Don't rewind the temporary stream on write to the main one #104
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Context: dbe3236 dbe3236 fixed an issue of data corruption when deleting files from the archive by properly creating temporary streams when `libzip` requested data modifications. However, a bug crept in which causes the temporary stream to be rewound, instead of the destination one, when data is written back. This has the effect of overwriting the ZIP local file header structure with, essentially, random data and causes errors similar to: error XABBA7000: Xamarin.Tools.Zip.ZipException: Zip archive inconsistent: entry 0: invalid WinZip AES extra field Xamarin.Android.Common.targets(2289,2): error ANDZA0000: zip W 01-25 15:03:13 9516 56652 WARNING: header mismatch The issue can be seen by either attempting to unpack the archive: $ 7z x base.zip ERROR: Headers Error : dex/classes.dex ERROR: Headers Error : root/assemblies/assemblies.blob $ unzip base.zip file #9: bad zipfile offset (local header sig): 49783 file #10: bad zipfile offset (local header sig): 127988 Or by looking at the file with `zipinfo -vv base.zip`: Central directory entry #10: --------------------------- There are an extra 9 bytes preceding this file. root/assemblies/assemblies.blob offset of local header from start of archive: 127988 (000000000001F3F4h) bytes Not only the local header is thought to be at the incorrect offset, it also doesn't have the correct signature: # show valid header $ hexdump -n 4 -C base.zip 00000000 50 4b 03 04 |PK..| # show invalid header $ hexdump -s 127988 -n 4 -C base.zip 0001f3f4 49 be 37 16 |I.7.| $ hexdump -s $((127988 - 9)) -n 4 -C base.zip 0001f3eb 88 26 de 2c |.&.,| Attempt to fix the problem by rewinding the destination stream on write. Fix found by Dean Ellis (@dellis1972)
grendello
force-pushed
the
fix-stream-rewind
branch
from
f0e18db to
be03e8f
Compare
dellis1972
approved these changes
Jan 25, 2022
grendello
pushed a commit
to dotnet/android-tools
that referenced
this pull request
Jan 26, 2022
Bump LibZipSharp to 2.0.3 Context: dotnet/android-libzipsharp#104 Changes - Don't rewind the temporary stream on write to the main one dotnet/android-libzipsharp@2.0.2...2.0.3
jonpryor
pushed a commit
to dotnet/android
that referenced
this pull request
Jan 28, 2022
Context: dotnet/android-libzipsharp#104 Changes: dotnet/android-libzipsharp@2.0.2...2.0.3 * dotnet/android-libzipsharp@9bccd74: Don't rewind the temporary stream on write to the main one (#104) We are seeing the following error on some builds error XABBA7000: Xamarin.Tools.Zip.ZipException: Zip archive inconsistent: entry 0: invalid WinZip AES extra field Verison 2.0.2 of LibZipSharp was supposed to fix this, but it had a bug (dotnet/android-libzipsharp#104), which would cause corruption in the zip file itself. We believe that this issue has been fixed in LibZipSharp 2.0.3; Bump!
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Context: dbe3236
dbe3236 fixed an issue of data corruption when deleting files from the
archive by properly creating temporary streams when
libziprequesteddata modifications. However, a bug crept in which causes the temporary
stream to be rewound, instead of the destination one, when data is
written back. This has the effect of overwriting the ZIP local file
header structure with, essentially, random data and causes errors
similar to:
The issue can be seen by either attempting to unpack the archive:
Or by looking at the file with
zipinfo -vv base.zip:Not only the local header is thought to be at the incorrect offset, it
also doesn't have the correct signature:
Attempt to fix the problem by rewinding the destination stream on write.
Fix found by Dean Ellis (@dellis1972)