| // Copyright 2017 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "chrome/common/safe_browsing/disk_image_type_sniffer_mac.h" |
| #include "base/threading/scoped_blocking_call.h" |
| |
| namespace safe_browsing { |
| |
| namespace { |
| |
| const uint8_t kKolySignature[4] = {'k', 'o', 'l', 'y'}; |
| constexpr size_t kSizeKolySignatureInBytes = sizeof(kKolySignature); |
| const size_t kSizeKolyTrailerInBytes = 512; |
| |
| } // namespace |
| |
| DiskImageTypeSnifferMac::DiskImageTypeSnifferMac() {} |
| |
| // static |
| bool DiskImageTypeSnifferMac::IsAppleDiskImage(const base::FilePath& dmg_file) { |
| // TODO(drubery): Macs accept DMGs with koly blocks at the beginning of the |
| // file. Investigate if this is a problem, and if so, update this function. |
| base::ScopedBlockingCall scoped_blocking_call(FROM_HERE, |
| base::BlockingType::MAY_BLOCK); |
| |
| base::File file(dmg_file, base::File::FLAG_OPEN | base::File::FLAG_READ); |
| if (!file.IsValid()) |
| return false; |
| |
| char data[kSizeKolySignatureInBytes]; |
| |
| if (file.Seek(base::File::FROM_END, -1 * kSizeKolyTrailerInBytes) == -1) |
| return false; |
| |
| if (file.ReadAtCurrentPos(data, kSizeKolySignatureInBytes) != |
| kSizeKolySignatureInBytes) |
| return false; |
| |
| return IsAppleDiskImageTrailer(base::span<uint8_t>( |
| reinterpret_cast<uint8_t*>(data), kSizeKolySignatureInBytes)); |
| } |
| |
| // static |
| bool DiskImageTypeSnifferMac::IsAppleDiskImageTrailer( |
| const base::span<const uint8_t>& trailer) { |
| if (trailer.size() < kSizeKolySignatureInBytes) |
| return false; |
| |
| const base::span<const uint8_t> subspan = |
| trailer.last(kSizeKolySignatureInBytes); |
| |
| return (memcmp(subspan.data(), kKolySignature, kSizeKolySignatureInBytes) == |
| 0); |
| } |
| |
| // static |
| size_t DiskImageTypeSnifferMac::AppleDiskImageTrailerSize() { |
| return kSizeKolyTrailerInBytes; |
| } |
| |
| DiskImageTypeSnifferMac::~DiskImageTypeSnifferMac() = default; |
| |
| } // namespace safe_browsing |