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 * Externally-callable APIs
6 * (Firmware portion)
7 */
8
9 #include "2sysincludes.h"
10 #include "2api.h"
11 #include "2common.h"
12 #include "2misc.h"
13 #include "2nvstorage.h"
14 #include "2secdata.h"
15 #include "2sha.h"
16 #include "2rsa.h"
17 #include "2tpm_bootmode.h"
18
vb2api_secdata_check(const struct vb2_context * ctx)19 int vb2api_secdata_check(const struct vb2_context *ctx)
20 {
21 return vb2_secdata_check_crc(ctx);
22 }
23
vb2api_secdata_create(struct vb2_context * ctx)24 int vb2api_secdata_create(struct vb2_context *ctx)
25 {
26 return vb2_secdata_create(ctx);
27 }
28
vb2api_fail(struct vb2_context * ctx,uint8_t reason,uint8_t subcode)29 void vb2api_fail(struct vb2_context *ctx, uint8_t reason, uint8_t subcode)
30 {
31 /* Initialize the vboot context if it hasn't been yet */
32 vb2_init_context(ctx);
33
34 vb2_fail(ctx, reason, subcode);
35 }
36
vb2api_fw_phase1(struct vb2_context * ctx)37 int vb2api_fw_phase1(struct vb2_context *ctx)
38 {
39 int rv;
40
41 /* Initialize the vboot context if it hasn't been yet */
42 vb2_init_context(ctx);
43
44 /* Initialize NV context */
45 vb2_nv_init(ctx);
46
47 /* Initialize secure data */
48 rv = vb2_secdata_init(ctx);
49 if (rv)
50 vb2_fail(ctx, VB2_RECOVERY_SECDATA_INIT, rv);
51
52 /* Load and parse the GBB header */
53 rv = vb2_fw_parse_gbb(ctx);
54 if (rv)
55 vb2_fail(ctx, VB2_RECOVERY_GBB_HEADER, rv);
56
57 /* Check for dev switch */
58 rv = vb2_check_dev_switch(ctx);
59 if (rv)
60 vb2_fail(ctx, VB2_RECOVERY_DEV_SWITCH, rv);
61
62 /*
63 * Check for recovery. Note that this function returns void, since
64 * any errors result in requesting recovery.
65 */
66 vb2_check_recovery(ctx);
67
68 /* Return error if recovery is needed */
69 if (ctx->flags & VB2_CONTEXT_RECOVERY_MODE) {
70 /* Always clear RAM when entering recovery mode */
71 ctx->flags |= VB2_CONTEXT_CLEAR_RAM;
72
73 return VB2_ERROR_API_PHASE1_RECOVERY;
74 }
75
76 return VB2_SUCCESS;
77 }
78
vb2api_fw_phase2(struct vb2_context * ctx)79 int vb2api_fw_phase2(struct vb2_context *ctx)
80 {
81 int rv;
82
83 /* Always clear RAM when entering developer mode */
84 if (ctx->flags & VB2_CONTEXT_DEVELOPER_MODE)
85 ctx->flags |= VB2_CONTEXT_CLEAR_RAM;
86
87 /* Check for explicit request to clear TPM */
88 rv = vb2_check_tpm_clear(ctx);
89 if (rv) {
90 vb2_fail(ctx, VB2_RECOVERY_TPM_CLEAR_OWNER, rv);
91 return rv;
92 }
93
94 /* Decide which firmware slot to try this boot */
95 rv = vb2_select_fw_slot(ctx);
96 if (rv) {
97 vb2_fail(ctx, VB2_RECOVERY_FW_SLOT, rv);
98 return rv;
99 }
100
101 return VB2_SUCCESS;
102 }
103
vb2api_extend_hash(struct vb2_context * ctx,const void * buf,uint32_t size)104 int vb2api_extend_hash(struct vb2_context *ctx,
105 const void *buf,
106 uint32_t size)
107 {
108 struct vb2_shared_data *sd = vb2_get_sd(ctx);
109 struct vb2_digest_context *dc = (struct vb2_digest_context *)
110 (ctx->workbuf + sd->workbuf_hash_offset);
111
112 /* Must have initialized hash digest work area */
113 if (!sd->workbuf_hash_size)
114 return VB2_ERROR_API_EXTEND_HASH_WORKBUF;
115
116 /* Don't extend past the data we expect to hash */
117 if (!size || size > sd->hash_remaining_size)
118 return VB2_ERROR_API_EXTEND_HASH_SIZE;
119
120 sd->hash_remaining_size -= size;
121
122 if (dc->using_hwcrypto)
123 return vb2ex_hwcrypto_digest_extend(buf, size);
124 else
125 return vb2_digest_extend(dc, buf, size);
126 }
127
vb2api_get_pcr_digest(struct vb2_context * ctx,enum vb2_pcr_digest which_digest,uint8_t * dest,uint32_t * dest_size)128 int vb2api_get_pcr_digest(struct vb2_context *ctx,
129 enum vb2_pcr_digest which_digest,
130 uint8_t *dest,
131 uint32_t *dest_size)
132 {
133 const uint8_t *digest;
134 uint32_t digest_size;
135
136 switch (which_digest) {
137 case BOOT_MODE_PCR:
138 digest = vb2_get_boot_state_digest(ctx);
139 digest_size = VB2_SHA1_DIGEST_SIZE;
140 break;
141 case HWID_DIGEST_PCR:
142 digest = vb2_get_sd(ctx)->gbb_hwid_digest;
143 digest_size = VB2_GBB_HWID_DIGEST_SIZE;
144 break;
145 default:
146 return VB2_ERROR_API_PCR_DIGEST;
147 }
148
149 if (digest == NULL || *dest_size < digest_size)
150 return VB2_ERROR_API_PCR_DIGEST_BUF;
151
152 memcpy(dest, digest, digest_size);
153 *dest_size = digest_size;
154
155 return VB2_SUCCESS;
156 }
157