1 /* Testing module to load key from trusted PKCS#7 message
3 * Copyright (C) 2014 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) "PKCS7key: "fmt
13 #include <linux/key.h>
14 #include <linux/err.h>
15 #include <linux/module.h>
16 #include <linux/key-type.h>
17 #include <keys/asymmetric-type.h>
18 #include <crypto/pkcs7.h>
19 #include <keys/user-type.h>
20 #include <keys/system_keyring.h>
21 #include "pkcs7_parser.h"
23 static unsigned pkcs7_usage;
24 module_param_named(usage, pkcs7_usage, uint, S_IWUSR | S_IRUGO);
25 MODULE_PARM_DESC(pkcs7_usage,
26 "Usage to specify when verifying the PKCS#7 message");
29 * Preparse a PKCS#7 wrapped and validated data blob.
31 static int pkcs7_preparse(struct key_preparsed_payload *prep)
33 enum key_being_used_for usage = pkcs7_usage;
34 struct pkcs7_message *pkcs7;
35 const void *data, *saved_prep_data;
36 size_t datalen, saved_prep_datalen;
42 if (usage >= NR__KEY_BEING_USED_FOR) {
43 pr_err("Invalid usage type %d\n", usage);
47 saved_prep_data = prep->data;
48 saved_prep_datalen = prep->datalen;
49 pkcs7 = pkcs7_parse_message(saved_prep_data, saved_prep_datalen);
55 ret = pkcs7_verify(pkcs7, usage);
59 ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted);
63 pr_warn("PKCS#7 message doesn't chain back to a trusted key\n");
65 ret = pkcs7_get_content_data(pkcs7, &data, &datalen, false);
70 prep->datalen = datalen;
71 ret = user_preparse(prep);
72 prep->data = saved_prep_data;
73 prep->datalen = saved_prep_datalen;
76 pkcs7_free_message(pkcs7);
83 * user defined keys take an arbitrary string as the description and an
84 * arbitrary blob of data as the payload
86 static struct key_type key_type_pkcs7 = {
88 .preparse = pkcs7_preparse,
89 .free_preparse = user_free_preparse,
90 .instantiate = generic_key_instantiate,
91 .revoke = user_revoke,
92 .destroy = user_destroy,
93 .describe = user_describe,
100 static int __init pkcs7_key_init(void)
102 return register_key_type(&key_type_pkcs7);
105 static void __exit pkcs7_key_cleanup(void)
107 unregister_key_type(&key_type_pkcs7);
110 module_init(pkcs7_key_init);
111 module_exit(pkcs7_key_cleanup);