--- /dev/null
+/*
+ * RNG: Random Number Generator algorithms under the crypto API
+ *
+ * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#ifndef _CRYPTO_RNG_H
+#define _CRYPTO_RNG_H
+
+#include <linux/crypto.h>
+
+extern struct crypto_rng *crypto_default_rng;
+
+int crypto_get_default_rng(void);
+void crypto_put_default_rng(void);
+
+/**
+ * DOC: Random number generator API
+ *
+ * The random number generator API is used with the ciphers of type
+ * CRYPTO_ALG_TYPE_RNG (listed as type "rng" in /proc/crypto)
+ */
+
+static inline struct crypto_rng *__crypto_rng_cast(struct crypto_tfm *tfm)
+{
+ return (struct crypto_rng *)tfm;
+}
+
+/**
+ * crypto_alloc_rng() -- allocate RNG handle
+ * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
+ * message digest cipher
+ * @type: specifies the type of the cipher
+ * @mask: specifies the mask for the cipher
+ *
+ * Allocate a cipher handle for a random number generator. The returned struct
+ * crypto_rng is the cipher handle that is required for any subsequent
+ * API invocation for that random number generator.
+ *
+ * For all random number generators, this call creates a new private copy of
+ * the random number generator that does not share a state with other
+ * instances. The only exception is the "krng" random number generator which
+ * is a kernel crypto API use case for the get_random_bytes() function of the
+ * /dev/random driver.
+ *
+ * Return: allocated cipher handle in case of success; IS_ERR() is true in case
+ * of an error, PTR_ERR() returns the error code.
+ */
+static inline struct crypto_rng *crypto_alloc_rng(const char *alg_name,
+ u32 type, u32 mask)
+{
+ type &= ~CRYPTO_ALG_TYPE_MASK;
+ type |= CRYPTO_ALG_TYPE_RNG;
+ mask |= CRYPTO_ALG_TYPE_MASK;
+
+ return __crypto_rng_cast(crypto_alloc_base(alg_name, type, mask));
+}
+
+static inline struct crypto_tfm *crypto_rng_tfm(struct crypto_rng *tfm)
+{
+ return &tfm->base;
+}
+
+/**
+ * crypto_rng_alg - obtain name of RNG
+ * @tfm: cipher handle
+ *
+ * Return the generic name (cra_name) of the initialized random number generator
+ *
+ * Return: generic name string
+ */
+static inline struct rng_alg *crypto_rng_alg(struct crypto_rng *tfm)
+{
+ return &crypto_rng_tfm(tfm)->__crt_alg->cra_rng;
+}
+
+static inline struct rng_tfm *crypto_rng_crt(struct crypto_rng *tfm)
+{
+ return &crypto_rng_tfm(tfm)->crt_rng;
+}
+
+/**
+ * crypto_free_rng() - zeroize and free RNG handle
+ * @tfm: cipher handle to be freed
+ */
+static inline void crypto_free_rng(struct crypto_rng *tfm)
+{
+ crypto_free_tfm(crypto_rng_tfm(tfm));
+}
+
+/**
+ * crypto_rng_get_bytes() - get random number
+ * @tfm: cipher handle
+ * @rdata: output buffer holding the random numbers
+ * @dlen: length of the output buffer
+ *
+ * This function fills the caller-allocated buffer with random numbers using the
+ * random number generator referenced by the cipher handle.
+ *
+ * Return: 0 function was successful; < 0 if an error occurred
+ */
+static inline int crypto_rng_get_bytes(struct crypto_rng *tfm,
+ u8 *rdata, unsigned int dlen)
+{
+ return crypto_rng_crt(tfm)->rng_gen_random(tfm, rdata, dlen);
+}
+
+/**
+ * crypto_rng_reset() - re-initialize the RNG
+ * @tfm: cipher handle
+ * @seed: seed input data
+ * @slen: length of the seed input data
+ *
+ * The reset function completely re-initializes the random number generator
+ * referenced by the cipher handle by clearing the current state. The new state
+ * is initialized with the caller provided seed or automatically, depending
+ * on the random number generator type (the ANSI X9.31 RNG requires
+ * caller-provided seed, the SP800-90A DRBGs perform an automatic seeding).
+ * The seed is provided as a parameter to this function call. The provided seed
+ * should have the length of the seed size defined for the random number
+ * generator as defined by crypto_rng_seedsize.
+ *
+ * Return: 0 if the setting of the key was successful; < 0 if an error occurred
+ */
+static inline int crypto_rng_reset(struct crypto_rng *tfm,
+ u8 *seed, unsigned int slen)
+{
+ return crypto_rng_crt(tfm)->rng_reset(tfm, seed, slen);
+}
+
+/**
+ * crypto_rng_seedsize() - obtain seed size of RNG
+ * @tfm: cipher handle
+ *
+ * The function returns the seed size for the random number generator
+ * referenced by the cipher handle. This value may be zero if the random
+ * number generator does not implement or require a reseeding. For example,
+ * the SP800-90A DRBGs implement an automated reseeding after reaching a
+ * pre-defined threshold.
+ *
+ * Return: seed size for the random number generator
+ */
+static inline int crypto_rng_seedsize(struct crypto_rng *tfm)
+{
+ return crypto_rng_alg(tfm)->seedsize;
+}
+
+#endif
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