Crypto++ 8.2
Free C&
randpool.h
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1// randpool.h - originally written and placed in the public domain by Wei Dai
2// OldRandPool added by JW in August, 2017.
3
4/// \file randpool.h
5/// \brief Class file for Randomness Pool
6/// \details RandomPool can be used to generate cryptographic quality pseudorandom bytes
7/// after seeding the pool with IncorporateEntropy(). Internally, the generator uses
8/// AES-256 to produce the stream. Entropy is stirred in using SHA-256.
9/// \details RandomPool used to follow the design of randpool in PGP 2.6.x. At version 5.5
10/// RandomPool was redesigned to reduce the risk of reusing random numbers after state
11/// rollback (which may occur when running in a virtual machine like VMware or a hosted
12/// environment).
13/// \details If you need the pre-Crypto++ 5.5 generator then use OldRandomPool class. You
14/// should migrate away from OldRandomPool at the earliest opportunity. Use RandomPool
15/// or AutoSeededRandomPool instead.
16/// \since Crypto++ 4.0 (PGP 2.6.x style), Crypto++ 5.5 (AES-256 based)
17
18#ifndef CRYPTOPP_RANDPOOL_H
19#define CRYPTOPP_RANDPOOL_H
20
21#include "cryptlib.h"
22#include "filters.h"
23#include "secblock.h"
24#include "smartptr.h"
25#include "aes.h"
26
27NAMESPACE_BEGIN(CryptoPP)
28
29/// \brief Randomness Pool based on AES-256
30/// \details RandomPool can be used to generate cryptographic quality pseudorandom bytes
31/// after seeding the pool with IncorporateEntropy(). Internally, the generator uses
32/// AES-256 to produce the stream. Entropy is stirred in using SHA-256.
33/// \details RandomPool used to follow the design of randpool in PGP 2.6.x. At version 5.5
34/// RandomPool was redesigned to reduce the risk of reusing random numbers after state
35/// rollback, which may occur when running in a virtual machine like VMware or a hosted
36/// environment.
37/// \details If you need the pre-Crypto++ 5.5 generator then use OldRandomPool class. You
38/// should migrate away from OldRandomPool at the earliest opportunity.
39/// \sa OldRandomPool
40/// \since Crypto++ 4.0 (PGP 2.6.x style), Crypto++ 5.5 (AES-256 based)
41class CRYPTOPP_DLL RandomPool : public RandomNumberGenerator, public NotCopyable
42{
43public:
44 /// \brief Construct a RandomPool
45 RandomPool();
46
47 bool CanIncorporateEntropy() const {return true;}
48 void IncorporateEntropy(const byte *input, size_t length);
49 void GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword size);
50
51private:
55 bool m_keySet;
56};
57
58/// \brief Randomness Pool based on PGP 2.6.x with MDC
59/// \details If you need the pre-Crypto++ 5.5 generator then use OldRandomPool class. The
60/// OldRandomPool class is always available so you dont need to define
61/// CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY. OldRandomPool also provides the modern
62/// interface, including <tt>CanIncorporateEntropy</tt>, <tt>IncorporateEntropy</tt> and
63/// <tt>GenerateIntoBufferedTransformation</tt>.
64/// \details You should migrate away from OldRandomPool at the earliest opportunity. Use a
65/// modern random number generator or key derivation function, like AutoSeededRandomPool or
66/// HKDF.
67/// \warning This class uses an old style PGP 2.6.x with MDC. The generator risks reusing
68/// random random numbers after state rollback. You should migrate away from OldRandomPool
69/// at the earliest opportunity.
70/// \sa RandomPool, AutoSeededRandomPool, HKDF, P1363_KDF2, PKCS12_PBKDF, PKCS5_PBKDF2_HMAC
71/// \since Crypto++ 6.0 (PGP 2.6.x style)
72class CRYPTOPP_DLL OldRandomPool : public RandomNumberGenerator
73{
74public:
75 /// \brief Construct an OldRandomPool
76 /// \param poolSize internal pool size of the generator
77 /// \details poolSize must be greater than 16
78 OldRandomPool(unsigned int poolSize=384);
79
80 // RandomNumberGenerator interface (Crypto++ 5.5 and above)
81 bool CanIncorporateEntropy() const {return true;}
82 void IncorporateEntropy(const byte *input, size_t length);
83 void GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword size);
84
85 byte GenerateByte();
86 void GenerateBlock(byte *output, size_t size);
87
88protected:
89 void Stir();
90
91private:
92 SecByteBlock pool, key;
93 size_t addPos, getPos;
94};
95
96NAMESPACE_END
97
98#endif
Class file for the AES cipher (Rijndael)
Interface for buffered transformations.
Definition: cryptlib.h:1599
Fixed size stack-based SecBlock with 16-byte alignment.
Definition: secblock.h:1090
Ensures an object is not copyable.
Definition: misc.h:201
Randomness Pool based on PGP 2.6.x with MDC.
Definition: randpool.h:73
bool CanIncorporateEntropy() const
Determines if a generator can accept additional entropy.
Definition: randpool.h:81
Interface for random number generators.
Definition: cryptlib.h:1384
virtual void GenerateBlock(byte *output, size_t size)
Generate random array of bytes.
Definition: cryptlib.cpp:311
virtual void GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword length)
Generate random bytes into a BufferedTransformation.
Definition: cryptlib.cpp:324
virtual void IncorporateEntropy(const byte *input, size_t length)
Update RNG state with additional unpredictable values.
Definition: cryptlib.h:1396
virtual byte GenerateByte()
Generate new random byte and return it.
Definition: cryptlib.cpp:276
Randomness Pool based on AES-256.
Definition: randpool.h:42
bool CanIncorporateEntropy() const
Determines if a generator can accept additional entropy.
Definition: randpool.h:47
SecBlock<byte> typedef.
Definition: secblock.h:1058
Pointer that overloads operator ->
Definition: smartptr.h:37
Abstract base classes that provide a uniform interface to this library.
Implementation of BufferedTransformation's attachment interface.
Crypto++ library namespace.
Classes and functions for secure memory allocations.
Classes for automatic resource management.