Botan 3.0.0-alpha0
Crypto and TLS for C&
getentropy.cpp
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1/*
2* System Call getentropy(2)
3* (C) 2017 Alexander Bluhm (genua GmbH)
4*
5* Botan is released under the Simplified BSD License (see license.txt)
6*/
7
8#include <botan/internal/getentropy.h>
9
10#if defined(BOTAN_TARGET_OS_IS_OPENBSD) || defined(BOTAN_TARGET_OS_IS_FREEBSD) || defined(BOTAN_TARGET_OS_IS_SOLARIS)
11 #include <unistd.h>
12#else
13 #include <sys/types.h> // older macOS needs this before sys/random.h
14 #include <sys/random.h>
15#endif
16
17namespace Botan {
18
19/**
20* Gather 256 bytes entropy from getentropy(2). Note that maximum
21* buffer size is limited to 256 bytes. On OpenBSD this does neither
22* block nor fail.
23*/
25 {
27
28 if(::getentropy(buf.data(), buf.size()) == 0)
29 {
30 rng.add_entropy(buf.data(), buf.size());
31 return buf.size() * 8;
32 }
33
34 return 0;
35 }
36}
size_t poll(RandomNumberGenerator &rng) override
Definition: getentropy.cpp:24
virtual void add_entropy(const uint8_t input[], size_t length)=0
Definition: alg_id.cpp:13
std::vector< T, secure_allocator< T > > secure_vector
Definition: secmem.h:65