<AWT Dev> Fwd: [8] Review request for 6550588: java.awt.Desktop cannot open file with Windows UNC filename

[Anton Litvinov]

Hello Alexey,

Thank you for a review of the fix and source code of a solution that you 
provided. Unfortunately, I do not think that the solution which encloses 
a file path into the quotation marks would be better, because Windows 
Shell function "ShellExecute" does not require presence of the quotation 
marks in a value of "LPCTSTR lpFile" parameter. Practically the function 
successfully handles both absolute file paths not enclosed into the 
quotation marks and enclosed. For example, the following two calls are 
executed successfully in my local environment:

::ShellExecute(NULL, _T("open"), _T("D:/Documents/Test Dir 1/Read 
Me.txt"), NULL, NULL, SW_SHOWNORMAL);
::ShellExecute(NULL, _T("open"), _T("\"D:/Documents/Test Dir 1/Read 
Me.txt\""), NULL, NULL, SW_SHOWNORMAL);

The main reason of the bug is a way in which "java.io.File.toURI" method 
converts absolute file path to URI with the protocol "file" and the way 
in which "ShellExecute" function interprets this URI. In such a case it 
would make sense to remove all the code converting "java.io.File" 
pathnames to URI from the file "sun.awt.windows.WDesktopPeer.java" and 
to transfer the result of a call to "File.getAbsolutePath()" directly to 
the method

private static native String ShellExecute(String uri, String verb);

But the signature of the method states that it expects the URI, thus a 
transfer of Windows UNC pathname or a local Windows file path instead of 
a URI with "file" scheme will be incorrect. Also URI prohibits presence 
of the quotation marks (double-quote characters) in its body according 
to chapter "2.4.3. Excluded US-ASCII Characters" of "RFC 2396" available 
at (http://www.ietf.org/rfc/rfc2396.txt).

Thank you,
Anton

On 3/4/2013 2:16 PM, Alexey Utkin wrote:
> It seems that file name escaping by ["] is better solution.
> http://www.speechcomputing.com/node/2577
>
>>     private static boolean isQuoted(String arg, String errorMessage) {
>>         int lastPos = arg.length() - 1;
>>         if (lastPos >=1 && arg.charAt(0) == '"' && 
>> arg.charAt(lastPos) == '"') {
>>             // The argument has already been quoted.
>>             if (arg.indexOf('"', 1) != lastPos) {
>>                 // There is ["] inside.
>>                 throw new IllegalArgumentException(errorMessage);
>>             }
>>             return true;
>>         }
>>         if (arg.indexOf('"') >= 0) {
>>             // There is ["] inside.
>>             throw new IllegalArgumentException(errorMessage);
>>         }
>>         return false;
>>     }
>>
>>     private static String getExecutablePath(File file)
>>         throws IOException
>>     {
>>         String path = file.getPath();
>>         boolean pathIsQuoted = isQuoted(path,
>>                 "File name has embedded quote");
>>         return pathIsQuoted
>>             ? path
>>             : ("\"" + path + "\"");
>>     }
>
>  this.ShellExecute(getExecutablePath(file), ACTION_XXXX_VERB);
>
> That reduces the injection scenario and is more compatible with 
> [ShellExecute] spec:
> http://msdn.microsoft.com/en-gb/library/windows/desktop/bb762153%28v=vs.85%29.aspx 
>
>
> Regards,
> -uta
>
>
>
>
> On 01.03.2013 19:17, Artem Ananiev wrote:
>>
>> Your comments are welcome ;)
>>
>> Thanks,
>>
>> Artem
>>
>> -------- Original Message --------
>> Subject:     <AWT Dev> [8] Review request for 6550588: java.awt.Desktop
>> cannot open file with Windows UNC filename
>> Date:     Fri, 01 Mar 2013 18:38:03 +0400
>> From:     Anton Litvinov <anton.litvinov at oracle.com>
>> Organization:     Oracle Corporation
>> To:     awt-dev at openjdk.java.net
>>
>>
>>
>> Hello,
>>
>> Please review the following fix for a bug.
>>
>> Bug: http://bugs.sun.com/view_bug.do?bug_id=6550588
>> Webrev: http://cr.openjdk.java.net/~alitvinov/6550588/webrev.00
>>
>> The bug consists in inability to open a file with Windows UNC pathname
>> by means of "java.awt.Desktop.open" method. The solution adds code to
>> "sun.awt.windows.WDesktopPeer" class which modifies URI received as a
>> result of a call to "java.io.File.toURI" method to make it satisfy the
>> requirements of Windows API concerning a number of consecutive '/'
>> characters following a scheme part of URI. Also regression tests related
>> to "java.awt.Desktop" were run on Windows XP and Windows 7, no negative
>> changes were detected.
>>
>> A comment with the latest information about the analysis of this issue
>> was added to the bug's page, but it is not available at
>> "http://bugs.sun.com" yet, because of the time required for
>> synchronization. Therefore it is provided below.
>>
>> The comment:
>>
>>     During analysis of this bug the following facts were defined:
>>     1. URI strings constructed from Windows UNC pathnames like former
>>     mentioned "\\host\path\to\f i l e.txt" can still be handled by
>>     "ShellExecute()" Windows Shell function, if the URI string is not
>>     encoded. Presence of space characters in the URI string does not
>>     make the function fail, for example "file:////host/path/to/f i l
>>     e.txt" can be successfully processed by "ShellExecute()" function.
>>     2. Windows API is designed to handle URI strings with "file"
>>     protocol scheme correctly, when the strings have certain number of
>>     '/' characters after the scheme name:
>>          - 2 slashes for URI converted from a Windows UNC pathname. For
>>     example, "\\host\path\to\f i l e.txt" corresponds to the URI
>>     "file://host/path/to/f%20i%20l%20e.txt".
>>          - 3 slashes for URI converted from a local Windows file path.
>>     For example, "C:\Temp Dir\f i l e.txt" corresponds to the URI
>>     "file:///C:/Temp%20Dir/f%20i%20l%20e.txt".
>>          This fact is described in the article at the following URL
>>
>> (http://blogs.msdn.com/b/ie/archive/2006/12/06/file-uris-in-windows.aspx). 
>>
>>
>>     3. Current implementation of the class "java.io.File" converts
>>     abstract file names to URI in the following way:
>>          - "C:\Temp\File.txt" -> "file:/C:/Temp/File.txt".
>>          - "\\host\SharedFolder\Temp\File.txt" ->
>>     "file:////host/SharedFolder/Temp/File.txt".
>>
>>     Since "java.io.File" is cross-platform and stable, perhaps,
>>     additional modification of the URI string to the format expected by
>>     Windows API can be implemented in Windows specific part of
>>     "java.awt.Desktop" class.
>>
>> Thank you,
>> Anton
>>
>>
>>
>>
>