90 lines
1.8 KiB
C++
90 lines
1.8 KiB
C++
/**
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* \brief Add random support for CGD
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* \author Sebastian Sumpf
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* \author Josef Soentgen
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* \date 2015-02-13
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*/
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/*
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* Copyright (C) 2015-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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/* Genode includes */
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#include <base/log.h>
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/* local rump includes */
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#include <rump/env.h>
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#include <util/random.h>
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/* library includes */
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#include <jitterentropy.h>
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typedef Genode::size_t size_t;
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/***********************************
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** Jitter entropy for randomness **
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***********************************/
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struct Entropy
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{
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struct rand_data *ec_stir;
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struct Initialization_failed : Genode::Exception { };
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Entropy(Genode::Allocator &alloc)
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{
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jitterentropy_init(alloc);
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int err = jent_entropy_init();
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if (err) {
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Genode::error("could not initialize jitterentropy library");
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throw Initialization_failed();
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}
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ec_stir = jent_entropy_collector_alloc(0, 0);
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if (ec_stir == nullptr) {
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Genode::error("could not initialize jitterentropy library");
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throw Initialization_failed();
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}
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}
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size_t read(char *buf, size_t len)
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{
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int err;
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if ((err = jent_read_entropy(ec_stir, buf, len) < 0)) {
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Genode::error("failed to read entropy: ", err);
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return 0;
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}
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return len;
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}
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};
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static Genode::Constructible<Entropy> _entropy;
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static bool _init_failed;
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int rumpuser_getrandom_backend(void *buf, size_t buflen, int flags, Genode::size_t *retp)
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{
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if (!_entropy.constructed()) {
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if (_init_failed) {
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*retp = 0;
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return -1;
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}
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try { _entropy.construct(Rump::env().heap()); }
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catch (Entropy::Initialization_failed) {
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_init_failed = true;
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return -1;
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}
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}
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*retp = _entropy->read((char *)buf, buflen);
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return 0;
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}
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