crypto/krng.c

   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
  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
  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 */
  49 static int __init krng_mod_init(void)
  50 {
  51         return crypto_register_alg(&krng_alg);
  52 }
  53
  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");