Re: uzip extfs sanity patch

[Standa Opichal <opichals seznam cz>]

Hi!

On Wed, 20 Nov 2002, Pavel Roskin wrote:

> > Here is a small patch I needed to display one particular archive 
> > contents without errors. If it is convenient to neglect errors like weird 
> > dates then it can be usefull. Maybe even the other archive scripts should 
> > have such checks? What do you think?
> ...
> My suspicion is that the problem is not specific to that archive.  Maybe
> the months are displayed in some other language, or something like that.

The problem is the archive. It is Atari ST filesystem (according to the 
unzip -Zv) entry. Atari ST computers didn't have the real time clock 
backup so that the clock sets some weird date after switch off/on of the 
machine. User needed to set it up manually by themselves. I simply checked 
the month (in the wrong entries - 015) to the range it should be. IIRC ST 
displays the Dec 31 2028. Actuall there is the date stamp like 0xffff ( => 
year = 0x7f+1980, mon = 0xf, day = 0x1f ) and this is exactly what is 
happening here. The only value that can be wrong here (at least for 
unzip executables - studying its sources) is the month number so the 
sanity range shrinkage is IMO ok here. And maybe there should be the same 
(range) checks also for the year, date and other data?

best regards

STan


PS: Here are the snippets:

$ unzip -Z MagiC_61_Atari.zip 
Archive:  MagiC_61_Atari.zip   851674 bytes   85 files
-rwxrwxrwx  2.0 atr     9092 b- defN 31-015-07 31:23 MAGX_1/_COPY/GEMSYS/OFF65KPK.OSD
-rwxrwxrwx  2.0 atr    10045 b- defN 31-015-07 31:23 MAGX_1/_COPY/GEMSYS/OFF32KPK.OSD
-rwxrwxrwx  2.0 atr     8787 b- defN  9-Apr-01 01:28 MAGX_1/_COPY/GEMSYS/OFF32KFL.OSD
-rwxrwxrwx  2.0 atr    17482 b- defN  9-Apr-01 01:28 MAGX_1/_COPY/GEMSYS/OFF256PK.OSD

$ perl /tmp/uzip list MagiC_61_Atari.zip 2>/dev/null
Use of uninitialized value in printf at /tmp/uzip line 288.
-rw-r--r--    1 644      100          9092  31 2107 31:23 MAGX_1/_COPY/GEMSYS/OFF65KPK.OSD
Use of uninitialized value in printf at /tmp/uzip line 288.
-rw-r--r--    1 644      100         10045  31 2107 31:23 MAGX_1/_COPY/GEMSYS/OFF32KPK.OSD
-rw-r--r--    1 644      100          8787 Apr 09 2001 01:28 MAGX_1/_COPY/GEMSYS/OFF32KFL.OSD
-rw-r--r--    1 644      100         17482 Apr 09 2001 01:28 MAGX_1/_COPY/GEMSYS/OFF256PK.OSD

$ perl /tmp/uzip-fixed list MagiC_61_Atari.zip
-rw-r--r--    1 644      100          9092 Dec 31 2107 31:23 MAGX_1/_COPY/GEMSYS/OFF65KPK.OSD
-rw-r--r--    1 644      100         10045 Dec 31 2107 31:23 MAGX_1/_COPY/GEMSYS/OFF32KPK.OSD
-rw-r--r--    1 644      100          8787 Apr 09 2001 01:28 MAGX_1/_COPY/GEMSYS/OFF32KFL.OSD
-rw-r--r--    1 644      100         17482 Apr 09 2001 01:28 MAGX_1/_COPY/GEMSYS/OFF256PK.OSD


$ "extract from" zipinfo.c

    {       
        yr = ((unsigned)(*datetimez >> 25) & 0x7f) + 80;
        mo = ((unsigned)(*datetimez >> 21) & 0x0f);
        dy = ((unsigned)(*datetimez >> 16) & 0x1f);

        hh = (((unsigned)*datetimez >> 11) & 0x1f);
        mm = (((unsigned)*datetimez >> 5) & 0x3f);
        ss = (((unsigned)*datetimez << 1) & 0x3e);
    }