extra.fld

完整的解压zip文件的源码。包含密码功能

The following are the known types of zipfile extra fields as of this
writing.  Extra fields are documented in PKWARE's appnote.txt and are
intended to allow for backward- and forward-compatible extensions to
the zipfile format.  Multiple extra-field types may be chained together,
provided that the total length of all extra-field data is less than 64KB.
(In fact, PKWARE requires that the total length of the entire file header,
including timestamp, file attributes, filename, comment, extra field, etc.,
be no more than 64KB.)

Each extra-field type (or subblock) must contain a four-byte header con-
sisting of a two-byte header ID and a two-byte length (little-endian) for
the remaining data in the subblock.  If there are additional subblocks
within the extra field, the header for each one will appear immediately
following the data for the previous subblock (i.e., with no padding for
alignment).

All integer fields in the descriptions below are in little-endian (Intel)
format unless otherwise specified.  Note that "Short" means two bytes,
"Long" means four bytes, and "Long-Long" means eight bytes, regardless
of their native sizes.  Unless specifically noted, all integer fields should
be interpreted as unsigned (non-negative) numbers.

Christian Spieler, 19980918

                        -------------------------

          Header ID's of 0 thru 31 are reserved for use by PKWARE.
          The remaining ID's can be used by third party vendors for
          proprietary usage.

          The current Header ID mappings defined by PKWARE are:

          0x0007        AV Info
          0x0009        OS/2 extended attributes      (also Info-ZIP)
          0x000a        PKWARE Win95/WinNT FileTimes  [undocumented!]
          0x000c        PKWARE VAX/VMS                (also Info-ZIP)
          0x000d        PKWARE Unix
          0x000f        Patch Descriptor

          The Header ID mappings defined by Info-ZIP and third parties are:

          0x07c8        Info-ZIP Macintosh (old, J. Lee)
          0x2605        ZipIt Macintosh (first version)
          0x2705        ZipIt Macintosh v 1.3.5 and newer (w/o full filename)
          0x334d        Info-ZIP Macintosh (new, D. Haase's 'Mac3' field )
          0x4341        Acorn/SparkFS (David Pilling)
          0x4453        Windows NT security descriptor (binary ACL)
          0x4704        VM/CMS
          0x470f        MVS
          0x4b46        FWKCS MD5 (third party, see below)
          0x4c41        OS/2 access control list (text ACL)
          0x4d49        Info-ZIP VMS (VAX or Alpha)
          0x5356        AOS/VS (binary ACL)
          0x5455        extended timestamp
          0x5855        Info-ZIP Unix (original; also OS/2, NT, etc.)
          0x6542        BeOS (BeBox, PowerMac, etc.)
          0x756e        ASi Unix
          0x7855        Info-ZIP Unix (new)
          0xfb4a        SMS/QDOS

The following are detailed descriptions of the known extra-field block types:

         -OS/2 Extended Attributes Extra Field:
          ====================================

          The following is the layout of the OS/2 extended attributes "extra"
          block.  (Last Revision 19960922)

          Note: all fields stored in Intel low-byte/high-byte order.

          Local-header version:

          Value         Size            Description
          -----         ----            -----------
  (OS/2)  0x0009        Short           tag for this extra block type
          TSize         Short           total data size for this block
          BSize         Long            uncompressed EA data size
          CType         Short           compression type
          EACRC         Long            CRC value for uncompressed EA data
          (var.)        variable        compressed EA data

          Central-header version:

          Value         Size            Description
          -----         ----            -----------
  (OS/2)  0x0009        Short           tag for this extra block type
          TSize         Short           total data size for this block
          BSize         Long            size of uncompressed local EA data

          The value of CType is interpreted according to the "compression
          method" section above; i.e., 0 for stored, 8 for deflated, etc.

          The OS/2 extended attribute structure (FEA2LIST) is compressed and
          then stored in its entirety within this structure.  There will only
          ever be one block of data in the variable-length field.


         -OS/2 Access Control List Extra Field:
          ====================================

          The following is the layout of the OS/2 ACL extra block.
          (Last Revision 19960922)

          Local-header version:

          Value         Size            Description
          -----         ----            -----------
  (ACL)   0x4c41        Short           tag for this extra block type
          TSize         Short           total data size for this block
          BSize         Long            uncompressed ACL data size
          CType         Short           compression type
          EACRC         Long            CRC value for uncompressed ACL data
          (var.)        variable        compressed ACL data

          Central-header version:

          Value         Size            Description
          -----         ----            -----------
  (ACL)   0x4c41        Short           tag for this extra block type
          TSize         Short           total data size for this block
          BSize         Long            size of uncompressed local ACL data

          The value of CType is interpreted according to the "compression
          method" section above; i.e., 0 for stored, 8 for deflated, etc.

          The uncompressed ACL data consist of a text header of the form
          "ACL1:%hX,%hd\n", where the first field is the OS/2 ACCINFO acc_attr
          member and the second is acc_count, followed by acc_count strings
          of the form "%s,%hx\n", where the first field is acl_ugname (user
          group name) and the second acl_access.  This block type will be
          extended for other operating systems as needed.


         -Windows NT Security Descriptor Extra Field:
          ==========================================

          The following is the layout of the NT Security Descriptor (another
          type of ACL) extra block.  (Last Revision 19960922)

          Local-header version:

          Value         Size            Description
          -----         ----            -----------
  (SD)    0x4453        Short           tag for this extra block type
          TSize         Short           total data size for this block
          BSize         Long            uncompressed SD data size
          Version       Byte            version of uncompressed SD data format
          CType         Short           compression type
          EACRC         Long            CRC value for uncompressed SD data
          (var.)        variable        compressed SD data

          Central-header version:

          Value         Size            Description
          -----         ----            -----------
  (SD)    0x4453        Short           tag for this extra block type
          TSize         Short           total data size for this block
          BSize         Long            size of uncompressed local SD data

          The value of CType is interpreted according to the "compression
          method" section above; i.e., 0 for stored, 8 for deflated, etc.
          Version specifies how the compressed data are to be interpreted
          and allows for future expansion of this extra field type.  Currently
          only version 0 is defined.

          For version 0, the compressed data are to be interpreted as a single
          valid Windows NT SECURITY_DESCRIPTOR data structure, in self-relative
          format.


         -PKWARE Win95/WinNT Extra Field:
          ==============================

          The following description covers PKWARE's undocumented
          Windows 95 & Windows NT extra field, introduced with the
          release of PKZIP for Windows 2.50. (Last Revision 19980425)

          This field has a fixed data size of 32 bytes and is only stored
          as local extra field.

          Value         Size            Description
          -----         ----            -----------
 (WinNT)  0x000a        Short           Tag for this "extra" block type
          TSize         Short           Total Data Size for this block
          Unknwn1       Long            ???? (all 0 ?)
          Unknwn2       Long            ????
          ModTime       Long-Long       64-bit NTFS last-modified filetime
          AccTime       Long-Long       64-bit NTFS last-access filetime
          CreTime       Long-Long       64-bit NTFS creation filetime

          The NTFS filetimes are 64-bit unsigned integers, stored in Intel
          (least significant byte first) byte order. They determine the
          number of 1.0E-07 seconds (1/10th microseconds!) past WinNT "epoch",
          which is "01-Jan-1601 00:00:00 UTC".


         -PKWARE VAX/VMS Extra Field:
          ==========================

          The following is the layout of PKWARE's VAX/VMS attributes "extra"
          block.  (Last Revision 12/17/91)

          Note: all fields stored in Intel low-byte/high-byte order.

          Value         Size            Description
          -----         ----            -----------
  (VMS)   0x000c        Short           Tag for this "extra" block type
          TSize         Short           Total Data Size for this block
          CRC           Long            32-bit CRC for remainder of the block
          Tag1          Short           VMS attribute tag value #1
          Size1         Short           Size of attribute #1, in bytes
          (var.)        Size1           Attribute #1 data
          .
          .
          .
          TagN          Short           VMS attribute tage value #N
          SizeN         Short           Size of attribute #N, in bytes
          (var.)        SizeN           Attribute #N data

          Rules:

          1. There will be one or more of attributes present, which will
             each be preceded by the above TagX & SizeX values.  These
             values are identical to the ATR$C_XXXX and ATR$S_XXXX constants
             which are defined in ATR.H under VMS C.  Neither of these values
             will ever be zero.

          2. No word alignment or padding is performed.

          3. A well-behaved PKZIP/VMS program should never produce more than
             one sub-block with the same TagX value.  Also, there will never
             be more than one "extra" block of type 0x000c in a particular
             directory record.


         -Info-ZIP VMS Extra Field:
          ========================

          The following is the layout of Info-ZIP's VMS attributes extra
          block for VAX or Alpha AXP.  The local-header and central-header
          versions are identical.  (Last Revision 19960922)

          Value         Size            Description
          -----         ----            -----------
  (VMS2)  0x4d49        Short           tag for this extra block type
          TSize         Short           total data size for this block
          ID            Long            block ID
          Flags         Short           info bytes
          BSize         Short           uncompressed block size
          Reserved      Long            (reserved)
          (var.)        variable        compressed VMS file-attributes block

          The block ID is one of the following unterminated strings:

                "VFAB"          struct FAB
                "VALL"          struct XABALL
                "VFHC"          struct XABFHC
                "VDAT"          struct XABDAT
                "VRDT"          struct XABRDT
                "VPRO"          struct XABPRO
                "VKEY"          struct XABKEY
                "VMSV"          version (e.g., "V6.1"; truncated at hyphen)
                "VNAM"          reserved

          The lower three bits of Flags indicate the compression method.  The
          currently defined methods are:

                0       stored (not compressed)
                1       simple "RLE"
                2       deflated

          The "RLE" method simply replaces zero-valued bytes with zero-valued
          bits and non-zero-valued bytes with a "1" bit followed by the byte
          value.

          The variable-length compressed data contains only the data corre-
          sponding to the indicated structure or string.  Typically multiple
          VMS2 extra fields are present (each with a unique block type).


         -Info-ZIP Macintosh Extra Field:
          ==============================

          The following is the layout of the (old) Info-ZIP resource-fork extra
          block for Macintosh.  The local-header and central-header versions
          are identical.  (Last Revision 19960922)

          Value         Size            Description
          -----         ----            -----------
  (Mac)   0x07c8        Short           tag for this extra block type
          TSize         Short           total data size for this block
          "JLEE"        beLong          extra-field signature
          FInfo         16 bytes        Macintosh FInfo structure
          CrDat         beLong          HParamBlockRec fileParam.ioFlCrDat
          MdDat         beLong          HParamBlockRec fileParam.ioFlMdDat
          Flags         beLong          info bits
          DirID         beLong          HParamBlockRec fileParam.ioDirID
          VolName       28 bytes        volume name (optional)

          All fields but the first two are in native Macintosh format
          (big-endian Motorola order, not little-endian Intel).  The least
          significant bit of Flags is 1 if the file is a data fork, 0 other-
          wise.  In addition, if this extra field is present, the filename
          has an extra 'd' or 'r' appended to indicate data fork or resource
          fork.  The 28-byte VolName field may be omitted.


         -ZipIt Macintosh Extra Field (long):
          ==================================