| /* 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. |
| * |
| * Misc functions which need access to vb2_context but are not public APIs |
| */ |
| |
| #include "2sysincludes.h" |
| #include "2api.h" |
| #include "2common.h" |
| #include "2misc.h" |
| #include "2nvstorage.h" |
| #include "2secdata.h" |
| #include "2sha.h" |
| #include "2rsa.h" |
| #include "vb2_common.h" |
| |
| /** |
| * Read an object with a common struct header from a verified boot resource. |
| * |
| * On success, an object buffer will be allocated in the work buffer, the |
| * object will be stored into the buffer, and *buf_ptr will point to the |
| * object. |
| * |
| * @param ctx Vboot context |
| * @param index Resource index to read |
| * @param offset Byte offset within resource to start at |
| * @param buf_ptr Destination for object pointer |
| * @return VB2_SUCCESS, or error code on error. |
| */ |
| int vb2_read_resource_object(struct vb2_context *ctx, |
| enum vb2_resource_index index, |
| uint32_t offset, |
| struct vb2_workbuf *wb, |
| void **buf_ptr) |
| { |
| struct vb2_struct_common c; |
| void *buf; |
| int rv; |
| |
| *buf_ptr = NULL; |
| |
| /* Read the common header */ |
| rv = vb2ex_read_resource(ctx, index, offset, &c, sizeof(c)); |
| if (rv) |
| return rv; |
| |
| /* Allocate a buffer for the object, now that we know how big it is */ |
| buf = vb2_workbuf_alloc(wb, c.total_size); |
| if (!buf) |
| return VB2_ERROR_READ_RESOURCE_OBJECT_BUF; |
| |
| /* Read the object */ |
| rv = vb2ex_read_resource(ctx, index, offset, buf, c.total_size); |
| if (rv) { |
| vb2_workbuf_free(wb, c.total_size); |
| return rv; |
| } |
| |
| /* Save the pointer */ |
| *buf_ptr = buf; |
| return VB2_SUCCESS; |
| } |
| |
| int vb2_load_fw_keyblock(struct vb2_context *ctx) |
| { |
| struct vb2_shared_data *sd = vb2_get_sd(ctx); |
| struct vb2_workbuf wb; |
| |
| uint8_t *key_data; |
| uint32_t key_size; |
| struct vb2_packed_key *packed_key; |
| struct vb2_public_key root_key; |
| struct vb2_keyblock *kb; |
| |
| int rv; |
| |
| vb2_workbuf_from_ctx(ctx, &wb); |
| |
| /* Read the root key */ |
| key_size = sd->gbb_rootkey_size; |
| key_data = vb2_workbuf_alloc(&wb, key_size); |
| if (!key_data) |
| return VB2_ERROR_FW_KEYBLOCK_WORKBUF_ROOT_KEY; |
| |
| rv = vb2ex_read_resource(ctx, VB2_RES_GBB, sd->gbb_rootkey_offset, |
| key_data, key_size); |
| if (rv) |
| return rv; |
| |
| /* Unpack the root key */ |
| rv = vb2_unpack_key(&root_key, key_data, key_size); |
| if (rv) |
| return rv; |
| |
| /* |
| * Load the firmware keyblock common header into the work buffer after |
| * the root key. |
| */ |
| rv = vb2_read_resource_object(ctx, VB2_RES_FW_VBLOCK, 0, &wb, |
| (void **)&kb); |
| if (rv) |
| return rv; |
| |
| /* Verify the keyblock */ |
| rv = vb2_verify_keyblock(kb, kb->c.total_size, &root_key, &wb); |
| if (rv) { |
| vb2_fail(ctx, VB2_RECOVERY_FW_KEYBLOCK, rv); |
| return rv; |
| } |
| |
| /* Preamble follows the keyblock in the vblock */ |
| sd->vblock_preamble_offset = kb->c.total_size; |
| |
| packed_key = (struct vb2_packed_key *)((uint8_t *)kb + kb->key_offset); |
| |
| /* Key version is the upper 16 bits of the composite firmware version */ |
| if (packed_key->key_version > 0xffff) |
| rv = VB2_ERROR_FW_KEYBLOCK_VERSION_RANGE; |
| if (!rv && packed_key->key_version < (sd->fw_version_secdata >> 16)) |
| rv = VB2_ERROR_FW_KEYBLOCK_VERSION_ROLLBACK; |
| if (rv) { |
| vb2_fail(ctx, VB2_RECOVERY_FW_KEY_ROLLBACK, rv); |
| return rv; |
| } |
| |
| sd->fw_version = packed_key->key_version << 16; |
| |
| /* |
| * Save the data key in the work buffer. This overwrites the root key |
| * we read above. That's ok, because now that we have the data key we |
| * no longer need the root key. |
| * |
| * Use memmove() instead of memcpy(). In theory, the destination will |
| * never overlap with the source because the root key is likely to be |
| * at least as large as the data key, but there's no harm here in being |
| * paranoid. |
| */ |
| memmove(key_data, packed_key, packed_key->c.total_size); |
| packed_key = (struct vb2_packed_key *)key_data; |
| |
| /* Save the packed key offset and size */ |
| sd->workbuf_data_key_offset = vb2_offset_of(ctx->workbuf, key_data); |
| sd->workbuf_data_key_size = packed_key->c.total_size; |
| |
| /* Data key will persist in the workbuf after we return */ |
| ctx->workbuf_used = sd->workbuf_data_key_offset + |
| sd->workbuf_data_key_size; |
| |
| return VB2_SUCCESS; |
| } |
| |
| int vb2_load_fw_preamble(struct vb2_context *ctx) |
| { |
| struct vb2_shared_data *sd = vb2_get_sd(ctx); |
| struct vb2_workbuf wb; |
| |
| uint8_t *key_data = ctx->workbuf + sd->workbuf_data_key_offset; |
| uint32_t key_size = sd->workbuf_data_key_size; |
| struct vb2_public_key data_key; |
| |
| /* Preamble goes in the next unused chunk of work buffer */ |
| struct vb2_fw_preamble *pre; |
| |
| int rv; |
| |
| vb2_workbuf_from_ctx(ctx, &wb); |
| |
| /* Unpack the firmware data key */ |
| if (!sd->workbuf_data_key_size) |
| return VB2_ERROR_FW_PREAMBLE2_DATA_KEY; |
| |
| rv = vb2_unpack_key(&data_key, key_data, key_size); |
| if (rv) |
| return rv; |
| |
| /* Load the firmware preamble */ |
| rv = vb2_read_resource_object(ctx, VB2_RES_FW_VBLOCK, |
| sd->vblock_preamble_offset, &wb, |
| (void **)&pre); |
| if (rv) |
| return rv; |
| |
| /* Work buffer now contains the data subkey data and the preamble */ |
| |
| /* Verify the preamble */ |
| rv = vb2_verify_fw_preamble(pre, pre->c.total_size, &data_key, &wb); |
| if (rv) { |
| vb2_fail(ctx, VB2_RECOVERY_FW_PREAMBLE, rv); |
| return rv; |
| } |
| |
| /* Move the preamble down now that the data key is no longer used */ |
| memmove(key_data, pre, pre->c.total_size); |
| pre = (struct vb2_fw_preamble *)key_data; |
| |
| /* Data key is now gone */ |
| sd->workbuf_data_key_offset = sd->workbuf_data_key_size = 0; |
| |
| /* |
| * Firmware version is the lower 16 bits of the composite firmware |
| * version. |
| */ |
| if (pre->fw_version > 0xffff) |
| rv = VB2_ERROR_FW_PREAMBLE_VERSION_RANGE; |
| /* Combine with the key version from vb2_load_fw_keyblock() */ |
| sd->fw_version |= pre->fw_version; |
| if (!rv && sd->fw_version < sd->fw_version_secdata) |
| rv = VB2_ERROR_FW_PREAMBLE_VERSION_ROLLBACK; |
| if (rv) { |
| vb2_fail(ctx, VB2_RECOVERY_FW_ROLLBACK, rv); |
| return rv; |
| } |
| |
| /* |
| * If this is a newer version than in secure storage, and we |
| * successfully booted the same slot last boot, roll forward the |
| * version in secure storage. |
| */ |
| if (sd->fw_version > sd->fw_version_secdata && |
| sd->last_fw_slot == sd->fw_slot && |
| sd->last_fw_result == VB2_FW_RESULT_SUCCESS) { |
| |
| sd->fw_version_secdata = sd->fw_version; |
| rv = vb2_secdata_set(ctx, VB2_SECDATA_VERSIONS, sd->fw_version); |
| if (rv) |
| return rv; |
| } |
| |
| /* Keep track of where we put the preamble */ |
| sd->workbuf_preamble_offset = vb2_offset_of(ctx->workbuf, pre); |
| sd->workbuf_preamble_size = pre->c.total_size; |
| |
| /* Preamble will persist in work buffer after we return */ |
| ctx->workbuf_used = sd->workbuf_preamble_offset + |
| sd->workbuf_preamble_size; |
| |
| return VB2_SUCCESS; |
| } |