| /* 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" |
| |
| int vb2_secdata_check_crc(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; |
| } |
| |
| int vb2_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; |
| } |
| |
| int vb2_secdata_init(struct vb2_context *ctx) |
| { |
| struct vb2_shared_data *sd = vb2_get_sd(ctx); |
| int rv; |
| |
| rv = vb2_secdata_check_crc(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; |
| } |
| |
| int 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; |
| } |
| } |
| |
| int 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; |
| } |