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
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "ask-password-api.h"
#include "cryptenroll-fido2.h"
#include "cryptsetup-fido2.h"
#include "hexdecoct.h"
#include "json.h"
#include "libfido2-util.h"
#include "memory-util.h"
#include "random-util.h"
int load_volume_key_fido2(
struct crypt_device *cd,
const char *cd_node,
const char *device,
void *ret_vk,
size_t *ret_vks) {
_cleanup_(erase_and_freep) void *decrypted_key = NULL;
_cleanup_(erase_and_freep) char *passphrase = NULL;
size_t decrypted_key_size;
ssize_t passphrase_size;
int r;
assert_se(cd);
assert_se(cd_node);
assert_se(ret_vk);
assert_se(ret_vks);
r = acquire_fido2_key_auto(
cd,
cd_node,
cd_node,
device,
/* until= */ 0,
/* headless= */ false,
&decrypted_key,
&decrypted_key_size,
ASK_PASSWORD_PUSH_CACHE|ASK_PASSWORD_ACCEPT_CACHED);
if (r == -EAGAIN)
return log_error_errno(r, "FIDO2 token does not exist, or UV is blocked. Please try again.");
if (r < 0)
return r;
/* Because cryptenroll requires a LUKS header, we can assume that this device is not
* a PLAIN device. In this case, we need to base64 encode the secret to use as the passphrase */
passphrase_size = base64mem(decrypted_key, decrypted_key_size, &passphrase);
if (passphrase_size < 0)
return log_oom();
r = crypt_volume_key_get(
cd,
CRYPT_ANY_SLOT,
ret_vk,
ret_vks,
passphrase,
passphrase_size);
if (r < 0)
return log_error_errno(r, "Unlocking via FIDO2 device failed: %m");
return r;
}
int enroll_fido2(
struct crypt_device *cd,
const void *volume_key,
size_t volume_key_size,
const char *device,
Fido2EnrollFlags lock_with,
int cred_alg) {
_cleanup_(erase_and_freep) void *salt = NULL, *secret = NULL;
_cleanup_(erase_and_freep) char *base64_encoded = NULL;
_cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
_cleanup_free_ char *keyslot_as_string = NULL;
size_t cid_size, salt_size, secret_size;
_cleanup_free_ void *cid = NULL;
ssize_t base64_encoded_size;
const char *node, *un;
int r, keyslot;
assert_se(cd);
assert_se(volume_key);
assert_se(volume_key_size > 0);
assert_se(device);
assert_se(node = crypt_get_device_name(cd));
un = strempty(crypt_get_uuid(cd));
r = fido2_generate_hmac_hash(
device,
/* rp_id= */ "io.systemd.cryptsetup",
/* rp_name= */ "Encrypted Volume",
/* user_id= */ un, strlen(un), /* We pass the user ID and name as the same: the disk's UUID if we have it */
/* user_name= */ un,
/* user_display_name= */ node,
/* user_icon_name= */ NULL,
/* askpw_icon_name= */ "drive-harddisk",
lock_with,
cred_alg,
&cid, &cid_size,
&salt, &salt_size,
&secret, &secret_size,
NULL,
&lock_with);
if (r < 0)
return r;
/* Before we use the secret, we base64 encode it, for compat with homed, and to make it easier to type in manually */
base64_encoded_size = base64mem(secret, secret_size, &base64_encoded);
if (base64_encoded_size < 0)
return log_error_errno(base64_encoded_size, "Failed to base64 encode secret key: %m");
r = cryptsetup_set_minimal_pbkdf(cd);
if (r < 0)
return log_error_errno(r, "Failed to set minimal PBKDF: %m");
keyslot = crypt_keyslot_add_by_volume_key(
cd,
CRYPT_ANY_SLOT,
volume_key,
volume_key_size,
base64_encoded,
base64_encoded_size);
if (keyslot < 0)
return log_error_errno(keyslot, "Failed to add new FIDO2 key to %s: %m", node);
if (asprintf(&keyslot_as_string, "%i", keyslot) < 0)
return log_oom();
r = json_build(&v,
JSON_BUILD_OBJECT(
JSON_BUILD_PAIR("type", JSON_BUILD_CONST_STRING("systemd-fido2")),
JSON_BUILD_PAIR("keyslots", JSON_BUILD_ARRAY(JSON_BUILD_STRING(keyslot_as_string))),
JSON_BUILD_PAIR("fido2-credential", JSON_BUILD_BASE64(cid, cid_size)),
JSON_BUILD_PAIR("fido2-salt", JSON_BUILD_BASE64(salt, salt_size)),
JSON_BUILD_PAIR("fido2-rp", JSON_BUILD_CONST_STRING("io.systemd.cryptsetup")),
JSON_BUILD_PAIR("fido2-clientPin-required", JSON_BUILD_BOOLEAN(FLAGS_SET(lock_with, FIDO2ENROLL_PIN))),
JSON_BUILD_PAIR("fido2-up-required", JSON_BUILD_BOOLEAN(FLAGS_SET(lock_with, FIDO2ENROLL_UP))),
JSON_BUILD_PAIR("fido2-uv-required", JSON_BUILD_BOOLEAN(FLAGS_SET(lock_with, FIDO2ENROLL_UV)))));
if (r < 0)
return log_error_errno(r, "Failed to prepare FIDO2 JSON token object: %m");
r = cryptsetup_add_token_json(cd, v);
if (r < 0)
return log_error_errno(r, "Failed to add FIDO2 JSON token to LUKS2 header: %m");
log_info("New FIDO2 token enrolled as key slot %i.", keyslot);
return keyslot;
}
|
