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
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "alloc-util.h"
#include "ask-password-api.h"
#include "env-util.h"
#include "hexdecoct.h"
#include "json.h"
#include "log.h"
#include "luks2-tpm2.h"
#include "parse-util.h"
#include "random-util.h"
#include "sha256.h"
#include "strv.h"
#include "tpm2-util.h"
int acquire_luks2_key(
const char *device,
uint32_t hash_pcr_mask,
uint16_t pcr_bank,
const void *pubkey,
size_t pubkey_size,
uint32_t pubkey_pcr_mask,
const char *signature_path,
const char *pin,
const char *pcrlock_path,
uint16_t primary_alg,
const void *key_data,
size_t key_data_size,
const void *policy_hash,
size_t policy_hash_size,
const void *salt,
size_t salt_size,
const void *srk_buf,
size_t srk_buf_size,
TPM2Flags flags,
void **ret_decrypted_key,
size_t *ret_decrypted_key_size) {
_cleanup_(json_variant_unrefp) JsonVariant *signature_json = NULL;
_cleanup_free_ char *auto_device = NULL;
_cleanup_(erase_and_freep) char *b64_salted_pin = NULL;
int r;
assert(salt || salt_size == 0);
assert(ret_decrypted_key);
assert(ret_decrypted_key_size);
if (!device) {
r = tpm2_find_device_auto(&auto_device);
if (r == -ENODEV)
return -EAGAIN; /* Tell the caller to wait for a TPM2 device to show up */
if (r < 0)
return log_error_errno(r, "Could not find TPM2 device: %m");
device = auto_device;
}
if ((flags & TPM2_FLAGS_USE_PIN) && !pin)
return -ENOANO;
if (pin && salt_size > 0) {
uint8_t salted_pin[SHA256_DIGEST_SIZE] = {};
CLEANUP_ERASE(salted_pin);
r = tpm2_util_pbkdf2_hmac_sha256(pin, strlen(pin), salt, salt_size, salted_pin);
if (r < 0)
return log_error_errno(r, "Failed to perform PBKDF2: %m");
r = base64mem(salted_pin, sizeof(salted_pin), &b64_salted_pin);
if (r < 0)
return log_error_errno(r, "Failed to base64 encode salted pin: %m");
pin = b64_salted_pin;
}
if (pubkey_pcr_mask != 0) {
r = tpm2_load_pcr_signature(signature_path, &signature_json);
if (r < 0)
return log_error_errno(r, "Failed to load PCR signature: %m");
}
_cleanup_(tpm2_pcrlock_policy_done) Tpm2PCRLockPolicy pcrlock_policy = {};
if (FLAGS_SET(flags, TPM2_FLAGS_USE_PCRLOCK)) {
r = tpm2_pcrlock_policy_load(pcrlock_path, &pcrlock_policy);
if (r < 0)
return r;
}
_cleanup_(tpm2_context_unrefp) Tpm2Context *tpm2_context = NULL;
r = tpm2_context_new_or_warn(device, &tpm2_context);
if (r < 0)
return r;
r = tpm2_unseal(tpm2_context,
hash_pcr_mask,
pcr_bank,
pubkey, pubkey_size,
pubkey_pcr_mask,
signature_json,
pin,
FLAGS_SET(flags, TPM2_FLAGS_USE_PCRLOCK) ? &pcrlock_policy : NULL,
primary_alg,
key_data, key_data_size,
policy_hash, policy_hash_size,
srk_buf, srk_buf_size,
ret_decrypted_key, ret_decrypted_key_size);
if (r < 0)
return log_error_errno(r, "Failed to unseal secret using TPM2: %m");
return r;
}
|
