[jira] [Commented] (COMPRESS-337) TAR header parsing attempts OLDGNU format on POSIX/STAR header

["Stefan Bodewig (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/COMPRESS-337?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15146468#comment-15146468 ] 

Stefan Bodewig commented on COMPRESS-337:
-----------------------------------------

GNU tar doesn't like the example you've attached:

{code}
tar: This does not look like a tar archive
tar: Exiting with failure status due to previous errors
{code}

so it seems as stumped as you are :-)

> TAR header parsing attempts OLDGNU format on POSIX/STAR header
> --------------------------------------------------------------
>
>                 Key: COMPRESS-337
>                 URL: https://issues.apache.org/jira/browse/COMPRESS-337
>             Project: Commons Compress
>          Issue Type: Bug
>          Components: Archivers
>    Affects Versions: 1.10
>            Reporter: Jeremy Gustie
>
> This is at least tangentially related to COMPRESS-336, we found an archive which is misinterpreted as an OLDGNU header format when it appears to some type of STAR header (unlike COMPRESS-336 this one uses a NULL delimiter instead of space terminators for the time stamps). Apparently the archive itself comes from an [EyeFi card|https://github.com/golang/go/issues/5290](?!).
> Both the original archive ([available here|https://storage.googleapis.com/go-attachment/5290/0/in.tar]) and the (presumably hand made) version for testing ([here|https://github.com/golang/go/raw/master/src/archive/tar/testdata/nil-uid.tar]) exhibit the same behavior: they fail with an {{IllegalArgumentException}} attempting to parse the old GNU {{realSize}} from a buffer partially filled with the {{atime}}/{{ctime}} values.
> At first I thought if the {{TarArchiveEntry.evaluateType}} were to also look at the {{version}} field for {{VERSION_GNU_SPACE}} before returning {{FORMAT_OLDGNU}} it _should_ be enough (according to something I saw in [the GNU documentation|http://www.gnu.org/software/tar/manual/tar.html#SEC184] which defines {{OLDGNU_MAGIC "ustar  "  /* 7 chars and a null */}}). Unfortunately it looks like that is the magic/version used by the archives in question, leaving me stumped as to how to identify which of the three prevailing header formats needs to be parsed.



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