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
|
/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*
* Functions for updating the TPM state with the status of boot path.
*/
#include "sysincludes.h"
#include "tlcl.h"
#include "tpm_bootmode.h"
#include "utility.h"
#include "vboot_api.h"
/* TPM PCR to use for storing boot mode measurements. */
#define BOOT_MODE_PCR 0
/*
* Input digests for PCR extend.
* These are calculated as:
* SHA1("|Developer_Mode||Recovery_Mode||Keyblock_Mode|").
* Developer_Mode can be 0 or 1.
* Recovery_Mode can be 0 or 1.
* Keyblock flags are defined in vboot_struct.h
*
* We map them to Keyblock_Mode as follows:
* -----------------------------------------
* Keyblock Flags | Keyblock Mode
* -----------------------------------------
* 6 (Dev-signed firmware) | 2
* 7 Normal-signed firmware | 1
* (anything else) | 0
*/
const char* kBootStateSHA1Digests[] = {
/* SHA1("\x00\x00\x00") */
"\x29\xe2\xdc\xfb\xb1\x6f\x63\xbb\x02\x54\xdf\x75\x85\xa1\x5b\xb6"
"\xfb\x5e\x92\x7d",
/* SHA1("\x00\x00\x01") */
"\x25\x47\xcc\x73\x6e\x95\x1f\xa4\x91\x98\x53\xc4\x3a\xe8\x90\x86"
"\x1a\x3b\x32\x64",
/* SHA1("\x00\x00\x02") */
"\x1e\xf6\x24\x48\x2d\x62\x0e\x43\xe6\xd3\x4d\xa1\xaf\xe4\x62\x67"
"\xfc\x69\x5d\x9b",
/* SHA1("\x00\x01\x00") */
"\x62\x57\x18\x91\x21\x5b\x4e\xfc\x1c\xea\xb7\x44\xce\x59\xdd\x0b"
"\x66\xea\x6f\x73",
/* SHA1("\x00\x01\x01") */
"\xee\xe4\x47\xed\xc7\x9f\xea\x1c\xa7\xc7\xd3\x4e\x46\x32\x61\xcd"
"\xa4\xba\x33\x9e",
/* SHA1("\x00\x01\x02") */
"\x0c\x7a\x62\x3f\xd2\xbb\xc0\x5b\x06\x42\x3b\xe3\x59\xe4\x02\x1d"
"\x36\xe7\x21\xad",
/* SHA1("\x01\x00\x00") */
"\x95\x08\xe9\x05\x48\xb0\x44\x0a\x4a\x61\xe5\x74\x3b\x76\xc1\xe3"
"\x09\xb2\x3b\x7f",
/* SHA1("\x01\x00\x01") */
"\xc4\x2a\xc1\xc4\x6f\x1d\x4e\x21\x1c\x73\x5c\xc7\xdf\xad\x4f\xf8"
"\x39\x11\x10\xe9",
/* SHA1("\x01\x00\x02") */
"\xfa\x01\x0d\x26\x64\xcc\x5b\x3b\x82\xee\x48\x8f\xe2\xb9\xf5\x0f"
"\x49\x32\xeb\x8f",
/* SHA1("\x01\x01\x00") */
"\x47\xec\x8d\x98\x36\x64\x33\xdc\x00\x2e\x77\x21\xc9\xe3\x7d\x50"
"\x67\x54\x79\x37",
/* SHA1("\x01\x01\x01") */
"\x28\xd8\x6c\x56\xb3\xbf\x26\xd2\x36\x56\x9b\x8d\xc8\xc3\xf9\x1f"
"\x32\xf4\x7b\xc7",
/* SHA1("\x01\x01\x02") */
"\x12\xa3\x40\xd7\x89\x7f\xe7\x13\xfc\x8f\x02\xac\x53\x65\xb8\x6e"
"\xbf\x35\x31\x78",
};
#define MAX_BOOT_STATE_INDEX (sizeof(kBootStateSHA1Digests)/sizeof(char *))
/*
* Used for PCR extend when the passed-in boot state is invalid or if there is
* an internal error.
*/
const uint8_t kBootInvalidSHA1Digest[] = {
"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"
"\xff\xff\xff\xff"
};
/**
* Given the boot state, return the correct SHA1 digest index for TPMExtend
* in kBootStateSHA1Digests[].
*/
static int GetBootStateIndex(int dev_mode, int rec_mode,
uint64_t keyblock_flags)
{
int index = 0;
/*
* Convert keyblock flags into keyblock mode which we use to index into
* kBootStateSHA1Digest[].
*/
switch(keyblock_flags) {
case 6:
/*
* KEY_BLOCK_FLAG_RECOVERY_0 | KEY_BLOCK_FLAG_DEVELOPER_1
*
* Developer firmware. */
index = 2;
break;
case 7:
/*
* KEY_BLOCK_FLAG_RECOVERY_0 | KEY_BLOCK_FLAG_DEVELOPER_0
* | KEY_BLOCK_FLAGS_DEVELOPER_1
*/
index = 1;
break;
default:
/* Any other keyblock flags. */
index = 0;
};
if (rec_mode)
index += 3;
if (dev_mode)
index += 6;
return index;
}
uint32_t SetTPMBootModeState(int developer_mode, int recovery_mode,
uint64_t fw_keyblock_flags)
{
uint32_t result;
const uint8_t *in_digest = NULL;
uint8_t out_digest[20]; /* For PCR extend output. */
int digest_index = GetBootStateIndex(developer_mode, recovery_mode,
fw_keyblock_flags);
if (digest_index >= 0 && digest_index < MAX_BOOT_STATE_INDEX) {
in_digest = (const uint8_t*)
kBootStateSHA1Digests[digest_index];
} else {
/* Internal out of bounds error. */
in_digest = kBootInvalidSHA1Digest;
}
result = TlclExtend(BOOT_MODE_PCR, in_digest, out_digest);
VBDEBUG(("TPM: SetTPMBootModeState boot mode PCR out_digest "
"%02x %02x %02x %02x\n",
out_digest[0], out_digest[1], out_digest[2], out_digest[3]));
return result;
}
|
