Botan 2.19.2
Crypto and TLS for C&
entropy_src.h
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1/*
2* EntropySource
3* (C) 2008,2009,2014,2015,2016 Jack Lloyd
4*
5* Botan is released under the Simplified BSD License (see license.txt)
6*/
7
8#ifndef BOTAN_ENTROPY_H_
9#define BOTAN_ENTROPY_H_
10
11#include <botan/secmem.h>
12#include <botan/rng.h>
13#include <string>
14#include <chrono>
15#include <memory>
16#include <vector>
17
18namespace Botan {
19
20class RandomNumberGenerator;
21
22/**
23* Abstract interface to a source of entropy
24*/
26 {
27 public:
28 /**
29 * Return a new entropy source of a particular type, or null
30 * Each entropy source may require substantial resources (eg, a file handle
31 * or socket instance), so try to share them among multiple RNGs, or just
32 * use the preconfigured global list accessed by Entropy_Sources::global_sources()
33 */
34 static std::unique_ptr<Entropy_Source> create(const std::string& type);
35
36 /**
37 * @return name identifying this entropy source
38 */
39 virtual std::string name() const = 0;
40
41 /**
42 * Perform an entropy gathering poll
43 * @param rng will be provided with entropy via calls to add_entropy
44 * @return conservative estimate of actual entropy added to rng during poll
45 */
46 virtual size_t poll(RandomNumberGenerator& rng) = 0;
47
48 Entropy_Source() = default;
49 Entropy_Source(const Entropy_Source& other) = delete;
50 Entropy_Source(Entropy_Source&& other) = delete;
51 Entropy_Source& operator=(const Entropy_Source& other) = delete;
52
53 virtual ~Entropy_Source() = default;
54 };
55
57 {
58 public:
59 static Entropy_Sources& global_sources();
60
61 void add_source(std::unique_ptr<Entropy_Source> src);
62
63 std::vector<std::string> enabled_sources() const;
64
65 size_t poll(RandomNumberGenerator& rng,
66 size_t bits,
67 std::chrono::milliseconds timeout);
68
69 /**
70 * Poll just a single named source. Ordinally only used for testing
71 */
72 size_t poll_just(RandomNumberGenerator& rng, const std::string& src);
73
74 Entropy_Sources() = default;
75 explicit Entropy_Sources(const std::vector<std::string>& sources);
76
77 Entropy_Sources(const Entropy_Sources& other) = delete;
79 Entropy_Sources& operator=(const Entropy_Sources& other) = delete;
80
81 private:
82 std::vector<std::unique_ptr<Entropy_Source>> m_srcs;
83 };
84
85}
86
87#endif
virtual std::string name() const =0
Entropy_Source(const Entropy_Source &other)=delete
virtual size_t poll(RandomNumberGenerator &rng)=0
Entropy_Source(Entropy_Source &&other)=delete
virtual ~Entropy_Source()=default
Entropy_Source & operator=(const Entropy_Source &other)=delete
Entropy_Sources(Entropy_Sources &&other)=delete
Entropy_Sources(const Entropy_Sources &other)=delete
Entropy_Sources & operator=(const Entropy_Sources &other)=delete
int(* final)(unsigned char *, CTX *)
#define BOTAN_PUBLIC_API(maj, min)
Definition: compiler.h:31
Definition: alg_id.cpp:13
MechanismType type