-
Notifications
You must be signed in to change notification settings - Fork 543
/
file_crypto.cpp
287 lines (226 loc) · 8.73 KB
/
file_crypto.cpp
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
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
/*
* Copyright (C) 2011-2021 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "protected_fs_file.h"
#include <tseal_migration_attr.h>
#include <sgx_utils.h>
#include <sgx_trts.h>
#define MASTER_KEY_NAME "SGX-PROTECTED-FS-MASTER-KEY"
#define RANDOM_KEY_NAME "SGX-PROTECTED-FS-RANDOM-KEY"
#define METADATA_KEY_NAME "SGX-PROTECTED-FS-METADATA-KEY"
#define MAX_LABEL_LEN 64
typedef struct {
uint32_t index;
char label[MAX_LABEL_LEN];
uint64_t node_number; // context 1
union { // context 2
sgx_cmac_128bit_tag_t nonce16;
sgx_key_id_t nonce32;
};
uint32_t output_len; // in bits
} kdf_input_t;
#define MAX_MASTER_KEY_USAGES 65536
bool protected_fs_file::generate_secure_blob(sgx_aes_gcm_128bit_key_t* key, const char* label, uint64_t physical_node_number, sgx_aes_gcm_128bit_tag_t* output)
{
kdf_input_t buf = {0, "", 0, "", 0};
uint32_t len = (uint32_t)strnlen(label, MAX_LABEL_LEN + 1);
if (len > MAX_LABEL_LEN)
{
last_error = EINVAL;
return false;
}
// index
// SP800-108:
// i - A counter, a binary string of length r that is an input to each iteration of a PRF in counter mode [...].
buf.index = 0x01;
// label
// SP800-108:
// Label - A string that identifies the purpose for the derived keying material, which is encoded as a binary string.
// The encoding method for the Label is defined in a larger context, for example, in the protocol that uses a KDF.
strncpy(buf.label, label, len);
// context and nonce
// SP800-108:
// Context - A binary string containing the information related to the derived keying material.
// It may include identities of parties who are deriving and / or using the derived keying material and,
// optionally, a nonce known by the parties who derive the keys.
buf.node_number = physical_node_number;
sgx_status_t status = sgx_read_rand((unsigned char*)&(buf.nonce16), sizeof(sgx_cmac_128bit_tag_t));
if (status != SGX_SUCCESS)
{
last_error = status;
return false;
}
// length of output (128 bits)
buf.output_len = 0x80;
status = sgx_rijndael128_cmac_msg(key, (const uint8_t*)&buf, sizeof(kdf_input_t), output);
if (status != SGX_SUCCESS)
{
last_error = status;
return false;
}
memset_s(&buf, sizeof(kdf_input_t), 0, sizeof(kdf_input_t));
return true;
}
bool protected_fs_file::generate_secure_blob_from_user_kdk(bool restore)
{
kdf_input_t buf = {0, "", 0, "", 0};
sgx_status_t status = SGX_SUCCESS;
// index
// SP800-108:
// i - A counter, a binary string of length r that is an input to each iteration of a PRF in counter mode [...].
buf.index = 0x01;
// label
// SP800-108:
// Label - A string that identifies the purpose for the derived keying material, which is encoded as a binary string.
// The encoding method for the Label is defined in a larger context, for example, in the protocol that uses a KDF.
strncpy(buf.label, METADATA_KEY_NAME, strlen(METADATA_KEY_NAME));
// context and nonce
// SP800-108:
// Context - A binary string containing the information related to the derived keying material.
// It may include identities of parties who are deriving and / or using the derived keying material and,
// optionally, a nonce known by the parties who derive the keys.
buf.node_number = 0;
// use 32 bytes here just for compatibility with the seal key API
if (restore == false)
{
status = sgx_read_rand((unsigned char*)&(buf.nonce32), sizeof(sgx_key_id_t));
if (status != SGX_SUCCESS)
{
last_error = status;
return false;
}
}
else
{
memcpy(&buf.nonce32, &file_meta_data.plain_part.meta_data_key_id, sizeof(sgx_key_id_t));
}
// length of output (128 bits)
buf.output_len = 0x80;
status = sgx_rijndael128_cmac_msg(&user_kdk_key, (const uint8_t*)&buf, sizeof(kdf_input_t), &cur_key);
if (status != SGX_SUCCESS)
{
last_error = status;
return false;
}
if (restore == false)
{
memcpy(&file_meta_data.plain_part.meta_data_key_id, &buf.nonce32, sizeof(sgx_key_id_t));
}
memset_s(&buf, sizeof(kdf_input_t), 0, sizeof(kdf_input_t));
return true;
}
bool protected_fs_file::init_session_master_key()
{
sgx_aes_gcm_128bit_key_t empty_key = {0};
if (generate_secure_blob(&empty_key, MASTER_KEY_NAME, 0, (sgx_aes_gcm_128bit_tag_t*)&session_master_key) == false)
return false;
master_key_count = 0;
return true;
}
bool protected_fs_file::derive_random_node_key(uint64_t physical_node_number)
{
if (master_key_count++ > MAX_MASTER_KEY_USAGES)
{
if (init_session_master_key() == false)
return false;
}
if (generate_secure_blob(&session_master_key, RANDOM_KEY_NAME, physical_node_number, (sgx_aes_gcm_128bit_tag_t*)&cur_key) == false)
return false;
return true;
}
bool protected_fs_file::generate_random_meta_data_key()
{
if (use_user_kdk_key == 1)
{
return generate_secure_blob_from_user_kdk(false);
}
// derive a random key from the enclave sealing key
sgx_key_request_t key_request;
memset(&key_request, 0, sizeof(sgx_key_request_t));
key_request.key_name = SGX_KEYSELECT_SEAL;
key_request.key_policy = SGX_KEYPOLICY_MRSIGNER;
memcpy(&key_request.cpu_svn, &report.body.cpu_svn, sizeof(sgx_cpu_svn_t));
memcpy(&key_request.isv_svn, &report.body.isv_svn, sizeof(sgx_isv_svn_t));
key_request.attribute_mask.flags = TSEAL_DEFAULT_FLAGSMASK;
key_request.attribute_mask.xfrm = 0x0;
key_request.misc_mask = TSEAL_DEFAULT_MISCMASK;
sgx_status_t status = sgx_read_rand((unsigned char*)&key_request.key_id, sizeof(sgx_key_id_t));
if (status != SGX_SUCCESS)
{
last_error = status;
return false;
}
status = sgx_get_key(&key_request, &cur_key);
if (status != SGX_SUCCESS)
{
last_error = status;
return false;
}
// save the key_id and svn's so the key can be restored even if svn's are updated
memcpy(&file_meta_data.plain_part.meta_data_key_id, &key_request.key_id, sizeof(sgx_key_id_t)); // save this value in the meta data
memcpy(&file_meta_data.plain_part.cpu_svn, &key_request.cpu_svn, sizeof(sgx_cpu_svn_t));
memcpy(&file_meta_data.plain_part.isv_svn, &key_request.isv_svn, sizeof(sgx_isv_svn_t));
return true;
}
bool protected_fs_file::restore_current_meta_data_key(const sgx_aes_gcm_128bit_key_t* import_key)
{
if (import_key != NULL)
{
memcpy(&cur_key, import_key, sizeof(sgx_aes_gcm_128bit_key_t));
return true;
}
if (use_user_kdk_key == 1)
{
return generate_secure_blob_from_user_kdk(true);
}
sgx_key_id_t empty_key_id = {0};
if (consttime_memequal(&file_meta_data.plain_part.meta_data_key_id, &empty_key_id, sizeof(sgx_key_id_t)) == 1)
{
last_error = SGX_ERROR_FILE_NO_KEY_ID;
return false;
}
sgx_key_request_t key_request;
memset(&key_request, 0, sizeof(sgx_key_request_t));
key_request.key_name = SGX_KEYSELECT_SEAL;
key_request.key_policy = SGX_KEYPOLICY_MRSIGNER;
key_request.attribute_mask.flags = TSEAL_DEFAULT_FLAGSMASK;
key_request.attribute_mask.xfrm = 0x0;
key_request.misc_mask = TSEAL_DEFAULT_MISCMASK;
memcpy(&key_request.cpu_svn, &file_meta_data.plain_part.cpu_svn, sizeof(sgx_cpu_svn_t));
memcpy(&key_request.isv_svn, &file_meta_data.plain_part.isv_svn, sizeof(sgx_isv_svn_t));
memcpy(&key_request.key_id, &file_meta_data.plain_part.meta_data_key_id, sizeof(sgx_key_id_t));
sgx_status_t status = sgx_get_key(&key_request, &cur_key);
if (status != SGX_SUCCESS)
{
last_error = status;
return false;
}
return true;
}