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Diffstat (limited to 'src/libstrongswan/utils/randomizer.c')
| -rw-r--r-- | src/libstrongswan/utils/randomizer.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/src/libstrongswan/utils/randomizer.c b/src/libstrongswan/utils/randomizer.c new file mode 100644 index 000000000..c15d108c7 --- /dev/null +++ b/src/libstrongswan/utils/randomizer.c @@ -0,0 +1,165 @@ +/** + * @file randomizer.c + * + * @brief Implementation of randomizer_t. + * + */ + +/* + * Copyright (C) 2005-2006 Martin Willi + * Copyright (C) 2005 Jan Hutter + * Hochschule fuer Technik Rapperswil + * + * 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. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> + +#include "randomizer.h" + + +typedef struct private_randomizer_t private_randomizer_t; + +/** + * Private data of an randomizer_t object. + */ +struct private_randomizer_t { + + /** + * Public randomizer_t interface. + */ + randomizer_t public; + + /** + * @brief Reads a specific number of bytes from random or pseudo random device. + * + * @param this calling object + * @param pseudo_random TRUE, if from pseudo random bytes should be read, + * FALSE for true random bytes + * @param bytes number of bytes to read + * @param[out] buffer pointer to buffer where to write the data in. + * Size of buffer has to be at least bytes. + */ + status_t (*get_bytes_from_device) (private_randomizer_t *this,bool pseudo_random, size_t bytes, u_int8_t *buffer); +}; + + +/** + * Implementation of private_randomizer_t.get_bytes_from_device. + */ +static status_t get_bytes_from_device(private_randomizer_t *this,bool pseudo_random, size_t bytes, u_int8_t *buffer) +{ + size_t ndone; + int device; + size_t got; + char * device_name; + + device_name = pseudo_random ? DEV_URANDOM : DEV_RANDOM; + + device = open(device_name, 0); + if (device < 0) { + return FAILED; + } + ndone = 0; + + /* read until nbytes are read */ + while (ndone < bytes) + { + got = read(device, buffer + ndone, bytes - ndone); + if (got <= 0) { + close(device); + return FAILED; + } + ndone += got; + } + close(device); + return SUCCESS; +} + +/** + * Implementation of randomizer_t.get_random_bytes. + */ +static status_t get_random_bytes(private_randomizer_t *this,size_t bytes, u_int8_t *buffer) +{ + return this->get_bytes_from_device(this, FALSE, bytes, buffer); +} + +/** + * Implementation of randomizer_t.allocate_random_bytes. + */ +static status_t allocate_random_bytes(private_randomizer_t *this, size_t bytes, chunk_t *chunk) +{ + status_t status; + chunk->len = bytes; + chunk->ptr = malloc(bytes); + status = this->get_bytes_from_device(this, FALSE, bytes, chunk->ptr); + if (status != SUCCESS) + { + free(chunk->ptr); + } + return status; +} + +/** + * Implementation of randomizer_t.get_pseudo_random_bytes. + */ +static status_t get_pseudo_random_bytes(private_randomizer_t *this,size_t bytes, u_int8_t *buffer) +{ + return (this->get_bytes_from_device(this, TRUE, bytes, buffer)); +} + +/** + * Implementation of randomizer_t.allocate_pseudo_random_bytes. + */ +static status_t allocate_pseudo_random_bytes(private_randomizer_t *this, size_t bytes, chunk_t *chunk) +{ + status_t status; + chunk->len = bytes; + chunk->ptr = malloc(bytes); + status = this->get_bytes_from_device(this, TRUE, bytes, chunk->ptr); + if (status != SUCCESS) + { + free(chunk->ptr); + } + return status; +} + +/** + * Implementation of randomizer_t.destroy. + */ +static void destroy(private_randomizer_t *this) +{ + free(this); +} + +/* + * Described in header. + */ +randomizer_t *randomizer_create(void) +{ + private_randomizer_t *this = malloc_thing(private_randomizer_t); + + /* public functions */ + this->public.get_random_bytes = (status_t (*) (randomizer_t *,size_t, u_int8_t *)) get_random_bytes; + this->public.allocate_random_bytes = (status_t (*) (randomizer_t *,size_t, chunk_t *)) allocate_random_bytes; + this->public.get_pseudo_random_bytes = (status_t (*) (randomizer_t *,size_t, u_int8_t *)) get_pseudo_random_bytes; + this->public.allocate_pseudo_random_bytes = (status_t (*) (randomizer_t *,size_t, chunk_t *)) allocate_pseudo_random_bytes; + this->public.destroy = (void (*) (randomizer_t *))destroy; + + /* private functions */ + this->get_bytes_from_device = get_bytes_from_device; + + return &(this->public); +} |