1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* Testing module to load key from trusted PKCS#7 message |
3 | * |
4 | * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved. |
5 | * Written by David Howells (dhowells@redhat.com) |
6 | */ |
7 | |
8 | #define pr_fmt(fmt) "PKCS7key: "fmt |
9 | #include <linux/key.h> |
10 | #include <linux/err.h> |
11 | #include <linux/module.h> |
12 | #include <linux/verification.h> |
13 | #include <linux/key-type.h> |
14 | #include <keys/user-type.h> |
15 | |
16 | MODULE_LICENSE("GPL" ); |
17 | MODULE_DESCRIPTION("PKCS#7 testing key type" ); |
18 | MODULE_AUTHOR("Red Hat, Inc." ); |
19 | |
20 | static unsigned pkcs7_usage; |
21 | module_param_named(usage, pkcs7_usage, uint, S_IWUSR | S_IRUGO); |
22 | MODULE_PARM_DESC(pkcs7_usage, |
23 | "Usage to specify when verifying the PKCS#7 message" ); |
24 | |
25 | /* |
26 | * Retrieve the PKCS#7 message content. |
27 | */ |
28 | static int pkcs7_view_content(void *ctx, const void *data, size_t len, |
29 | size_t asn1hdrlen) |
30 | { |
31 | struct key_preparsed_payload *prep = ctx; |
32 | const void *saved_prep_data; |
33 | size_t saved_prep_datalen; |
34 | int ret; |
35 | |
36 | saved_prep_data = prep->data; |
37 | saved_prep_datalen = prep->datalen; |
38 | prep->data = data; |
39 | prep->datalen = len; |
40 | |
41 | ret = user_preparse(prep); |
42 | |
43 | prep->data = saved_prep_data; |
44 | prep->datalen = saved_prep_datalen; |
45 | return ret; |
46 | } |
47 | |
48 | /* |
49 | * Preparse a PKCS#7 wrapped and validated data blob. |
50 | */ |
51 | static int pkcs7_preparse(struct key_preparsed_payload *prep) |
52 | { |
53 | enum key_being_used_for usage = pkcs7_usage; |
54 | |
55 | if (usage >= NR__KEY_BEING_USED_FOR) { |
56 | pr_err("Invalid usage type %d\n" , usage); |
57 | return -EINVAL; |
58 | } |
59 | |
60 | return verify_pkcs7_signature(NULL, len: 0, |
61 | raw_pkcs7: prep->data, pkcs7_len: prep->datalen, |
62 | VERIFY_USE_SECONDARY_KEYRING, usage, |
63 | view_content: pkcs7_view_content, ctx: prep); |
64 | } |
65 | |
66 | /* |
67 | * user defined keys take an arbitrary string as the description and an |
68 | * arbitrary blob of data as the payload |
69 | */ |
70 | static struct key_type key_type_pkcs7 = { |
71 | .name = "pkcs7_test" , |
72 | .preparse = pkcs7_preparse, |
73 | .free_preparse = user_free_preparse, |
74 | .instantiate = generic_key_instantiate, |
75 | .revoke = user_revoke, |
76 | .destroy = user_destroy, |
77 | .describe = user_describe, |
78 | .read = user_read, |
79 | }; |
80 | |
81 | /* |
82 | * Module stuff |
83 | */ |
84 | static int __init pkcs7_key_init(void) |
85 | { |
86 | return register_key_type(ktype: &key_type_pkcs7); |
87 | } |
88 | |
89 | static void __exit pkcs7_key_cleanup(void) |
90 | { |
91 | unregister_key_type(ktype: &key_type_pkcs7); |
92 | } |
93 | |
94 | module_init(pkcs7_key_init); |
95 | module_exit(pkcs7_key_cleanup); |
96 | |