/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef APR_RANDOM_H
#define APR_RANDOM_H
/**
* @file apr_random.h
* @brief APR PRNG routines
*/
#include "apr_pools.h"
#include "apr_thread_proc.h"
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* @defgroup apr_random PRNG Routines
* @ingroup APR
* @{
*/
typedef struct apr_crypto_hash_t apr_crypto_hash_t;
typedef void apr_crypto_hash_init_t(apr_crypto_hash_t *hash);
typedef void apr_crypto_hash_add_t(apr_crypto_hash_t *hash, const void *data,
apr_size_t bytes);
typedef void apr_crypto_hash_finish_t(apr_crypto_hash_t *hash,
unsigned char *result);
/* FIXME: make this opaque */
struct apr_crypto_hash_t {
apr_crypto_hash_init_t *init;
apr_crypto_hash_add_t *add;
apr_crypto_hash_finish_t *finish;
apr_size_t size;
void *data;
};
/**
* Allocate and initialize the SHA-256 context
* @param p The pool to allocate from
*/
APR_DECLARE(apr_crypto_hash_t *) apr_crypto_sha256_new(apr_pool_t *p);
/** Opaque PRNG structure. */
typedef struct apr_random_t apr_random_t;
/**
* Initialize a PRNG state
* @param g The PRNG state
* @param p The pool to allocate from
* @param pool_hash Pool hash functions
* @param key_hash Key hash functions
* @param prng_hash PRNG hash functions
*/
APR_DECLARE(void) apr_random_init(apr_random_t *g, apr_pool_t *p,
apr_crypto_hash_t *pool_hash,
apr_crypto_hash_t *key_hash,
apr_crypto_hash_t *prng_hash);
/**
* Allocate and initialize (apr_crypto_sha256_new) a new PRNG state.
* @param p The pool to allocate from
*/
APR_DECLARE(apr_random_t *) apr_random_standard_new(apr_pool_t *p);
/**
* Mix the randomness pools.
* @param g The PRNG state
* @param entropy_ Entropy buffer
* @param bytes Length of entropy_ in bytes
*/
APR_DECLARE(void) apr_random_add_entropy(apr_random_t *g,
const void *entropy_,
apr_size_t bytes);
/**
* Generate cryptographically insecure random bytes.
* @param g The RNG state
* @param random Buffer to fill with random bytes
* @param bytes Length of buffer in bytes
*/
APR_DECLARE(apr_status_t) apr_random_insecure_bytes(apr_random_t *g,
void *random,
apr_size_t bytes);
/**
* Generate cryptographically secure random bytes.
* @param g The RNG state
* @param random Buffer to fill with random bytes
* @param bytes Length of buffer in bytes
*/
APR_DECLARE(apr_status_t) apr_random_secure_bytes(apr_random_t *g,
void *random,
apr_size_t bytes);
/**
* Ensures that E bits of conditional entropy are mixed into the PRNG
* before any further randomness is extracted.
* @param g The RNG state
*/
APR_DECLARE(void) apr_random_barrier(apr_random_t *g);
/**
* Return APR_SUCCESS if the cryptographic PRNG has been seeded with
* enough data, APR_ENOTENOUGHENTROPY otherwise.
* @param r The RNG state
*/
APR_DECLARE(apr_status_t) apr_random_secure_ready(apr_random_t *r);
/**
* Return APR_SUCCESS if the PRNG has been seeded with enough data,
* APR_ENOTENOUGHENTROPY otherwise.
* @param r The PRNG state
*/
APR_DECLARE(apr_status_t) apr_random_insecure_ready(apr_random_t *r);
/**
* Mix the randomness pools after forking.
* @param proc The resulting process handle from apr_proc_fork()
* @remark Call this in the child after forking to mix the randomness
* pools. Note that its generally a bad idea to fork a process with a
* real PRNG in it - better to have the PRNG externally and get the
* randomness from there. However, if you really must do it, then you
* should supply all your entropy to all the PRNGs - don't worry, they
* won't produce the same output.
* @remark Note that apr_proc_fork() calls this for you, so only weird
* applications need ever call it themselves.
* @internal
*/
APR_DECLARE(void) apr_random_after_fork(apr_proc_t *proc);
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* !APR_RANDOM_H */
