[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 <crypto/skcipher.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) */
	unsigned char *Vbuf;
	/* hash: static value 10.1.1.1 1b) hmac / ctr: key */
	unsigned char *C;
	unsigned char *Cbuf;
	/* 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;
	unsigned char *scratchpadbuf;
	void *priv_data;	/* Cipher handle */

	struct crypto_skcipher *ctr_handle;	/* CTR mode cipher handle */
	struct skcipher_request *ctr_req;	/* CTR mode request handle */
	__u8 *outscratchpadbuf;			/* CTR mode output scratchpad */
        __u8 *outscratchpad;			/* CTR mode aligned outbuf */
	struct crypto_wait ctr_wait;		/* CTR mode async wait obj */
	struct scatterlist sg_in, sg_out;	/* CTR mode SGLs */

	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>
35591285	46	#include <crypto/skcipher.h>
3e16f959 SM	47	#include <linux/module.h>
	48	#include <linux/crypto.h>
	49	#include <linux/slab.h>
	50	#include <crypto/internal/rng.h>
	51	#include <crypto/rng.h>
	52	#include <linux/fips.h>
76899a41	53	#include <linux/mutex.h>
8c987166	54	#include <linux/list.h>
4c787990	55	#include <linux/workqueue.h>
3e16f959 SM	56
	57	/*
	58	* Concatenation Helper and string operation helper
	59	*
	60	* SP800-90A requires the concatenation of different data. To avoid copying
	61	* buffers around or allocate additional memory, the following data structure
	62	* is used to point to the original memory with its size. In addition, it
	63	* is used to build a linked list. The linked list defines the concatenation
	64	* of individual buffers. The order of memory block referenced in that
	65	* linked list determines the order of concatenation.
	66	*/
	67	struct drbg_string {
	68	const unsigned char *buf;
	69	size_t len;
8c987166	70	struct list_head list;
3e16f959 SM	71	};
	72
	73	static inline void drbg_string_fill(struct drbg_string *string,
	74	const unsigned char *buf, size_t len)
	75	{
	76	string->buf = buf;
	77	string->len = len;
8c987166	78	INIT_LIST_HEAD(&string->list);
3e16f959 SM	79	}
	80
	81	struct drbg_state;
	82	typedef uint32_t drbg_flag_t;
	83
	84	struct drbg_core {
	85	drbg_flag_t flags; /* flags for the cipher */
	86	__u8 statelen; /* maximum state length */
3e16f959 SM	87	__u8 blocklen_bytes; /* block size of output in bytes */
	88	char cra_name[CRYPTO_MAX_ALG_NAME]; /* mapping to kernel crypto API */
	89	/* kernel crypto API backend cipher name */
	90	char backend_cra_name[CRYPTO_MAX_ALG_NAME];
	91	};
	92
	93	struct drbg_state_ops {
8c987166	94	int (update)(struct drbg_state drbg, struct list_head *seed,
3e16f959 SM	95	int reseed);
	96	int (generate)(struct drbg_state drbg,
	97	unsigned char *buf, unsigned int buflen,
27e4de2b	98	struct list_head *addtl);
3e16f959 SM	99	int (crypto_init)(struct drbg_state drbg);
	100	int (crypto_fini)(struct drbg_state drbg);
	101
	102	};
	103
	104	struct drbg_test_data {
	105	struct drbg_string testentropy; / TEST PARAMETER: test entropy */
	106	};
	107
	108	struct drbg_state {
76899a41	109	struct mutex drbg_mutex; /* lock around DRBG */
3e16f959	110	unsigned char V; / internal state 10.1.1.1 1a) */
3cfc3b97	111	unsigned char *Vbuf;
3e16f959 SM	112	/* hash: static value 10.1.1.1 1b) hmac / ctr: key */
3e16f959 SM	113	unsigned char *C;
3cfc3b97	114	unsigned char *Cbuf;
3e16f959 SM	115	/* Number of RNG requests since last reseed -- 10.1.1.1 1c) */
3e16f959 SM	116	size_t reseed_ctr;
42ea507f	117	size_t reseed_threshold;
3e16f959 SM	118	/* some memory the DRBG can use for its operation */
3e16f959 SM	119	unsigned char *scratchpad;
3cfc3b97	120	unsigned char *scratchpadbuf;
3e16f959	121	void priv_data; / Cipher handle */
35591285 SM	122
	123	struct crypto_skcipher ctr_handle; / CTR mode cipher handle */
	124	struct skcipher_request ctr_req; / CTR mode request handle */
51029812 SM	125	__u8 outscratchpadbuf; / CTR mode output scratchpad */
51029812 SM	126	__u8 outscratchpad; / CTR mode aligned outbuf */
85a2dea4	127	struct crypto_wait ctr_wait; /* CTR mode async wait obj */
cf862cbc	128	struct scatterlist sg_in, sg_out; /* CTR mode SGLs */
35591285	129
3e16f959 SM	130	bool seeded; /* DRBG fully seeded? */
3e16f959 SM	131	bool pr; /* Prediction resistance enabled? */
4c787990	132	struct work_struct seed_work; /* asynchronous seeding support */
b8ec5ba4	133	struct crypto_rng *jent;
3e16f959 SM	134	const struct drbg_state_ops *d_ops;
3e16f959 SM	135	const struct drbg_core *core;
8fded592	136	struct drbg_string test_data;
57225e67	137	struct random_ready_callback random_ready;
3e16f959 SM	138	};
	139
	140	static inline __u8 drbg_statelen(struct drbg_state *drbg)
	141	{
	142	if (drbg && drbg->core)
	143	return drbg->core->statelen;
	144	return 0;
	145	}
	146
	147	static inline __u8 drbg_blocklen(struct drbg_state *drbg)
	148	{
	149	if (drbg && drbg->core)
	150	return drbg->core->blocklen_bytes;
	151	return 0;
	152	}
	153
	154	static inline __u8 drbg_keylen(struct drbg_state *drbg)
	155	{
	156	if (drbg && drbg->core)
	157	return (drbg->core->statelen - drbg->core->blocklen_bytes);
	158	return 0;
	159	}
	160
	161	static inline size_t drbg_max_request_bytes(struct drbg_state *drbg)
	162	{
05c81ccd SM	163	/* SP800-90A requires the limit 2*19 bits, but we return bytes /
05c81ccd SM	164	return (1 << 16);
3e16f959 SM	165	}
	166
	167	static inline size_t drbg_max_addtl(struct drbg_state *drbg)
	168	{
05c81ccd	169	/* SP800-90A requires 2*35 bytes additional info str / pers str /
b9347aff SM	170	#if (__BITS_PER_LONG == 32)
	171	/*
	172	* SP800-90A allows smaller maximum numbers to be returned -- we
	173	* return SIZE_MAX - 1 to allow the verification of the enforcement
	174	* of this value in drbg_healthcheck_sanity.
	175	*/
	176	return (SIZE_MAX - 1);
	177	#else
05c81ccd	178	return (1UL<<35);
b9347aff	179	#endif
3e16f959 SM	180	}
	181
	182	static inline size_t drbg_max_requests(struct drbg_state *drbg)
	183	{
05c81ccd	184	/* SP800-90A requires 2*48 maximum requests before reseeding /
b9347aff SM	185	#if (__BITS_PER_LONG == 32)
	186	return SIZE_MAX;
	187	#else
05c81ccd	188	return (1UL<<48);
b9347aff	189	#endif
3e16f959 SM	190	}
3e16f959 SM	191
3e16f959 SM	192	/*
3e16f959 SM	193	* This is a wrapper to the kernel crypto API function of
8fded592	194	* crypto_rng_generate() to allow the caller to provide additional data.
3e16f959 SM	195	*
	196	* @drng DRBG handle -- see crypto_rng_get_bytes
	197	* @outbuf output buffer -- see crypto_rng_get_bytes
	198	* @outlen length of output buffer -- see crypto_rng_get_bytes
	199	* @addtl_input additional information string input buffer
	200	* @addtllen length of additional information string buffer
	201	*
	202	* return
	203	* see crypto_rng_get_bytes
	204	*/
	205	static inline int crypto_drbg_get_bytes_addtl(struct crypto_rng *drng,
	206	unsigned char *outbuf, unsigned int outlen,
	207	struct drbg_string *addtl)
	208	{
8fded592 HX	209	return crypto_rng_generate(drng, addtl->buf, addtl->len,
8fded592 HX	210	outbuf, outlen);
3e16f959 SM	211	}
	212
	213	/*
	214	* TEST code
	215	*
	216	* This is a wrapper to the kernel crypto API function of
8fded592	217	* crypto_rng_generate() to allow the caller to provide additional data and
3e16f959 SM	218	* allow furnishing of test_data
	219	*
	220	* @drng DRBG handle -- see crypto_rng_get_bytes
	221	* @outbuf output buffer -- see crypto_rng_get_bytes
	222	* @outlen length of output buffer -- see crypto_rng_get_bytes
	223	* @addtl_input additional information string input buffer
	224	* @addtllen length of additional information string buffer
	225	* @test_data filled test data
	226	*
	227	* return
	228	* see crypto_rng_get_bytes
	229	*/
	230	static inline int crypto_drbg_get_bytes_addtl_test(struct crypto_rng *drng,
	231	unsigned char *outbuf, unsigned int outlen,
	232	struct drbg_string *addtl,
	233	struct drbg_test_data *test_data)
	234	{
8fded592 HX	235	crypto_rng_set_entropy(drng, test_data->testentropy->buf,
	236	test_data->testentropy->len);
	237	return crypto_rng_generate(drng, addtl->buf, addtl->len,
	238	outbuf, outlen);
3e16f959 SM	239	}
	240
	241	/*
	242	* TEST code
	243	*
	244	* This is a wrapper to the kernel crypto API function of
	245	* crypto_rng_reset() to allow the caller to provide test_data
	246	*
	247	* @drng DRBG handle -- see crypto_rng_reset
	248	* @pers personalization string input buffer
	249	* @perslen length of additional information string buffer
	250	* @test_data filled test data
	251	*
	252	* return
	253	* see crypto_rng_reset
	254	*/
	255	static inline int crypto_drbg_reset_test(struct crypto_rng *drng,
	256	struct drbg_string *pers,
	257	struct drbg_test_data *test_data)
	258	{
8fded592 HX	259	crypto_rng_set_entropy(drng, test_data->testentropy->buf,
	260	test_data->testentropy->len);
	261	return crypto_rng_reset(drng, pers->buf, pers->len);
3e16f959 SM	262	}
	263
	264	/* DRBG type flags */
	265	#define DRBG_CTR ((drbg_flag_t)1<<0)
	266	#define DRBG_HMAC ((drbg_flag_t)1<<1)
	267	#define DRBG_HASH ((drbg_flag_t)1<<2)
	268	#define DRBG_TYPE_MASK (DRBG_CTR \| DRBG_HMAC \| DRBG_HASH)
	269	/* DRBG strength flags */
	270	#define DRBG_STRENGTH128 ((drbg_flag_t)1<<3)
	271	#define DRBG_STRENGTH192 ((drbg_flag_t)1<<4)
	272	#define DRBG_STRENGTH256 ((drbg_flag_t)1<<5)
	273	#define DRBG_STRENGTH_MASK (DRBG_STRENGTH128 \| DRBG_STRENGTH192 \| \
	274	DRBG_STRENGTH256)
	275
	276	enum drbg_prefixes {
	277	DRBG_PREFIX0 = 0x00,
	278	DRBG_PREFIX1,
	279	DRBG_PREFIX2,
	280	DRBG_PREFIX3
	281	};
	282
	283	#endif /* _DRBG_H */