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
19int vb2api_secdata_check(const struct vb2_context *ctx)
20{
21	return vb2_secdata_check_crc(ctx);
22}
23
24int vb2api_secdata_create(struct vb2_context *ctx)
25{
26	return vb2_secdata_create(ctx);
27}
28
29void 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
37int 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
79int 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
104int 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
128int 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