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/* Copyright (c) 2014 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.
*
* Secure storage APIs
*/
#include "2sysincludes.h"
#include "2common.h"
#include "2crc8.h"
#include "2misc.h"
#include "2secdata.h"
vb2_error_t vb2api_secdata_check(const struct vb2_context *ctx)
{
const struct vb2_secdata *sec =
(const struct vb2_secdata *)ctx->secdata;
/* Verify CRC */
if (sec->crc8 != vb2_crc8(sec, offsetof(struct vb2_secdata, crc8)))
return VB2_ERROR_SECDATA_CRC;
/* CRC(<000...00>) is 0, so check version as well (should never be 0) */
if (!sec->struct_version)
return VB2_ERROR_SECDATA_ZERO;
return VB2_SUCCESS;
}
vb2_error_t vb2api_secdata_create(struct vb2_context *ctx)
{
struct vb2_secdata *sec = (struct vb2_secdata *)ctx->secdata;
/* Clear the entire struct */
memset(sec, 0, sizeof(*sec));
/* Set to current version */
sec->struct_version = VB2_SECDATA_VERSION;
/* Calculate initial CRC */
sec->crc8 = vb2_crc8(sec, offsetof(struct vb2_secdata, crc8));
ctx->flags |= VB2_CONTEXT_SECDATA_CHANGED;
return VB2_SUCCESS;
}
vb2_error_t vb2_secdata_init(struct vb2_context *ctx)
{
struct vb2_shared_data *sd = vb2_get_sd(ctx);
vb2_error_t rv;
rv = vb2api_secdata_check(ctx);
if (rv)
return rv;
/* Set status flag */
sd->status |= VB2_SD_STATUS_SECDATA_INIT;
/* TODO: unit test for that */
/* Read this now to make sure crossystem has it even in rec mode. */
rv = vb2_secdata_get(ctx, VB2_SECDATA_VERSIONS,
&sd->fw_version_secdata);
if (rv)
return rv;
return VB2_SUCCESS;
}
vb2_error_t vb2_secdata_get(struct vb2_context *ctx,
enum vb2_secdata_param param, uint32_t *dest)
{
struct vb2_secdata *sec = (struct vb2_secdata *)ctx->secdata;
if (!(vb2_get_sd(ctx)->status & VB2_SD_STATUS_SECDATA_INIT))
return VB2_ERROR_SECDATA_GET_UNINITIALIZED;
switch(param) {
case VB2_SECDATA_FLAGS:
*dest = sec->flags;
return VB2_SUCCESS;
case VB2_SECDATA_VERSIONS:
*dest = sec->fw_versions;
return VB2_SUCCESS;
default:
return VB2_ERROR_SECDATA_GET_PARAM;
}
}
vb2_error_t vb2_secdata_set(struct vb2_context *ctx,
enum vb2_secdata_param param, uint32_t value)
{
struct vb2_secdata *sec = (struct vb2_secdata *)ctx->secdata;
uint32_t now;
if (!(vb2_get_sd(ctx)->status & VB2_SD_STATUS_SECDATA_INIT))
return VB2_ERROR_SECDATA_SET_UNINITIALIZED;
/* If not changing the value, don't regenerate the CRC. */
if (vb2_secdata_get(ctx, param, &now) == VB2_SUCCESS && now == value)
return VB2_SUCCESS;
switch(param) {
case VB2_SECDATA_FLAGS:
/* Make sure flags is in valid range */
if (value > 0xff)
return VB2_ERROR_SECDATA_SET_FLAGS;
sec->flags = value;
break;
case VB2_SECDATA_VERSIONS:
sec->fw_versions = value;
break;
default:
return VB2_ERROR_SECDATA_SET_PARAM;
}
/* Regenerate CRC */
sec->crc8 = vb2_crc8(sec, offsetof(struct vb2_secdata, crc8));
ctx->flags |= VB2_CONTEXT_SECDATA_CHANGED;
return VB2_SUCCESS;
}
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