strongswan/src/libtpmtss/plugins/tpm/tpm_rng.c

95 lines
1.8 KiB
C

/*
* Copyright (C) 2017 Andreas Steffen
* HSR 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 "tpm_rng.h"
#include <tpm_tss.h>
#include <utils/debug.h>
typedef struct private_tpm_rng_t private_tpm_rng_t;
/**
* Private data of an tpm_rng_t object.
*/
struct private_tpm_rng_t {
/**
* Public interface.
*/
tpm_rng_t public;
/**
* Trusted Platform Module
*/
tpm_tss_t *tpm;
};
METHOD(rng_t, get_bytes, bool,
private_tpm_rng_t *this, size_t bytes, uint8_t *buffer)
{
return this->tpm->get_random(this->tpm, bytes, buffer);
}
METHOD(rng_t, allocate_bytes, bool,
private_tpm_rng_t *this, size_t bytes, chunk_t *chunk)
{
*chunk = chunk_alloc(bytes);
if (!get_bytes(this, chunk->len, chunk->ptr))
{
chunk_clear(chunk);
return FALSE;
}
return TRUE;
}
METHOD(rng_t, destroy, void,
private_tpm_rng_t *this)
{
this->tpm->destroy(this->tpm);
free(this);
}
/*
* Described in header.
*/
tpm_rng_t *tpm_rng_create(rng_quality_t quality)
{
private_tpm_rng_t *this;
tpm_tss_t *tpm;
/* try to find a TPM 2.0 */
tpm = tpm_tss_probe(TPM_VERSION_2_0);
if (!tpm)
{
DBG1(DBG_LIB, "no TPM 2.0 found");
return NULL;
}
INIT(this,
.public = {
.rng = {
.get_bytes = _get_bytes,
.allocate_bytes = _allocate_bytes,
.destroy = _destroy,
},
},
.tpm = tpm,
);
return &this->public;
}