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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.
*
* Common functions between firmware and kernel verified boot.
*/
#ifndef VBOOT_REFERENCE_VB2_COMMON_H_
#define VBOOT_REFERENCE_VB2_COMMON_H_
#include "2common.h"
#include "2return_codes.h"
#include "2struct.h"
#include "vb2_struct.h"
/**
* Return the description of an object starting with a vb2_struct_common header.
*
* Does not sanity-check the buffer; merely returns the pointer.
*
* @param buf Pointer to common object
* @return A pointer to description or an empty string if none.
*/
const char *vb2_common_desc(const void *buf);
/**
* Verify the common struct header is fully contained in its parent data
*
* Also verifies the description is either zero-length or null-terminated.
*
* @param parent Parent data
* @param parent_size Parent size in bytes
* @return VB2_SUCCESS, or non-zero if error.
*/
int vb2_verify_common_header(const void *parent, uint32_t parent_size);
/**
* Verify a member is within the data for a parent object
*
* @param parent Parent data (starts with struct vb2_struct_common)
* @param min_offset Pointer to minimum offset where member can be located.
* If this offset is 0 on input, uses the size of the
* fixed header (and description, if any). This will be
* updated on return to the end of the passed member. On
* error, the value of min_offset is undefined.
* @param member_offset Offset of member data from start of parent, in bytes
* @param member_size Size of member data, in bytes
* @return VB2_SUCCESS, or non-zero if error.
*/
int vb2_verify_common_member(const void *parent,
uint32_t *min_offset,
uint32_t member_offset,
uint32_t member_size);
/**
* Verify a member which starts with a common header is within the parent
*
* This does not verify the contents of the member or its header, only that the
* member's claimed total size fits within the parent's claimed total size at
* the specified offset.
*
* @param parent Parent data (starts with struct vb2_struct_common)
* @param min_offset Pointer to minimum offset where member can be located.
* If this offset is 0 on input, uses the size of the
* fixed header (and description, if any). This will be
* updated on return to the end of the passed member. On
* error, the value of min_offset is undefined.
* @param member_offset Offset of member data from start of parent, in bytes.
* This should be the start of the common header of the
* member.
* @return VB2_SUCCESS, or non-zero if error.
*/
int vb2_verify_common_subobject(const void *parent,
uint32_t *min_offset,
uint32_t member_offset);
/**
* Unpack a key for use in verification
*
* The elements of the unpacked key will point into the source buffer, so don't
* free the source buffer until you're done with the key.
*
* @param key Destintion for unpacked key
* @param buf Source buffer containing packed key
* @param size Size of buffer in bytes
* @return VB2_SUCCESS, or non-zero error code if error.
*/
int vb2_unpack_key(struct vb2_public_key *key,
const uint8_t *buf,
uint32_t size);
/**
* Unpack the RSA data fields for a public key
*
* This is called by vb2_unpack_key() to extract the arrays from a packed key.
* These elements of *key will point inside the key_data buffer.
*
* @param key Destination key for RSA data fields
* @param key_data Packed key data (from inside a packed key buffer)
* @param key_size Size of packed key data in bytes
*/
int vb2_unpack_key_data(struct vb2_public_key *key,
const uint8_t *key_data,
uint32_t key_size);
/**
* Verify the integrity of a signature struct
* @param sig Signature struct
* @param size Size of buffer containing signature struct
* @return VB2_SUCCESS, or non-zero if error.
*/
int vb2_verify_signature(const struct vb2_signature *sig,
uint32_t size);
/**
* Verify a signature against an expected hash digest.
*
* @param key Key to use in signature verification
* @param sig Signature to verify (may be destroyed in process)
* @param digest Digest of signed data
* @param wb Work buffer
* @return VB2_SUCCESS, or non-zero if error.
*/
int vb2_verify_digest(const struct vb2_public_key *key,
struct vb2_signature *sig,
const uint8_t *digest,
const struct vb2_workbuf *wb);
/**
* Verify data matches signature.
*
* @param data Data to verify
* @param size Size of data buffer. Note that amount of data to
* actually validate is contained in sig->data_size.
* @param sig Signature of data (destroyed in process)
* @param key Key to use to validate signature
* @param wb Work buffer
* @return VB2_SUCCESS, or non-zero error code if error.
*/
int vb2_verify_data(const void *data,
uint32_t size,
struct vb2_signature *sig,
const struct vb2_public_key *key,
const struct vb2_workbuf *wb);
/**
* Check the sanity of a key block using a public key.
*
* Header fields are also checked for sanity. Does not verify key index or key
* block flags. Signature inside block is destroyed during check.
*
* @param block Key block to verify
* @param size Size of key block buffer
* @param key Key to use to verify block
* @param wb Work buffer
* @return VB2_SUCCESS, or non-zero error code if error.
*/
int vb2_verify_keyblock(struct vb2_keyblock *block,
uint32_t size,
const struct vb2_public_key *key,
const struct vb2_workbuf *wb);
/**
* Check the sanity of a firmware preamble using a public key.
*
* The signature in the preamble is destroyed during the check.
*
* @param preamble Preamble to verify
* @param size Size of preamble buffer
* @param key Key to use to verify preamble
* @param wb Work buffer
* @return VB2_SUCCESS, or non-zero error code if error.
*/
int vb2_verify_fw_preamble(struct vb2_fw_preamble *preamble,
uint32_t size,
const struct vb2_public_key *key,
const struct vb2_workbuf *wb);
#endif /* VBOOT_REFERENCE_VB2_COMMON_H_ */