Botan  2.8.0
Crypto and TLS for C++11
rng.cpp
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1 /*
2 * (C) 2016 Jack Lloyd
3 *
4 * Botan is released under the Simplified BSD License (see license.txt)
5 */
6 
7 #include <botan/rng.h>
8 #include <botan/entropy_src.h>
9 #include <botan/loadstor.h>
10 #include <botan/internal/os_utils.h>
11 
12 #if defined(BOTAN_HAS_AUTO_SEEDING_RNG)
13  #include <botan/auto_rng.h>
14 #endif
15 
16 namespace Botan {
17 
18 void RandomNumberGenerator::randomize_with_ts_input(uint8_t output[], size_t output_len)
19  {
20  if(this->accepts_input())
21  {
22  /*
23  Form additional input which is provided to the PRNG implementation
24  to paramaterize the KDF output.
25  */
26  uint8_t additional_input[16] = { 0 };
27  store_le(OS::get_system_timestamp_ns(), additional_input);
28  store_le(OS::get_high_resolution_clock(), additional_input + 8);
29 
30  this->randomize_with_input(output, output_len, additional_input, sizeof(additional_input));
31  }
32  else
33  {
34  this->randomize(output, output_len);
35  }
36  }
37 
38 void RandomNumberGenerator::randomize_with_input(uint8_t output[], size_t output_len,
39  const uint8_t input[], size_t input_len)
40  {
41  this->add_entropy(input, input_len);
42  this->randomize(output, output_len);
43  }
44 
46  size_t poll_bits,
47  std::chrono::milliseconds poll_timeout)
48  {
49  if(this->accepts_input())
50  {
51  return srcs.poll(*this, poll_bits, poll_timeout);
52  }
53  else
54  {
55  return 0;
56  }
57  }
58 
60  {
61  if(this->accepts_input())
62  {
63  secure_vector<uint8_t> buf(poll_bits / 8);
64  rng.randomize(buf.data(), buf.size());
65  this->add_entropy(buf.data(), buf.size());
66  }
67  }
68 
70  {
71 #if defined(BOTAN_HAS_AUTO_SEEDING_RNG)
72  return new AutoSeeded_RNG;
73 #else
74  throw Exception("make_rng failed, no AutoSeeded_RNG in this build");
75 #endif
76  }
77 
78 #if defined(BOTAN_TARGET_OS_HAS_THREADS)
79 
80 #if defined(BOTAN_HAS_AUTO_SEEDING_RNG)
81 Serialized_RNG::Serialized_RNG() : m_rng(new AutoSeeded_RNG) {}
82 #else
83 Serialized_RNG::Serialized_RNG()
84  {
85  throw Exception("Serialized_RNG default constructor failed: AutoSeeded_RNG disabled in build");
86  }
87 #endif
88 
89 #endif
90 
91 }
virtual void add_entropy(const uint8_t input[], size_t length)=0
virtual void randomize_with_input(uint8_t output[], size_t output_len, const uint8_t input[], size_t input_len)
Definition: rng.cpp:38
virtual void randomize(uint8_t output[], size_t length)=0
virtual void randomize_with_ts_input(uint8_t output[], size_t output_len)
Definition: rng.cpp:18
static RandomNumberGenerator * make_rng()
Definition: rng.cpp:69
virtual size_t reseed(Entropy_Sources &srcs, size_t poll_bits=BOTAN_RNG_RESEED_POLL_BITS, std::chrono::milliseconds poll_timeout=BOTAN_RNG_RESEED_DEFAULT_TIMEOUT)
Definition: rng.cpp:45
virtual bool accepts_input() const =0
uint64_t BOTAN_TEST_API get_system_timestamp_ns()
Definition: os_utils.cpp:203
Definition: alg_id.cpp:13
virtual void reseed_from_rng(RandomNumberGenerator &rng, size_t poll_bits=BOTAN_RNG_RESEED_POLL_BITS)
Definition: rng.cpp:59
std::vector< T, secure_allocator< T > > secure_vector
Definition: secmem.h:88
size_t poll(RandomNumberGenerator &rng, size_t bits, std::chrono::milliseconds timeout)
void store_le(uint16_t in, uint8_t out[2])
Definition: loadstor.h:450
uint64_t BOTAN_TEST_API get_high_resolution_clock()
Definition: os_utils.cpp:155