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CZipCryptograph Class Reference

#include <ZipCryptograph.h>

Inheritance diagram for CZipCryptograph:

Inheritance graph
[legend]

List of all members.


Public Types

enum  EncryptionMethod {
  encStandard, encWinZipAes128, encWinZipAes192, encWinZipAes256,
  encNone = 0xFF
}

Public Member Functions

virtual bool CanHandle (int iEncryptionMethod)
virtual void Decode (char *pBuffer, DWORD uSize)=0
virtual void Encode (char *pBuffer, DWORD uSize)=0
virtual void FinishDecode (CZipFileHeader &currentFile, CZipStorage &storage)
virtual void FinishEncode (CZipFileHeader &currentFile, CZipStorage &storage)
virtual bool InitDecode (CZipAutoBuffer &password, CZipFileHeader &currentFile, CZipStorage &storage)=0
virtual void InitEncode (CZipAutoBuffer &password, CZipFileHeader &currentFile, CZipStorage &storage)=0

Static Public Member Functions

static CZipCryptograph * CreateCryptograph (int iEncryptionMethod)
static DWORD GetEncryptedInfoSize (int iEncryptionMethod)
static DWORD GetEncryptedInfoSizeAfterData (int iEncryptionMethod)
static DWORD GetEncryptedInfoSizeBeforeData (int iEncryptionMethod)
static bool IsEncryptionSupported (int iEncryptionMethod)
static bool IsWinZipAesEncryption (int iEncryptionMethod)

Detailed Description

The base class for cryptographs used in encryption and decryption of file data.

See also:
Encryption Methods: How to Best Protect Your Data

Member Enumeration Documentation

enum CZipCryptograph::EncryptionMethod

The encryption method.

See also:
Encryption Methods: How to Best Protect Your Data
Enumerator:
encStandard  The traditional zip encryption.
encWinZipAes128  WinZip AES 128-bit encryption.
encWinZipAes192  WinZip AES 192-bit encryption.
encWinZipAes256  WinZip AES 256-bit encryption.
encNone  Indicates no encryption.

Member Function Documentation

virtual bool CZipCryptograph::CanHandle ( int  iEncryptionMethod  )  [inline, virtual]

Returns the value indicating whether the current compressor can handle the given encryption method.

Parameters:
iEncryptionMethod The encryption method to test. Can be one of EncryptionMethod values.
Returns:
true, if the current compressor can handle the given encryption method; false otherwise.

Reimplemented in CZipCrc32Cryptograph.

static CZipCryptograph* CZipCryptograph::CreateCryptograph ( int  iEncryptionMethod  )  [static]

A factory method that creates an appropriate cryptograph for the given method.

Parameters:
iEncryptionMethod The encryption method to create a cryptograph for. Can be one of EncryptionMethod values.
Returns:
The new cryptograph. The caller is responsible for destroying the object. If the method is not supported, creates CZipCrc32Cryptograph.

virtual void CZipCryptograph::Decode ( char *  pBuffer,
DWORD  uSize 
) [pure virtual]

Decodes the given data.

Parameters:
pBuffer The buffer that holds the data to decode and that receives the results.
uSize The size of pBuffer.

Implemented in CZipCrc32Cryptograph.

virtual void CZipCryptograph::Encode ( char *  pBuffer,
DWORD  uSize 
) [pure virtual]

Encodes the given data.

Parameters:
pBuffer The buffer that holds the data to encode and that receives the results.
uSize The size of pBuffer.

Implemented in CZipCrc32Cryptograph.

virtual void CZipCryptograph::FinishDecode ( CZipFileHeader &  currentFile,
CZipStorage &  storage 
) [inline, virtual]

The method called at the end of the decoding process.

Parameters:
currentFile The file being decoded and extracted.
storage The current CZipStorage.

virtual void CZipCryptograph::FinishEncode ( CZipFileHeader &  currentFile,
CZipStorage &  storage 
) [inline, virtual]

The method called at the end of the decoding process.

Parameters:
currentFile The file being compressed and encoded.
storage The current CZipStorage.

static DWORD CZipCryptograph::GetEncryptedInfoSize ( int  iEncryptionMethod  )  [static]

Returns the total size of the extra data that is added to the compression stream during encryption with the given method.

Parameters:
iEncryptionMethod The encryption method. Can be one of EncryptionMethod values.
Returns:
The total size of extra data for the given encryption method.

static DWORD CZipCryptograph::GetEncryptedInfoSizeAfterData ( int  iEncryptionMethod  )  [static]

Returns the size of the extra data that is added after the compression stream during encryption with the given method.

Parameters:
iEncryptionMethod The encryption method. Can be one of EncryptionMethod values.
Returns:
The size of extra data at the end of the compression stream for the given encryption method.

static DWORD CZipCryptograph::GetEncryptedInfoSizeBeforeData ( int  iEncryptionMethod  )  [static]

Returns the size of the extra data that is added before the compression stream during encryption with the given method.

Parameters:
iEncryptionMethod The encryption method. Can be one of EncryptionMethod values.
Returns:
The size of extra data at the beginning of the compression stream for the given encryption method.

virtual bool CZipCryptograph::InitDecode ( CZipAutoBuffer &  password,
CZipFileHeader &  currentFile,
CZipStorage &  storage 
) [pure virtual]

The method called when an existing file is opened for extraction.

Parameters:
password The supplied password with the CZipArchive::SetPassword method.
currentFile The file being decoded and extracted.
storage The current CZipStorage.
Returns:
true, if the password is initially considered correct; false otherwise.

Implemented in CZipCrc32Cryptograph.

virtual void CZipCryptograph::InitEncode ( CZipAutoBuffer &  password,
CZipFileHeader &  currentFile,
CZipStorage &  storage 
) [pure virtual]

The method called when a new file is opened for compression.

Parameters:
password The supplied password with the CZipArchive::SetPassword method.
currentFile The file being compressed and encoded.
storage The current CZipStorage.

Implemented in CZipCrc32Cryptograph.

static bool CZipCryptograph::IsEncryptionSupported ( int  iEncryptionMethod  )  [inline, static]

Determines if the given encryption method is supported by the current compilation of the ZipArchive Library.

Parameters:
iEncryptionMethod The encryption method to test. Can be one of EncryptionMethod values.
Returns:
true, if the method is supported; false otherwise.

static bool CZipCryptograph::IsWinZipAesEncryption ( int  iEncryptionMethod  )  [inline, static]

Determines if the given method is one of the WinZip AES encryption method.

Parameters:
iEncryptionMethod The encryption method to test. Can be one of EncryptionMethod values.
Returns:
true, if the method is one the WinZip AES encryption methods; false otherwise.

The documentation for this class was generated from the following file:
Copyright © 2000 - 2007 Artpol Software - Tadeusz Dracz
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