Botan 2.17.3
Crypto and TLS for C&
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
15namespace Botan {
16
17void Sodium::randombytes_buf(void* buf, size_t len)
18 {
19 system_rng().randomize(static_cast<uint8_t*>(buf), len);
20 }
21
22uint32_t Sodium::randombytes_uniform(uint32_t upper_bound)
23 {
24 if(upper_bound <= 1)
25 return 0;
26
27 // Not completely uniform
28 uint64_t x;
29 randombytes_buf(&x, sizeof(x));
30 return x % upper_bound;
31 }
32
33void Sodium::randombytes_buf_deterministic(void* buf, size_t size, const uint8_t seed[randombytes_SEEDBYTES])
34 {
35 const unsigned char nonce[12] = {
36 'L', 'i', 'b', 's', 'o', 'd', 'i', 'u', 'm', 'D', 'R', 'G'
37 };
38
39 ChaCha chacha(20);
40 chacha.set_key(seed, randombytes_SEEDBYTES);
41 chacha.set_iv(nonce, sizeof(nonce));
42 chacha.write_keystream(static_cast<uint8_t*>(buf), size);
43 }
44
45int Sodium::crypto_verify_16(const uint8_t x[16], const uint8_t y[16])
46 {
47 return same_mem(x, y, 16);
48 }
49
50int Sodium::crypto_verify_32(const uint8_t x[32], const uint8_t y[32])
51 {
52 return same_mem(x, y, 32);
53 }
54
55int Sodium::crypto_verify_64(const uint8_t x[64], const uint8_t y[64])
56 {
57 return same_mem(x, y, 64);
58 }
59
60void Sodium::sodium_memzero(void* ptr, size_t len)
61 {
62 secure_scrub_memory(ptr, len);
63 }
64
65int Sodium::sodium_memcmp(const void* x, const void* y, size_t len)
66 {
67 const bool same = constant_time_compare(static_cast<const uint8_t*>(x), static_cast<const uint8_t*>(y), len);
68 return same ? 0 : -1;
69 }
70
71int Sodium::sodium_compare(const uint8_t x[], const uint8_t y[], size_t len)
72 {
73 const uint8_t LT = static_cast<uint8_t>(-1);
74 const uint8_t EQ = 0;
75 const uint8_t GT = 1;
76
77 uint8_t result = EQ; // until found otherwise
78
79 for(size_t i = 0; i != len; ++i)
80 {
81 const auto is_eq = CT::Mask<uint8_t>::is_equal(x[i], y[i]);
82 const auto is_lt = CT::Mask<uint8_t>::is_lt(x[i], y[i]);
83 result = is_eq.select(result, is_lt.select(LT, GT));
84 }
85
86 return static_cast<int8_t>(result);
87 }
88
89int Sodium::sodium_is_zero(const uint8_t b[], size_t len)
90 {
91 uint8_t sum = 0;
92 for(size_t i = 0; i != len; ++i)
93 sum |= b[i];
94 return static_cast<int>(CT::Mask<uint8_t>::expand(sum).if_not_set_return(1));
95 }
96
97void Sodium::sodium_increment(uint8_t b[], size_t len)
98 {
99 uint8_t carry = 1;
100 for(size_t i = 0; i != len; ++i)
101 {
102 b[i] += carry;
103 carry &= (b[i] == 0);
104 }
105 }
106
107void Sodium::sodium_add(uint8_t a[], const uint8_t b[], size_t len)
108 {
109 uint8_t carry = 0;
110 for(size_t i = 0; i != len; ++i)
111 {
112 a[i] += b[i] + carry;
113 carry = (a[i] < b[i]);
114 }
115 }
116
117void* Sodium::sodium_malloc(size_t size)
118 {
119 const uint64_t len = size;
120
121 if(size + sizeof(len) < size)
122 return nullptr;
123
124 uint8_t* p = static_cast<uint8_t*>(std::calloc(size + sizeof(len), 1));
125 store_le(len, p);
126 return p + 8;
127 }
128
129void Sodium::sodium_free(void* ptr)
130 {
131 if(ptr == nullptr)
132 return;
133
134 uint8_t* p = static_cast<uint8_t*>(ptr) - 8;
135 const uint64_t len = load_le<uint64_t>(p, 0);
136 secure_scrub_memory(ptr, static_cast<size_t>(len));
137 std::free(p);
138 }
139
140void* Sodium::sodium_allocarray(size_t count, size_t size)
141 {
142 const size_t bytes = count * size;
143 if(bytes < count || bytes < size)
144 return nullptr;
145 return sodium_malloc(bytes);
146 }
147
149 {
151 return 0;
152 }
153
155 {
157 return 0;
158 }
159
160}
static Mask< T > is_equal(T x, T y)
Definition: ct_utils.h:149
static Mask< T > expand(T v)
Definition: ct_utils.h:123
static Mask< T > is_lt(T x, T y)
Definition: ct_utils.h:157
void set_iv(const uint8_t iv[], size_t iv_len) override
Definition: chacha.cpp:300
void write_keystream(uint8_t out[], size_t len) override
Definition: chacha.cpp:196
virtual void randomize(uint8_t output[], size_t length)=0
void set_key(const SymmetricKey &key)
Definition: sym_algo.h:147
void page_allow_access(void *page)
Definition: os_utils.cpp:547
void page_prohibit_access(void *page)
Definition: os_utils.cpp:562
int crypto_verify_32(const uint8_t x[32], const uint8_t y[32])
int crypto_verify_16(const uint8_t x[16], const uint8_t y[16])
void * sodium_allocarray(size_t count, size_t size)
int sodium_memcmp(const void *x, const void *y, size_t len)
@ randombytes_SEEDBYTES
Definition: sodium.h:149
int crypto_verify_64(const uint8_t x[64], const uint8_t y[64])
void sodium_add(uint8_t a[], const uint8_t b[], size_t len)
void * sodium_malloc(size_t size)
void sodium_increment(uint8_t n[], size_t nlen)
int sodium_compare(const uint8_t x[], const uint8_t y[], size_t len)
int sodium_mprotect_noaccess(void *ptr)
void randombytes_buf_deterministic(void *buf, size_t size, const uint8_t seed[randombytes_SEEDBYTES])
int sodium_is_zero(const uint8_t nonce[], size_t nlen)
void sodium_free(void *ptr)
uint32_t randombytes_uniform(uint32_t upper_bound)
int sodium_mprotect_readwrite(void *ptr)
void sodium_memzero(void *ptr, size_t len)
void randombytes_buf(void *buf, size_t size)
Definition: alg_id.cpp:13
RandomNumberGenerator & system_rng()
Definition: system_rng.cpp:283
void carry(int64_t &h0, int64_t &h1)
void secure_scrub_memory(void *ptr, size_t n)
Definition: os_utils.cpp:66
bool constant_time_compare(const uint8_t x[], const uint8_t y[], size_t len)
Definition: mem_ops.h:82
bool same_mem(const T *p1, const T *p2, size_t n)
Definition: mem_ops.h:217
void store_le(uint16_t in, uint8_t out[2])
Definition: loadstor.h:454
uint64_t load_le< uint64_t >(const uint8_t in[], size_t off)
Definition: loadstor.h:237