Botan
2.19.3
Crypto and TLS for C&
src
lib
entropy
getentropy
getentropy.cpp
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/*
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* System Call getentropy(2)
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* (C) 2017 Alexander Bluhm (genua GmbH)
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*
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* Botan is released under the Simplified BSD License (see license.txt)
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*/
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#include <botan/internal/getentropy.h>
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#if defined(BOTAN_TARGET_OS_IS_OPENBSD) || defined(BOTAN_TARGET_OS_IS_FREEBSD)
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#include <unistd.h>
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#else
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#if defined(BOTAN_TARGET_OS_HAS_POSIX1)
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// Allows successful compilation on macOS older than 10.12: Provides a missing typedef for `u_int`.
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#include <sys/types.h>
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#endif
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#include <sys/random.h>
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#endif
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namespace
Botan
{
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/**
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* Gather 256 bytes entropy from getentropy(2). Note that maximum
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* buffer size is limited to 256 bytes. On OpenBSD this does neither
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* block nor fail.
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*/
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size_t
Getentropy::poll
(
RandomNumberGenerator
& rng)
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{
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secure_vector<uint8_t>
buf(256);
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if
(::getentropy(buf.data(), buf.size()) == 0)
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{
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rng.
add_entropy
(buf.data(), buf.size());
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return
buf.size() * 8;
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}
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return
0;
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}
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}
Botan::Getentropy::poll
size_t poll(RandomNumberGenerator &rng) override
Definition
getentropy.cpp:27
Botan::RandomNumberGenerator
Definition
rng.h:26
Botan::RandomNumberGenerator::add_entropy
virtual void add_entropy(const uint8_t input[], size_t length)=0
Botan
Definition
alg_id.cpp:13
Botan::secure_vector
std::vector< T, secure_allocator< T > > secure_vector
Definition
secmem.h:65
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