OpenCellular/host/lib/host_common.c

/* Copyright (c) 2010 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.
 *
 * Host functions for verified boot.
 */

/* TODO: change all 'return 0', 'return 1' into meaningful return codes */

#include "host_common.h"

#include "cryptolib.h"
#include "utility.h"
#include "vboot_common.h"


VbKeyBlockHeader* CreateKeyBlock(const VbPublicKey* data_key,
                                 const VbPrivateKey* signing_key,
                                 uint64_t flags) {

  VbKeyBlockHeader* h;
  uint64_t signed_size = sizeof(VbKeyBlockHeader) + data_key->key_size;
  uint64_t block_size = (signed_size + SHA512_DIGEST_SIZE +
                         siglen_map[signing_key->algorithm]);
  uint8_t* data_key_dest;
  uint8_t* block_sig_dest;
  uint8_t* block_chk_dest;
  VbSignature *sigtmp;

  /* Allocate key block */
  h = (VbKeyBlockHeader*)Malloc(block_size);
  if (!h)
    return NULL;
  data_key_dest = (uint8_t*)(h + 1);
  block_chk_dest = data_key_dest + data_key->key_size;
  block_sig_dest = block_chk_dest + SHA512_DIGEST_SIZE;

  Memcpy(h->magic, KEY_BLOCK_MAGIC, KEY_BLOCK_MAGIC_SIZE);
  h->header_version_major = KEY_BLOCK_HEADER_VERSION_MAJOR;
  h->header_version_minor = KEY_BLOCK_HEADER_VERSION_MINOR;
  h->key_block_size = block_size;
  h->key_block_flags = flags;

  /* Copy data key */
  PublicKeyInit(&h->data_key, data_key_dest, data_key->key_size);
  PublicKeyCopy(&h->data_key, data_key);

  /* Set up signature structs so we can calculate the signatures */
  SignatureInit(&h->key_block_checksum, block_chk_dest,
                SHA512_DIGEST_SIZE, signed_size);
  SignatureInit(&h->key_block_signature, block_sig_dest,
                siglen_map[signing_key->algorithm], signed_size);

  /* Calculate checksum */
  sigtmp = CalculateChecksum((uint8_t*)h, signed_size);
  SignatureCopy(&h->key_block_checksum, sigtmp);
  Free(sigtmp);

  /* Calculate signature */
  sigtmp = CalculateSignature((uint8_t*)h, signed_size, signing_key);
  SignatureCopy(&h->key_block_signature, sigtmp);
  Free(sigtmp);

  /* Return the header */
  return h;
}


VbFirmwarePreambleHeader* CreateFirmwarePreamble(
    uint64_t firmware_version,
    const VbPublicKey* kernel_subkey,
    const VbSignature* body_signature,
    const VbPrivateKey* signing_key) {

  VbFirmwarePreambleHeader* h;
  uint64_t signed_size = (sizeof(VbFirmwarePreambleHeader) +
                          kernel_subkey->key_size +
                          body_signature->sig_size);
  uint64_t block_size = signed_size + siglen_map[signing_key->algorithm];
  uint8_t* kernel_subkey_dest;
  uint8_t* body_sig_dest;
  uint8_t* block_sig_dest;
  VbSignature *sigtmp;

  /* Allocate key block */
  h = (VbFirmwarePreambleHeader*)Malloc(block_size);
  if (!h)
    return NULL;
  kernel_subkey_dest = (uint8_t*)(h + 1);
  body_sig_dest = kernel_subkey_dest + kernel_subkey->key_size;
  block_sig_dest = body_sig_dest + body_signature->sig_size;

  h->header_version_major = FIRMWARE_PREAMBLE_HEADER_VERSION_MAJOR;
  h->header_version_minor = FIRMWARE_PREAMBLE_HEADER_VERSION_MINOR;
  h->preamble_size = block_size;
  h->firmware_version = firmware_version;

  /* Copy data key */
  PublicKeyInit(&h->kernel_subkey, kernel_subkey_dest,
                kernel_subkey->key_size);
  PublicKeyCopy(&h->kernel_subkey, kernel_subkey);

  /* Copy body signature */
  SignatureInit(&h->body_signature, body_sig_dest,
                body_signature->sig_size, 0);
  SignatureCopy(&h->body_signature, body_signature);

  /* Set up signature struct so we can calculate the signature */
  SignatureInit(&h->preamble_signature, block_sig_dest,
                siglen_map[signing_key->algorithm], signed_size);

  /* Calculate signature */
  sigtmp = CalculateSignature((uint8_t*)h, signed_size, signing_key);
  SignatureCopy(&h->preamble_signature, sigtmp);
  Free(sigtmp);

  /* Return the header */
  return h;
}


/* Creates a kernel preamble, signed with [signing_key].
 * Caller owns the returned pointer, and must free it with Free().
 *
 * Returns NULL if error. */
VbKernelPreambleHeader* CreateKernelPreamble(
    uint64_t kernel_version,
    uint64_t body_load_address,
    uint64_t bootloader_address,
    uint64_t bootloader_size,
    const VbSignature* body_signature,
    uint64_t desired_size,
    const VbPrivateKey* signing_key) {

  VbKernelPreambleHeader* h;
  uint64_t signed_size = (sizeof(VbKernelPreambleHeader) +
                          body_signature->sig_size);
  uint64_t block_size = signed_size + siglen_map[signing_key->algorithm];
  uint8_t* body_sig_dest;
  uint8_t* block_sig_dest;
  VbSignature *sigtmp;

  /* If the block size is smaller than the desired size, pad it */
  if (block_size < desired_size)
    block_size = desired_size;

  /* Allocate key block */
  h = (VbKernelPreambleHeader*)Malloc(block_size);
  if (!h)
    return NULL;
  body_sig_dest = (uint8_t*)(h + 1);
  block_sig_dest = body_sig_dest + body_signature->sig_size;

  h->header_version_major = KERNEL_PREAMBLE_HEADER_VERSION_MAJOR;
  h->header_version_minor = KERNEL_PREAMBLE_HEADER_VERSION_MINOR;
  h->preamble_size = block_size;
  h->kernel_version = kernel_version;
  h->body_load_address = body_load_address;
  h->bootloader_address = bootloader_address;
  h->bootloader_size = bootloader_size;

  /* Copy body signature */
  SignatureInit(&h->body_signature, body_sig_dest,
                body_signature->sig_size, 0);
  SignatureCopy(&h->body_signature, body_signature);

  /* Set up signature struct so we can calculate the signature */
  SignatureInit(&h->preamble_signature, block_sig_dest,
                siglen_map[signing_key->algorithm], signed_size);

  /* Calculate signature */
  sigtmp = CalculateSignature((uint8_t*)h, signed_size, signing_key);
  SignatureCopy(&h->preamble_signature, sigtmp);
  Free(sigtmp);

  /* Return the header */
  return h;
}