crypto: drbg - header file for DRBG
The header file includes the definition of:
* DRBG data structures with
- struct drbg_state as main structure
- struct drbg_core referencing the backend ciphers
- struct drbg_state_ops callbach handlers for specific code
supporting the Hash, HMAC, CTR DRBG implementations
- struct drbg_conc defining a linked list for input data
- struct drbg_test_data holding the test "entropy" data for CAVS
testing and testmgr.c
- struct drbg_gen allowing test data, additional information
string and personalization string data to be funneled through
the kernel crypto API -- the DRBG requires additional
parameters when invoking the reset and random number
generation requests than intended by the kernel crypto API
* wrapper function to the kernel crypto API functions using struct
drbg_gen to pass through all data needed for DRBG
* wrapper functions to kernel crypto API functions usable for testing
code to inject test_data into the DRBG as needed by CAVS testing and
testmgr.c.
* DRBG flags required for the operation of the DRBG and for selecting
the particular DRBG type and backend cipher
* getter functions for data from struct drbg_core
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Stephan Mueller
Herbert Xu
parent
541af946fe
commit
3e16f959b9
|
|
@ -0,0 +1,289 @@
|
|||
/*
|
||||
* DRBG based on NIST SP800-90A
|
||||
*
|
||||
* Copyright Stephan Mueller <smueller@chronox.de>, 2014
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, and the entire permission notice in its entirety,
|
||||
* including the disclaimer of warranties.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
* 3. The name of the author may not be used to endorse or promote
|
||||
* products derived from this software without specific prior
|
||||
* written permission.
|
||||
*
|
||||
* ALTERNATIVELY, this product may be distributed under the terms of
|
||||
* the GNU General Public License, in which case the provisions of the GPL are
|
||||
* required INSTEAD OF the above restrictions. (This clause is
|
||||
* necessary due to a potential bad interaction between the GPL and
|
||||
* the restrictions contained in a BSD-style copyright.)
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
|
||||
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
||||
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
|
||||
* WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
|
||||
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
||||
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
|
||||
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
|
||||
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
||||
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
|
||||
* USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
|
||||
* DAMAGE.
|
||||
*/
|
||||
|
||||
#ifndef _DRBG_H
|
||||
#define _DRBG_H
|
||||
|
||||
|
||||
#include <linux/random.h>
|
||||
#include <linux/scatterlist.h>
|
||||
#include <crypto/hash.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/crypto.h>
|
||||
#include <linux/slab.h>
|
||||
#include <crypto/internal/rng.h>
|
||||
#include <crypto/rng.h>
|
||||
#include <linux/fips.h>
|
||||
#include <linux/spinlock.h>
|
||||
|
||||
/*
|
||||
* Concatenation Helper and string operation helper
|
||||
*
|
||||
* SP800-90A requires the concatenation of different data. To avoid copying
|
||||
* buffers around or allocate additional memory, the following data structure
|
||||
* is used to point to the original memory with its size. In addition, it
|
||||
* is used to build a linked list. The linked list defines the concatenation
|
||||
* of individual buffers. The order of memory block referenced in that
|
||||
* linked list determines the order of concatenation.
|
||||
*/
|
||||
struct drbg_string {
|
||||
const unsigned char *buf;
|
||||
size_t len;
|
||||
struct drbg_string *next;
|
||||
};
|
||||
|
||||
static inline void drbg_string_fill(struct drbg_string *string,
|
||||
const unsigned char *buf, size_t len)
|
||||
{
|
||||
string->buf = buf;
|
||||
string->len = len;
|
||||
string->next = NULL;
|
||||
}
|
||||
|
||||
struct drbg_state;
|
||||
typedef uint32_t drbg_flag_t;
|
||||
|
||||
struct drbg_core {
|
||||
drbg_flag_t flags; /* flags for the cipher */
|
||||
__u8 statelen; /* maximum state length */
|
||||
/*
|
||||
* maximum length of personalization string or additional input
|
||||
* string -- exponent for base 2
|
||||
*/
|
||||
__u8 max_addtllen;
|
||||
/* maximum bits per RNG request -- exponent for base 2*/
|
||||
__u8 max_bits;
|
||||
/* maximum number of requests -- exponent for base 2 */
|
||||
__u8 max_req;
|
||||
__u8 blocklen_bytes; /* block size of output in bytes */
|
||||
char cra_name[CRYPTO_MAX_ALG_NAME]; /* mapping to kernel crypto API */
|
||||
/* kernel crypto API backend cipher name */
|
||||
char backend_cra_name[CRYPTO_MAX_ALG_NAME];
|
||||
};
|
||||
|
||||
struct drbg_state_ops {
|
||||
int (*update)(struct drbg_state *drbg, struct drbg_string *seed,
|
||||
int reseed);
|
||||
int (*generate)(struct drbg_state *drbg,
|
||||
unsigned char *buf, unsigned int buflen,
|
||||
struct drbg_string *addtl);
|
||||
int (*crypto_init)(struct drbg_state *drbg);
|
||||
int (*crypto_fini)(struct drbg_state *drbg);
|
||||
|
||||
};
|
||||
|
||||
struct drbg_test_data {
|
||||
struct drbg_string *testentropy; /* TEST PARAMETER: test entropy */
|
||||
};
|
||||
|
||||
struct drbg_state {
|
||||
spinlock_t drbg_lock; /* lock around DRBG */
|
||||
unsigned char *V; /* internal state 10.1.1.1 1a) */
|
||||
/* hash: static value 10.1.1.1 1b) hmac / ctr: key */
|
||||
unsigned char *C;
|
||||
/* Number of RNG requests since last reseed -- 10.1.1.1 1c) */
|
||||
size_t reseed_ctr;
|
||||
/* some memory the DRBG can use for its operation */
|
||||
unsigned char *scratchpad;
|
||||
void *priv_data; /* Cipher handle */
|
||||
bool seeded; /* DRBG fully seeded? */
|
||||
bool pr; /* Prediction resistance enabled? */
|
||||
#ifdef CONFIG_CRYPTO_FIPS
|
||||
bool fips_primed; /* Continuous test primed? */
|
||||
unsigned char *prev; /* FIPS 140-2 continuous test value */
|
||||
#endif
|
||||
const struct drbg_state_ops *d_ops;
|
||||
const struct drbg_core *core;
|
||||
struct drbg_test_data *test_data;
|
||||
};
|
||||
|
||||
static inline __u8 drbg_statelen(struct drbg_state *drbg)
|
||||
{
|
||||
if (drbg && drbg->core)
|
||||
return drbg->core->statelen;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline __u8 drbg_blocklen(struct drbg_state *drbg)
|
||||
{
|
||||
if (drbg && drbg->core)
|
||||
return drbg->core->blocklen_bytes;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline __u8 drbg_keylen(struct drbg_state *drbg)
|
||||
{
|
||||
if (drbg && drbg->core)
|
||||
return (drbg->core->statelen - drbg->core->blocklen_bytes);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline size_t drbg_max_request_bytes(struct drbg_state *drbg)
|
||||
{
|
||||
/* max_bits is in bits, but buflen is in bytes */
|
||||
return (1 << (drbg->core->max_bits - 3));
|
||||
}
|
||||
|
||||
static inline size_t drbg_max_addtl(struct drbg_state *drbg)
|
||||
{
|
||||
return (1UL<<(drbg->core->max_addtllen));
|
||||
}
|
||||
|
||||
static inline size_t drbg_max_requests(struct drbg_state *drbg)
|
||||
{
|
||||
return (1UL<<(drbg->core->max_req));
|
||||
}
|
||||
|
||||
/*
|
||||
* kernel crypto API input data structure for DRBG generate in case dlen
|
||||
* is set to 0
|
||||
*/
|
||||
struct drbg_gen {
|
||||
unsigned char *outbuf; /* output buffer for random numbers */
|
||||
unsigned int outlen; /* size of output buffer */
|
||||
struct drbg_string *addtl; /* additional information string */
|
||||
struct drbg_test_data *test_data; /* test data */
|
||||
};
|
||||
|
||||
/*
|
||||
* This is a wrapper to the kernel crypto API function of
|
||||
* crypto_rng_get_bytes() to allow the caller to provide additional data.
|
||||
*
|
||||
* @drng DRBG handle -- see crypto_rng_get_bytes
|
||||
* @outbuf output buffer -- see crypto_rng_get_bytes
|
||||
* @outlen length of output buffer -- see crypto_rng_get_bytes
|
||||
* @addtl_input additional information string input buffer
|
||||
* @addtllen length of additional information string buffer
|
||||
*
|
||||
* return
|
||||
* see crypto_rng_get_bytes
|
||||
*/
|
||||
static inline int crypto_drbg_get_bytes_addtl(struct crypto_rng *drng,
|
||||
unsigned char *outbuf, unsigned int outlen,
|
||||
struct drbg_string *addtl)
|
||||
{
|
||||
int ret;
|
||||
struct drbg_gen genbuf;
|
||||
genbuf.outbuf = outbuf;
|
||||
genbuf.outlen = outlen;
|
||||
genbuf.addtl = addtl;
|
||||
genbuf.test_data = NULL;
|
||||
ret = crypto_rng_get_bytes(drng, (u8 *)&genbuf, 0);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* TEST code
|
||||
*
|
||||
* This is a wrapper to the kernel crypto API function of
|
||||
* crypto_rng_get_bytes() to allow the caller to provide additional data and
|
||||
* allow furnishing of test_data
|
||||
*
|
||||
* @drng DRBG handle -- see crypto_rng_get_bytes
|
||||
* @outbuf output buffer -- see crypto_rng_get_bytes
|
||||
* @outlen length of output buffer -- see crypto_rng_get_bytes
|
||||
* @addtl_input additional information string input buffer
|
||||
* @addtllen length of additional information string buffer
|
||||
* @test_data filled test data
|
||||
*
|
||||
* return
|
||||
* see crypto_rng_get_bytes
|
||||
*/
|
||||
static inline int crypto_drbg_get_bytes_addtl_test(struct crypto_rng *drng,
|
||||
unsigned char *outbuf, unsigned int outlen,
|
||||
struct drbg_string *addtl,
|
||||
struct drbg_test_data *test_data)
|
||||
{
|
||||
int ret;
|
||||
struct drbg_gen genbuf;
|
||||
genbuf.outbuf = outbuf;
|
||||
genbuf.outlen = outlen;
|
||||
genbuf.addtl = addtl;
|
||||
genbuf.test_data = test_data;
|
||||
ret = crypto_rng_get_bytes(drng, (u8 *)&genbuf, 0);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* TEST code
|
||||
*
|
||||
* This is a wrapper to the kernel crypto API function of
|
||||
* crypto_rng_reset() to allow the caller to provide test_data
|
||||
*
|
||||
* @drng DRBG handle -- see crypto_rng_reset
|
||||
* @pers personalization string input buffer
|
||||
* @perslen length of additional information string buffer
|
||||
* @test_data filled test data
|
||||
*
|
||||
* return
|
||||
* see crypto_rng_reset
|
||||
*/
|
||||
static inline int crypto_drbg_reset_test(struct crypto_rng *drng,
|
||||
struct drbg_string *pers,
|
||||
struct drbg_test_data *test_data)
|
||||
{
|
||||
int ret;
|
||||
struct drbg_gen genbuf;
|
||||
genbuf.outbuf = NULL;
|
||||
genbuf.outlen = 0;
|
||||
genbuf.addtl = pers;
|
||||
genbuf.test_data = test_data;
|
||||
ret = crypto_rng_reset(drng, (u8 *)&genbuf, 0);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* DRBG type flags */
|
||||
#define DRBG_CTR ((drbg_flag_t)1<<0)
|
||||
#define DRBG_HMAC ((drbg_flag_t)1<<1)
|
||||
#define DRBG_HASH ((drbg_flag_t)1<<2)
|
||||
#define DRBG_TYPE_MASK (DRBG_CTR | DRBG_HMAC | DRBG_HASH)
|
||||
/* DRBG strength flags */
|
||||
#define DRBG_STRENGTH128 ((drbg_flag_t)1<<3)
|
||||
#define DRBG_STRENGTH192 ((drbg_flag_t)1<<4)
|
||||
#define DRBG_STRENGTH256 ((drbg_flag_t)1<<5)
|
||||
#define DRBG_STRENGTH_MASK (DRBG_STRENGTH128 | DRBG_STRENGTH192 | \
|
||||
DRBG_STRENGTH256)
|
||||
|
||||
enum drbg_prefixes {
|
||||
DRBG_PREFIX0 = 0x00,
|
||||
DRBG_PREFIX1,
|
||||
DRBG_PREFIX2,
|
||||
DRBG_PREFIX3
|
||||
};
|
||||
|
||||
#endif /* _DRBG_H */
|
||||
Loading…
Reference in New Issue