Botan 2.17.3
Crypto and TLS for C&
getentropy.cpp
Go to the documentation of this file.
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)
11 #include <unistd.h>
12#else
13 #include <sys/random.h>
14#endif
15
16namespace Botan {
17
18/**
19* Gather 256 bytes entropy from getentropy(2). Note that maximum
20* buffer size is limited to 256 bytes. On OpenBSD this does neither
21* block nor fail.
22*/
24 {
26
27 if(::getentropy(buf.data(), buf.size()) == 0)
28 {
29 rng.add_entropy(buf.data(), buf.size());
30 return buf.size() * 8;
31 }
32
33 return 0;
34 }
35}
size_t poll(RandomNumberGenerator &rng) override
Definition: getentropy.cpp:23
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