1 /* Copyright (c) 2014 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  * Host functions for keyblocks
6  */
7 
8 #include "2sysincludes.h"
9 #include "2common.h"
10 #include "2rsa.h"
11 #include "host_common.h"
12 #include "host_fw_preamble2.h"
13 #include "host_key2.h"
14 #include "host_keyblock2.h"
15 #include "host_misc.h"
16 #include "host_signature2.h"
17 #include "vb2_common.h"
18 
vb2_fw_preamble_create(struct vb2_fw_preamble ** fp_ptr,const struct vb2_private_key * signing_key,const struct vb2_signature ** hash_list,uint32_t hash_count,uint32_t fw_version,uint32_t flags,const char * desc)19 int vb2_fw_preamble_create(struct vb2_fw_preamble **fp_ptr,
20 			   const struct vb2_private_key *signing_key,
21 			   const struct vb2_signature **hash_list,
22 			   uint32_t hash_count,
23 			   uint32_t fw_version,
24 			   uint32_t flags,
25 			   const char *desc)
26 {
27 	struct vb2_fw_preamble fp = {
28 		.c.magic = VB2_MAGIC_FW_PREAMBLE,
29 		.c.struct_version_major = VB2_FW_PREAMBLE_VERSION_MAJOR,
30 		.c.struct_version_minor = VB2_FW_PREAMBLE_VERSION_MAJOR,
31 		.c.fixed_size = sizeof(fp),
32 		.c.desc_size = vb2_desc_size(desc),
33 		.flags = flags,
34 		.fw_version = fw_version,
35 		.hash_count = hash_count,
36 	};
37 
38 	uint32_t hash_next;
39 	uint32_t sig_size;
40 	uint8_t *buf;
41 	int i;
42 
43 	*fp_ptr = NULL;
44 
45 	/* Determine component sizes */
46 	hash_next = fp.hash_offset = fp.c.fixed_size + fp.c.desc_size;
47 
48 	for (i = 0; i < hash_count; i++)
49 		hash_next += hash_list[i]->c.total_size;
50 
51 	fp.sig_offset = hash_next;
52 
53 	if (vb2_sig_size_for_key(&sig_size, signing_key, NULL))
54 		return VB2_FW_PREAMBLE_CREATE_SIG_SIZE;
55 
56 	fp.c.total_size = fp.sig_offset + sig_size;
57 
58 	/* Allocate buffer and copy components */
59 	buf = calloc(fp.c.total_size, 1);
60 	if (!buf)
61 		return VB2_FW_PREAMBLE_CREATE_ALLOC;
62 
63 	memcpy(buf, &fp, sizeof(fp));
64 	if (fp.c.desc_size)
65 		strcpy((char *)buf + fp.c.fixed_size, desc);
66 
67 	hash_next = fp.hash_offset;
68 	for (i = 0; i < hash_count; i++) {
69 		memcpy(buf + hash_next, hash_list[i],
70 		       hash_list[i]->c.total_size);
71 		hash_next += hash_list[i]->c.total_size;
72 	}
73 
74 	/* Sign the preamble */
75 	if (vb2_sign_object(buf, fp.sig_offset, signing_key, NULL)) {
76 		free(buf);
77 		return VB2_FW_PREAMBLE_CREATE_SIGN;
78 	}
79 
80 	*fp_ptr = (struct vb2_fw_preamble *)buf;
81 	return VB2_SUCCESS;
82 }
83