[linux-2.6-block.git] / include / crypto / drbg.h

/*
 * 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>
#include <linux/list.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 list_head list;
};

static inline void drbg_string_fill(struct drbg_string *string,
				    const unsigned char *buf, size_t len)
{
	string->buf = buf;
	string->len = len;
	INIT_LIST_HEAD(&string->list);
}

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 */
	__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 list_head *seed,
		      int reseed);
	int (*generate)(struct drbg_state *drbg,
			unsigned char *buf, unsigned int buflen,
			struct list_head *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)
{
	/* SP800-90A requires the limit 2**19 bits, but we return bytes */
	return (1 << 16);
}

static inline size_t drbg_max_addtl(struct drbg_state *drbg)
{
	/* SP800-90A requires 2**35 bytes additional info str / pers str */
#if (__BITS_PER_LONG == 32)
	/*
	 * SP800-90A allows smaller maximum numbers to be returned -- we
	 * return SIZE_MAX - 1 to allow the verification of the enforcement
	 * of this value in drbg_healthcheck_sanity.
	 */
	return (SIZE_MAX - 1);
#else
	return (1UL<<35);
#endif
}

static inline size_t drbg_max_requests(struct drbg_state *drbg)
{
	/* SP800-90A requires 2**48 maximum requests before reseeding */
#if (__BITS_PER_LONG == 32)
	return SIZE_MAX;
#else
	return (1UL<<48);
#endif
}

/*
 * 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 */
Commit	Line	Data
3e16f959 SM	1	/*
	2	* DRBG based on NIST SP800-90A
	3	*
	4	* Copyright Stephan Mueller <smueller@chronox.de>, 2014
	5	*
	6	* Redistribution and use in source and binary forms, with or without
	7	* modification, are permitted provided that the following conditions
	8	* are met:
	9	* 1. Redistributions of source code must retain the above copyright
	10	* notice, and the entire permission notice in its entirety,
	11	* including the disclaimer of warranties.
	12	* 2. Redistributions in binary form must reproduce the above copyright
	13	* notice, this list of conditions and the following disclaimer in the
	14	* documentation and/or other materials provided with the distribution.
	15	* 3. The name of the author may not be used to endorse or promote
	16	* products derived from this software without specific prior
	17	* written permission.
	18	*
	19	* ALTERNATIVELY, this product may be distributed under the terms of
	20	* the GNU General Public License, in which case the provisions of the GPL are
	21	* required INSTEAD OF the above restrictions. (This clause is
	22	* necessary due to a potential bad interaction between the GPL and
	23	* the restrictions contained in a BSD-style copyright.)
	24	*
	25	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
	26	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	27	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
	28	* WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
	29	* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	30	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
	31	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
	32	* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
	33	* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	34	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
	35	* USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
	36	* DAMAGE.
	37	*/
	38
	39	#ifndef _DRBG_H
	40	#define _DRBG_H
	41
	42
	43	#include <linux/random.h>
	44	#include <linux/scatterlist.h>
	45	#include <crypto/hash.h>
	46	#include <linux/module.h>
	47	#include <linux/crypto.h>
	48	#include <linux/slab.h>
	49	#include <crypto/internal/rng.h>
	50	#include <crypto/rng.h>
	51	#include <linux/fips.h>
	52	#include <linux/spinlock.h>
8c987166	53	#include <linux/list.h>
3e16f959 SM	54
	55	/*
	56	* Concatenation Helper and string operation helper
	57	*
	58	* SP800-90A requires the concatenation of different data. To avoid copying
	59	* buffers around or allocate additional memory, the following data structure
	60	* is used to point to the original memory with its size. In addition, it
	61	* is used to build a linked list. The linked list defines the concatenation
	62	* of individual buffers. The order of memory block referenced in that
	63	* linked list determines the order of concatenation.
	64	*/
	65	struct drbg_string {
	66	const unsigned char *buf;
	67	size_t len;
8c987166	68	struct list_head list;
3e16f959 SM	69	};
	70
	71	static inline void drbg_string_fill(struct drbg_string *string,
	72	const unsigned char *buf, size_t len)
	73	{
	74	string->buf = buf;
	75	string->len = len;
8c987166	76	INIT_LIST_HEAD(&string->list);
3e16f959 SM	77	}
	78
	79	struct drbg_state;
	80	typedef uint32_t drbg_flag_t;
	81
	82	struct drbg_core {
	83	drbg_flag_t flags; /* flags for the cipher */
	84	__u8 statelen; /* maximum state length */
3e16f959 SM	85	__u8 blocklen_bytes; /* block size of output in bytes */
	86	char cra_name[CRYPTO_MAX_ALG_NAME]; /* mapping to kernel crypto API */
	87	/* kernel crypto API backend cipher name */
	88	char backend_cra_name[CRYPTO_MAX_ALG_NAME];
	89	};
	90
	91	struct drbg_state_ops {
8c987166	92	int (update)(struct drbg_state drbg, struct list_head *seed,
3e16f959 SM	93	int reseed);
	94	int (generate)(struct drbg_state drbg,
	95	unsigned char *buf, unsigned int buflen,
27e4de2b	96	struct list_head *addtl);
3e16f959 SM	97	int (crypto_init)(struct drbg_state drbg);
	98	int (crypto_fini)(struct drbg_state drbg);
	99
	100	};
	101
	102	struct drbg_test_data {
	103	struct drbg_string testentropy; / TEST PARAMETER: test entropy */
	104	};
	105
	106	struct drbg_state {
	107	spinlock_t drbg_lock; /* lock around DRBG */
	108	unsigned char V; / internal state 10.1.1.1 1a) */
	109	/* hash: static value 10.1.1.1 1b) hmac / ctr: key */
	110	unsigned char *C;
	111	/* Number of RNG requests since last reseed -- 10.1.1.1 1c) */
	112	size_t reseed_ctr;
	113	/* some memory the DRBG can use for its operation */
	114	unsigned char *scratchpad;
	115	void priv_data; / Cipher handle */
	116	bool seeded; /* DRBG fully seeded? */
	117	bool pr; /* Prediction resistance enabled? */
	118	#ifdef CONFIG_CRYPTO_FIPS
	119	bool fips_primed; /* Continuous test primed? */
	120	unsigned char prev; / FIPS 140-2 continuous test value */
	121	#endif
	122	const struct drbg_state_ops *d_ops;
	123	const struct drbg_core *core;
	124	struct drbg_test_data *test_data;
	125	};
	126
	127	static inline __u8 drbg_statelen(struct drbg_state *drbg)
	128	{
	129	if (drbg && drbg->core)
	130	return drbg->core->statelen;
	131	return 0;
	132	}
	133
	134	static inline __u8 drbg_blocklen(struct drbg_state *drbg)
	135	{
	136	if (drbg && drbg->core)
	137	return drbg->core->blocklen_bytes;
	138	return 0;
	139	}
	140
	141	static inline __u8 drbg_keylen(struct drbg_state *drbg)
	142	{
	143	if (drbg && drbg->core)
	144	return (drbg->core->statelen - drbg->core->blocklen_bytes);
	145	return 0;
	146	}
	147
	148	static inline size_t drbg_max_request_bytes(struct drbg_state *drbg)
	149	{
05c81ccd SM	150	/* SP800-90A requires the limit 2*19 bits, but we return bytes /
05c81ccd SM	151	return (1 << 16);
3e16f959 SM	152	}
	153
	154	static inline size_t drbg_max_addtl(struct drbg_state *drbg)
	155	{
05c81ccd	156	/* SP800-90A requires 2*35 bytes additional info str / pers str /
b9347aff SM	157	#if (__BITS_PER_LONG == 32)
	158	/*
	159	* SP800-90A allows smaller maximum numbers to be returned -- we
	160	* return SIZE_MAX - 1 to allow the verification of the enforcement
	161	* of this value in drbg_healthcheck_sanity.
	162	*/
	163	return (SIZE_MAX - 1);
	164	#else
05c81ccd	165	return (1UL<<35);
b9347aff	166	#endif
3e16f959 SM	167	}
	168
	169	static inline size_t drbg_max_requests(struct drbg_state *drbg)
	170	{
05c81ccd	171	/* SP800-90A requires 2*48 maximum requests before reseeding /
b9347aff SM	172	#if (__BITS_PER_LONG == 32)
	173	return SIZE_MAX;
	174	#else
05c81ccd	175	return (1UL<<48);
b9347aff	176	#endif
3e16f959 SM	177	}
	178
	179	/*
	180	* kernel crypto API input data structure for DRBG generate in case dlen
	181	* is set to 0
	182	*/
	183	struct drbg_gen {
	184	unsigned char outbuf; / output buffer for random numbers */
	185	unsigned int outlen; /* size of output buffer */
	186	struct drbg_string addtl; / additional information string */
	187	struct drbg_test_data test_data; / test data */
	188	};
	189
	190	/*
	191	* This is a wrapper to the kernel crypto API function of
	192	* crypto_rng_get_bytes() to allow the caller to provide additional data.
	193	*
	194	* @drng DRBG handle -- see crypto_rng_get_bytes
	195	* @outbuf output buffer -- see crypto_rng_get_bytes
	196	* @outlen length of output buffer -- see crypto_rng_get_bytes
	197	* @addtl_input additional information string input buffer
	198	* @addtllen length of additional information string buffer
	199	*
	200	* return
	201	* see crypto_rng_get_bytes
	202	*/
	203	static inline int crypto_drbg_get_bytes_addtl(struct crypto_rng *drng,
	204	unsigned char *outbuf, unsigned int outlen,
	205	struct drbg_string *addtl)
	206	{
	207	int ret;
	208	struct drbg_gen genbuf;
	209	genbuf.outbuf = outbuf;
	210	genbuf.outlen = outlen;
	211	genbuf.addtl = addtl;
	212	genbuf.test_data = NULL;
	213	ret = crypto_rng_get_bytes(drng, (u8 *)&genbuf, 0);
	214	return ret;
	215	}
	216
	217	/*
	218	* TEST code
	219	*
	220	* This is a wrapper to the kernel crypto API function of
	221	* crypto_rng_get_bytes() to allow the caller to provide additional data and
	222	* allow furnishing of test_data
	223	*
	224	* @drng DRBG handle -- see crypto_rng_get_bytes
	225	* @outbuf output buffer -- see crypto_rng_get_bytes
	226	* @outlen length of output buffer -- see crypto_rng_get_bytes
	227	* @addtl_input additional information string input buffer
	228	* @addtllen length of additional information string buffer
	229	* @test_data filled test data
	230	*
	231	* return
	232	* see crypto_rng_get_bytes
	233	*/
	234	static inline int crypto_drbg_get_bytes_addtl_test(struct crypto_rng *drng,
	235	unsigned char *outbuf, unsigned int outlen,
	236	struct drbg_string *addtl,
	237	struct drbg_test_data *test_data)
	238	{
	239	int ret;
	240	struct drbg_gen genbuf;
241	genbuf.outbuf = outbuf;
242	genbuf.outlen = outlen;
243	genbuf.addtl = addtl;
244	genbuf.test_data = test_data;
245	ret = crypto_rng_get_bytes(drng, (u8 *)&genbuf, 0);
246	return ret;
247	}
248
249	/*
250	* TEST code
251	*
252	* This is a wrapper to the kernel crypto API function of
253	* crypto_rng_reset() to allow the caller to provide test_data
254	*
255	* @drng DRBG handle -- see crypto_rng_reset
256	* @pers personalization string input buffer
257	* @perslen length of additional information string buffer
258	* @test_data filled test data
259	*
260	* return
261	* see crypto_rng_reset
262	*/
263	static inline int crypto_drbg_reset_test(struct crypto_rng *drng,
264	struct drbg_string *pers,
265	struct drbg_test_data *test_data)
266	{
267	int ret;
268	struct drbg_gen genbuf;
269	genbuf.outbuf = NULL;
270	genbuf.outlen = 0;
271	genbuf.addtl = pers;
272	genbuf.test_data = test_data;
273	ret = crypto_rng_reset(drng, (u8 *)&genbuf, 0);
274	return ret;
275	}
276
277	/* DRBG type flags */
278	#define DRBG_CTR ((drbg_flag_t)1<<0)
279	#define DRBG_HMAC ((drbg_flag_t)1<<1)
280	#define DRBG_HASH ((drbg_flag_t)1<<2)
281	#define DRBG_TYPE_MASK (DRBG_CTR \| DRBG_HMAC \| DRBG_HASH)
282	/* DRBG strength flags */
283	#define DRBG_STRENGTH128 ((drbg_flag_t)1<<3)
284	#define DRBG_STRENGTH192 ((drbg_flag_t)1<<4)
285	#define DRBG_STRENGTH256 ((drbg_flag_t)1<<5)
286	#define DRBG_STRENGTH_MASK (DRBG_STRENGTH128 \| DRBG_STRENGTH192 \| \
287	DRBG_STRENGTH256)
288
289	enum drbg_prefixes {
290	DRBG_PREFIX0 = 0x00,
291	DRBG_PREFIX1,
292	DRBG_PREFIX2,
293	DRBG_PREFIX3
294	};
295
296	#endif /* _DRBG_H */