| // 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. |
| |
| #ifndef EXTENSIONS_COMMON_CRX_FILE_H_ |
| #define EXTENSIONS_COMMON_CRX_FILE_H_ |
| |
| #include <sys/types.h> |
| #include "base/basictypes.h" |
| #include "base/memory/scoped_ptr.h" |
| |
| namespace extensions { |
| |
| // CRX files have a header that includes a magic key, version number, and |
| // some signature sizing information. Use CrxFile object to validate whether |
| // the header is valid or not. |
| class CrxFile { |
| public: |
| // The size of the magic character sequence at the beginning of each crx |
| // file, in bytes. This should be a multiple of 4. |
| static const size_t kCrxFileHeaderMagicSize = 4; |
| |
| // This header is the first data at the beginning of an extension. Its |
| // contents are purposely 32-bit aligned so that it can just be slurped into |
| // a struct without manual parsing. |
| struct Header { |
| char magic[kCrxFileHeaderMagicSize]; |
| uint32 version; |
| uint32 key_size; // The size of the public key, in bytes. |
| uint32 signature_size; // The size of the signature, in bytes. |
| // An ASN.1-encoded PublicKeyInfo structure follows. |
| // The signature follows. |
| }; |
| |
| enum Error { |
| kWrongMagic, |
| kInvalidVersion, |
| kInvalidKeyTooLarge, |
| kInvalidKeyTooSmall, |
| kInvalidSignatureTooLarge, |
| kInvalidSignatureTooSmall, |
| }; |
| |
| // Construct a new CRX file header object with bytes of a header |
| // read from a CRX file. If a null scoped_ptr is returned, |error| |
| // contains an error code with additional information. |
| static scoped_ptr<CrxFile> Parse(const Header& header, Error* error); |
| |
| // Construct a new header for the given key and signature sizes. |
| // Returns a null scoped_ptr if erroneous values of |key_size| and/or |
| // |signature_size| are provided. |error| contains an error code with |
| // additional information. |
| // Use this constructor and then .header() to obtain the Header |
| // for writing out to a CRX file. |
| static scoped_ptr<CrxFile> Create(const uint32 key_size, |
| const uint32 signature_size, |
| Error* error); |
| |
| // Returns the header structure for writing out to a CRX file. |
| const Header& header() const { return header_; } |
| |
| // Checks a valid |header| to determine whether or not the CRX represents a |
| // differential CRX. |
| static bool HeaderIsDelta(const Header& header); |
| |
| private: |
| Header header_; |
| |
| // Constructor is private. Clients should use static factory methods above. |
| explicit CrxFile(const Header& header); |
| |
| // Checks the |header| for validity and returns true if the values are valid. |
| // If false is returned, more detailed error code is returned in |error|. |
| static bool HeaderIsValid(const Header& header, Error* error); |
| }; |
| |
| } // namespace extensions |
| |
| #endif // EXTENSIONS_COMMON_CRX_FILE_H_ |