Skip to content

Add a path for checking ZoneInformation without throwing an exception #8025

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
iSazonov merged 5 commits into from
Oct 24, 2018
Merged

Add a path for checking ZoneInformation without throwing an exception #8025

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
0f31976
Add exception free standard path for checking zone identifier
powercode Oct 14, 2018
d5dc2bb
Addressing Ilya's comments.
powercode Oct 15, 2018
fa724c4
Removing Trim call on streamName.
powercode Oct 16, 2018
13163fb
Removing the second trim call.
iSazonov Oct 17, 2018
afbb6c7
Use nameof()
iSazonov Oct 18, 2018
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
50 changes: 40 additions & 10 deletions src/System.Management.Automation/namespaces/FileSystemProvider.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -8242,24 +8242,54 @@ internal static List<AlternateStreamData> GetStreams(string path)
/// <returns>A FileStream that can be used to interact with the file.</returns>
internal static FileStream CreateFileStream(string path, string streamName, FileMode mode, FileAccess access, FileShare share)
{
if (path == null) throw new ArgumentNullException("path");
if (streamName == null) throw new ArgumentNullException("streamName");
if (!TryCreateFileStream(path, streamName, mode, access, share, out var stream))
{
string errorMessage = StringUtil.Format(
FileSystemProviderStrings.AlternateDataStreamNotFound, streamName, path);
throw new FileNotFoundException(errorMessage, $"{path}:{streamName}");
}

string adjustedStreamName = streamName.Trim();
adjustedStreamName = ":" + adjustedStreamName;
string resultPath = path + adjustedStreamName;
return stream;
}

/// <summary>
/// Tries to create a file stream on a file.
/// </summary>
/// <param name="path">The fully-qualified path to the file.</param>
/// <param name="streamName">The name of the alternate data stream to open.</param>
/// <param name="mode">The FileMode of the file.</param>
/// <param name="access">The FileAccess of the file.</param>
/// <param name="share">The FileShare of the file.</param>
/// <param name="stream">A FileStream that can be used to interact with the file.</param>
/// <returns>true if the stream was successfully created, otherwise false.</returns>
internal static bool TryCreateFileStream(string path, string streamName, FileMode mode, FileAccess access, FileShare share, out FileStream stream)
{
if (path == null)
{
throw new ArgumentNullException(nameof(path));
}

if (streamName == null)
{
throw new ArgumentNullException(nameof(streamName));
}

if (mode == FileMode.Append)
{
mode = FileMode.OpenOrCreate;
}

if (mode == FileMode.Append) mode = FileMode.OpenOrCreate;
var resultPath = $"{path}:{streamName}";
SafeFileHandle handle = NativeMethods.CreateFile(resultPath, access, share, IntPtr.Zero, mode, 0, IntPtr.Zero);

if (handle.IsInvalid)
{
string errorMessage = StringUtil.Format(
FileSystemProviderStrings.AlternateDataStreamNotFound, streamName, path);
throw new FileNotFoundException(errorMessage, resultPath);
stream = null;
return false;
}

return new FileStream(handle, access);
stream = new FileStream(handle, access);
return true;
}

/// <summary>
Expand Down
81 changes: 37 additions & 44 deletions src/System.Management.Automation/utils/ClrFacade.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -224,57 +224,50 @@ private static SecurityZone MapSecurityZone(string filePath)
/// </summary>
private static SecurityZone ReadFromZoneIdentifierDataStream(string filePath)
{
try
if (!AlternateDataStreamUtilities.TryCreateFileStream(filePath, "Zone.Identifier", FileMode.Open, FileAccess.Read, FileShare.Read, out var zoneDataStream))
{
FileStream zoneDataSteam = AlternateDataStreamUtilities.CreateFileStream(
filePath, "Zone.Identifier", FileMode.Open,
FileAccess.Read, FileShare.Read);
return SecurityZone.NoZone;
}

// If we successfully get the zone data stream, try to read the ZoneId information
using (StreamReader zoneDataReader = new StreamReader(zoneDataSteam, GetDefaultEncoding()))
// If we successfully get the zone data stream, try to read the ZoneId information
using (StreamReader zoneDataReader = new StreamReader(zoneDataStream, GetDefaultEncoding()))
{
string line = null;
bool zoneTransferMatched = false;

// After a lot experiments with Zone.CreateFromUrl/Zone.SecurityZone, the way it handles the alternate
// data stream 'Zone.Identifier' is observed as follows:
// 1. Read content of the data stream line by line. Each line is trimmed.
// 2. Try to match the current line with '^\[ZoneTransfer\]'.
// - if matching, then do step #3 starting from the next line
// - if not matching, then continue to do step #2 with the next line.
// 3. Try to match the current line with '^ZoneId\s*=\s*(.*)'
// - if matching, check if the ZoneId is valid. Then return the corresponding SecurityZone if valid, or 'NoZone' if invalid.
// - if not matching, then continue to do step #3 with the next line.
// 4. Reach EOF, then return 'NoZone'.
while ((line = zoneDataReader.ReadLine()) != null)
{
string line = null;
bool zoneTransferMatched = false;

// After a lot experiments with Zone.CreateFromUrl/Zone.SecurityZone, the way it handles the alternate
// data stream 'Zone.Identifier' is observed as follows:
// 1. Read content of the data stream line by line. Each line is trimmed.
// 2. Try to match the current line with '^\[ZoneTransfer\]'.
// - if matching, then do step #3 starting from the next line
// - if not matching, then continue to do step #2 with the next line.
// 3. Try to match the current line with '^ZoneId\s*=\s*(.*)'
// - if matching, check if the ZoneId is valid. Then return the corresponding SecurityZone if valid, or 'NoZone' if invalid.
// - if not matching, then continue to do step #3 with the next line.
// 4. Reach EOF, then return 'NoZone'.
while ((line = zoneDataReader.ReadLine()) != null)
line = line.Trim();
if (!zoneTransferMatched)
{
zoneTransferMatched = Regex.IsMatch(line, @"^\[ZoneTransfer\]", RegexOptions.IgnoreCase);
}
else
{
line = line.Trim();
if (!zoneTransferMatched)
{
zoneTransferMatched = Regex.IsMatch(line, @"^\[ZoneTransfer\]", RegexOptions.IgnoreCase);
}
else
{
Match match = Regex.Match(line, @"^ZoneId\s*=\s*(.*)", RegexOptions.IgnoreCase);
if (!match.Success) { continue; }

// Match found. Validate ZoneId value.
string zoneIdRawValue = match.Groups[1].Value;
match = Regex.Match(zoneIdRawValue, @"^[+-]?\d+", RegexOptions.IgnoreCase);
if (!match.Success) { return SecurityZone.NoZone; }

string zoneId = match.Groups[0].Value;
SecurityZone result;
return LanguagePrimitives.TryConvertTo(zoneId, out result) ? result : SecurityZone.NoZone;
}
Match match = Regex.Match(line, @"^ZoneId\s*=\s*(.*)", RegexOptions.IgnoreCase);
if (!match.Success) { continue; }

// Match found. Validate ZoneId value.
string zoneIdRawValue = match.Groups[1].Value;
match = Regex.Match(zoneIdRawValue, @"^[+-]?\d+", RegexOptions.IgnoreCase);
if (!match.Success) { return SecurityZone.NoZone; }

string zoneId = match.Groups[0].Value;
SecurityZone result;
return LanguagePrimitives.TryConvertTo(zoneId, out result) ? result : SecurityZone.NoZone;
}
}
}
catch (FileNotFoundException)
{
// FileNotFoundException may be thrown by AlternateDataStreamUtilities.CreateFileStream when the data stream 'Zone.Identifier'
// does not exist, or when the underlying file system doesn't support alternate data stream.
}

return SecurityZone.NoZone;
}
Expand Down