| Copyright | (c) 2008-2012 Duncan Coutts 2011 Max Bolingbroke |
|---|---|
| License | BSD3 |
| Maintainer | duncan@community.haskell.org |
| Portability | portable |
| Safe Haskell | None |
| Language | Haskell2010 |
Codec.Archive.Tar.Check
Contents
Description
Perform various checks on tar file entries.
Synopsis
- checkSecurity :: Entries e -> GenEntries FilePath FilePath (Either (Either e DecodeLongNamesError) FileNameError)
- checkEntrySecurity :: GenEntry FilePath FilePath -> Maybe FileNameError
- data FileNameError
- = InvalidFileName FilePath
- | AbsoluteFileName FilePath
- | UnsafeLinkTarget FilePath
- checkTarbomb :: FilePath -> Entries e -> GenEntries FilePath FilePath (Either (Either e DecodeLongNamesError) TarBombError)
- checkEntryTarbomb :: FilePath -> GenEntry FilePath linkTarget -> Maybe TarBombError
- data TarBombError = TarBombError FilePath FilePath
- checkPortability :: Entries e -> GenEntries FilePath FilePath (Either (Either e DecodeLongNamesError) PortabilityError)
- checkEntryPortability :: GenEntry FilePath linkTarget -> Maybe PortabilityError
- data PortabilityError
- type PortabilityPlatform = String
Security
checkSecurity :: Entries e -> GenEntries FilePath FilePath (Either (Either e DecodeLongNamesError) FileNameError) Source #
This function checks a sequence of tar entries for file name security problems. It checks that:
- file paths are not absolute
- file paths do not refer outside of the archive
- file names are valid
These checks are from the perspective of the current OS. That means we check
for "C:blah" files on Windows and "/blah" files on Unix. For archive
entry types HardLink and SymbolicLink the same checks are done for the
link target. A failure in any entry terminates the sequence of entries with
an error.
Whenever possible, consider fusing checkSecurity
with packing / unpacking by using
packAndCheck / unpackAndCheck
with checkEntrySecurity.
Not only it is faster, but also alleviates issues with lazy I/O
such as exhaustion of file handlers.
checkEntrySecurity :: GenEntry FilePath FilePath -> Maybe FileNameError Source #
Worker of checkSecurity.
Since: 0.6.0.0
data FileNameError Source #
Errors arising from tar file names being in some way invalid or dangerous
Constructors
| InvalidFileName FilePath | |
| AbsoluteFileName FilePath | |
| UnsafeLinkTarget FilePath | Since: 0.6.0.0 |
Instances
| Exception FileNameError Source # | |
Defined in Codec.Archive.Tar.Check.Internal Methods toException :: FileNameError -> SomeException fromException :: SomeException -> Maybe FileNameError displayException :: FileNameError -> String | |
| Show FileNameError Source # | |
Defined in Codec.Archive.Tar.Check.Internal Methods showsPrec :: Int -> FileNameError -> ShowS show :: FileNameError -> String showList :: [FileNameError] -> ShowS | |
Tarbombs
checkTarbomb :: FilePath -> Entries e -> GenEntries FilePath FilePath (Either (Either e DecodeLongNamesError) TarBombError) Source #
This function checks a sequence of tar entries for being a "tar bomb". This means that the tar file does not follow the standard convention that all entries are within a single subdirectory, e.g. a file "foo.tar" would usually have all entries within the "foo/" subdirectory.
Given the expected subdirectory, this function checks all entries are within that subdirectroy.
Note: This check must be used in conjunction with checkSecurity
(or checkPortability).
Whenever possible, consider fusing checkTarbomb
with packing / unpacking by using
packAndCheck / unpackAndCheck
with checkEntryTarbomb.
Not only it is faster, but also alleviates issues with lazy I/O
such as exhaustion of file handlers.
checkEntryTarbomb :: FilePath -> GenEntry FilePath linkTarget -> Maybe TarBombError Source #
Worker of checkTarbomb.
Since: 0.6.0.0
data TarBombError Source #
An error that occurs if a tar file is a "tar bomb" that would extract files outside of the intended directory.
Constructors
| TarBombError | |
Fields
| |
Instances
| Exception TarBombError Source # | |
Defined in Codec.Archive.Tar.Check.Internal Methods toException :: TarBombError -> SomeException fromException :: SomeException -> Maybe TarBombError displayException :: TarBombError -> String | |
| Show TarBombError Source # | |
Defined in Codec.Archive.Tar.Check.Internal Methods showsPrec :: Int -> TarBombError -> ShowS show :: TarBombError -> String showList :: [TarBombError] -> ShowS | |
Portability
checkPortability :: Entries e -> GenEntries FilePath FilePath (Either (Either e DecodeLongNamesError) PortabilityError) Source #
This function checks a sequence of tar entries for a number of portability issues. It will complain if:
- The old "Unix V7" or "gnu" formats are used. For maximum portability only the POSIX standard "ustar" format should be used.
- A non-portable entry type is used. Only ordinary files, hard links, symlinks and directories are portable. Device files, pipes and others are not portable between all common operating systems.
- Non-ASCII characters are used in file names. There is no agreed portable convention for Unicode or other extended character sets in file names in tar archives.
- File names that would not be portable to both Unix and Windows. This check includes characters that are valid in both systems and the '/' vs '\' directory separator conventions.
Whenever possible, consider fusing checkPortability with packing / unpacking by using
packAndCheck / unpackAndCheck
with checkEntryPortability.
Not only it is faster, but also alleviates issues with lazy I/O
such as exhaustion of file handlers.
checkEntryPortability :: GenEntry FilePath linkTarget -> Maybe PortabilityError Source #
Worker of checkPortability.
Since: 0.6.0.0
data PortabilityError Source #
Portability problems in a tar archive
Constructors
| NonPortableFormat Format | |
| NonPortableFileType | |
| NonPortableEntryNameChar FilePath | |
| NonPortableFileName PortabilityPlatform FileNameError |
Instances
| Exception PortabilityError Source # | |
Defined in Codec.Archive.Tar.Check.Internal Methods toException :: PortabilityError -> SomeException fromException :: SomeException -> Maybe PortabilityError displayException :: PortabilityError -> String | |
| Show PortabilityError Source # | |
Defined in Codec.Archive.Tar.Check.Internal Methods showsPrec :: Int -> PortabilityError -> ShowS show :: PortabilityError -> String showList :: [PortabilityError] -> ShowS | |
type PortabilityPlatform = String Source #
The name of a platform that portability issues arise from