process.c

完整的解压zip文件的源码。包含密码功能

            case VMS_:        /* our Zip uses lowercase, but ASi's doesn't */
        /*  case Z_SYSTEM_:   ? */
        /*  case QDOS_:       ? */
                G.pInfo->lcflag = 1;   /* convert filename to lowercase */
                break;

            default:     /* AMIGA_, FS_HPFS_, FS_NTFS_, MAC_, UNIX_, ATARI_, */
                break;   /*  FS_VFAT_, BEOS_ (Z_SYSTEM_):  no conversion */
        }

    /* do Amigas (AMIGA_) also have volume labels? */
    if (IS_VOLID(G.crec.external_file_attributes) &&
        (G.pInfo->hostnum == FS_FAT_ || G.pInfo->hostnum == FS_HPFS_ ||
         G.pInfo->hostnum == FS_NTFS_ || G.pInfo->hostnum == ATARI_))
    {
        G.pInfo->vollabel = TRUE;
        G.pInfo->lcflag = 0;        /* preserve case of volume labels */
    } else
        G.pInfo->vollabel = FALSE;

    return PK_COOL;

} /* end function process_cdir_file_hdr() */





/***************************/
/* Function get_cdir_ent() */
/***************************/

int get_cdir_ent(__G)   /* return PK-type error code */
    __GDEF
{
    cdir_byte_hdr byterec;


/*---------------------------------------------------------------------------
    Read the next central directory entry and do any necessary machine-type
    conversions (byte ordering, structure padding compensation--do so by
    copying the data from the array into which it was read (byterec) to the
    usable struct (crec)).
  ---------------------------------------------------------------------------*/

    if (readbuf(__G__ (char *)byterec, CREC_SIZE) == 0)
        return PK_EOF;

    G.crec.version_made_by[0] = byterec[C_VERSION_MADE_BY_0];
    G.crec.version_made_by[1] = byterec[C_VERSION_MADE_BY_1];
    G.crec.version_needed_to_extract[0] =
      byterec[C_VERSION_NEEDED_TO_EXTRACT_0];
    G.crec.version_needed_to_extract[1] =
      byterec[C_VERSION_NEEDED_TO_EXTRACT_1];

    G.crec.general_purpose_bit_flag =
      makeword(&byterec[C_GENERAL_PURPOSE_BIT_FLAG]);
    G.crec.compression_method =
      makeword(&byterec[C_COMPRESSION_METHOD]);
    G.crec.last_mod_dos_datetime =
      makelong(&byterec[C_LAST_MOD_DOS_DATETIME]);
    G.crec.crc32 =
      makelong(&byterec[C_CRC32]);
    G.crec.csize =
      makelong(&byterec[C_COMPRESSED_SIZE]);
    G.crec.ucsize =
      makelong(&byterec[C_UNCOMPRESSED_SIZE]);
    G.crec.filename_length =
      makeword(&byterec[C_FILENAME_LENGTH]);
    G.crec.extra_field_length =
      makeword(&byterec[C_EXTRA_FIELD_LENGTH]);
    G.crec.file_comment_length =
      makeword(&byterec[C_FILE_COMMENT_LENGTH]);
    G.crec.disk_number_start =
      makeword(&byterec[C_DISK_NUMBER_START]);
    G.crec.internal_file_attributes =
      makeword(&byterec[C_INTERNAL_FILE_ATTRIBUTES]);
    G.crec.external_file_attributes =
      makelong(&byterec[C_EXTERNAL_FILE_ATTRIBUTES]);  /* LONG, not word! */
    G.crec.relative_offset_local_header =
      makelong(&byterec[C_RELATIVE_OFFSET_LOCAL_HEADER]);

    return PK_COOL;

} /* end function get_cdir_ent() */





/*************************************/
/* Function process_local_file_hdr() */
/*************************************/

int process_local_file_hdr(__G)    /* return PK-type error code */
    __GDEF
{
    local_byte_hdr byterec;


/*---------------------------------------------------------------------------
    Read the next local file header and do any necessary machine-type con-
    versions (byte ordering, structure padding compensation--do so by copy-
    ing the data from the array into which it was read (byterec) to the
    usable struct (lrec)).
  ---------------------------------------------------------------------------*/

    if (readbuf(__G__ (char *)byterec, LREC_SIZE) == 0)
        return PK_EOF;

    G.lrec.version_needed_to_extract[0] =
      byterec[L_VERSION_NEEDED_TO_EXTRACT_0];
    G.lrec.version_needed_to_extract[1] =
      byterec[L_VERSION_NEEDED_TO_EXTRACT_1];

    G.lrec.general_purpose_bit_flag =
      makeword(&byterec[L_GENERAL_PURPOSE_BIT_FLAG]);
    G.lrec.compression_method = makeword(&byterec[L_COMPRESSION_METHOD]);
    G.lrec.last_mod_dos_datetime = makelong(&byterec[L_LAST_MOD_DOS_DATETIME]);
    G.lrec.crc32 = makelong(&byterec[L_CRC32]);
    G.lrec.csize = makelong(&byterec[L_COMPRESSED_SIZE]);
    G.lrec.ucsize = makelong(&byterec[L_UNCOMPRESSED_SIZE]);
    G.lrec.filename_length = makeword(&byterec[L_FILENAME_LENGTH]);
    G.lrec.extra_field_length = makeword(&byterec[L_EXTRA_FIELD_LENGTH]);

    G.csize = (long) G.lrec.csize;
    G.ucsize = (long) G.lrec.ucsize;

    if ((G.lrec.general_purpose_bit_flag & 8) != 0) {
        /* can't trust local header, use central directory: */
        G.lrec.crc32 = G.pInfo->crc;
        G.csize = (long)(G.lrec.csize = G.pInfo->compr_size);
        G.ucsize = (long)(G.lrec.ucsize = G.pInfo->uncompr_size);
    }

    return PK_COOL;

} /* end function process_local_file_hdr() */


#ifdef USE_EF_UT_TIME

/*******************************/
/* Function ef_scan_for_izux() */
/*******************************/

unsigned ef_scan_for_izux(ef_buf, ef_len, ef_is_c, dos_mdatetime,
                          z_utim, z_uidgid)
    uch *ef_buf;        /* buffer containing extra field */
    unsigned ef_len;    /* total length of extra field */
    int ef_is_c;        /* flag indicating "is central extra field" */
    ulg dos_mdatetime;  /* last_mod_file_date_time in DOS format */
    iztimes *z_utim;    /* return storage: atime, mtime, ctime */
    ush *z_uidgid;      /* return storage: uid and gid */
{
    unsigned flags = 0;
    unsigned eb_id;
    unsigned eb_len;
    int have_new_type_eb = FALSE;
    int ut_zip_unzip_compatible = FALSE;

/*---------------------------------------------------------------------------
    This function scans the extra field for EF_TIME, EF_IZUNIX2, EF_IZUNIX, or
    EF_PKUNIX blocks containing Unix-style time_t (GMT) values for the entry's
    access, creation, and modification time.
    If a valid block is found, the time stamps are copied to the iztimes
    structure (provided the z_utim pointer is not NULL).
    If a IZUNIX2 block is found or the IZUNIX block contains UID/GID fields,
    and the z_uidgid array pointer is valid (!= NULL), the owner info is
    transfered as well.
    The presence of an EF_TIME or EF_IZUNIX2 block results in ignoring all
    data from probably present obsolete EF_IZUNIX blocks.
    If multiple blocks of the same type are found, only the information from
    the last block is used.
    The return value is a combination of the EF_TIME Flags field with an
    additional flag bit indicating the presence of valid UID/GID info,
    or 0 in case of failure.
  ---------------------------------------------------------------------------*/

    if (ef_len == 0 || ef_buf == NULL || (z_utim == 0 && z_uidgid == NULL))
        return 0;

    TTrace((stderr,"\nef_scan_for_izux: scanning extra field of length %u\n",
      ef_len));

    while (ef_len >= EB_HEADSIZE) {
        eb_id = makeword(EB_ID + ef_buf);
        eb_len = makeword(EB_LEN + ef_buf);

        if (eb_len > (ef_len - EB_HEADSIZE)) {
            /* discovered some extra field inconsistency! */
            TTrace((stderr,
              "ef_scan_for_izux: block length %u > rest ef_size %u\n", eb_len,
              ef_len - EB_HEADSIZE));
            break;
        }

        switch (eb_id) {
          case EF_TIME:
            flags &= ~0x0ff;    /* ignore previous IZUNIX or EF_TIME fields */
            have_new_type_eb = TRUE;
            if ( eb_len >= EB_UT_MINLEN && z_utim != NULL) {
                unsigned eb_idx = EB_UT_TIME1;
                TTrace((stderr,"ef_scan_for_izux: found TIME extra field\n"));
                flags |= (ef_buf[EB_HEADSIZE+EB_UT_FLAGS] & 0x0ff);
                if ((flags & EB_UT_FL_MTIME)) {
                    if ((eb_idx+4) <= eb_len) {
                        z_utim->mtime = makelong((EB_HEADSIZE+eb_idx) + ef_buf);
                        eb_idx += 4;
                        TTrace((stderr,"  UT e.f. modification time = %ld\n",
                                z_utim->mtime));

                        if ((ulg)(z_utim->mtime) & (ulg)(0x80000000L)) {
                            ut_zip_unzip_compatible =
                              ((time_t)0x80000000L < (time_t)0L)
                              ? (dos_mdatetime == DOSTIME_MINIMUM)
                              : (dos_mdatetime >= DOSTIME_2038_01_18);
                            if (!ut_zip_unzip_compatible) {
                            /* UnZip interpretes mtime differently than Zip;
                               without modtime: ignore complete UT field */
                              flags &= ~0x0ff;  /* no time_t times available */
                              TTrace((stderr,
                                "  UT modtime range error; ignore e.f.!\n"));
                              break;            /* stop scanning this field */
                            }
                        } else {
                            /* cannot determine, safe assumption is FALSE */
                            ut_zip_unzip_compatible = FALSE;
                        }
                    } else {
                        flags &= ~EB_UT_FL_MTIME;
                        TTrace((stderr,"  UT e.f. truncated; no modtime\n"));
                    }
                }
                if (ef_is_c) {
                    break;      /* central version of TIME field ends here */
                }

                if (flags & EB_UT_FL_ATIME) {
                    if ((eb_idx+4) <= eb_len) {
                        z_utim->atime = makelong((EB_HEADSIZE+eb_idx) + ef_buf);
                        eb_idx += 4;
                        TTrace((stderr,"  UT e.f. access time = %ld\n",
                                z_utim->atime));
                        if (((ulg)(z_utim->atime) & (ulg)(0x80000000L)) &&
                            !ut_zip_unzip_compatible) {
                            flags &= ~EB_UT_FL_ATIME;
                            TTrace((stderr,
                              "  UT access time range error: skip time!\n"));
                        }
                    } else {
                        flags &= ~EB_UT_FL_ATIME;
                    }
                }
                if (flags & EB_UT_FL_CTIME) {
                    if ((eb_idx+4) <= eb_len) {
                        z_utim->ctime = makelong((EB_HEADSIZE+eb_idx) + ef_buf);
                        TTrace((stderr,"  UT e.f. creation time = %ld\n",
                                z_utim->ctime));
                        if (((ulg)(z_utim->ctime) & (ulg)(0x80000000L)) &&
                            !ut_zip_unzip_compatible) {
                            flags &= ~EB_UT_FL_CTIME;
                            TTrace((stderr,
                              "  UT creation time range error: skip time!\n"));
                        }
                    } else {
                        flags &= ~EB_UT_FL_CTIME;
                    }
                }
            }
            break;

          case EF_IZUNIX2:
            if (!have_new_type_eb) {
                flags &= ~0x0ff;        /* ignore any previous IZUNIX field */
                have_new_type_eb = TRUE;
            }
            if (eb_len >= EB_UX2_MINLEN && z_uidgid != NULL) {
                z_uidgid[0] = makeword((EB_HEADSIZE+EB_UX2_UID) + ef_buf);
                z_uidgid[1] = makeword((EB_HEADSIZE+EB_UX2_GID) + ef_buf);
                flags |= EB_UX2_VALID;   /* signal success */
            }
            break;

          case EF_IZUNIX:
          case EF_PKUNIX:       /* PKUNIX e.f. layout is identical to IZUNIX */
            if (eb_len >= EB_UX_MINLEN) {
                TTrace((stderr,"ef_scan_for_izux: found %s extra field\n",
                        (eb_id == EF_IZUNIX ? "IZUNIX" : "PKUNIX")));
                if (have_new_type_eb) {
                    break;      /* Ignore IZUNIX extra field block ! */
                }
                if (z_utim != NULL) {
                    z_utim->atime = makelong((EB_HEADSIZE+EB_UX_ATIME)+ef_buf);
                    z_utim->mtime = makelong((EB_HEADSIZE+EB_UX_MTIME)+ef_buf);
                    TTrace((stderr,"  Unix EF actime = %ld\n", z_utim->atime));
                    TTrace((stderr,"  Unix EF modtime = %ld\n", z_utim->mtime));
                    flags |= (EB_UT_FL_MTIME | EB_UT_FL_ATIME);
                    if ((ulg)(z_utim->mtime) & (ulg)(0x80000000L)) {
                        ut_zip_unzip_compatible =
                          ((time_t)0x80000000L < (time_t)0L)
                          ? (dos_mdatetime == DOSTIME_MINIMUM)
                          : (dos_mdatetime >= DOSTIME_2038_01_18);
                        if (!ut_zip_unzip_compatible) {
                            /* UnZip interpretes mtime differently than Zip;
                               without modtime: ignore complete UT field */
                            flags &= ~0x0ff;    /* no time_t times available */
                            TTrace((stderr,
                                  "  UX modtime range error: ignore e.f.!\n"));
                        }
                    } else {
                        /* cannot determine, safe assumption is FALSE */
                        ut_zip_unzip_compatible = FALSE;
                    }
                    if ((ulg)(z_utim->atime) & (ulg)(0x80000000L) &&
                        !ut_zip_unzip_compatible && (flags & 0x0ff)) {
                        /* atime not in range of UnZip's time_t */
                        flags &= ~EB_UT_FL_ATIME;
                        TTrace((stderr,
                                "  UX access time range error: skip time!\n"));
                    }
                }
                if (eb_len >= EB_UX_FULLSIZE && z_uidgid != NULL) {
                    z_uidgid[0] = makeword((EB_HEADSIZE+EB_UX_UID) + ef_buf);
                    z_uidgid[1] = makeword((EB_HEADSIZE+EB_UX_GID) + ef_buf);
                    flags |= EB_UX2_VALID;
                }
            }
            break;

          default:
            break;
        }

        /* Skip this extra field block */
        ef_buf += (eb_len + EB_HEADSIZE);
        ef_len -= (eb_len + EB_HEADSIZE);
    }

    return flags;
}

#endif /* USE_EF_UT_TIME */