/* * 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? */	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 */