1 /* Copyright 2015 The Chromium OS Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 *
5 * Functions for updating the TPM state with the status of boot path.
6 */
7
8 #include "2sysincludes.h"
9 #include "2common.h"
10 #include "2sha.h"
11 #include "2tpm_bootmode.h"
12
13 /*
14 * Input digests for PCR extend.
15 * These are calculated as:
16 * SHA1("|Developer_Mode||Recovery_Mode||Keyblock_Mode|").
17 * Developer_Mode can be 0 or 1.
18 * Recovery_Mode can be 0 or 1.
19 * Keyblock flags are defined in 2struct.h and assumed always 0 in recovery mode
20 * or 7 in non-recovery mode.
21 *
22 * We map them to Keyblock_Mode as follows:
23 * -----------------------------------------
24 * Keyblock Flags | Keyblock Mode
25 * -----------------------------------------
26 * 0 recovery mode | 0
27 * 7 Normal-signed firmware | 1
28 */
29
30 const uint8_t kBootStateSHA1Digests[][VB2_SHA1_DIGEST_SIZE] = {
31 /* SHA1(0x00|0x00|0x01) */
32 {0x25, 0x47, 0xcc, 0x73, 0x6e, 0x95, 0x1f, 0xa4, 0x91, 0x98, 0x53, 0xc4,
33 0x3a, 0xe8, 0x90, 0x86, 0x1a, 0x3b, 0x32, 0x64},
34
35 /* SHA1(0x01|0x00|0x01) */
36 {0xc4, 0x2a, 0xc1, 0xc4, 0x6f, 0x1d, 0x4e, 0x21, 0x1c, 0x73, 0x5c, 0xc7,
37 0xdf, 0xad, 0x4f, 0xf8, 0x39, 0x11, 0x10, 0xe9},
38
39 /* SHA1(0x00|0x01|0x00) */
40 {0x62, 0x57, 0x18, 0x91, 0x21, 0x5b, 0x4e, 0xfc, 0x1c, 0xea, 0xb7, 0x44,
41 0xce, 0x59, 0xdd, 0x0b, 0x66, 0xea, 0x6f, 0x73},
42
43 /* SHA1(0x01|0x01|0x00) */
44 {0x47, 0xec, 0x8d, 0x98, 0x36, 0x64, 0x33, 0xdc, 0x00, 0x2e, 0x77, 0x21,
45 0xc9, 0xe3, 0x7d, 0x50, 0x67, 0x54, 0x79, 0x37},
46 };
47
vb2_get_boot_state_digest(struct vb2_context * ctx)48 const uint8_t *vb2_get_boot_state_digest(struct vb2_context *ctx)
49 {
50 int index = (ctx->flags & VB2_CONTEXT_RECOVERY_MODE ? 2 : 0) +
51 (ctx->flags & VB2_CONTEXT_DEVELOPER_MODE ? 1 : 0);
52
53 return kBootStateSHA1Digests[index];
54 }
55