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
203
204
205
206
207
208
209
|
/*
* (C) 2011,2017 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/nist_keywrap.h>
#include <botan/block_cipher.h>
#include <botan/loadstor.h>
#include <botan/exceptn.h>
namespace Botan {
namespace {
std::vector<uint8_t>
raw_nist_key_wrap(const uint8_t input[],
size_t input_len,
const BlockCipher& bc,
uint64_t ICV)
{
const size_t n = (input_len + 7) / 8;
secure_vector<uint8_t> R((n + 1) * 8);
secure_vector<uint8_t> A(16);
store_be(ICV, A.data());
copy_mem(&R[8], input, input_len);
for(size_t j = 0; j <= 5; ++j)
{
for(size_t i = 1; i <= n; ++i)
{
const uint32_t t = static_cast<uint32_t>((n * j) + i);
copy_mem(&A[8], &R[8*i], 8);
bc.encrypt(A.data());
copy_mem(&R[8*i], &A[8], 8);
uint8_t t_buf[4] = { 0 };
store_be(t, t_buf);
xor_buf(&A[4], t_buf, 4);
}
}
copy_mem(R.data(), A.data(), 8);
return std::vector<uint8_t>(R.begin(), R.end());
}
secure_vector<uint8_t>
raw_nist_key_unwrap(const uint8_t input[],
size_t input_len,
const BlockCipher& bc,
uint64_t& ICV_out)
{
if(input_len < 16 || input_len % 8 != 0)
throw Invalid_Argument("Bad input size for NIST key unwrap");
const size_t n = (input_len - 8) / 8;
secure_vector<uint8_t> R(n * 8);
secure_vector<uint8_t> A(16);
for(size_t i = 0; i != 8; ++i)
A[i] = input[i];
copy_mem(R.data(), input + 8, input_len - 8);
for(size_t j = 0; j <= 5; ++j)
{
for(size_t i = n; i != 0; --i)
{
const uint32_t t = static_cast<uint32_t>((5 - j) * n + i);
uint8_t t_buf[4] = { 0 };
store_be(t, t_buf);
xor_buf(&A[4], t_buf, 4);
copy_mem(&A[8], &R[8*(i-1)], 8);
bc.decrypt(A.data());
copy_mem(&R[8*(i-1)], &A[8], 8);
}
}
ICV_out = load_be<uint64_t>(A.data(), 0);
return R;
}
}
std::vector<uint8_t>
nist_key_wrap(const uint8_t input[],
size_t input_len,
const BlockCipher& bc)
{
if(bc.block_size() != 16)
throw Invalid_Argument("NIST key wrap algorithm requires a 128-bit cipher");
if(input_len % 8 != 0)
throw Invalid_Argument("Bad input size for NIST key wrap");
return raw_nist_key_wrap(input, input_len, bc, 0xA6A6A6A6A6A6A6A6);
}
secure_vector<uint8_t>
nist_key_unwrap(const uint8_t input[],
size_t input_len,
const BlockCipher& bc)
{
if(bc.block_size() != 16)
throw Invalid_Argument("NIST key wrap algorithm requires a 128-bit cipher");
if(input_len < 16 || input_len % 8 != 0)
throw Invalid_Argument("Bad input size for NIST key unwrap");
uint64_t ICV_out = 0;
secure_vector<uint8_t> R = raw_nist_key_unwrap(input, input_len, bc, ICV_out);
if(ICV_out != 0xA6A6A6A6A6A6A6A6)
throw Integrity_Failure("NIST key unwrap failed");
return R;
}
std::vector<uint8_t>
nist_key_wrap_padded(const uint8_t input[],
size_t input_len,
const BlockCipher& bc)
{
if(bc.block_size() != 16)
throw Invalid_Argument("NIST key wrap algorithm requires a 128-bit cipher");
const uint64_t ICV = 0xA65959A600000000 | static_cast<uint32_t>(input_len);
if(input_len <= 8)
{
/*
* Special case for small inputs: if input <= 8 bytes just use ECB
*/
std::vector<uint8_t> block(16);
store_be(ICV, block.data());
copy_mem(block.data() + 8, input, input_len);
bc.encrypt(block);
return block;
}
else
{
return raw_nist_key_wrap(input, input_len, bc, ICV);
}
}
secure_vector<uint8_t>
nist_key_unwrap_padded(const uint8_t input[],
size_t input_len,
const BlockCipher& bc)
{
if(bc.block_size() != 16)
throw Invalid_Argument("NIST key wrap algorithm requires a 128-bit cipher");
if(input_len < 16 || input_len % 8 != 0)
throw Invalid_Argument("Bad input size for NIST key unwrap");
uint64_t ICV_out = 0;
secure_vector<uint8_t> R;
if(input_len == 16)
{
secure_vector<uint8_t> block(input, input + input_len);
bc.decrypt(block);
ICV_out = load_be<uint64_t>(block.data(), 0);
R.resize(8);
copy_mem(R.data(), block.data() + 8, 8);
}
else
{
R = raw_nist_key_unwrap(input, input_len, bc, ICV_out);
}
if((ICV_out >> 32) != 0xA65959A6)
throw Integrity_Failure("NIST key unwrap failed");
const size_t len = (ICV_out & 0xFFFFFFFF);
if(len > R.size() || len < R.size() - 8)
throw Integrity_Failure("NIST key unwrap failed");
const size_t padding = R.size() - len;
for(size_t i = 0; i != padding; ++i)
{
if(R[R.size() - i - 1] != 0)
throw Integrity_Failure("NIST key unwrap failed");
}
R.resize(R.size() - padding);
return R;
}
}
|
