1 /*
2 * RNG implementation using standard kernel RNG.
3 *
4 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * any later version.
10 *
11 */
12
13 #include <crypto/internal/rng.h>
14 #include <linux/err.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/random.h>
18
krng_get_random(struct crypto_rng * tfm,u8 * rdata,unsigned int dlen)19 static int krng_get_random(struct crypto_rng *tfm, u8 *rdata, unsigned int dlen)
20 {
21 get_random_bytes(rdata, dlen);
22 return 0;
23 }
24
krng_reset(struct crypto_rng * tfm,u8 * seed,unsigned int slen)25 static int krng_reset(struct crypto_rng *tfm, u8 *seed, unsigned int slen)
26 {
27 return 0;
28 }
29
30 static struct crypto_alg krng_alg = {
31 .cra_name = "stdrng",
32 .cra_driver_name = "krng",
33 .cra_priority = 200,
34 .cra_flags = CRYPTO_ALG_TYPE_RNG,
35 .cra_ctxsize = 0,
36 .cra_type = &crypto_rng_type,
37 .cra_module = THIS_MODULE,
38 .cra_u = {
39 .rng = {
40 .rng_make_random = krng_get_random,
41 .rng_reset = krng_reset,
42 .seedsize = 0,
43 }
44 }
45 };
46
47
48 /* Module initalization */
krng_mod_init(void)49 static int __init krng_mod_init(void)
50 {
51 return crypto_register_alg(&krng_alg);
52 }
53
krng_mod_fini(void)54 static void __exit krng_mod_fini(void)
55 {
56 crypto_unregister_alg(&krng_alg);
57 return;
58 }
59
60 module_init(krng_mod_init);
61 module_exit(krng_mod_fini);
62
63 MODULE_LICENSE("GPL");
64 MODULE_DESCRIPTION("Kernel Random Number Generator");
65 MODULE_ALIAS_CRYPTO("stdrng");
66 MODULE_ALIAS_CRYPTO("krng");
67