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 * Secure storage APIs
6 */
7
8 #include "2sysincludes.h"
9 #include "2common.h"
10 #include "2crc8.h"
11 #include "2misc.h"
12 #include "2secdata.h"
13
vb2_secdata_check_crc(const struct vb2_context * ctx)14 int vb2_secdata_check_crc(const struct vb2_context *ctx)
15 {
16 const struct vb2_secdata *sec =
17 (const struct vb2_secdata *)ctx->secdata;
18
19 /* Verify CRC */
20 if (sec->crc8 != vb2_crc8(sec, offsetof(struct vb2_secdata, crc8)))
21 return VB2_ERROR_SECDATA_CRC;
22
23 return VB2_SUCCESS;
24 }
25
vb2_secdata_create(struct vb2_context * ctx)26 int vb2_secdata_create(struct vb2_context *ctx)
27 {
28 struct vb2_secdata *sec = (struct vb2_secdata *)ctx->secdata;
29
30 /* Clear the entire struct */
31 memset(sec, 0, sizeof(*sec));
32
33 /* Set to current version */
34 sec->struct_version = VB2_SECDATA_VERSION;
35
36 /* Calculate initial CRC */
37 sec->crc8 = vb2_crc8(sec, offsetof(struct vb2_secdata, crc8));
38 ctx->flags |= VB2_CONTEXT_SECDATA_CHANGED;
39 return VB2_SUCCESS;
40 }
41
vb2_secdata_init(struct vb2_context * ctx)42 int vb2_secdata_init(struct vb2_context *ctx)
43 {
44 struct vb2_shared_data *sd = vb2_get_sd(ctx);
45 int rv;
46
47 rv = vb2_secdata_check_crc(ctx);
48 if (rv)
49 return rv;
50
51 /* Set status flag */
52 sd->status |= VB2_SD_STATUS_SECDATA_INIT;
53 // TODO: unit test for that
54
55 /* Read this now to make sure crossystem has it even in rec mode. */
56 rv = vb2_secdata_get(ctx, VB2_SECDATA_VERSIONS,
57 &sd->fw_version_secdata);
58 if (rv)
59 return rv;
60
61 return VB2_SUCCESS;
62 }
63
vb2_secdata_get(struct vb2_context * ctx,enum vb2_secdata_param param,uint32_t * dest)64 int vb2_secdata_get(struct vb2_context *ctx,
65 enum vb2_secdata_param param,
66 uint32_t *dest)
67 {
68 struct vb2_secdata *sec = (struct vb2_secdata *)ctx->secdata;
69
70 if (!(vb2_get_sd(ctx)->status & VB2_SD_STATUS_SECDATA_INIT))
71 return VB2_ERROR_SECDATA_GET_UNINITIALIZED;
72
73 switch(param) {
74 case VB2_SECDATA_FLAGS:
75 *dest = sec->flags;
76 return VB2_SUCCESS;
77
78 case VB2_SECDATA_VERSIONS:
79 *dest = sec->fw_versions;
80 return VB2_SUCCESS;
81
82 default:
83 return VB2_ERROR_SECDATA_GET_PARAM;
84 }
85 }
86
vb2_secdata_set(struct vb2_context * ctx,enum vb2_secdata_param param,uint32_t value)87 int vb2_secdata_set(struct vb2_context *ctx,
88 enum vb2_secdata_param param,
89 uint32_t value)
90 {
91 struct vb2_secdata *sec = (struct vb2_secdata *)ctx->secdata;
92 uint32_t now;
93
94 if (!(vb2_get_sd(ctx)->status & VB2_SD_STATUS_SECDATA_INIT))
95 return VB2_ERROR_SECDATA_SET_UNINITIALIZED;
96
97 /* If not changing the value, don't regenerate the CRC. */
98 if (vb2_secdata_get(ctx, param, &now) == VB2_SUCCESS && now == value)
99 return VB2_SUCCESS;
100
101 switch(param) {
102 case VB2_SECDATA_FLAGS:
103 /* Make sure flags is in valid range */
104 if (value > 0xff)
105 return VB2_ERROR_SECDATA_SET_FLAGS;
106
107 sec->flags = value;
108 break;
109
110 case VB2_SECDATA_VERSIONS:
111 sec->fw_versions = value;
112 break;
113
114 default:
115 return VB2_ERROR_SECDATA_SET_PARAM;
116 }
117
118 /* Regenerate CRC */
119 sec->crc8 = vb2_crc8(sec, offsetof(struct vb2_secdata, crc8));
120 ctx->flags |= VB2_CONTEXT_SECDATA_CHANGED;
121 return VB2_SUCCESS;
122 }
123