forked from Minki/linux
f7d76e05d0
All crypto_stats functions use the struct xxx_request for feeding stats,
but in some case this structure could already be freed.
For fixing this, the needed parameters (len and alg) will be stored
before the request being executed.
Fixes: cac5818c25 ("crypto: user - Implement a generic crypto statistics")
Reported-by: syzbot <syzbot+6939a606a5305e9e9799@syzkaller.appspotmail.com>
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
207 lines
6.7 KiB
C
207 lines
6.7 KiB
C
/*
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* RNG: Random Number Generator algorithms under the crypto API
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*
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* Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
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* Copyright (c) 2015 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#ifndef _CRYPTO_RNG_H
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#define _CRYPTO_RNG_H
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#include <linux/crypto.h>
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struct crypto_rng;
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/**
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* struct rng_alg - random number generator definition
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*
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* @generate: The function defined by this variable obtains a
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* random number. The random number generator transform
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* must generate the random number out of the context
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* provided with this call, plus any additional data
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* if provided to the call.
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* @seed: Seed or reseed the random number generator. With the
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* invocation of this function call, the random number
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* generator shall become ready for generation. If the
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* random number generator requires a seed for setting
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* up a new state, the seed must be provided by the
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* consumer while invoking this function. The required
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* size of the seed is defined with @seedsize .
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* @set_ent: Set entropy that would otherwise be obtained from
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* entropy source. Internal use only.
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* @seedsize: The seed size required for a random number generator
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* initialization defined with this variable. Some
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* random number generators does not require a seed
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* as the seeding is implemented internally without
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* the need of support by the consumer. In this case,
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* the seed size is set to zero.
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* @base: Common crypto API algorithm data structure.
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*/
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struct rng_alg {
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int (*generate)(struct crypto_rng *tfm,
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const u8 *src, unsigned int slen,
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u8 *dst, unsigned int dlen);
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int (*seed)(struct crypto_rng *tfm, const u8 *seed, unsigned int slen);
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void (*set_ent)(struct crypto_rng *tfm, const u8 *data,
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unsigned int len);
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unsigned int seedsize;
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struct crypto_alg base;
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};
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struct crypto_rng {
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struct crypto_tfm base;
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};
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extern struct crypto_rng *crypto_default_rng;
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int crypto_get_default_rng(void);
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void crypto_put_default_rng(void);
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/**
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* DOC: Random number generator API
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*
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* The random number generator API is used with the ciphers of type
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* CRYPTO_ALG_TYPE_RNG (listed as type "rng" in /proc/crypto)
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*/
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/**
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* crypto_alloc_rng() -- allocate RNG handle
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* @alg_name: is the cra_name / name or cra_driver_name / driver name of the
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* message digest cipher
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* @type: specifies the type of the cipher
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* @mask: specifies the mask for the cipher
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*
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* Allocate a cipher handle for a random number generator. The returned struct
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* crypto_rng is the cipher handle that is required for any subsequent
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* API invocation for that random number generator.
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*
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* For all random number generators, this call creates a new private copy of
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* the random number generator that does not share a state with other
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* instances. The only exception is the "krng" random number generator which
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* is a kernel crypto API use case for the get_random_bytes() function of the
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* /dev/random driver.
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*
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* Return: allocated cipher handle in case of success; IS_ERR() is true in case
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* of an error, PTR_ERR() returns the error code.
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*/
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struct crypto_rng *crypto_alloc_rng(const char *alg_name, u32 type, u32 mask);
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static inline struct crypto_tfm *crypto_rng_tfm(struct crypto_rng *tfm)
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{
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return &tfm->base;
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}
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/**
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* crypto_rng_alg - obtain name of RNG
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* @tfm: cipher handle
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*
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* Return the generic name (cra_name) of the initialized random number generator
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*
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* Return: generic name string
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*/
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static inline struct rng_alg *crypto_rng_alg(struct crypto_rng *tfm)
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{
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return container_of(crypto_rng_tfm(tfm)->__crt_alg,
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struct rng_alg, base);
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}
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/**
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* crypto_free_rng() - zeroize and free RNG handle
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* @tfm: cipher handle to be freed
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*/
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static inline void crypto_free_rng(struct crypto_rng *tfm)
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{
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crypto_destroy_tfm(tfm, crypto_rng_tfm(tfm));
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}
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/**
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* crypto_rng_generate() - get random number
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* @tfm: cipher handle
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* @src: Input buffer holding additional data, may be NULL
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* @slen: Length of additional data
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* @dst: output buffer holding the random numbers
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* @dlen: length of the output buffer
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*
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* This function fills the caller-allocated buffer with random
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* numbers using the random number generator referenced by the
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* cipher handle.
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*
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* Return: 0 function was successful; < 0 if an error occurred
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*/
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static inline int crypto_rng_generate(struct crypto_rng *tfm,
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const u8 *src, unsigned int slen,
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u8 *dst, unsigned int dlen)
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{
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struct crypto_alg *alg = tfm->base.__crt_alg;
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int ret;
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crypto_stats_get(alg);
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ret = crypto_rng_alg(tfm)->generate(tfm, src, slen, dst, dlen);
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crypto_stats_rng_generate(alg, dlen, ret);
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return ret;
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}
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/**
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* crypto_rng_get_bytes() - get random number
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* @tfm: cipher handle
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* @rdata: output buffer holding the random numbers
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* @dlen: length of the output buffer
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*
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* This function fills the caller-allocated buffer with random numbers using the
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* random number generator referenced by the cipher handle.
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*
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* Return: 0 function was successful; < 0 if an error occurred
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*/
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static inline int crypto_rng_get_bytes(struct crypto_rng *tfm,
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u8 *rdata, unsigned int dlen)
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{
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return crypto_rng_generate(tfm, NULL, 0, rdata, dlen);
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}
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/**
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* crypto_rng_reset() - re-initialize the RNG
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* @tfm: cipher handle
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* @seed: seed input data
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* @slen: length of the seed input data
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*
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* The reset function completely re-initializes the random number generator
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* referenced by the cipher handle by clearing the current state. The new state
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* is initialized with the caller provided seed or automatically, depending
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* on the random number generator type (the ANSI X9.31 RNG requires
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* caller-provided seed, the SP800-90A DRBGs perform an automatic seeding).
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* The seed is provided as a parameter to this function call. The provided seed
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* should have the length of the seed size defined for the random number
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* generator as defined by crypto_rng_seedsize.
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*
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* Return: 0 if the setting of the key was successful; < 0 if an error occurred
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*/
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int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed,
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unsigned int slen);
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/**
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* crypto_rng_seedsize() - obtain seed size of RNG
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* @tfm: cipher handle
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*
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* The function returns the seed size for the random number generator
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* referenced by the cipher handle. This value may be zero if the random
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* number generator does not implement or require a reseeding. For example,
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* the SP800-90A DRBGs implement an automated reseeding after reaching a
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* pre-defined threshold.
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*
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* Return: seed size for the random number generator
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*/
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static inline int crypto_rng_seedsize(struct crypto_rng *tfm)
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{
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return crypto_rng_alg(tfm)->seedsize;
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}
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#endif
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