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Commit | Line | Data |
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17f0f4a4 NH |
1 | /* |
2 | * Cryptographic API. | |
3 | * | |
4 | * RNG operations. | |
5 | * | |
6 | * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by the Free | |
10 | * Software Foundation; either version 2 of the License, or (at your option) | |
11 | * any later version. | |
12 | * | |
13 | */ | |
14 | ||
60063497 | 15 | #include <linux/atomic.h> |
17f0f4a4 NH |
16 | #include <crypto/internal/rng.h> |
17 | #include <linux/err.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/mutex.h> | |
20 | #include <linux/random.h> | |
21 | #include <linux/seq_file.h> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
17f0f4a4 | 23 | #include <linux/string.h> |
792608e9 SK |
24 | #include <linux/cryptouser.h> |
25 | #include <net/netlink.h> | |
17f0f4a4 | 26 | |
d0e83059 HX |
27 | #include "internal.h" |
28 | ||
17f0f4a4 NH |
29 | static DEFINE_MUTEX(crypto_default_rng_lock); |
30 | struct crypto_rng *crypto_default_rng; | |
31 | EXPORT_SYMBOL_GPL(crypto_default_rng); | |
32 | static int crypto_default_rng_refcnt; | |
33 | ||
d0e83059 HX |
34 | static inline struct crypto_rng *__crypto_rng_cast(struct crypto_tfm *tfm) |
35 | { | |
36 | return container_of(tfm, struct crypto_rng, base); | |
37 | } | |
38 | ||
ff030b09 HX |
39 | static int generate(struct crypto_rng *tfm, const u8 *src, unsigned int slen, |
40 | u8 *dst, unsigned int dlen) | |
41 | { | |
42 | return crypto_rng_alg(tfm)->rng_make_random(tfm, dst, dlen); | |
43 | } | |
44 | ||
3c5d8fa9 HX |
45 | static int rngapi_reset(struct crypto_rng *tfm, const u8 *seed, |
46 | unsigned int slen) | |
47 | { | |
48 | u8 *buf = NULL; | |
49 | u8 *src = (u8 *)seed; | |
50 | int err; | |
51 | ||
52 | if (slen) { | |
53 | buf = kmalloc(slen, GFP_KERNEL); | |
54 | if (!buf) | |
55 | return -ENOMEM; | |
56 | ||
57 | memcpy(buf, seed, slen); | |
58 | src = buf; | |
59 | } | |
60 | ||
61 | err = crypto_rng_alg(tfm)->rng_reset(tfm, src, slen); | |
62 | ||
63 | kzfree(buf); | |
64 | return err; | |
65 | } | |
66 | ||
67 | int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen) | |
17f0f4a4 NH |
68 | { |
69 | u8 *buf = NULL; | |
70 | int err; | |
71 | ||
72 | if (!seed && slen) { | |
73 | buf = kmalloc(slen, GFP_KERNEL); | |
74 | if (!buf) | |
75 | return -ENOMEM; | |
76 | ||
77 | get_random_bytes(buf, slen); | |
78 | seed = buf; | |
79 | } | |
80 | ||
3c5d8fa9 | 81 | err = tfm->seed(tfm, seed, slen); |
17f0f4a4 NH |
82 | |
83 | kfree(buf); | |
84 | return err; | |
85 | } | |
3c5d8fa9 | 86 | EXPORT_SYMBOL_GPL(crypto_rng_reset); |
17f0f4a4 | 87 | |
d0e83059 | 88 | static int crypto_rng_init_tfm(struct crypto_tfm *tfm) |
17f0f4a4 | 89 | { |
d0e83059 | 90 | struct crypto_rng *rng = __crypto_rng_cast(tfm); |
17f0f4a4 | 91 | |
ff030b09 | 92 | rng->generate = generate; |
d0e83059 | 93 | rng->seed = rngapi_reset; |
17f0f4a4 NH |
94 | |
95 | return 0; | |
96 | } | |
97 | ||
3acc8473 | 98 | #ifdef CONFIG_NET |
792608e9 SK |
99 | static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg) |
100 | { | |
101 | struct crypto_report_rng rrng; | |
102 | ||
9a5467bf | 103 | strncpy(rrng.type, "rng", sizeof(rrng.type)); |
792608e9 SK |
104 | |
105 | rrng.seedsize = alg->cra_rng.seedsize; | |
106 | ||
6662df33 DM |
107 | if (nla_put(skb, CRYPTOCFGA_REPORT_RNG, |
108 | sizeof(struct crypto_report_rng), &rrng)) | |
109 | goto nla_put_failure; | |
792608e9 SK |
110 | return 0; |
111 | ||
112 | nla_put_failure: | |
113 | return -EMSGSIZE; | |
114 | } | |
3acc8473 HX |
115 | #else |
116 | static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg) | |
117 | { | |
118 | return -ENOSYS; | |
119 | } | |
120 | #endif | |
792608e9 | 121 | |
17f0f4a4 NH |
122 | static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg) |
123 | __attribute__ ((unused)); | |
124 | static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg) | |
125 | { | |
126 | seq_printf(m, "type : rng\n"); | |
127 | seq_printf(m, "seedsize : %u\n", alg->cra_rng.seedsize); | |
128 | } | |
129 | ||
17f0f4a4 | 130 | const struct crypto_type crypto_rng_type = { |
d0e83059 HX |
131 | .extsize = crypto_alg_extsize, |
132 | .init_tfm = crypto_rng_init_tfm, | |
17f0f4a4 NH |
133 | #ifdef CONFIG_PROC_FS |
134 | .show = crypto_rng_show, | |
135 | #endif | |
792608e9 | 136 | .report = crypto_rng_report, |
d0e83059 HX |
137 | .maskclear = ~CRYPTO_ALG_TYPE_MASK, |
138 | .maskset = CRYPTO_ALG_TYPE_MASK, | |
139 | .type = CRYPTO_ALG_TYPE_RNG, | |
140 | .tfmsize = offsetof(struct crypto_rng, base), | |
17f0f4a4 NH |
141 | }; |
142 | EXPORT_SYMBOL_GPL(crypto_rng_type); | |
143 | ||
d0e83059 HX |
144 | struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask) |
145 | { | |
146 | return crypto_alloc_tfm(alg_name, &crypto_rng_type, type, mask); | |
147 | } | |
148 | EXPORT_SYMBOL_GPL(crypto_alloc_rng); | |
149 | ||
17f0f4a4 NH |
150 | int crypto_get_default_rng(void) |
151 | { | |
152 | struct crypto_rng *rng; | |
153 | int err; | |
154 | ||
155 | mutex_lock(&crypto_default_rng_lock); | |
156 | if (!crypto_default_rng) { | |
157 | rng = crypto_alloc_rng("stdrng", 0, 0); | |
158 | err = PTR_ERR(rng); | |
159 | if (IS_ERR(rng)) | |
160 | goto unlock; | |
161 | ||
162 | err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng)); | |
163 | if (err) { | |
164 | crypto_free_rng(rng); | |
165 | goto unlock; | |
166 | } | |
167 | ||
168 | crypto_default_rng = rng; | |
169 | } | |
170 | ||
171 | crypto_default_rng_refcnt++; | |
172 | err = 0; | |
173 | ||
174 | unlock: | |
175 | mutex_unlock(&crypto_default_rng_lock); | |
176 | ||
177 | return err; | |
178 | } | |
179 | EXPORT_SYMBOL_GPL(crypto_get_default_rng); | |
180 | ||
181 | void crypto_put_default_rng(void) | |
182 | { | |
183 | mutex_lock(&crypto_default_rng_lock); | |
184 | if (!--crypto_default_rng_refcnt) { | |
185 | crypto_free_rng(crypto_default_rng); | |
186 | crypto_default_rng = NULL; | |
187 | } | |
188 | mutex_unlock(&crypto_default_rng_lock); | |
189 | } | |
190 | EXPORT_SYMBOL_GPL(crypto_put_default_rng); | |
191 | ||
192 | MODULE_LICENSE("GPL"); | |
a8ccc393 | 193 | MODULE_DESCRIPTION("Random Number Generator"); |