TIP: 61 Title: Make TK_NO_SECURITY Run-Time Switchable Version: $Revision: 1.4 $ Author: Jeff Hobbs Author: Donal K. Fellows State: Deferred Type: Project Vote: Pending Created: 12-Sep-2001 Post-History: Tcl-Version: 8.5 ~ Abstract This TIP changes the compile time Tk define TK_NO_SECURITY to be switchable at run-time. ~ Rationale The TK_NO_SECURITY compile time #define is available to disable some security checking when send is used. The direct comments in the Makefile are: | # To turn off the security checks that disallow incoming sends when | # the X server appears to be insecure, reverse the comments on the | # following lines: | SECURITY_FLAGS = | #SECURITY_FLAGS = -DTK_NO_SECURITY I propose to make this switch configurable at runtime through a ''tk securesend'' option. ~ Benefits Users would be able to debug between Tk applications on Unix using ''send'' without having to compile a special version of Tk or manipulating the security settings of their X server to Tk's liking (which can then conflict with other work). It is common for users in internal ("safe") networks to open up access to an X server with ''xhost +machine''. ~ Drawbacks By allowing security to be disabled, users do possibly open up their system to attack. However, secure is the default setting, and any paranoid users can ''rename send {}'' to ensure that it is not used at all. ~ Reference Implementation A full patch for this feature is available at: http://sf.net/tracker/?func=detail&aid=456732&group_id=12997&atid=312997 The proposal adds one element to the private ''TkDisplay'' structure (configuration for secure send is done per display), and creates the Tcl level command: | tk securesend ?-displayof window? ?boolean? It leaves the TK_NO_SECURITY flag alone. If specified, send is insecure by default, otherwise it is secure. ~ Comments ''DKF'' - It should be possible to control the setting of the compile-time TK_NO_SECURITY flag from the ''configure'' script; having to edit the Makefile by hand to adjust it makes it too easy to inadvertently break something by introducing an unfortunate typo. Being able to pass a ''--disable-security'' flag would make thing much easier from a user's point of view, and will make it less likely that the Tk maintainers will have to deal with bug reports that ultimately stem from a dumb mistake made in a sensitive spot... ~ Copyright This document has been placed in the public domain.