Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 1 | /* |
| 2 | * Cryptographic API. |
| 3 | * |
| 4 | * RNG operations. |
| 5 | * |
| 6 | * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com> |
Herbert Xu | 94f1bb1 | 2015-04-21 10:46:46 +0800 | [diff] [blame] | 7 | * Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au> |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify it |
| 10 | * under the terms of the GNU General Public License as published by the Free |
| 11 | * Software Foundation; either version 2 of the License, or (at your option) |
| 12 | * any later version. |
| 13 | * |
| 14 | */ |
| 15 | |
Arun Sharma | 60063497 | 2011-07-26 16:09:06 -0700 | [diff] [blame] | 16 | #include <linux/atomic.h> |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 17 | #include <crypto/internal/rng.h> |
| 18 | #include <linux/err.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/mutex.h> |
| 21 | #include <linux/random.h> |
| 22 | #include <linux/seq_file.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 23 | #include <linux/slab.h> |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 24 | #include <linux/string.h> |
Steffen Klassert | 792608e | 2011-09-27 07:47:11 +0200 | [diff] [blame] | 25 | #include <linux/cryptouser.h> |
Gideon Israel Dsouza | d8c34b9 | 2016-12-31 21:26:23 +0530 | [diff] [blame] | 26 | #include <linux/compiler.h> |
Steffen Klassert | 792608e | 2011-09-27 07:47:11 +0200 | [diff] [blame] | 27 | #include <net/netlink.h> |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 28 | |
Herbert Xu | d0e8305 | 2015-04-20 13:39:03 +0800 | [diff] [blame] | 29 | #include "internal.h" |
| 30 | |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 31 | static DEFINE_MUTEX(crypto_default_rng_lock); |
| 32 | struct crypto_rng *crypto_default_rng; |
| 33 | EXPORT_SYMBOL_GPL(crypto_default_rng); |
| 34 | static int crypto_default_rng_refcnt; |
| 35 | |
Herbert Xu | 3c5d8fa | 2015-04-21 10:46:37 +0800 | [diff] [blame] | 36 | int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen) |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 37 | { |
| 38 | u8 *buf = NULL; |
| 39 | int err; |
| 40 | |
| 41 | if (!seed && slen) { |
| 42 | buf = kmalloc(slen, GFP_KERNEL); |
| 43 | if (!buf) |
| 44 | return -ENOMEM; |
| 45 | |
Jason A. Donenfeld | c2176f0 | 2017-07-16 19:22:06 +0200 | [diff] [blame] | 46 | err = get_random_bytes_wait(buf, slen); |
| 47 | if (err) |
| 48 | goto out; |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 49 | seed = buf; |
| 50 | } |
| 51 | |
Herbert Xu | 94f1bb1 | 2015-04-21 10:46:46 +0800 | [diff] [blame] | 52 | err = crypto_rng_alg(tfm)->seed(tfm, seed, slen); |
Jason A. Donenfeld | c2176f0 | 2017-07-16 19:22:06 +0200 | [diff] [blame] | 53 | out: |
Herbert Xu | b617b70 | 2015-04-21 10:46:49 +0800 | [diff] [blame] | 54 | kzfree(buf); |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 55 | return err; |
| 56 | } |
Herbert Xu | 3c5d8fa | 2015-04-21 10:46:37 +0800 | [diff] [blame] | 57 | EXPORT_SYMBOL_GPL(crypto_rng_reset); |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 58 | |
Herbert Xu | d0e8305 | 2015-04-20 13:39:03 +0800 | [diff] [blame] | 59 | static int crypto_rng_init_tfm(struct crypto_tfm *tfm) |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 60 | { |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 61 | return 0; |
| 62 | } |
| 63 | |
Herbert Xu | acec27f | 2015-04-21 10:46:38 +0800 | [diff] [blame] | 64 | static unsigned int seedsize(struct crypto_alg *alg) |
| 65 | { |
| 66 | struct rng_alg *ralg = container_of(alg, struct rng_alg, base); |
| 67 | |
Herbert Xu | 94f1bb1 | 2015-04-21 10:46:46 +0800 | [diff] [blame] | 68 | return ralg->seedsize; |
Herbert Xu | acec27f | 2015-04-21 10:46:38 +0800 | [diff] [blame] | 69 | } |
| 70 | |
Herbert Xu | 3acc847 | 2011-11-03 23:46:07 +1100 | [diff] [blame] | 71 | #ifdef CONFIG_NET |
Steffen Klassert | 792608e | 2011-09-27 07:47:11 +0200 | [diff] [blame] | 72 | static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg) |
| 73 | { |
| 74 | struct crypto_report_rng rrng; |
| 75 | |
Mathias Krause | 9a5467bf | 2013-02-05 18:19:13 +0100 | [diff] [blame] | 76 | strncpy(rrng.type, "rng", sizeof(rrng.type)); |
Steffen Klassert | 792608e | 2011-09-27 07:47:11 +0200 | [diff] [blame] | 77 | |
Herbert Xu | acec27f | 2015-04-21 10:46:38 +0800 | [diff] [blame] | 78 | rrng.seedsize = seedsize(alg); |
Steffen Klassert | 792608e | 2011-09-27 07:47:11 +0200 | [diff] [blame] | 79 | |
David S. Miller | 6662df3 | 2012-04-01 20:19:05 -0400 | [diff] [blame] | 80 | if (nla_put(skb, CRYPTOCFGA_REPORT_RNG, |
| 81 | sizeof(struct crypto_report_rng), &rrng)) |
| 82 | goto nla_put_failure; |
Steffen Klassert | 792608e | 2011-09-27 07:47:11 +0200 | [diff] [blame] | 83 | return 0; |
| 84 | |
| 85 | nla_put_failure: |
| 86 | return -EMSGSIZE; |
| 87 | } |
Herbert Xu | 3acc847 | 2011-11-03 23:46:07 +1100 | [diff] [blame] | 88 | #else |
| 89 | static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg) |
| 90 | { |
| 91 | return -ENOSYS; |
| 92 | } |
| 93 | #endif |
Steffen Klassert | 792608e | 2011-09-27 07:47:11 +0200 | [diff] [blame] | 94 | |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 95 | static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg) |
Gideon Israel Dsouza | d8c34b9 | 2016-12-31 21:26:23 +0530 | [diff] [blame] | 96 | __maybe_unused; |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 97 | static void crypto_rng_show(struct seq_file *m, struct crypto_alg *alg) |
| 98 | { |
| 99 | seq_printf(m, "type : rng\n"); |
Herbert Xu | acec27f | 2015-04-21 10:46:38 +0800 | [diff] [blame] | 100 | seq_printf(m, "seedsize : %u\n", seedsize(alg)); |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 101 | } |
| 102 | |
Herbert Xu | 94f1bb1 | 2015-04-21 10:46:46 +0800 | [diff] [blame] | 103 | static const struct crypto_type crypto_rng_type = { |
Herbert Xu | d0e8305 | 2015-04-20 13:39:03 +0800 | [diff] [blame] | 104 | .extsize = crypto_alg_extsize, |
| 105 | .init_tfm = crypto_rng_init_tfm, |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 106 | #ifdef CONFIG_PROC_FS |
| 107 | .show = crypto_rng_show, |
| 108 | #endif |
Steffen Klassert | 792608e | 2011-09-27 07:47:11 +0200 | [diff] [blame] | 109 | .report = crypto_rng_report, |
Herbert Xu | d0e8305 | 2015-04-20 13:39:03 +0800 | [diff] [blame] | 110 | .maskclear = ~CRYPTO_ALG_TYPE_MASK, |
| 111 | .maskset = CRYPTO_ALG_TYPE_MASK, |
| 112 | .type = CRYPTO_ALG_TYPE_RNG, |
| 113 | .tfmsize = offsetof(struct crypto_rng, base), |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 114 | }; |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 115 | |
Herbert Xu | d0e8305 | 2015-04-20 13:39:03 +0800 | [diff] [blame] | 116 | struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask) |
| 117 | { |
| 118 | return crypto_alloc_tfm(alg_name, &crypto_rng_type, type, mask); |
| 119 | } |
| 120 | EXPORT_SYMBOL_GPL(crypto_alloc_rng); |
| 121 | |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 122 | int crypto_get_default_rng(void) |
| 123 | { |
| 124 | struct crypto_rng *rng; |
| 125 | int err; |
| 126 | |
| 127 | mutex_lock(&crypto_default_rng_lock); |
| 128 | if (!crypto_default_rng) { |
| 129 | rng = crypto_alloc_rng("stdrng", 0, 0); |
| 130 | err = PTR_ERR(rng); |
| 131 | if (IS_ERR(rng)) |
| 132 | goto unlock; |
| 133 | |
| 134 | err = crypto_rng_reset(rng, NULL, crypto_rng_seedsize(rng)); |
| 135 | if (err) { |
| 136 | crypto_free_rng(rng); |
| 137 | goto unlock; |
| 138 | } |
| 139 | |
| 140 | crypto_default_rng = rng; |
| 141 | } |
| 142 | |
| 143 | crypto_default_rng_refcnt++; |
| 144 | err = 0; |
| 145 | |
| 146 | unlock: |
| 147 | mutex_unlock(&crypto_default_rng_lock); |
| 148 | |
| 149 | return err; |
| 150 | } |
| 151 | EXPORT_SYMBOL_GPL(crypto_get_default_rng); |
| 152 | |
| 153 | void crypto_put_default_rng(void) |
| 154 | { |
| 155 | mutex_lock(&crypto_default_rng_lock); |
Herbert Xu | 7cecadb | 2015-06-21 19:11:43 +0800 | [diff] [blame] | 156 | crypto_default_rng_refcnt--; |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 157 | mutex_unlock(&crypto_default_rng_lock); |
| 158 | } |
| 159 | EXPORT_SYMBOL_GPL(crypto_put_default_rng); |
| 160 | |
Herbert Xu | 7cecadb | 2015-06-21 19:11:43 +0800 | [diff] [blame] | 161 | #if defined(CONFIG_CRYPTO_RNG) || defined(CONFIG_CRYPTO_RNG_MODULE) |
| 162 | int crypto_del_default_rng(void) |
| 163 | { |
| 164 | int err = -EBUSY; |
| 165 | |
| 166 | mutex_lock(&crypto_default_rng_lock); |
| 167 | if (crypto_default_rng_refcnt) |
| 168 | goto out; |
| 169 | |
| 170 | crypto_free_rng(crypto_default_rng); |
| 171 | crypto_default_rng = NULL; |
| 172 | |
| 173 | err = 0; |
| 174 | |
| 175 | out: |
| 176 | mutex_unlock(&crypto_default_rng_lock); |
| 177 | |
| 178 | return err; |
| 179 | } |
| 180 | EXPORT_SYMBOL_GPL(crypto_del_default_rng); |
| 181 | #endif |
| 182 | |
Herbert Xu | acec27f | 2015-04-21 10:46:38 +0800 | [diff] [blame] | 183 | int crypto_register_rng(struct rng_alg *alg) |
| 184 | { |
| 185 | struct crypto_alg *base = &alg->base; |
| 186 | |
| 187 | if (alg->seedsize > PAGE_SIZE / 8) |
| 188 | return -EINVAL; |
| 189 | |
| 190 | base->cra_type = &crypto_rng_type; |
| 191 | base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; |
| 192 | base->cra_flags |= CRYPTO_ALG_TYPE_RNG; |
| 193 | |
| 194 | return crypto_register_alg(base); |
| 195 | } |
| 196 | EXPORT_SYMBOL_GPL(crypto_register_rng); |
| 197 | |
| 198 | void crypto_unregister_rng(struct rng_alg *alg) |
| 199 | { |
| 200 | crypto_unregister_alg(&alg->base); |
| 201 | } |
| 202 | EXPORT_SYMBOL_GPL(crypto_unregister_rng); |
| 203 | |
Herbert Xu | 881cd6c | 2015-04-21 10:46:40 +0800 | [diff] [blame] | 204 | int crypto_register_rngs(struct rng_alg *algs, int count) |
| 205 | { |
| 206 | int i, ret; |
| 207 | |
| 208 | for (i = 0; i < count; i++) { |
| 209 | ret = crypto_register_rng(algs + i); |
| 210 | if (ret) |
| 211 | goto err; |
| 212 | } |
| 213 | |
| 214 | return 0; |
| 215 | |
| 216 | err: |
| 217 | for (--i; i >= 0; --i) |
| 218 | crypto_unregister_rng(algs + i); |
| 219 | |
| 220 | return ret; |
| 221 | } |
| 222 | EXPORT_SYMBOL_GPL(crypto_register_rngs); |
| 223 | |
| 224 | void crypto_unregister_rngs(struct rng_alg *algs, int count) |
| 225 | { |
| 226 | int i; |
| 227 | |
| 228 | for (i = count - 1; i >= 0; --i) |
| 229 | crypto_unregister_rng(algs + i); |
| 230 | } |
| 231 | EXPORT_SYMBOL_GPL(crypto_unregister_rngs); |
| 232 | |
Neil Horman | 17f0f4a | 2008-08-14 22:15:52 +1000 | [diff] [blame] | 233 | MODULE_LICENSE("GPL"); |
Christian Kujau | a8ccc39 | 2009-08-13 11:53:56 +1000 | [diff] [blame] | 234 | MODULE_DESCRIPTION("Random Number Generator"); |