(-ENOMEM);
120 ctx = kzalloc(sizeof(struct pkcs7_parse_context), GFP_KERNEL);
123 ctx->msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
126 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
129 ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
131 if (!ctx->sinfo->sig)
134 ctx->data = (unsigned long)data;
135 ctx->ppcerts = &ctx->certs;
136 ctx->ppsinfo = &ctx->msg->signed_infos;
138 /* Attempt to decode the signature */
139 ret = asn1_ber_decoder(&pkcs7_decoder, ctx, data, datalen);
145 ret = pkcs7_check_authattrs(ctx->msg);
154 struct x509_certificate *cert = ctx->certs;
155 ctx->certs = cert->next;
156 x509_free_certificate(cert);
159 pkcs7_free_signed_info(ctx->sinfo);
161 pkcs7_free_message(ctx->msg);
167 EXPORT_SYMBOL_GPL(pkcs7_parse_message);
170 * pkcs7_get_content_data - Get access to the PKCS#7 content
171 * @pkcs7: The preparsed PKCS#7 message to access
172 * @_data: Place to return a pointer to the data
173 * @_data_len: Place to return the data length
174 * @_headerlen: Size of ASN.1 header not included in _data
176 * Get access to the data content of the PKCS#7 message. The size of the
177 * header of the ASN.1 object that contains it is also provided and can be used
178 * to adjust *_data and *_data_len to get the entire object.
180 * Returns -ENODATA if the data object was missing from the message.
182 int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
183 const void **_data, size_t *_data_len,
189 *_data = pkcs7->data;
190 *_data_len = pkcs7->data_len;
192 *_headerlen = pkcs7->data_hdrlen;
195 EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
198 * Note an OID when we find one for later processing when we know how
201 int pkcs7_note_OID(void *context, size_t hdrlen,
203 const void *value, size_t vlen)
205 struct pkcs7_parse_context *ctx = context;
207 ctx->last_oid = look_up_OID(value, vlen);
208 if (ctx->last_oid == OID__NR) {
210 sprint_oid(value, vlen, buffer, sizeof(buffer));
211 printk("PKCS7: Unknown OID: [%lu] %s\n",
212 (unsigned long)value - ctx->data, buffer);
218 * Note the digest algorithm for the signature.
220 int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
222 const void *value, size_t vlen)
224 struct pkcs7_parse_context *ctx = context;
226 switch (ctx->last_oid) {
228 ctx->sinfo->sig->hash_algo = "md4";
231 ctx->sinfo->sig->hash_algo = "md5";
234 ctx->sinfo->sig->hash_algo = "sha1";
237 ctx->sinfo->sig->hash_algo = "sha256";
240 ctx->sinfo->sig->hash_algo = "sha384";
243 ctx->sinfo->sig->hash_algo = "sha512";
246 ctx->sinfo->sig->hash_algo = "sha224";
249 printk("Unsupported digest algo: %u\n", ctx->last_oid);
256 * Note the public key algorithm for the signature.
258 int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
260 const void *value, size_t vlen)
262 struct pkcs7_parse_context *ctx = context;
264 switch (ctx->last_oid) {
265 case OID_rsaEncryption:
266 ctx->sinfo->sig->pkey_algo = "rsa";
269 printk("Unsupported pkey algo: %u\n", ctx->last_oid);
276 * We only support signed data [RFC2315 sec 9].
278 int pkcs7_check_content_type(void *context, size_t hdrlen,
280 const void *value, size_t vlen)
282 struct pkcs7_parse_context *ctx = context;
284 if (ctx->last_oid != OID_signed_data) {
285 pr_warn("Only support pkcs7_signedData type\n");
293 * Note the SignedData version
295 int pkcs7_note_signeddata_version(void *context, size_t hdrlen,
297 const void *value, size_t vlen)
299 struct pkcs7_parse_context *ctx = context;
305 ctx->msg->version = version = *(const u8 *)value;
308 /* PKCS#7 SignedData [RFC2315 sec 9.1]
309 * CMS ver 1 SignedData [RFC5652 sec 5.1]
313 /* CMS ver 3 SignedData [RFC2315 sec 5.1] */
322 pr_warn("Unsupported SignedData version\n");
327 * Note the SignerInfo version
329 int pkcs7_note_signerinfo_version(void *context, size_t hdrlen,
331 const void *value, size_t vlen)
333 struct pkcs7_parse_context *ctx = context;
339 version = *(const u8 *)value;
342 /* PKCS#7 SignerInfo [RFC2315 sec 9.2]
343 * CMS ver 1 SignerInfo [RFC5652 sec 5.3]
345 if (ctx->msg->version != 1)
346 goto version_mismatch;
347 ctx->expect_skid = false;
350 /* CMS ver 3 SignerInfo [RFC2315 sec 5.3] */
351 if (ctx->msg->version == 1)
352 goto version_mismatch;
353 ctx->expect_skid = true;
362 pr_warn("Unsupported SignerInfo version\n");
365 pr_warn("SignedData-SignerInfo version mismatch\n");
370 * Extract a certificate and store it in the context.
372 int pkcs7_extract_cert(void *context, size_t hdrlen,
374 const void *value, size_t vlen)
376 struct pkcs7_parse_context *ctx = context;
377 struct x509_certificate *x509;
379 if (tag != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | ASN1_SEQ)) {
380 pr_debug("Cert began with tag %02x at %lu\n",
381 tag, (unsigned long)ctx - ctx->data);
385 /* We have to correct for the header so that the X.509 parser can start
386 * from the beginning. Note that since X.509 stipulates DER, there
387 * probably shouldn't be an EOC trailer - but it is in PKCS#7 (which
393 if (((u8*)value)[1] == 0x80)
394 vlen += 2; /* Indefinite length - there should be an EOC */
396 x509 = x509_cert_parse(value, vlen);
398 return PTR_ERR(x509);
400 x509->index = ++ctx->x509_index;
401 pr_debug("Got cert %u for %s\n", x509->index, x509->subject);
402 pr_debug("- fingerprint %*phN\n", x509->id->len, x509->id->data);
404 *ctx->ppcerts = x509;
405 ctx->ppcerts = &x509->next;
410 * Save the certificate list
412 int pkcs7_note_certificate_list(void *context, size_t hdrlen,
414 const void *value, size_t vlen)
416 struct pkcs7_parse_context *ctx = context;
418 pr_devel("Got cert list (%02x)\n", tag);
420 *ctx->ppcerts = ctx->msg->certs;
421 ctx->msg->certs = ctx->certs;
423 ctx->ppcerts = &ctx->certs;
428 * Note the content type.
430 int pkcs7_note_content(void *context, size_t hdrlen,
432 const void *value, size_t vlen)
434 struct pkcs7_parse_context *ctx = context;
436 if (ctx->last_oid != OID_data &&
437 ctx->last_oid != OID_msIndirectData) {
438 pr_warn("Unsupported data type %d\n", ctx->last_oid);
442 ctx->msg->data_type = ctx->last_oid;
447 * Extract the data from the message and store that and its content type OID in
450 int pkcs7_note_data(void *context, size_t hdrlen,
452 const void *value, size_t vlen)
454 struct pkcs7_parse_context *ctx = context;
456 pr_debug("Got data\n");
458 ctx->msg->data = value;
459 ctx->msg->data_len = vlen;
460 ctx->msg->data_hdrlen = hdrlen;
465 * Parse authenticated attributes.
467 int pkcs7_sig_note_authenticated_attr(void *context, size_t hdrlen,
469 const void *value, size_t vlen)
471 struct pkcs7_parse_context *ctx = context;
472 struct pkcs7_signed_info *sinfo = ctx->sinfo;
473 enum OID content_type;
475 pr_devel("AuthAttr: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
477 switch (ctx->last_oid) {
478 case OID_contentType:
479 if (__test_and_set_bit(sinfo_has_content_type, &sinfo->aa_set))
481 content_type = look_up_OID(value, vlen);
482 if (content_type != ctx->msg->data_type) {
483 pr_warn("Mismatch between global data type (%d) and sinfo %u (%d)\n",
484 ctx->msg->data_type, sinfo->index,
490 case OID_signingTime:
491 if (__test_and_set_bit(sinfo_has_signing_time, &sinfo->aa_set))
493 /* Should we check that the signing time is consistent
494 * with the signer's X.509 cert?
496 return x509_decode_time(&sinfo->signing_time,
497 hdrlen, tag, value, vlen);
499 case OID_messageDigest:
500 if (__test_and_set_bit(sinfo_has_message_digest, &sinfo->aa_set))
504 sinfo->msgdigest = value;
505 sinfo->msgdigest_len = vlen;
508 case OID_smimeCapabilites:
509 if (__test_and_set_bit(sinfo_has_smime_caps, &sinfo->aa_set))
511 if (ctx->msg->data_type != OID_msIndirectData) {
512 pr_warn("S/MIME Caps only allowed with Authenticode\n");
513 return -EKEYREJECTED;
517 /* Microsoft SpOpusInfo seems to be contain cont[0] 16-bit BE
518 * char URLs and cont[1] 8-bit char URLs.
520 * Microsoft StatementType seems to contain a list of OIDs that
521 * are also used as extendedKeyUsage types in X.509 certs.
523 case OID_msSpOpusInfo:
524 if (__test_and_set_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))
526 goto authenticode_check;
527 case OID_msStatementType:
528 if (__test_and_set_bit(sinfo_has_ms_statement_type, &sinfo->aa_set))
531 if (ctx->msg->data_type != OID_msIndirectData) {
532 pr_warn("Authenticode AuthAttrs only allowed with Authenticode\n");
533 return -EKEYREJECTED;
535 /* I'm not sure how to validate these */
542 /* We permit max one item per AuthenticatedAttribute and no repeats */
543 pr_warn("Repeated/multivalue AuthAttrs not permitted\n");
544 return -EKEYREJECTED;
548 * Note the set of auth attributes for digestion purposes [RFC2315 sec 9.3]
550 int pkcs7_sig_note_set_of_authattrs(void *context, size_t hdrlen,
552 const void *value, size_t vlen)
554 struct pkcs7_parse_context *ctx = context;
555 struct pkcs7_signed_info *sinfo = ctx->sinfo;
557 if (!test_bit(sinfo_has_content_type, &sinfo->aa_set) ||
558 !test_bit(sinfo_has_message_digest, &sinfo->aa_set)) {
559 pr_warn("Missing required AuthAttr\n");
563 if (ctx->msg->data_type != OID_msIndirectData &&
564 test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set)) {
565 pr_warn("Unexpected Authenticode AuthAttr\n");
569 /* We need to switch the 'CONT 0' to a 'SET OF' when we digest */
570 sinfo->authattrs = value - (hdrlen - 1);
571 sinfo->authattrs_len = vlen + (hdrlen - 1);
576 * Note the issuing certificate serial number
578 int pkcs7_sig_note_serial(void *context, size_t hdrlen,
580 const void *value, size_t vlen)
582 struct pkcs7_parse_context *ctx = context;
583 ctx->raw_serial = value;
584 ctx->raw_serial_size = vlen;
589 * Note the issuer's name
591 int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
593 const void *value, size_t vlen)
595 struct pkcs7_parse_context *ctx = context;
596 ctx->raw_issuer = value;
597 ctx->raw_issuer_size = vlen;
602 * Note the issuing cert's subjectKeyIdentifier
604 int pkcs7_sig_note_skid(void *context, size_t hdrlen,
606 const void *value, size_t vlen)
608 struct pkcs7_parse_context *ctx = context;
610 pr_devel("SKID: %02x %zu [%*ph]\n", tag, vlen, (unsigned)vlen, value);
612 ctx->raw_skid = value;
613 ctx->raw_skid_size = vlen;
618 * Note the signature data
620 int pkcs7_sig_note_signature(void *context, size_t hdrlen,
622 const void *value, size_t vlen)
624 struct pkcs7_parse_context *ctx = context;
626 ctx->sinfo->sig->s = kmemdup(value, vlen, GFP_KERNEL);
627 if (!ctx->sinfo->sig->s)
630 ctx->sinfo->sig->s_size = vlen;
635 * Note a signature information block
637 int pkcs7_note_signed_info(void *context, size_t hdrlen,
639 const void *value, size_t vlen)
641 struct pkcs7_parse_context *ctx = context;
642 struct pkcs7_signed_info *sinfo = ctx->sinfo;
643 struct asymmetric_key_id *kid;
645 if (ctx->msg->data_type == OID_msIndirectData && !sinfo->authattrs) {
646 pr_warn("Authenticode requires AuthAttrs\n");
650 /* Generate cert issuer + serial number key ID */
651 if (!ctx->expect_skid) {
652 kid = asymmetric_key_generate_id(ctx->raw_serial,
653 ctx->raw_serial_size,
655 ctx->raw_issuer_size);
657 kid = asymmetric_key_generate_id(ctx->raw_skid,
664 pr_devel("SINFO KID: %u [%*phN]\n", kid->len, kid->len, kid->data);
666 sinfo->sig->auth_ids[0] = kid;
667 sinfo->index = ++ctx->sinfo_index;
668 *ctx->ppsinfo = sinfo;
669 ctx->ppsinfo = &sinfo->next;
670 ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
673 ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
675 if (!ctx->sinfo->sig)