include/crypto/drbg.h - kernel/common - Git at Google

 /*
  * DRBG based on NIST SP800-90A
  *
  * Copyright Stephan Mueller <[email protected]>, 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? */
 	bool fips_primed;	/* Continuous test primed? */
 	unsigned char *prev;	/* FIPS 140-2 continuous test value */
 	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 */
 	return (1<<20);
 }

 /*
  * 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 */
	/*
	* DRBG based on NIST SP800-90A
	*
	* Copyright Stephan Mueller <[email protected]>, 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? */
	bool fips_primed; /* Continuous test primed? */
	unsigned char prev; / FIPS 140-2 continuous test value */
	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 /
	return (1<<20);
	}

	/*
	* 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 */