VCLZip 4 AES encryption with CheckArchive Fails

[ZipZap]

Kevin,

The patch works fine if the compression method is Deflate, but what if the file is Stored? Shouldn't the correct method be to change file_info.compression_method to the compression method stored in the AES_Extra field when file_info.compression_method is 99? Just assuming that the AES compression method is Deflate is going to cause problems later.

John

[Kevin]

Yep, I think you are absolutely correct. Good catch. I'll take a look and it looks like another build will have to go out this weekend.

Thanks again.

Kevin

[ZipZap]

Kevin,

Here is a patch that works.

kpZipObj.pas
add published function:

function TZipHeaderInfo.GetAESCompression:word;
begin
if (FAES_Extra <> nil) and (Fcompression_method = 99) then
Result := FAES_Extra^.compression_method
else
Result := Fcompression_method;
end;

kpUnZipp.pas

in Do_Unzip:

add var
CompressionLevel : word;

before:

If (file_info.Encrypted) then
if (file_info.EncryptionStrength = esPKStandard) then
begin
NewPassword := Password;
While NewPassword = Password do

add:
CompressionLevel := file_info.compression_method;

change
{ TODO : Add capability to skip this check and rely on checking after unzipping }
begin
NewPassword := Password;
While NewPassword = Password do

to
{ TODO : Add capability to skip this check and rely on checking after unzipping }
begin
NewPassword := Password;
CompressionLevel := file_info.GetAESCompression;
While NewPassword = Password do

change:
Case file_info.compression_method of
STORED: UnStore;
to:
Case Compressionlevel of
STORED: UnStore;

While I've got you...
TVCLZip.TemporaryPath
doesn't check for a '\' at the end of the path and it should since the code that uses it assumes there is a '\' at the end of the path.

[Kevin]

Build 3 has been uploaded. The CheckArchive problem is fixed as well as assuring that there is a '/' at the end of the TempPath property.

Thanks ZipZap!

Kevin