Botan 3.1.1
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
9#include <botan/mem_ops.h>
10#include <botan/system_rng.h>
11#include <botan/internal/chacha.h>
12#include <botan/internal/ct_utils.h>
13#include <botan/internal/loadstor.h>
14#include <botan/internal/os_utils.h>
15#include <cstdlib>
16
17namespace Botan {
18
19void Sodium::randombytes_buf(void* buf, size_t len) {
20 system_rng().randomize(static_cast<uint8_t*>(buf), len);
21}
22
23uint32_t Sodium::randombytes_uniform(uint32_t upper_bound) {
24 if(upper_bound <= 1) {
25 return 0;
26 }
27
28 // Not completely uniform
29 uint64_t x;
30 randombytes_buf(&x, sizeof(x));
31 return x % upper_bound;
32}
33
34void Sodium::randombytes_buf_deterministic(void* buf, size_t size, const uint8_t seed[randombytes_SEEDBYTES]) {
35 const unsigned char nonce[12] = {'L', 'i', 'b', 's', 'o', 'd', 'i', 'u', 'm', 'D', 'R', 'G'};
36
37 ChaCha chacha(20);
38 chacha.set_key(seed, randombytes_SEEDBYTES);
39 chacha.set_iv(nonce, sizeof(nonce));
40 chacha.write_keystream(static_cast<uint8_t*>(buf), size);
41}
42
43int Sodium::crypto_verify_16(const uint8_t x[16], const uint8_t y[16]) {
44 return same_mem(x, y, 16);
45}
46
47int Sodium::crypto_verify_32(const uint8_t x[32], const uint8_t y[32]) {
48 return same_mem(x, y, 32);
49}
50
51int Sodium::crypto_verify_64(const uint8_t x[64], const uint8_t y[64]) {
52 return same_mem(x, y, 64);
53}
54
55void Sodium::sodium_memzero(void* ptr, size_t len) {
56 secure_scrub_memory(ptr, len);
57}
58
59int Sodium::sodium_memcmp(const void* x, const void* y, size_t len) {
60 const bool same = constant_time_compare(static_cast<const uint8_t*>(x), static_cast<const uint8_t*>(y), len);
61 return same ? 0 : -1;
62}
63
64int Sodium::sodium_compare(const uint8_t x[], const uint8_t y[], size_t len) {
65 const uint8_t LT = static_cast<uint8_t>(-1);
66 const uint8_t EQ = 0;
67 const uint8_t GT = 1;
68
69 uint8_t result = EQ; // until found otherwise
70
71 for(size_t i = 0; i != len; ++i) {
72 const auto is_eq = CT::Mask<uint8_t>::is_equal(x[i], y[i]);
73 const auto is_lt = CT::Mask<uint8_t>::is_lt(x[i], y[i]);
74 result = is_eq.select(result, is_lt.select(LT, GT));
75 }
76
77 return static_cast<int8_t>(result);
78}
79
80int Sodium::sodium_is_zero(const uint8_t b[], size_t len) {
81 uint8_t sum = 0;
82 for(size_t i = 0; i != len; ++i) {
83 sum |= b[i];
84 }
85 return static_cast<int>(CT::Mask<uint8_t>::expand(sum).if_not_set_return(1));
86}
87
88void Sodium::sodium_increment(uint8_t b[], size_t len) {
89 uint8_t carry = 1;
90 for(size_t i = 0; i != len; ++i) {
91 b[i] += carry;
92 carry &= (b[i] == 0);
93 }
94}
95
96void Sodium::sodium_add(uint8_t a[], const uint8_t b[], size_t len) {
97 uint8_t carry = 0;
98 for(size_t i = 0; i != len; ++i) {
99 a[i] += b[i] + carry;
100 carry = (a[i] < b[i]);
101 }
102}
103
104void* Sodium::sodium_malloc(size_t size) {
105 const uint64_t len = size;
106
107 if(size + sizeof(len) < size) {
108 return nullptr;
109 }
110
111 // NOLINTNEXTLINE(*-no-malloc)
112 uint8_t* p = static_cast<uint8_t*>(std::calloc(size + sizeof(len), 1));
113 store_le(len, p);
114 return p + 8;
115}
116
117void Sodium::sodium_free(void* ptr) {
118 if(ptr == nullptr) {
119 return;
120 }
121
122 uint8_t* p = static_cast<uint8_t*>(ptr) - 8;
123 const uint64_t len = load_le<uint64_t>(p, 0);
124 secure_scrub_memory(ptr, static_cast<size_t>(len));
125 // NOLINTNEXTLINE(*-no-malloc)
126 std::free(p);
127}
128
129void* Sodium::sodium_allocarray(size_t count, size_t size) {
130 const size_t bytes = count * size;
131 if(bytes < count || bytes < size) {
132 return nullptr;
133 }
134 return sodium_malloc(bytes);
135}
136
139 return 0;
140}
141
144 return 0;
145}
146
147} // namespace Botan
static Mask< T > is_equal(T x, T y)
Definition: ct_utils.h:128
static Mask< T > expand(T v)
Definition: ct_utils.h:109
static Mask< T > is_lt(T x, T y)
Definition: ct_utils.h:133
void randomize(std::span< uint8_t > output)
Definition: rng.h:52
void set_iv(const uint8_t iv[], size_t iv_len)
void write_keystream(uint8_t out[], size_t len)
Definition: stream_cipher.h:78
void set_key(const SymmetricKey &key)
Definition: sym_algo.h:113
void page_allow_access(void *page)
Definition: os_utils.cpp:557
void page_prohibit_access(void *page)
Definition: os_utils.cpp:571
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:151
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
constexpr void store_le(uint16_t in, uint8_t out[2])
Definition: loadstor.h:422
RandomNumberGenerator & system_rng()
Definition: system_rng.cpp:362
void secure_scrub_memory(void *ptr, size_t n)
Definition: os_utils.cpp:78
bool constant_time_compare(const uint8_t x[], const uint8_t y[], size_t len)
Definition: mem_ops.h:80
void carry(int64_t &h0, int64_t &h1)
bool same_mem(const T *p1, const T *p2, size_t n)
Definition: mem_ops.h:201
constexpr uint64_t load_le< uint64_t >(const uint8_t in[], size_t off)
Definition: loadstor.h:228