1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
// Copyright 2022 Huawei Cloud Computing Technology Co., Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "src/buildtool/crypto/hasher.hpp"
#include <array>
#include <exception>
#include <limits>
#include <string_view>
#include <variant>
#include "gsl/gsl"
#include "openssl/sha.h"
#include "src/buildtool/logging/log_level.hpp"
#include "src/buildtool/logging/logger.hpp"
// Since it is impossible either forward declare SHA*_CTX (they are typedefs),
// nor their basic classes (they are called differently in OpenSSL and
// BoringSSL), an intermediate struct is forward declared in the header.
using VariantContext = std::variant<SHA_CTX, SHA256_CTX, SHA512_CTX>;
struct Hasher::ShaContext final : VariantContext {
using VariantContext::VariantContext;
};
namespace {
inline constexpr int kOpenSslTrue = 1;
[[nodiscard]] auto CreateShaContext(Hasher::HashType type) noexcept
-> std::unique_ptr<Hasher::ShaContext> {
switch (type) {
case Hasher::HashType::SHA1:
return std::make_unique<Hasher::ShaContext>(SHA_CTX{});
case Hasher::HashType::SHA256:
return std::make_unique<Hasher::ShaContext>(SHA256_CTX{});
case Hasher::HashType::SHA512:
return std::make_unique<Hasher::ShaContext>(SHA512_CTX{});
}
return nullptr; // make gcc happy
}
template <typename TVisitor, typename... Args>
[[nodiscard]] auto Visit(gsl::not_null<VariantContext*> const& ctx,
Args&&... visitor_args) noexcept {
try {
return std::visit(TVisitor{std::forward<Args>(visitor_args)...}, *ctx);
} catch (std::exception const& e) {
Logger::Log(LogLevel::Error,
"HashFunction::{} failed with an exception:\n{}",
TVisitor::kLogInfo,
e.what());
Ensures(false);
}
}
struct InitializeVisitor final {
static constexpr std::string_view kLogInfo = "Initialize";
// NOLINTNEXTLINE(google-runtime-references)
[[nodiscard]] auto operator()(SHA_CTX& ctx) const -> bool {
return SHA1_Init(&ctx) == kOpenSslTrue;
}
// NOLINTNEXTLINE(google-runtime-references)
[[nodiscard]] auto operator()(SHA256_CTX& ctx) const -> bool {
return SHA256_Init(&ctx) == kOpenSslTrue;
}
// NOLINTNEXTLINE(google-runtime-references)
[[nodiscard]] auto operator()(SHA512_CTX& ctx) const -> bool {
return SHA512_Init(&ctx) == kOpenSslTrue;
}
};
struct UpdateVisitor final {
static constexpr std::string_view kLogInfo = "Update";
explicit UpdateVisitor(gsl::not_null<std::string const*> const& data)
: data_{*data} {}
// NOLINTNEXTLINE(google-runtime-references)
[[nodiscard]] auto operator()(SHA_CTX& ctx) const -> bool {
return SHA1_Update(&ctx, data_.data(), data_.size()) == kOpenSslTrue;
}
// NOLINTNEXTLINE(google-runtime-references)
[[nodiscard]] auto operator()(SHA256_CTX& ctx) const -> bool {
return SHA256_Update(&ctx, data_.data(), data_.size()) == kOpenSslTrue;
}
// NOLINTNEXTLINE(google-runtime-references)
[[nodiscard]] auto operator()(SHA512_CTX& ctx) const -> bool {
return SHA512_Update(&ctx, data_.data(), data_.size()) == kOpenSslTrue;
}
private:
std::string const& data_;
};
struct FinalizeVisitor final {
static constexpr std::string_view kLogInfo = "Finalize";
// NOLINTNEXTLINE(google-runtime-references)
[[nodiscard]] inline auto operator()(SHA_CTX& ctx) const
-> std::optional<std::string>;
// NOLINTNEXTLINE(google-runtime-references)
[[nodiscard]] inline auto operator()(SHA256_CTX& ctx) const
-> std::optional<std::string>;
// NOLINTNEXTLINE(google-runtime-references)
[[nodiscard]] inline auto operator()(SHA512_CTX& ctx) const
-> std::optional<std::string>;
};
struct LengthVisitor final {
static constexpr std::string_view kLogInfo = "GetHashLength";
[[nodiscard]] constexpr auto operator()(SHA_CTX const& /*unused*/) const
-> std::size_t {
return SHA_DIGEST_LENGTH * kCharsPerNumber;
}
[[nodiscard]] constexpr auto operator()(SHA256_CTX const& /*unused*/) const
-> std::size_t {
return SHA256_DIGEST_LENGTH * kCharsPerNumber;
}
[[nodiscard]] constexpr auto operator()(SHA512_CTX const& /*unused*/) const
-> std::size_t {
return SHA512_DIGEST_LENGTH * kCharsPerNumber;
}
private:
static constexpr size_t kCharsPerNumber =
std::numeric_limits<std::uint8_t>::max() /
std::numeric_limits<signed char>::max();
};
} // namespace
Hasher::Hasher(std::unique_ptr<ShaContext> sha_ctx) noexcept
: sha_ctx_{std::move(sha_ctx)} {}
// Explicitly declared and then defaulted dtor and move ctor/operator are needed
// to compile std::unique_ptr of an incomplete type.
Hasher::Hasher(Hasher&& other) noexcept = default;
auto Hasher::operator=(Hasher&& other) noexcept -> Hasher& = default;
Hasher::~Hasher() noexcept = default;
auto Hasher::Create(HashType type) noexcept -> std::optional<Hasher> {
auto sha_ctx = CreateShaContext(type);
if (sha_ctx != nullptr and Visit<InitializeVisitor>(sha_ctx.get())) {
return std::optional<Hasher>{Hasher{std::move(sha_ctx)}};
}
return std::nullopt;
}
auto Hasher::Update(std::string const& data) noexcept -> bool {
return Visit<UpdateVisitor>(sha_ctx_.get(), &data);
}
auto Hasher::Finalize() && noexcept -> HashDigest {
if (auto hash = Visit<FinalizeVisitor>(sha_ctx_.get())) {
return HashDigest{std::move(*hash)};
}
Logger::Log(LogLevel::Error, "Failed to compute hash.");
Ensures(false);
}
auto Hasher::GetHashLength() const noexcept -> std::size_t {
return Visit<LengthVisitor>(sha_ctx_.get());
}
namespace {
auto FinalizeVisitor::operator()(SHA_CTX& ctx) const
-> std::optional<std::string> {
auto out = std::array<std::uint8_t, SHA_DIGEST_LENGTH>{};
if (SHA1_Final(out.data(), &ctx) == kOpenSslTrue) {
return std::string{out.begin(), out.end()};
}
return std::nullopt;
}
auto FinalizeVisitor::operator()(SHA256_CTX& ctx) const
-> std::optional<std::string> {
auto out = std::array<std::uint8_t, SHA256_DIGEST_LENGTH>{};
if (SHA256_Final(out.data(), &ctx) == kOpenSslTrue) {
return std::string{out.begin(), out.end()};
}
return std::nullopt;
}
auto FinalizeVisitor::operator()(SHA512_CTX& ctx) const
-> std::optional<std::string> {
auto out = std::array<std::uint8_t, SHA512_DIGEST_LENGTH>{};
if (SHA512_Final(out.data(), &ctx) == kOpenSslTrue) {
return std::string{out.begin(), out.end()};
}
return std::nullopt;
}
} // namespace
|
