228 строки
7.3 KiB
C
228 строки
7.3 KiB
C
/*
|
|
* RNG: Random Number Generator algorithms under the crypto API
|
|
*
|
|
* Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
|
|
* Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the Free
|
|
* Software Foundation; either version 2 of the License, or (at your option)
|
|
* any later version.
|
|
*
|
|
*/
|
|
|
|
#ifndef _CRYPTO_RNG_H
|
|
#define _CRYPTO_RNG_H
|
|
|
|
#include <linux/crypto.h>
|
|
|
|
struct crypto_rng;
|
|
|
|
/**
|
|
* struct rng_alg - random number generator definition
|
|
*
|
|
* @generate: The function defined by this variable obtains a
|
|
* random number. The random number generator transform
|
|
* must generate the random number out of the context
|
|
* provided with this call, plus any additional data
|
|
* if provided to the call.
|
|
* @seed: Seed or reseed the random number generator. With the
|
|
* invocation of this function call, the random number
|
|
* generator shall become ready for generation. If the
|
|
* random number generator requires a seed for setting
|
|
* up a new state, the seed must be provided by the
|
|
* consumer while invoking this function. The required
|
|
* size of the seed is defined with @seedsize .
|
|
* @set_ent: Set entropy that would otherwise be obtained from
|
|
* entropy source. Internal use only.
|
|
* @seedsize: The seed size required for a random number generator
|
|
* initialization defined with this variable. Some
|
|
* random number generators does not require a seed
|
|
* as the seeding is implemented internally without
|
|
* the need of support by the consumer. In this case,
|
|
* the seed size is set to zero.
|
|
* @base: Common crypto API algorithm data structure.
|
|
*/
|
|
struct rng_alg {
|
|
int (*generate)(struct crypto_rng *tfm,
|
|
const u8 *src, unsigned int slen,
|
|
u8 *dst, unsigned int dlen);
|
|
int (*seed)(struct crypto_rng *tfm, const u8 *seed, unsigned int slen);
|
|
void (*set_ent)(struct crypto_rng *tfm, const u8 *data,
|
|
unsigned int len);
|
|
|
|
unsigned int seedsize;
|
|
|
|
struct crypto_alg base;
|
|
};
|
|
|
|
struct crypto_rng {
|
|
struct crypto_tfm base;
|
|
};
|
|
|
|
extern struct crypto_rng *crypto_default_rng;
|
|
|
|
int crypto_get_default_rng(void);
|
|
void crypto_put_default_rng(void);
|
|
|
|
/**
|
|
* DOC: Random number generator API
|
|
*
|
|
* The random number generator API is used with the ciphers of type
|
|
* CRYPTO_ALG_TYPE_RNG (listed as type "rng" in /proc/crypto)
|
|
*/
|
|
|
|
/**
|
|
* crypto_alloc_rng() -- allocate RNG handle
|
|
* @alg_name: is the cra_name / name or cra_driver_name / driver name of the
|
|
* message digest cipher
|
|
* @type: specifies the type of the cipher
|
|
* @mask: specifies the mask for the cipher
|
|
*
|
|
* Allocate a cipher handle for a random number generator. The returned struct
|
|
* crypto_rng is the cipher handle that is required for any subsequent
|
|
* API invocation for that random number generator.
|
|
*
|
|
* For all random number generators, this call creates a new private copy of
|
|
* the random number generator that does not share a state with other
|
|
* instances. The only exception is the "krng" random number generator which
|
|
* is a kernel crypto API use case for the get_random_bytes() function of the
|
|
* /dev/random driver.
|
|
*
|
|
* Return: allocated cipher handle in case of success; IS_ERR() is true in case
|
|
* of an error, PTR_ERR() returns the error code.
|
|
*/
|
|
struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask);
|
|
|
|
static inline struct crypto_tfm *crypto_rng_tfm(struct crypto_rng *tfm)
|
|
{
|
|
return &tfm->base;
|
|
}
|
|
|
|
/**
|
|
* crypto_rng_alg - obtain name of RNG
|
|
* @tfm: cipher handle
|
|
*
|
|
* Return the generic name (cra_name) of the initialized random number generator
|
|
*
|
|
* Return: generic name string
|
|
*/
|
|
static inline struct rng_alg *crypto_rng_alg(struct crypto_rng *tfm)
|
|
{
|
|
return container_of(crypto_rng_tfm(tfm)->__crt_alg,
|
|
struct rng_alg, base);
|
|
}
|
|
|
|
/**
|
|
* crypto_free_rng() - zeroize and free RNG handle
|
|
* @tfm: cipher handle to be freed
|
|
*/
|
|
static inline void crypto_free_rng(struct crypto_rng *tfm)
|
|
{
|
|
crypto_destroy_tfm(tfm, crypto_rng_tfm(tfm));
|
|
}
|
|
|
|
static inline void crypto_stat_rng_seed(struct crypto_rng *tfm, int ret)
|
|
{
|
|
#ifdef CONFIG_CRYPTO_STATS
|
|
if (ret && ret != -EINPROGRESS && ret != -EBUSY)
|
|
atomic_inc(&tfm->base.__crt_alg->rng_err_cnt);
|
|
else
|
|
atomic_inc(&tfm->base.__crt_alg->seed_cnt);
|
|
#endif
|
|
}
|
|
|
|
static inline void crypto_stat_rng_generate(struct crypto_rng *tfm,
|
|
unsigned int dlen, int ret)
|
|
{
|
|
#ifdef CONFIG_CRYPTO_STATS
|
|
if (ret && ret != -EINPROGRESS && ret != -EBUSY) {
|
|
atomic_inc(&tfm->base.__crt_alg->rng_err_cnt);
|
|
} else {
|
|
atomic_inc(&tfm->base.__crt_alg->generate_cnt);
|
|
atomic64_add(dlen, &tfm->base.__crt_alg->generate_tlen);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* crypto_rng_generate() - get random number
|
|
* @tfm: cipher handle
|
|
* @src: Input buffer holding additional data, may be NULL
|
|
* @slen: Length of additional data
|
|
* @dst: output buffer holding the random numbers
|
|
* @dlen: length of the output buffer
|
|
*
|
|
* This function fills the caller-allocated buffer with random
|
|
* numbers using the random number generator referenced by the
|
|
* cipher handle.
|
|
*
|
|
* Return: 0 function was successful; < 0 if an error occurred
|
|
*/
|
|
static inline int crypto_rng_generate(struct crypto_rng *tfm,
|
|
const u8 *src, unsigned int slen,
|
|
u8 *dst, unsigned int dlen)
|
|
{
|
|
int ret;
|
|
|
|
ret = crypto_rng_alg(tfm)->generate(tfm, src, slen, dst, dlen);
|
|
crypto_stat_rng_generate(tfm, dlen, ret);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* crypto_rng_get_bytes() - get random number
|
|
* @tfm: cipher handle
|
|
* @rdata: output buffer holding the random numbers
|
|
* @dlen: length of the output buffer
|
|
*
|
|
* This function fills the caller-allocated buffer with random numbers using the
|
|
* random number generator referenced by the cipher handle.
|
|
*
|
|
* Return: 0 function was successful; < 0 if an error occurred
|
|
*/
|
|
static inline int crypto_rng_get_bytes(struct crypto_rng *tfm,
|
|
u8 *rdata, unsigned int dlen)
|
|
{
|
|
return crypto_rng_generate(tfm, NULL, 0, rdata, dlen);
|
|
}
|
|
|
|
/**
|
|
* crypto_rng_reset() - re-initialize the RNG
|
|
* @tfm: cipher handle
|
|
* @seed: seed input data
|
|
* @slen: length of the seed input data
|
|
*
|
|
* The reset function completely re-initializes the random number generator
|
|
* referenced by the cipher handle by clearing the current state. The new state
|
|
* is initialized with the caller provided seed or automatically, depending
|
|
* on the random number generator type (the ANSI X9.31 RNG requires
|
|
* caller-provided seed, the SP800-90A DRBGs perform an automatic seeding).
|
|
* The seed is provided as a parameter to this function call. The provided seed
|
|
* should have the length of the seed size defined for the random number
|
|
* generator as defined by crypto_rng_seedsize.
|
|
*
|
|
* Return: 0 if the setting of the key was successful; < 0 if an error occurred
|
|
*/
|
|
int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed,
|
|
unsigned int slen);
|
|
|
|
/**
|
|
* crypto_rng_seedsize() - obtain seed size of RNG
|
|
* @tfm: cipher handle
|
|
*
|
|
* The function returns the seed size for the random number generator
|
|
* referenced by the cipher handle. This value may be zero if the random
|
|
* number generator does not implement or require a reseeding. For example,
|
|
* the SP800-90A DRBGs implement an automated reseeding after reaching a
|
|
* pre-defined threshold.
|
|
*
|
|
* Return: seed size for the random number generator
|
|
*/
|
|
static inline int crypto_rng_seedsize(struct crypto_rng *tfm)
|
|
{
|
|
return crypto_rng_alg(tfm)->seedsize;
|
|
}
|
|
|
|
#endif
|