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
|
// Copyright (C) 2014-2015 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
#include <cryptolink.h>
#include <cryptolink/crypto_hmac.h>
#include <boost/scoped_ptr.hpp>
#include <openssl/hmac.h>
#include <cryptolink/openssl_common.h>
#include <cstring>
namespace isc {
namespace cryptolink {
/// @brief OpenSSL implementation of HMAC. Each method is the counterpart
/// of the HMAC corresponding method.
class HMACImpl {
public:
/// @brief Constructor from a secret and a hash algorithm
///
/// See constructor of the @ref isc::cryptolink::HMAC class for details.
///
/// @param secret The secret to sign with
/// @param secret_len The length of the secret
/// @param hash_algorithm The hash algorithm
explicit HMACImpl(const void* secret, size_t secret_len,
const HashAlgorithm hash_algorithm) {
const EVP_MD* algo = ossl::getHashAlgorithm(hash_algorithm);
if (algo == 0) {
isc_throw(UnsupportedAlgorithm,
"Unknown hash algorithm: " <<
static_cast<int>(hash_algorithm));
}
if (secret_len == 0) {
isc_throw(BadKey, "Bad HMAC secret length: 0");
}
md_.reset(new HMAC_CTX);
HMAC_CTX_init(md_.get());
HMAC_Init_ex(md_.get(), secret,
static_cast<int>(secret_len),
algo, NULL);
}
/// @brief Destructor
~HMACImpl() {
if (md_) {
HMAC_CTX_cleanup(md_.get());
}
}
/// @brief Returns the output size of the digest
///
/// @return output size of the digest
size_t getOutputLength() const {
int size = HMAC_size(md_.get());
if (size < 0) {
isc_throw(isc::cryptolink::LibraryError, "EVP_MD_CTX_size");
}
return (static_cast<size_t>(size));
}
/// @brief Add data to digest
///
/// See @ref isc::cryptolink::HMAC::update() for details.
void update(const void* data, const size_t len) {
HMAC_Update(md_.get(), static_cast<const unsigned char*>(data), len);
}
/// @brief Calculate the final signature
///
/// See @ref isc::cryptolink::HMAC::sign() for details.
void sign(isc::util::OutputBuffer& result, size_t len) {
size_t size = getOutputLength();
ossl::SecBuf<unsigned char> digest(size);
HMAC_Final(md_.get(), &digest[0], NULL);
if (len > size) {
len = size;
}
result.writeData(&digest[0], len);
}
/// @brief Calculate the final signature
///
/// See @ref isc::cryptolink::HMAC::sign() for details.
void sign(void* result, size_t len) {
size_t size = getOutputLength();
ossl::SecBuf<unsigned char> digest(size);
HMAC_Final(md_.get(), &digest[0], NULL);
if (len > size) {
len = size;
}
std::memcpy(result, &digest[0], len);
}
/// @brief Calculate the final signature
///
/// See @ref isc::cryptolink::HMAC::sign() for details.
std::vector<uint8_t> sign(size_t len) {
size_t size = getOutputLength();
ossl::SecBuf<unsigned char> digest(size);
HMAC_Final(md_.get(), &digest[0], NULL);
if (len < size) {
digest.resize(len);
}
return (std::vector<uint8_t>(digest.begin(), digest.end()));
}
/// @brief Verify an existing signature
///
/// See @ref isc::cryptolink::HMAC::verify() for details.
bool verify(const void* sig, size_t len) {
size_t size = getOutputLength();
if (len < 10 || len < size / 2) {
return (false);
}
ossl::SecBuf<unsigned char> digest(size);
HMAC_Final(md_.get(), &digest[0], NULL);
if (len > size) {
len = size;
}
return (digest.same(sig, len));
}
private:
/// @brief The protected pointer to the OpenSSL HMAC_CTX structure
boost::scoped_ptr<HMAC_CTX> md_;
};
HMAC::HMAC(const void* secret, size_t secret_length,
const HashAlgorithm hash_algorithm)
{
impl_ = new HMACImpl(secret, secret_length, hash_algorithm);
}
HMAC::~HMAC() {
delete impl_;
}
size_t
HMAC::getOutputLength() const {
return (impl_->getOutputLength());
}
void
HMAC::update(const void* data, const size_t len) {
impl_->update(data, len);
}
void
HMAC::sign(isc::util::OutputBuffer& result, size_t len) {
impl_->sign(result, len);
}
void
HMAC::sign(void* result, size_t len) {
impl_->sign(result, len);
}
std::vector<uint8_t>
HMAC::sign(size_t len) {
return impl_->sign(len);
}
bool
HMAC::verify(const void* sig, const size_t len) {
return (impl_->verify(sig, len));
}
} // namespace cryptolink
} // namespace isc
|
