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a9681bf3 DH |
1 | /* In-software asymmetric public-key crypto subtype |
2 | * | |
3 | * See Documentation/crypto/asymmetric-keys.txt | |
4 | * | |
5 | * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. | |
6 | * Written by David Howells (dhowells@redhat.com) | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public Licence | |
10 | * as published by the Free Software Foundation; either version | |
11 | * 2 of the Licence, or (at your option) any later version. | |
12 | */ | |
13 | ||
14 | #define pr_fmt(fmt) "PKEY: "fmt | |
15 | #include <linux/module.h> | |
16 | #include <linux/export.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/seq_file.h> | |
20 | #include <keys/asymmetric-subtype.h> | |
21 | #include "public_key.h" | |
22 | ||
23 | MODULE_LICENSE("GPL"); | |
24 | ||
9abc4e66 | 25 | const char *const pkey_algo_name[PKEY_ALGO__LAST] = { |
a9681bf3 DH |
26 | [PKEY_ALGO_DSA] = "DSA", |
27 | [PKEY_ALGO_RSA] = "RSA", | |
28 | }; | |
9abc4e66 | 29 | EXPORT_SYMBOL_GPL(pkey_algo_name); |
a9681bf3 | 30 | |
206ce59a DH |
31 | const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST] = { |
32 | #if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \ | |
33 | defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE) | |
34 | [PKEY_ALGO_RSA] = &RSA_public_key_algorithm, | |
35 | #endif | |
36 | }; | |
37 | EXPORT_SYMBOL_GPL(pkey_algo); | |
38 | ||
9abc4e66 | 39 | const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST] = { |
a9681bf3 DH |
40 | [PKEY_ID_PGP] = "PGP", |
41 | [PKEY_ID_X509] = "X509", | |
42 | }; | |
9abc4e66 | 43 | EXPORT_SYMBOL_GPL(pkey_id_type_name); |
a9681bf3 DH |
44 | |
45 | /* | |
46 | * Provide a part of a description of the key for /proc/keys. | |
47 | */ | |
48 | static void public_key_describe(const struct key *asymmetric_key, | |
49 | struct seq_file *m) | |
50 | { | |
51 | struct public_key *key = asymmetric_key->payload.data; | |
52 | ||
53 | if (key) | |
54 | seq_printf(m, "%s.%s", | |
9abc4e66 | 55 | pkey_id_type_name[key->id_type], key->algo->name); |
a9681bf3 DH |
56 | } |
57 | ||
58 | /* | |
59 | * Destroy a public key algorithm key. | |
60 | */ | |
61 | void public_key_destroy(void *payload) | |
62 | { | |
63 | struct public_key *key = payload; | |
64 | int i; | |
65 | ||
66 | if (key) { | |
67 | for (i = 0; i < ARRAY_SIZE(key->mpi); i++) | |
68 | mpi_free(key->mpi[i]); | |
69 | kfree(key); | |
70 | } | |
71 | } | |
72 | EXPORT_SYMBOL_GPL(public_key_destroy); | |
73 | ||
74 | /* | |
75 | * Verify a signature using a public key. | |
76 | */ | |
3d167d68 DH |
77 | int public_key_verify_signature(const struct public_key *pk, |
78 | const struct public_key_signature *sig) | |
a9681bf3 | 79 | { |
3d167d68 DH |
80 | const struct public_key_algorithm *algo; |
81 | ||
82 | BUG_ON(!pk); | |
83 | BUG_ON(!pk->mpi[0]); | |
84 | BUG_ON(!pk->mpi[1]); | |
85 | BUG_ON(!sig); | |
86 | BUG_ON(!sig->digest); | |
87 | BUG_ON(!sig->mpi[0]); | |
88 | ||
89 | algo = pk->algo; | |
90 | if (!algo) { | |
91 | if (pk->pkey_algo >= PKEY_ALGO__LAST) | |
92 | return -ENOPKG; | |
93 | algo = pkey_algo[pk->pkey_algo]; | |
94 | if (!algo) | |
95 | return -ENOPKG; | |
96 | } | |
a9681bf3 | 97 | |
3d167d68 | 98 | if (!algo->verify_signature) |
a9681bf3 DH |
99 | return -ENOTSUPP; |
100 | ||
3d167d68 | 101 | if (sig->nr_mpi != algo->n_sig_mpi) { |
a9681bf3 | 102 | pr_debug("Signature has %u MPI not %u\n", |
3d167d68 | 103 | sig->nr_mpi, algo->n_sig_mpi); |
a9681bf3 DH |
104 | return -EINVAL; |
105 | } | |
106 | ||
3d167d68 DH |
107 | return algo->verify_signature(pk, sig); |
108 | } | |
109 | EXPORT_SYMBOL_GPL(public_key_verify_signature); | |
110 | ||
111 | static int public_key_verify_signature_2(const struct key *key, | |
112 | const struct public_key_signature *sig) | |
113 | { | |
114 | const struct public_key *pk = key->payload.data; | |
115 | return public_key_verify_signature(pk, sig); | |
a9681bf3 DH |
116 | } |
117 | ||
118 | /* | |
119 | * Public key algorithm asymmetric key subtype | |
120 | */ | |
121 | struct asymmetric_key_subtype public_key_subtype = { | |
122 | .owner = THIS_MODULE, | |
123 | .name = "public_key", | |
876c6e3e | 124 | .name_len = sizeof("public_key") - 1, |
a9681bf3 DH |
125 | .describe = public_key_describe, |
126 | .destroy = public_key_destroy, | |
3d167d68 | 127 | .verify_signature = public_key_verify_signature_2, |
a9681bf3 DH |
128 | }; |
129 | EXPORT_SYMBOL_GPL(public_key_subtype); |