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Annotation of embedaddon/strongswan/src/libstrongswan/plugins/random/random_rng.c, revision 1.1.1.1

1.1       misho       1: /*
                      2:  * Copyright (C) 2005-2008 Martin Willi
                      3:  * Copyright (C) 2005 Jan Hutter
                      4:  * HSR Hochschule fuer Technik Rapperswil
                      5:  *
                      6:  * This program is free software; you can redistribute it and/or modify it
                      7:  * under the terms of the GNU General Public License as published by the
                      8:  * Free Software Foundation; either version 2 of the License, or (at your
                      9:  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
                     10:  *
                     11:  * This program is distributed in the hope that it will be useful, but
                     12:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
                     13:  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
                     14:  * for more details.
                     15:  */
                     16: 
                     17: #include <string.h>
                     18: #include <unistd.h>
                     19: #include <errno.h>
                     20: #include <utils/debug.h>
                     21: 
                     22: #include "random_rng.h"
                     23: #include "random_plugin.h"
                     24: 
                     25: typedef struct private_random_rng_t private_random_rng_t;
                     26: 
                     27: /**
                     28:  * Private data of an random_rng_t object.
                     29:  */
                     30: struct private_random_rng_t {
                     31: 
                     32:        /**
                     33:         * Public random_rng_t interface.
                     34:         */
                     35:        random_rng_t public;
                     36: 
                     37:        /**
                     38:         * random device, depends on quality
                     39:         */
                     40:        int fd;
                     41: };
                     42: 
                     43: METHOD(rng_t, get_bytes, bool,
                     44:        private_random_rng_t *this, size_t bytes, uint8_t *buffer)
                     45: {
                     46:        size_t done;
                     47:        ssize_t got;
                     48: 
                     49:        done = 0;
                     50: 
                     51:        while (done < bytes)
                     52:        {
                     53:                got = read(this->fd, buffer + done, bytes - done);
                     54:                if (got <= 0)
                     55:                {
                     56:                        DBG1(DBG_LIB, "reading from random FD %d failed: %s, retrying...",
                     57:                                 this->fd, strerror(errno));
                     58:                        sleep(1);
                     59:                        continue;
                     60:                }
                     61:                done += got;
                     62:        }
                     63:        return TRUE;
                     64: }
                     65: 
                     66: METHOD(rng_t, allocate_bytes, bool,
                     67:        private_random_rng_t *this, size_t bytes, chunk_t *chunk)
                     68: {
                     69:        *chunk = chunk_alloc(bytes);
                     70:        get_bytes(this, chunk->len, chunk->ptr);
                     71:        return TRUE;
                     72: }
                     73: 
                     74: METHOD(rng_t, destroy, void,
                     75:        private_random_rng_t *this)
                     76: {
                     77:        free(this);
                     78: }
                     79: 
                     80: /*
                     81:  * Described in header.
                     82:  */
                     83: random_rng_t *random_rng_create(rng_quality_t quality)
                     84: {
                     85:        private_random_rng_t *this;
                     86: 
                     87:        INIT(this,
                     88:                .public = {
                     89:                        .rng = {
                     90:                                .get_bytes = _get_bytes,
                     91:                                .allocate_bytes = _allocate_bytes,
                     92:                                .destroy = _destroy,
                     93:                        },
                     94:                },
                     95:        );
                     96: 
                     97:        switch (quality)
                     98:        {
                     99:                case RNG_TRUE:
                    100:                        this->fd = random_plugin_get_dev_random();
                    101:                        break;
                    102:                case RNG_STRONG:
                    103:                        this->fd = random_plugin_get_strong_equals_true() ?
                    104:                                                        random_plugin_get_dev_random() :
                    105:                                                        random_plugin_get_dev_urandom();
                    106:                        break;
                    107:                case RNG_WEAK:
                    108:                default:
                    109:                        this->fd = random_plugin_get_dev_urandom();
                    110:                        break;
                    111:        }
                    112: 
                    113:        return &this->public;
                    114: }
                    115: