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
|
/* Copyright (c) 2011 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.
*
* Host functions for verified boot.
*/
#include <stdio.h>
#include "2sysincludes.h"
#include "2api.h"
#include "2common.h"
#include "2rsa.h"
#include "2sha.h"
#include "host_common.h"
#include "host_key2.h"
#include "host_keyblock.h"
#include "host_key.h"
#include "vb2_common.h"
struct vb2_keyblock *vb2_create_keyblock(
const struct vb2_packed_key *data_key,
const struct vb2_private_key *signing_key,
uint32_t flags)
{
/* Allocate keyblock */
uint32_t signed_size = sizeof(struct vb2_keyblock) + data_key->key_size;
uint32_t sig_data_size =
(signing_key ? vb2_rsa_sig_size(signing_key->sig_alg) : 0);
uint32_t block_size =
signed_size + VB2_SHA512_DIGEST_SIZE + sig_data_size;
struct vb2_keyblock *h = (struct vb2_keyblock *)calloc(block_size, 1);
if (!h)
return NULL;
uint8_t *data_key_dest = (uint8_t *)(h + 1);
uint8_t *block_chk_dest = data_key_dest + data_key->key_size;
uint8_t *block_sig_dest = block_chk_dest + VB2_SHA512_DIGEST_SIZE;
memcpy(h->magic, VB2_KEYBLOCK_MAGIC, VB2_KEYBLOCK_MAGIC_SIZE);
h->header_version_major = VB2_KEYBLOCK_VERSION_MAJOR;
h->header_version_minor = VB2_KEYBLOCK_VERSION_MINOR;
h->keyblock_size = block_size;
h->keyblock_flags = flags;
/* Copy data key */
vb2_init_packed_key(&h->data_key, data_key_dest, data_key->key_size);
vb2_copy_packed_key(&h->data_key, data_key);
/* Set up signature structs so we can calculate the signatures */
vb2_init_signature(&h->keyblock_hash, block_chk_dest,
VB2_SHA512_DIGEST_SIZE, signed_size);
if (signing_key) {
vb2_init_signature(&h->keyblock_signature, block_sig_dest,
sig_data_size, signed_size);
} else {
memset(&h->keyblock_signature, 0,
sizeof(h->keyblock_signature));
}
/* Calculate hash */
struct vb2_signature *chk =
vb2_sha512_signature((uint8_t*)h, signed_size);
vb2_copy_signature(&h->keyblock_hash, chk);
free(chk);
/* Calculate signature */
if (signing_key) {
struct vb2_signature *sigtmp =
vb2_calculate_signature((uint8_t*)h,
signed_size,
signing_key);
vb2_copy_signature(&h->keyblock_signature, sigtmp);
free(sigtmp);
}
/* Return the header */
return h;
}
/* TODO(gauravsh): This could easily be integrated into the function above
* since the code is almost a mirror - I have kept it as such to avoid changing
* the existing interface. */
struct vb2_keyblock *vb2_create_keyblock_external(
const struct vb2_packed_key *data_key,
const char *signing_key_pem_file,
uint32_t algorithm,
uint32_t flags,
const char *external_signer)
{
if (!signing_key_pem_file || !data_key || !external_signer)
return NULL;
uint32_t signed_size = sizeof(struct vb2_keyblock) + data_key->key_size;
uint32_t sig_data_size = vb2_rsa_sig_size(vb2_crypto_to_signature(algorithm));
uint32_t block_size =
signed_size + VB2_SHA512_DIGEST_SIZE + sig_data_size;
/* Allocate keyblock */
struct vb2_keyblock *h = (struct vb2_keyblock *)calloc(block_size, 1);
if (!h)
return NULL;
uint8_t *data_key_dest = (uint8_t *)(h + 1);
uint8_t *block_chk_dest = data_key_dest + data_key->key_size;
uint8_t *block_sig_dest = block_chk_dest + VB2_SHA512_DIGEST_SIZE;
memcpy(h->magic, VB2_KEYBLOCK_MAGIC, VB2_KEYBLOCK_MAGIC_SIZE);
h->header_version_major = VB2_KEYBLOCK_VERSION_MAJOR;
h->header_version_minor = VB2_KEYBLOCK_VERSION_MINOR;
h->keyblock_size = block_size;
h->keyblock_flags = flags;
/* Copy data key */
vb2_init_packed_key(&h->data_key, data_key_dest, data_key->key_size);
vb2_copy_packed_key(&h->data_key, data_key);
/* Set up signature structs so we can calculate the signatures */
vb2_init_signature(&h->keyblock_hash, block_chk_dest,
VB2_SHA512_DIGEST_SIZE, signed_size);
vb2_init_signature(&h->keyblock_signature, block_sig_dest,
sig_data_size, signed_size);
/* Calculate checksum */
struct vb2_signature *chk =
vb2_sha512_signature((uint8_t*)h, signed_size);
vb2_copy_signature(&h->keyblock_hash, chk);
free(chk);
/* Calculate signature */
struct vb2_signature *sigtmp =
vb2_external_signature((uint8_t*)h, signed_size,
signing_key_pem_file, algorithm,
external_signer);
vb2_copy_signature(&h->keyblock_signature, sigtmp);
free(sigtmp);
/* Return the header */
return h;
}
struct vb2_keyblock *vb2_read_keyblock(const char *filename)
{
uint8_t workbuf[VB2_FIRMWARE_WORKBUF_RECOMMENDED_SIZE]
__attribute__((aligned(VB2_WORKBUF_ALIGN)));
struct vb2_workbuf wb;
vb2_workbuf_init(&wb, workbuf, sizeof(workbuf));
struct vb2_keyblock *block;
uint32_t file_size;
if (VB2_SUCCESS !=
vb2_read_file(filename, (uint8_t **)&block, &file_size)) {
fprintf(stderr, "Error reading keyblock file: %s\n", filename);
return NULL;
}
/* Verify the hash of the keyblock, since we can do that without
* the public signing key. */
if (VB2_SUCCESS != vb2_verify_keyblock_hash(block, file_size, &wb)) {
fprintf(stderr, "Invalid keyblock file: %s\n", filename);
free(block);
return NULL;
}
return block;
}
int vb2_write_keyblock(const char *filename,
const struct vb2_keyblock *keyblock)
{
return vb2_write_file(filename, keyblock, keyblock->keyblock_size);
}
|
