Botan  2.19.1
Crypto and TLS for C++11
sodium_utils.cpp
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1 /*
2 * (C) 2019 Jack Lloyd
3 *
4 * Botan is released under the Simplified BSD License (see license.txt)
5 */
6 
7 #include <botan/sodium.h>
8 #include <botan/chacha.h>
9 #include <botan/mem_ops.h>
10 #include <botan/system_rng.h>
11 #include <botan/internal/os_utils.h>
12 #include <botan/internal/ct_utils.h>
13 #include <botan/loadstor.h>
14 #include <cstdlib>
15 
16 namespace Botan {
17 
18 void Sodium::randombytes_buf(void* buf, size_t len)
19  {
20  system_rng().randomize(static_cast<uint8_t*>(buf), len);
21  }
22 
23 uint32_t Sodium::randombytes_uniform(uint32_t upper_bound)
24  {
25  if(upper_bound <= 1)
26  return 0;
27 
28  // Not completely uniform
29  uint64_t x;
30  randombytes_buf(&x, sizeof(x));
31  return x % upper_bound;
32  }
33 
34 void Sodium::randombytes_buf_deterministic(void* buf, size_t size, const uint8_t seed[randombytes_SEEDBYTES])
35  {
36  const unsigned char nonce[12] = {
37  'L', 'i', 'b', 's', 'o', 'd', 'i', 'u', 'm', 'D', 'R', 'G'
38  };
39 
40  ChaCha chacha(20);
41  chacha.set_key(seed, randombytes_SEEDBYTES);
42  chacha.set_iv(nonce, sizeof(nonce));
43  chacha.write_keystream(static_cast<uint8_t*>(buf), size);
44  }
45 
46 int Sodium::crypto_verify_16(const uint8_t x[16], const uint8_t y[16])
47  {
48  return same_mem(x, y, 16);
49  }
50 
51 int Sodium::crypto_verify_32(const uint8_t x[32], const uint8_t y[32])
52  {
53  return same_mem(x, y, 32);
54  }
55 
56 int Sodium::crypto_verify_64(const uint8_t x[64], const uint8_t y[64])
57  {
58  return same_mem(x, y, 64);
59  }
60 
61 void Sodium::sodium_memzero(void* ptr, size_t len)
62  {
63  secure_scrub_memory(ptr, len);
64  }
65 
66 int Sodium::sodium_memcmp(const void* x, const void* y, size_t len)
67  {
68  const bool same = constant_time_compare(static_cast<const uint8_t*>(x), static_cast<const uint8_t*>(y), len);
69  return same ? 0 : -1;
70  }
71 
72 int Sodium::sodium_compare(const uint8_t x[], const uint8_t y[], size_t len)
73  {
74  const uint8_t LT = static_cast<uint8_t>(-1);
75  const uint8_t EQ = 0;
76  const uint8_t GT = 1;
77 
78  uint8_t result = EQ; // until found otherwise
79 
80  for(size_t i = 0; i != len; ++i)
81  {
82  const auto is_eq = CT::Mask<uint8_t>::is_equal(x[i], y[i]);
83  const auto is_lt = CT::Mask<uint8_t>::is_lt(x[i], y[i]);
84  result = is_eq.select(result, is_lt.select(LT, GT));
85  }
86 
87  return static_cast<int8_t>(result);
88  }
89 
90 int Sodium::sodium_is_zero(const uint8_t b[], size_t len)
91  {
92  uint8_t sum = 0;
93  for(size_t i = 0; i != len; ++i)
94  sum |= b[i];
95  return static_cast<int>(CT::Mask<uint8_t>::expand(sum).if_not_set_return(1));
96  }
97 
98 void Sodium::sodium_increment(uint8_t b[], size_t len)
99  {
100  uint8_t carry = 1;
101  for(size_t i = 0; i != len; ++i)
102  {
103  b[i] += carry;
104  carry &= (b[i] == 0);
105  }
106  }
107 
108 void Sodium::sodium_add(uint8_t a[], const uint8_t b[], size_t len)
109  {
110  uint8_t carry = 0;
111  for(size_t i = 0; i != len; ++i)
112  {
113  a[i] += b[i] + carry;
114  carry = (a[i] < b[i]);
115  }
116  }
117 
118 void* Sodium::sodium_malloc(size_t size)
119  {
120  const uint64_t len = size;
121 
122  if(size + sizeof(len) < size)
123  return nullptr;
124 
125  uint8_t* p = static_cast<uint8_t*>(std::calloc(size + sizeof(len), 1));
126  store_le(len, p);
127  return p + 8;
128  }
129 
130 void Sodium::sodium_free(void* ptr)
131  {
132  if(ptr == nullptr)
133  return;
134 
135  uint8_t* p = static_cast<uint8_t*>(ptr) - 8;
136  const uint64_t len = load_le<uint64_t>(p, 0);
137  secure_scrub_memory(ptr, static_cast<size_t>(len));
138  std::free(p);
139  }
140 
141 void* Sodium::sodium_allocarray(size_t count, size_t size)
142  {
143  const size_t bytes = count * size;
144  if(bytes < count || bytes < size)
145  return nullptr;
146  return sodium_malloc(bytes);
147  }
148 
150  {
152  return 0;
153  }
154 
156  {
158  return 0;
159  }
160 
161 }
RandomNumberGenerator & system_rng()
Definition: system_rng.cpp:283
void write_keystream(uint8_t out[], size_t len) override
Definition: chacha.cpp:196
void sodium_memzero(void *ptr, size_t len)
void sodium_increment(uint8_t n[], size_t nlen)
void * sodium_allocarray(size_t count, size_t size)
bool same_mem(const T *p1, const T *p2, size_t n)
Definition: mem_ops.h:217
void * sodium_malloc(size_t size)
void randombytes_buf_deterministic(void *buf, size_t size, const uint8_t seed[randombytes_SEEDBYTES])
void carry(int64_t &h0, int64_t &h1)
void sodium_add(uint8_t a[], const uint8_t b[], size_t len)
virtual void randomize(uint8_t output[], size_t length)=0
int crypto_verify_16(const uint8_t x[16], const uint8_t y[16])
int sodium_mprotect_readwrite(void *ptr)
bool constant_time_compare(const uint8_t x[], const uint8_t y[], size_t len)
Definition: mem_ops.h:82
void page_prohibit_access(void *page)
Definition: os_utils.cpp:562
int sodium_mprotect_noaccess(void *ptr)
void set_iv(const uint8_t iv[], size_t iv_len) override
Definition: chacha.cpp:300
void sodium_free(void *ptr)
int sodium_memcmp(const void *x, const void *y, size_t len)
void randombytes_buf(void *buf, size_t size)
static Mask< T > expand(T v)
Definition: ct_utils.h:123
void set_key(const SymmetricKey &key)
Definition: sym_algo.h:147
int sodium_compare(const uint8_t x[], const uint8_t y[], size_t len)
int crypto_verify_64(const uint8_t x[64], const uint8_t y[64])
uint64_t load_le< uint64_t >(const uint8_t in[], size_t off)
Definition: loadstor.h:237
Definition: alg_id.cpp:13
void secure_scrub_memory(void *ptr, size_t n)
Definition: os_utils.cpp:66
int sodium_is_zero(const uint8_t nonce[], size_t nlen)
void page_allow_access(void *page)
Definition: os_utils.cpp:547
uint32_t randombytes_uniform(uint32_t upper_bound)
int crypto_verify_32(const uint8_t x[32], const uint8_t y[32])
static Mask< T > is_equal(T x, T y)
Definition: ct_utils.h:149
static Mask< T > is_lt(T x, T y)
Definition: ct_utils.h:157
void store_le(uint16_t in, uint8_t out[2])
Definition: loadstor.h:454