[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/mutex.h>
#include <linux/list.h>
#include <linux/workqueue.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 {
	struct mutex drbg_mutex;	/* 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;
	size_t reseed_threshold;
	 /* 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? */
	struct work_struct seed_work;	/* asynchronous seeding support */
	struct crypto_rng *jent;
	const struct drbg_state_ops *d_ops;
	const struct drbg_core *core;
	struct drbg_string test_data;
	struct random_ready_callback random_ready;
};

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
}

/*
 * This is a wrapper to the kernel crypto API function of
 * crypto_rng_generate() 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)
{
	return crypto_rng_generate(drng, addtl->buf, addtl->len,
				   outbuf, outlen);
}

/*
 * TEST code
 *
 * This is a wrapper to the kernel crypto API function of
 * crypto_rng_generate() 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)
{
	crypto_rng_set_entropy(drng, test_data->testentropy->buf,
			       test_data->testentropy->len);
	return crypto_rng_generate(drng, addtl->buf, addtl->len,
				   outbuf, outlen);
}

/*
 * 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)
{
	crypto_rng_set_entropy(drng, test_data->testentropy->buf,
			       test_data->testentropy->len);
	return crypto_rng_reset(drng, pers->buf, pers->len);
}

/* 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>
76899a41	52	#include <linux/mutex.h>
8c987166	53	#include <linux/list.h>
4c787990	54	#include <linux/workqueue.h>
3e16f959 SM	55
	56	/*
	57	* Concatenation Helper and string operation helper
	58	*
	59	* SP800-90A requires the concatenation of different data. To avoid copying
	60	* buffers around or allocate additional memory, the following data structure
	61	* is used to point to the original memory with its size. In addition, it
	62	* is used to build a linked list. The linked list defines the concatenation
	63	* of individual buffers. The order of memory block referenced in that
	64	* linked list determines the order of concatenation.
	65	*/
	66	struct drbg_string {
	67	const unsigned char *buf;
	68	size_t len;
8c987166	69	struct list_head list;
3e16f959 SM	70	};
	71
	72	static inline void drbg_string_fill(struct drbg_string *string,
	73	const unsigned char *buf, size_t len)
	74	{
	75	string->buf = buf;
	76	string->len = len;
8c987166	77	INIT_LIST_HEAD(&string->list);
3e16f959 SM	78	}
	79
	80	struct drbg_state;
	81	typedef uint32_t drbg_flag_t;
	82
	83	struct drbg_core {
	84	drbg_flag_t flags; /* flags for the cipher */
	85	__u8 statelen; /* maximum state length */
3e16f959 SM	86	__u8 blocklen_bytes; /* block size of output in bytes */
	87	char cra_name[CRYPTO_MAX_ALG_NAME]; /* mapping to kernel crypto API */
	88	/* kernel crypto API backend cipher name */
	89	char backend_cra_name[CRYPTO_MAX_ALG_NAME];
	90	};
	91
	92	struct drbg_state_ops {
8c987166	93	int (update)(struct drbg_state drbg, struct list_head *seed,
3e16f959 SM	94	int reseed);
	95	int (generate)(struct drbg_state drbg,
	96	unsigned char *buf, unsigned int buflen,
27e4de2b	97	struct list_head *addtl);
3e16f959 SM	98	int (crypto_init)(struct drbg_state drbg);
	99	int (crypto_fini)(struct drbg_state drbg);
	100
	101	};
	102
	103	struct drbg_test_data {
	104	struct drbg_string testentropy; / TEST PARAMETER: test entropy */
	105	};
	106
	107	struct drbg_state {
76899a41	108	struct mutex drbg_mutex; /* lock around DRBG */
3e16f959 SM	109	unsigned char V; / internal state 10.1.1.1 1a) */
	110	/* hash: static value 10.1.1.1 1b) hmac / ctr: key */
	111	unsigned char *C;
	112	/* Number of RNG requests since last reseed -- 10.1.1.1 1c) */
	113	size_t reseed_ctr;
42ea507f	114	size_t reseed_threshold;
3e16f959 SM	115	/* some memory the DRBG can use for its operation */
	116	unsigned char *scratchpad;
	117	void priv_data; / Cipher handle */
	118	bool seeded; /* DRBG fully seeded? */
	119	bool pr; /* Prediction resistance enabled? */
4c787990	120	struct work_struct seed_work; /* asynchronous seeding support */
b8ec5ba4	121	struct crypto_rng *jent;
3e16f959 SM	122	const struct drbg_state_ops *d_ops;
3e16f959 SM	123	const struct drbg_core *core;
8fded592	124	struct drbg_string test_data;
57225e67	125	struct random_ready_callback random_ready;
3e16f959 SM	126	};
	127
	128	static inline __u8 drbg_statelen(struct drbg_state *drbg)
	129	{
	130	if (drbg && drbg->core)
	131	return drbg->core->statelen;
	132	return 0;
	133	}
	134
	135	static inline __u8 drbg_blocklen(struct drbg_state *drbg)
	136	{
	137	if (drbg && drbg->core)
	138	return drbg->core->blocklen_bytes;
	139	return 0;
	140	}
	141
	142	static inline __u8 drbg_keylen(struct drbg_state *drbg)
	143	{
	144	if (drbg && drbg->core)
	145	return (drbg->core->statelen - drbg->core->blocklen_bytes);
	146	return 0;
	147	}
	148
	149	static inline size_t drbg_max_request_bytes(struct drbg_state *drbg)
	150	{
05c81ccd SM	151	/* SP800-90A requires the limit 2*19 bits, but we return bytes /
05c81ccd SM	152	return (1 << 16);
3e16f959 SM	153	}
	154
	155	static inline size_t drbg_max_addtl(struct drbg_state *drbg)
	156	{
05c81ccd	157	/* SP800-90A requires 2*35 bytes additional info str / pers str /
b9347aff SM	158	#if (__BITS_PER_LONG == 32)
	159	/*
	160	* SP800-90A allows smaller maximum numbers to be returned -- we
	161	* return SIZE_MAX - 1 to allow the verification of the enforcement
	162	* of this value in drbg_healthcheck_sanity.
	163	*/
	164	return (SIZE_MAX - 1);
	165	#else
05c81ccd	166	return (1UL<<35);
b9347aff	167	#endif
3e16f959 SM	168	}
	169
	170	static inline size_t drbg_max_requests(struct drbg_state *drbg)
	171	{
05c81ccd	172	/* SP800-90A requires 2*48 maximum requests before reseeding /
b9347aff SM	173	#if (__BITS_PER_LONG == 32)
	174	return SIZE_MAX;
	175	#else
05c81ccd	176	return (1UL<<48);
b9347aff	177	#endif
3e16f959 SM	178	}
3e16f959 SM	179
3e16f959 SM	180	/*
3e16f959 SM	181	* This is a wrapper to the kernel crypto API function of
8fded592	182	* crypto_rng_generate() to allow the caller to provide additional data.
3e16f959 SM	183	*
	184	* @drng DRBG handle -- see crypto_rng_get_bytes
	185	* @outbuf output buffer -- see crypto_rng_get_bytes
	186	* @outlen length of output buffer -- see crypto_rng_get_bytes
	187	* @addtl_input additional information string input buffer
	188	* @addtllen length of additional information string buffer
	189	*
	190	* return
	191	* see crypto_rng_get_bytes
	192	*/
	193	static inline int crypto_drbg_get_bytes_addtl(struct crypto_rng *drng,
	194	unsigned char *outbuf, unsigned int outlen,
	195	struct drbg_string *addtl)
	196	{
8fded592 HX	197	return crypto_rng_generate(drng, addtl->buf, addtl->len,
8fded592 HX	198	outbuf, outlen);
3e16f959 SM	199	}
	200
	201	/*
	202	* TEST code
	203	*
	204	* This is a wrapper to the kernel crypto API function of
8fded592	205	* crypto_rng_generate() to allow the caller to provide additional data and
3e16f959 SM	206	* allow furnishing of test_data
	207	*
	208	* @drng DRBG handle -- see crypto_rng_get_bytes
	209	* @outbuf output buffer -- see crypto_rng_get_bytes
	210	* @outlen length of output buffer -- see crypto_rng_get_bytes
	211	* @addtl_input additional information string input buffer
	212	* @addtllen length of additional information string buffer
	213	* @test_data filled test data
	214	*
	215	* return
	216	* see crypto_rng_get_bytes
	217	*/
	218	static inline int crypto_drbg_get_bytes_addtl_test(struct crypto_rng *drng,
	219	unsigned char *outbuf, unsigned int outlen,
	220	struct drbg_string *addtl,
	221	struct drbg_test_data *test_data)
	222	{
8fded592 HX	223	crypto_rng_set_entropy(drng, test_data->testentropy->buf,
	224	test_data->testentropy->len);
	225	return crypto_rng_generate(drng, addtl->buf, addtl->len,
	226	outbuf, outlen);
3e16f959 SM	227	}
	228
	229	/*
	230	* TEST code
	231	*
	232	* This is a wrapper to the kernel crypto API function of
	233	* crypto_rng_reset() to allow the caller to provide test_data
	234	*
	235	* @drng DRBG handle -- see crypto_rng_reset
	236	* @pers personalization string input buffer
	237	* @perslen length of additional information string buffer
	238	* @test_data filled test data
	239	*
	240	* return
	241	* see crypto_rng_reset
	242	*/
	243	static inline int crypto_drbg_reset_test(struct crypto_rng *drng,
	244	struct drbg_string *pers,
	245	struct drbg_test_data *test_data)
	246	{
8fded592 HX	247	crypto_rng_set_entropy(drng, test_data->testentropy->buf,
	248	test_data->testentropy->len);
	249	return crypto_rng_reset(drng, pers->buf, pers->len);
3e16f959 SM	250	}
	251
	252	/* DRBG type flags */
	253	#define DRBG_CTR ((drbg_flag_t)1<<0)
	254	#define DRBG_HMAC ((drbg_flag_t)1<<1)
	255	#define DRBG_HASH ((drbg_flag_t)1<<2)
	256	#define DRBG_TYPE_MASK (DRBG_CTR \| DRBG_HMAC \| DRBG_HASH)
	257	/* DRBG strength flags */
	258	#define DRBG_STRENGTH128 ((drbg_flag_t)1<<3)
	259	#define DRBG_STRENGTH192 ((drbg_flag_t)1<<4)
	260	#define DRBG_STRENGTH256 ((drbg_flag_t)1<<5)
	261	#define DRBG_STRENGTH_MASK (DRBG_STRENGTH128 \| DRBG_STRENGTH192 \| \
	262	DRBG_STRENGTH256)
	263
	264	enum drbg_prefixes {
	265	DRBG_PREFIX0 = 0x00,
	266	DRBG_PREFIX1,
	267	DRBG_PREFIX2,
	268	DRBG_PREFIX3
	269	};
	270
	271	#endif /* _DRBG_H */