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Strongswan

    1: /*
    2:  * Copyright (C) 2017 Andreas Steffen
    3:  * HSR Hochschule fuer Technik Rapperswil
    4:  *
    5:  * This program is free software; you can redistribute it and/or modify it
    6:  * under the terms of the GNU General Public License as published by the
    7:  * Free Software Foundation; either version 2 of the License, or (at your
    8:  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
    9:  *
   10:  * This program is distributed in the hope that it will be useful, but
   11:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   12:  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   13:  * for more details.
   14:  */
   15: 
   16: #include "tpm_rng.h"
   17: 
   18: #include <tpm_tss.h>
   19: #include <utils/debug.h>
   20: 
   21: typedef struct private_tpm_rng_t private_tpm_rng_t;
   22: 
   23: /**
   24:  * Private data of an tpm_rng_t object.
   25:  */
   26: struct private_tpm_rng_t {
   27: 
   28: 	/**
   29: 	 * Public interface.
   30: 	 */
   31: 	tpm_rng_t public;
   32: 
   33: 	/**
   34: 	 * Trusted Platform Module
   35: 	 */
   36: 	tpm_tss_t *tpm;
   37: 
   38: };
   39: 
   40: METHOD(rng_t, get_bytes, bool,
   41: 	private_tpm_rng_t *this, size_t bytes, uint8_t *buffer)
   42: {
   43: 	return this->tpm->get_random(this->tpm, bytes, buffer);
   44: }
   45: 
   46: METHOD(rng_t, allocate_bytes, bool,
   47: 	private_tpm_rng_t *this, size_t bytes, chunk_t *chunk)
   48: {
   49: 	*chunk = chunk_alloc(bytes);
   50: 	if (!get_bytes(this, chunk->len, chunk->ptr))
   51: 	{
   52: 		chunk_clear(chunk);
   53: 		return FALSE;
   54: 	}
   55: 	return TRUE;
   56: }
   57: 
   58: METHOD(rng_t, destroy, void,
   59: 	private_tpm_rng_t *this)
   60: {
   61: 	this->tpm->destroy(this->tpm);
   62: 	free(this);
   63: }
   64: 
   65: /*
   66:  * Described in header.
   67:  */
   68: tpm_rng_t *tpm_rng_create(rng_quality_t quality)
   69: {
   70: 	private_tpm_rng_t *this;
   71: 	tpm_tss_t *tpm;
   72: 
   73: 	/* try to find a TPM 2.0 */
   74: 	tpm = tpm_tss_probe(TPM_VERSION_2_0);
   75: 	if (!tpm)
   76: 	{
   77: 		DBG1(DBG_LIB, "no TPM 2.0 found");
   78: 		return NULL;
   79: 	}
   80: 
   81: 	INIT(this,
   82: 		.public = {
   83: 			.rng = {
   84: 				.get_bytes = _get_bytes,
   85: 				.allocate_bytes = _allocate_bytes,
   86: 				.destroy = _destroy,
   87: 			},
   88: 		},
   89: 		.tpm = tpm,
   90: 	);
   91: 
   92: 	return &this->public;
   93: }
   94: