From 6155ef4e5cc74b11bfb0eba745e4e9c9c5e5f6be Mon Sep 17 00:00:00 2001 From: dkf Date: Wed, 16 May 2012 14:11:45 +0000 Subject: [Bug 3445787]: Improve the compatibility of safe interpreters' version of 'file' with that of unsafe interpreters. --- ChangeLog | 10 +++++++- generic/tclCmdAH.c | 42 +++++++++++++++++++++++++++++-- library/safe.tcl | 73 ++++++++++++++++++++++-------------------------------- tests/safe.test | 4 +-- 4 files changed, 80 insertions(+), 49 deletions(-) diff --git a/ChangeLog b/ChangeLog index b4a6a8d..72af5c4 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2012-05-16 Donal K. Fellows + + * generic/tclCmdAH.c (TclMakeFileCommandSafe): [Bug 3445787]: Improve + the compatibility of safe interpreters' version of 'file' with that of + unsafe interpreters. + * library/safe.tcl (::safe::InterpInit): Teach the safe-interp scripts + about how to expose 'file' properly. + 2012-05-13 Jan Nijtmans * win/tclWinDde.c: Protect against receiving strings without ending \0, @@ -21,7 +29,7 @@ event(s) into the owner thread's event queue for execution in the correct context. Renamed the ForwardOpTo...Thread() function to match with our terminology. - + * tests/ioCmd.test [Bug 3522560]: Added a test which crashes the core if it were not disabled as knownBug. For a reflected channel transfered to a different thread the [chan postevent] run in the diff --git a/generic/tclCmdAH.c b/generic/tclCmdAH.c index 70aef8d..4292224 100644 --- a/generic/tclCmdAH.c +++ b/generic/tclCmdAH.c @@ -61,6 +61,7 @@ static Tcl_NRPostProc ForPostNextCallback; static Tcl_NRPostProc ForeachLoopStep; static Tcl_NRPostProc EvalCmdErrMsg; +static Tcl_ObjCmdProc BadFileSubcommand; static Tcl_ObjCmdProc FileAttrAccessTimeCmd; static Tcl_ObjCmdProc FileAttrIsDirectoryCmd; static Tcl_ObjCmdProc FileAttrIsExecutableCmd; @@ -581,7 +582,7 @@ Tcl_EncodingObjCmd( break; } case ENC_DIRS: - return EncodingDirsObjCmd(dummy, interp, objc-1, objv+1); + return EncodingDirsObjCmd(dummy, interp, objc, objv); case ENC_NAMES: if (objc > 2) { Tcl_WrongNumArgs(interp, 2, objv, NULL); @@ -628,10 +629,12 @@ EncodingDirsObjCmd( int objc, /* Number of arguments. */ Tcl_Obj *const objv[]) /* Argument objects. */ { - if (objc > 2) { + if (objc > 3) { Tcl_WrongNumArgs(interp, 1, objv, "?dirList?"); return TCL_ERROR; } + objc -= 1; + objv += 1; if (objc == 1) { Tcl_SetObjResult(interp, Tcl_GetEncodingSearchPath()); return TCL_OK; @@ -1057,6 +1060,8 @@ TclMakeFileCommandSafe( unsafeInfo[i].cmdName, Tcl_GetString(Tcl_GetObjResult(interp))); } + Tcl_CreateObjCommand(interp, oldName, BadFileSubcommand, + (ClientData) unsafeInfo[i].cmdName, NULL); } } Tcl_DStringFree(&oldBuf); @@ -1078,6 +1083,39 @@ TclMakeFileCommandSafe( /* *---------------------------------------------------------------------- * + * BadFileSubcommand -- + * + * Command used to act as a backstop implementation when subcommands of + * "file" are unsafe (the real implementations of the subcommands are + * hidden). The clientData is always the full official subcommand name. + * + * Results: + * A standard Tcl result (always a TCL_ERROR). + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static int +BadFileSubcommand( + ClientData clientData, + Tcl_Interp *interp, + int objc, + Tcl_Obj *const objv[]) +{ + const char *subcommandName = (const char *) clientData; + + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "not allowed to invoke subcommand %s of file", subcommandName)); + Tcl_SetErrorCode(interp, "TCL", "SAFE", "SUBCOMMAND", NULL); + return TCL_ERROR; +} + +/* + *---------------------------------------------------------------------- + * * FileAttrAccessTimeCmd -- * * This function is invoked to process the "file atime" Tcl command. See diff --git a/library/safe.tcl b/library/safe.tcl index 95db3b2..b9be5a7 100644 --- a/library/safe.tcl +++ b/library/safe.tcl @@ -465,8 +465,18 @@ proc ::safe::InterpInit { # This alias lets the slave have access to a subset of the 'file' # command functionality. - AliasSubset $slave file \ - file dir.* join root.* ext.* tail path.* split + ::interp expose $slave file + foreach subcommand {dirname extension rootname tail} { + ::interp alias $slave ::tcl::file::$subcommand {} file $subcommand + } + foreach subcommand { + atime attributes copy delete executable exists isdirectory isfile + link lstat mtime mkdir nativename normalize owned readable readlink + rename size stat tempfile type volumes writable + } { + ::interp alias $slave ::tcl::file::$subcommand {} \ + ::safe::BadSubcommand $slave file $subcommand + } # Subcommands of info foreach {subcommand alias} { @@ -980,58 +990,33 @@ proc ::safe::DirInAccessPath {slave dir} { } } -# This procedure enables access from a safe interpreter to only a subset -# of the subcommands of a command: +# This procedure is used to report an attempt to use an unsafe member of an +# ensemble command. -proc ::safe::Subset {slave command okpat args} { - set subcommand [lindex $args 0] - if {[regexp $okpat $subcommand]} { - return [$command {*}$args] - } +proc ::safe::BadSubcommand {slave command subcommand args} { set msg "not allowed to invoke subcommand $subcommand of $command" Log $slave $msg - return -code error $msg -} - -# This procedure installs an alias in a slave that invokes "safesubset" in -# the master to execute allowed subcommands. It precomputes the pattern of -# allowed subcommands; you can use wildcards in the pattern if you wish to -# allow subcommand abbreviation. -# -# Syntax is: AliasSubset slave alias target subcommand1 subcommand2... - -proc ::safe::AliasSubset {slave alias target args} { - set pat "^([join $args |])\$" - ::interp alias $slave $alias {}\ - [namespace current]::Subset $slave $target $pat + return -code error -errorcode {TCL SAFE SUBCOMMAND} $msg } # AliasEncoding is the target of the "encoding" alias in safe interpreters. proc ::safe::AliasEncoding {slave option args} { - # Careful; do not want empty option to get through to the [string equal] - if {[regexp {^(name.*|convert.*|)$} $option]} { - return [::interp invokehidden $slave encoding $option {*}$args] - } - - if {[string equal -length [string length $option] $option "system"]} { - if {![llength $args]} { - # passed all the tests , lets source it: - try { - return [::interp invokehidden $slave encoding system] - } on error msg { - Log $slave $msg - return -code error "script error" - } + # Note that [encoding dirs] is not supported in safe slaves at all + set subcommands {convertfrom convertto names system} + try { + set option [tcl::prefix match -error [list -level 1 -errorcode \ + [list TCL LOOKUP INDEX option $option]] $subcommands $option] + # Special case: [encoding system] ok, but [encoding system foo] not + if {$option eq "system" && [llength $args]} { + return -code error -errorcode {TCL WRONGARGS} \ + "wrong # args: should be \"encoding system\"" } - set msg "wrong # args: should be \"encoding system\"" - set code {TCL WRONGARGS} - } else { - set msg "bad option \"$option\": must be convertfrom, convertto, names, or system" - set code [list TCL LOOKUP INDEX option $option] + } on error {msg options} { + Log $slave $msg + return -options $options $msg } - Log $slave $msg - return -code error -errorcode $code $msg + tailcall ::interp invokehidden $slave encoding $option {*}$args } # Various minor hiding of platform features. [Bug 2913625] diff --git a/tests/safe.test b/tests/safe.test index 2d7f476..827ea11 100644 --- a/tests/safe.test +++ b/tests/safe.test @@ -94,7 +94,7 @@ test safe-3.2 {calling safe::interpCreate on trusted interp} -setup { lsort [a aliases] } -cleanup { safe::interpDelete a -} -result {::tcl::info::nameofexecutable clock encoding exit file glob load source} +} -result {::tcl::file::atime ::tcl::file::attributes ::tcl::file::copy ::tcl::file::delete ::tcl::file::dirname ::tcl::file::executable ::tcl::file::exists ::tcl::file::extension ::tcl::file::isdirectory ::tcl::file::isfile ::tcl::file::link ::tcl::file::lstat ::tcl::file::mkdir ::tcl::file::mtime ::tcl::file::nativename ::tcl::file::normalize ::tcl::file::owned ::tcl::file::readable ::tcl::file::readlink ::tcl::file::rename ::tcl::file::rootname ::tcl::file::size ::tcl::file::stat ::tcl::file::tail ::tcl::file::tempfile ::tcl::file::type ::tcl::file::volumes ::tcl::file::writable ::tcl::info::nameofexecutable clock encoding exit glob load source} test safe-3.3 {calling safe::interpCreate on trusted interp} -setup { catch {safe::interpDelete a} } -body { @@ -556,7 +556,7 @@ test safe-13.1 {safe file ensemble does not surprise code} -setup { lappend result [catch {interp eval $i {file isdirectory .}} msg] $msg } -cleanup { interp delete $i -} -result {1 {a b c} 1 {a b c} 1 {invalid command name "file"} 1 0 {a b c} 1 {invalid command name "::tcl::file::isdirectory"}} +} -result {1 {a b c} 1 {a b c} 1 {invalid command name "file"} 1 0 {a b c} 1 {not allowed to invoke subcommand isdirectory of file}} set ::auto_path $saveAutoPath # cleanup -- cgit v0.12