| // Copyright (c) 2012 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 "extensions/common/crx_file.h" |
| |
| namespace extensions { |
| |
| namespace { |
| |
| // The current version of the crx format. |
| static const uint32 kCurrentVersion = 2; |
| |
| // The current version of the crx diff format. |
| static const uint32 kCurrentDiffVersion = 0; |
| |
| // The maximum size the crx parser will tolerate for a public key. |
| static const uint32 kMaxPublicKeySize = 1 << 16; |
| |
| // The maximum size the crx parser will tolerate for a signature. |
| static const uint32 kMaxSignatureSize = 1 << 16; |
| |
| } // namespace |
| |
| // The magic string embedded in the header. |
| const char kCrxFileHeaderMagic[] = "Cr24"; |
| const char kCrxDiffFileHeaderMagic[] = "CrOD"; |
| |
| scoped_ptr<CrxFile> CrxFile::Parse(const CrxFile::Header& header, |
| CrxFile::Error* error) { |
| if (HeaderIsValid(header, error)) |
| return scoped_ptr<CrxFile>(new CrxFile(header)); |
| return scoped_ptr<CrxFile>(); |
| } |
| |
| scoped_ptr<CrxFile> CrxFile::Create(const uint32 key_size, |
| const uint32 signature_size, |
| CrxFile::Error* error) { |
| CrxFile::Header header; |
| memcpy(&header.magic, kCrxFileHeaderMagic, kCrxFileHeaderMagicSize); |
| header.version = kCurrentVersion; |
| header.key_size = key_size; |
| header.signature_size = signature_size; |
| if (HeaderIsValid(header, error)) |
| return scoped_ptr<CrxFile>(new CrxFile(header)); |
| return scoped_ptr<CrxFile>(); |
| } |
| |
| CrxFile::CrxFile(const Header& header) : header_(header) { |
| } |
| |
| bool CrxFile::HeaderIsDelta(const CrxFile::Header& header) { |
| return !strncmp(kCrxDiffFileHeaderMagic, header.magic, sizeof(header.magic)); |
| } |
| |
| bool CrxFile::HeaderIsValid(const CrxFile::Header& header, |
| CrxFile::Error* error) { |
| bool valid = false; |
| bool diffCrx = false; |
| if (!strncmp(kCrxDiffFileHeaderMagic, header.magic, sizeof(header.magic))) |
| diffCrx = true; |
| if (strncmp(kCrxFileHeaderMagic, header.magic, sizeof(header.magic)) && |
| !diffCrx) |
| *error = kWrongMagic; |
| else if (header.version != kCurrentVersion |
| && !(diffCrx && header.version == kCurrentDiffVersion)) |
| *error = kInvalidVersion; |
| else if (header.key_size > kMaxPublicKeySize) |
| *error = kInvalidKeyTooLarge; |
| else if (header.key_size == 0) |
| *error = kInvalidKeyTooSmall; |
| else if (header.signature_size > kMaxSignatureSize) |
| *error = kInvalidSignatureTooLarge; |
| else if (header.signature_size == 0) |
| *error = kInvalidSignatureTooSmall; |
| else |
| valid = true; |
| return valid; |
| } |
| |
| } // namespace extensions |