Re: do. command. safety. ?
When I first started writing things in Hypercard, I would take my creations to the Principle of the High School where I worked and he would set about trying to break my code. He was good at it. He told me that if it occured to him to try and break it, eventually it would occur to someone else. Smart guy. Bob S > On Apr 3, 2018, at 03:50 , Mark Waddingham via use-livecode > wrote: > > Put another way, all cases where code could be maliciously subverted are also > cases where your code could break through simple user error. > > I'm not sure if that makes the problem any simpler to think about - but it at > least removes the notion that maliciousness is the reason to be careful, and > replaces it with robustness (which seems slightly more positive, at least). > > Warmest Regards, > > Mark. > > -- > Mark Waddingham ~ m...@livecode.com ~ http://www.livecode.com/ > LiveCode: Everyone can create apps ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
On 2018-04-02 07:06, Richard Gaskin via use-livecode wrote: You were just thinking constructively. You look for outcomes that benefit people. That's a good perspective to have. Most devs do. Maliciously breaking things requires a different mindset. Or just recast the problem as an entirely constructive one... We're thinking of this problem in terms of 'how can someone maliciously cause damage through code I've written' - however that problem is no different from a much more benign one... "How can a completely benign user accidentally cause our code to get into an unintended state" In the case of the 'do' command which initiated this discussion - then imagine you are doing some sort of processing of user input on a form - and (for whatever reason - there are many) you are using do: on commitButtonPressed ... do "put" && quote & field "Username" & quote & "into tRecord[1]" ... end commitButtonPressed Here I'm imagining a card on a stack which is some sort of form. There's a 'continue/commit' button which causes commitButtonPressed to be called. The data you want to process is in fields on the card - in this case the user is required to enter a username - that goes into field "Username". The benign user (whether it be just because they have made a typo or are just slightly perverse) enters newuser" - i.e. newuser with the quote char at the end. This input will result in the above code not working correctly, as the do command will try and execute: put "newuser"" into tRecord[1] Which will fail, meaning that tRecord[1] will hold empty - which will mean the rest of the code will be faulty. Put another way, all cases where code could be maliciously subverted are also cases where your code could break through simple user error. I'm not sure if that makes the problem any simpler to think about - but it at least removes the notion that maliciousness is the reason to be careful, and replaces it with robustness (which seems slightly more positive, at least). Warmest Regards, Mark. -- Mark Waddingham ~ m...@livecode.com ~ http://www.livecode.com/ LiveCode: Everyone can create apps ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
J. Landman Gay wrote: > Thanks for the examples, Alex and Richard. I did understand the > principle behind the caution but I couldn't get any of my tests to > produce bad results. Both your examples do that. > > I think the problem was that I wasn't being imaginative enough. You were just thinking constructively. You look for outcomes that benefit people. That's a good perspective to have. Most devs do. Maliciously breaking things requires a different mindset. -- Richard Gaskin Fourth World Systems Software Design and Development for the Desktop, Mobile, and the Web ambassa...@fourthworld.comhttp://www.FourthWorld.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
So next time I'd better hire one of you guys, looks like. Malice isn't my strong point. Except maybe for certain distant relatives. -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com On April 1, 2018 5:42:26 PM Mark Wieder via use-livecode wrote: On 04/01/2018 11:40 AM, J. Landman Gay via use-livecode wrote: Thanks for the examples, Alex and Richard. I did understand the principle behind the caution but I couldn't get any of my tests to produce bad results. Both your examples do that. I think the problem was that I wasn't being imaginative enough. Yep. That's the problem with security coding - you have to be more imaginative keeping out of trouble than the imaginative folks who are looking for ways to cause mischief. -- Mark Wieder ahsoftw...@gmail.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
On 04/01/2018 11:40 AM, J. Landman Gay via use-livecode wrote: Thanks for the examples, Alex and Richard. I did understand the principle behind the caution but I couldn't get any of my tests to produce bad results. Both your examples do that. I think the problem was that I wasn't being imaginative enough. Yep. That's the problem with security coding - you have to be more imaginative keeping out of trouble than the imaginative folks who are looking for ways to cause mischief. -- Mark Wieder ahsoftw...@gmail.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
Thanks for the examples, Alex and Richard. I did understand the principle behind the caution but I couldn't get any of my tests to produce bad results. Both your examples do that. I think the problem was that I wasn't being imaginative enough. -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
Jacque wrote: > could you provide an example where the embedded command would actually > execute? A variant of Mark's example which executes when passed to fooEvil but not when pass to fooGood: on mouseUp put "into x ""e&";answer GOTCHA &cr& word 1 of the params #" \ into tUserInput fooGood tUserInput fooEvil tUserInput end mouseUp on fooGood pUserInput do "put pUserInput into x" end fooGood on fooEvil pUserInput do "put " "e& pUserInput "e&" into x" end fooEvil -- Richard Gaskin Fourth World Systems Software Design and Development for the Desktop, Mobile, and the Web ambassa...@fourthworld.comhttp://www.FourthWorld.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
The question is exactly what did you type into the field ? It's unclear whether the quotes in your email are part of the email, or part of the field content. Here's a case that definitely shows the difference: button "Button" on mouseup localtVar, tX do"put "&& quote& thetextoffld1& quote&& "into tx" put"now tx="&& tX &CRaftermsg end mouseup and button "safe" on mouseup localtVar, tX putfld1intotVar do"put tVar into tX" put"now tx="&& tX &CRaftermsg end mouseup and into the field I typed 1+2+3" into tt;set the backcolor of btn 1 to blue;put " Clicking button 'safe' gives now tx= 1+2+3" into tt;set the backcolor of btn 1 to blue;put " after the msg box; and repeated clicks there produce extra lines all the same. Clicking button 'button' gives now tx= in the msgbox, and the button color changes. So the embedded command within the field is being executed. -- Alex. On 31/03/2018 20:03, J. Landman Gay via use-livecode wrote: At the risk of appearing to be obtuse...I tried both versions of the "do" and got the same results. In each case, the variable was populated but no code was executed. In a test stack with one field and one button, I entered ";set the backcolor of btn 1 to blue;put ". In the button script I tried both versions of your example (substituting "fld 1" for "user input".) I also tried it without the semicolons and extra "put " at the end. In each case the variable x contained "set the backcolor of btn 1 to blue" and the button did not change color. I am quite sure you are right, but could you provide an example where the embedded command would actually execute? On 3/30/18 7:06 PM, Mark Waddingham via use-livecode wrote: The user input was indirected through a variable in the safe version - not made part of the do string... That's the critical difference. The unsafe version allows user input to change the do'd code, the safe version only changes the content of a variable the do string uses. Warmest Regards, Mark. Sent from my iPhone On 30 Mar 2018, at 19:24, J. Landman Gay via use-livecode wrote: Well yes, but as Bob mentioned, wouldn't a variable do the same thing? put ";delete hard drive;put " into x do x vs: do "put " && quote & ";delete hard drive;put " & quote && "into x" This actually came up way back in MetaCard where it was pointed out that the engine was about as secure as it gets as long as you validate all user input when using "do" or (I think) "value". In the first example above, input needs to be examined before the "do" command is issued. So I think there's a line or two missing in there somewhere. ;) On 3/30/18 12:15 PM, Mark Waddingham via use-livecode wrote: Think about the string that can be constructed in the quoted version - user input could be "; ...;put " where ... is any code you would like... Sent from my iPhone On 30 Mar 2018, at 18:09, J. Landman Gay via use-livecode wrote: These look the same to me. Both versions place content into a variable. Is the difference because of how the engine evaluates the input somehow? -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com On March 30, 2018 11:04:54 AM Mark Waddingham via use-livecode wrote: Using do safely is the same as making database queries safe, or URL requests. You 'just' need to make sure that any input from outside is sanitized to ensure that it doesn't change the meaning of the expression you are 'doing'. For example, don't interpolate strings directly in the script using quotes, use a local var instead: put user input into tVar1 do "put tVar1 into x" -- safe Rather than do "put " && quote & user input & quote && "into x" -- not safe Warmest Regards, Mark. Sent from my iPhone On 30 Mar 2018, at 16:43, Tom Glod via use-livecode wrote: Dear Geniuses Sometimes late at night just before falling asleep I think about the dangers of the do command. Is it possible to inject code into this mechanism through malware? I do not have enough understanding of operating systems and their processes ...and the livecode engineto be able to know if its a reasonable question or not. Thanks for any input on this. ___ -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailin
Re: do. command. safety. ?
On Fri, Mar 30, 2018 at 9:02 AM, Mark Waddingham via use-livecode < use-livecode@lists.runrev.com> wrote: > > do "put " && quote & user input & quote && "into x" -- not safe > Thus, do "initiate global thermonuclear war" :) Was shazam the statistical package that actually implemented that (only partially, we hoped!) -- Dr. Richard E. Hawkins, Esq. (702) 508-8462 ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
BTW, I know this works and is dangerous: do It's the insertions that don't seem to be affected. On 3/31/18 2:03 PM, J. Landman Gay via use-livecode wrote: At the risk of appearing to be obtuse...I tried both versions of the "do" and got the same results. In each case, the variable was populated but no code was executed. In a test stack with one field and one button, I entered ";set the backcolor of btn 1 to blue;put ". In the button script I tried both versions of your example (substituting "fld 1" for "user input".) I also tried it without the semicolons and extra "put " at the end. In each case the variable x contained "set the backcolor of btn 1 to blue" and the button did not change color. I am quite sure you are right, but could you provide an example where the embedded command would actually execute? On 3/30/18 7:06 PM, Mark Waddingham via use-livecode wrote: The user input was indirected through a variable in the safe version - not made part of the do string... That's the critical difference. The unsafe version allows user input to change the do'd code, the safe version only changes the content of a variable the do string uses. Warmest Regards, Mark. Sent from my iPhone On 30 Mar 2018, at 19:24, J. Landman Gay via use-livecode wrote: Well yes, but as Bob mentioned, wouldn't a variable do the same thing? put ";delete hard drive;put " into x do x vs: do "put " && quote & ";delete hard drive;put " & quote && "into x" This actually came up way back in MetaCard where it was pointed out that the engine was about as secure as it gets as long as you validate all user input when using "do" or (I think) "value". In the first example above, input needs to be examined before the "do" command is issued. So I think there's a line or two missing in there somewhere. ;) On 3/30/18 12:15 PM, Mark Waddingham via use-livecode wrote: Think about the string that can be constructed in the quoted version - user input could be "; ...;put " where ... is any code you would like... Sent from my iPhone On 30 Mar 2018, at 18:09, J. Landman Gay via use-livecode wrote: These look the same to me. Both versions place content into a variable. Is the difference because of how the engine evaluates the input somehow? -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com On March 30, 2018 11:04:54 AM Mark Waddingham via use-livecode wrote: Using do safely is the same as making database queries safe, or URL requests. You 'just' need to make sure that any input from outside is sanitized to ensure that it doesn't change the meaning of the expression you are 'doing'. For example, don't interpolate strings directly in the script using quotes, use a local var instead: put user input into tVar1 do "put tVar1 into x" -- safe Rather than do "put " && quote & user input & quote && "into x" -- not safe Warmest Regards, Mark. Sent from my iPhone On 30 Mar 2018, at 16:43, Tom Glod via use-livecode wrote: Dear Geniuses Sometimes late at night just before falling asleep I think about the dangers of the do command. Is it possible to inject code into this mechanism through malware? I do not have enough understanding of operating systems and their processes ...and the livecode engineto be able to know if its a reasonable question or not. Thanks for any input on this. ___ -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
At the risk of appearing to be obtuse...I tried both versions of the "do" and got the same results. In each case, the variable was populated but no code was executed. In a test stack with one field and one button, I entered ";set the backcolor of btn 1 to blue;put ". In the button script I tried both versions of your example (substituting "fld 1" for "user input".) I also tried it without the semicolons and extra "put " at the end. In each case the variable x contained "set the backcolor of btn 1 to blue" and the button did not change color. I am quite sure you are right, but could you provide an example where the embedded command would actually execute? On 3/30/18 7:06 PM, Mark Waddingham via use-livecode wrote: The user input was indirected through a variable in the safe version - not made part of the do string... That's the critical difference. The unsafe version allows user input to change the do'd code, the safe version only changes the content of a variable the do string uses. Warmest Regards, Mark. Sent from my iPhone On 30 Mar 2018, at 19:24, J. Landman Gay via use-livecode wrote: Well yes, but as Bob mentioned, wouldn't a variable do the same thing? put ";delete hard drive;put " into x do x vs: do "put " && quote & ";delete hard drive;put " & quote && "into x" This actually came up way back in MetaCard where it was pointed out that the engine was about as secure as it gets as long as you validate all user input when using "do" or (I think) "value". In the first example above, input needs to be examined before the "do" command is issued. So I think there's a line or two missing in there somewhere. ;) On 3/30/18 12:15 PM, Mark Waddingham via use-livecode wrote: Think about the string that can be constructed in the quoted version - user input could be "; ...;put " where ... is any code you would like... Sent from my iPhone On 30 Mar 2018, at 18:09, J. Landman Gay via use-livecode wrote: These look the same to me. Both versions place content into a variable. Is the difference because of how the engine evaluates the input somehow? -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com On March 30, 2018 11:04:54 AM Mark Waddingham via use-livecode wrote: Using do safely is the same as making database queries safe, or URL requests. You 'just' need to make sure that any input from outside is sanitized to ensure that it doesn't change the meaning of the expression you are 'doing'. For example, don't interpolate strings directly in the script using quotes, use a local var instead: put user input into tVar1 do "put tVar1 into x" -- safe Rather than do "put " && quote & user input & quote && "into x" -- not safe Warmest Regards, Mark. Sent from my iPhone On 30 Mar 2018, at 16:43, Tom Glod via use-livecode wrote: Dear Geniuses Sometimes late at night just before falling asleep I think about the dangers of the do command. Is it possible to inject code into this mechanism through malware? I do not have enough understanding of operating systems and their processes ...and the livecode engineto be able to know if its a reasonable question or not. Thanks for any input on this. ___ -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
The user input was indirected through a variable in the safe version - not made part of the do string... That's the critical difference. The unsafe version allows user input to change the do'd code, the safe version only changes the content of a variable the do string uses. Warmest Regards, Mark. Sent from my iPhone > On 30 Mar 2018, at 19:24, J. Landman Gay via use-livecode > wrote: > > Well yes, but as Bob mentioned, wouldn't a variable do the same thing? > > put ";delete hard drive;put " into x > do x > > vs: > > do "put " && quote & ";delete hard drive;put " & quote && "into x" > > This actually came up way back in MetaCard where it was pointed out that the > engine was about as secure as it gets as long as you validate all user input > when using "do" or (I think) "value". In the first example above, input needs > to be examined before the "do" command is issued. So I think there's a line > or two missing in there somewhere. ;) > > >> On 3/30/18 12:15 PM, Mark Waddingham via use-livecode wrote: >> Think about the string that can be constructed in the quoted version - user >> input could be "; ...;put " where ... is any code you would like... >> Sent from my iPhone >>> On 30 Mar 2018, at 18:09, J. Landman Gay via use-livecode >>> wrote: >>> >>> These look the same to me. Both versions place content into a variable. Is >>> the difference because of how the engine evaluates the input somehow? >>> >>> -- >>> Jacqueline Landman Gay | jac...@hyperactivesw.com >>> HyperActive Software | http://www.hyperactivesw.com On March 30, 2018 11:04:54 AM Mark Waddingham via use-livecode wrote: Using do safely is the same as making database queries safe, or URL requests. You 'just' need to make sure that any input from outside is sanitized to ensure that it doesn't change the meaning of the expression you are 'doing'. For example, don't interpolate strings directly in the script using quotes, use a local var instead: put user input into tVar1 do "put tVar1 into x" -- safe Rather than do "put " && quote & user input & quote && "into x" -- not safe Warmest Regards, Mark. Sent from my iPhone > On 30 Mar 2018, at 16:43, Tom Glod via use-livecode > wrote: > > Dear Geniuses > > Sometimes late at night just before falling asleep I think about the > dangers of the do command. Is it possible to inject code into this > mechanism through malware? > > I do not have enough understanding of operating systems and their > processes > ...and the livecode engineto be able to know if its a reasonable > question or not. > > Thanks for any input on this. > ___ > > > -- > Jacqueline Landman Gay | jac...@hyperactivesw.com > HyperActive Software | http://www.hyperactivesw.com > > ___ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
Tom Glod wrote: > Sometimes late at night just before falling asleep I think about > the dangers of the do command. Is it possible to inject code into > this mechanism through malware? Mark's discussion handled the security aspect well. The only thing I could add would be to examine each case and determine if "do" is even needed at all there. In addition to the risk of inviting arbitrary code execution, it's usually slower than any more direct alternative. And its use is often dependent on concatenated expressions, making code more cumbersome to both write and read. We used to use "do" a lot in HC, where we had to rely on it often to circumvent limitations with concatenated object references, variables with names that could not be known in advance, and others. LC has much more intelligent handling of concatenated object expressions, and with arrays we can handle any number of variables where we need the variable name determined on the fly. In LC "do" is still sometimes useful, but far less often. I can't remember the last time I needed to use, probably a couple years ago. -- Richard Gaskin Fourth World Systems Software Design and Development for the Desktop, Mobile, and the Web ambassa...@fourthworld.comhttp://www.FourthWorld.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
Well yes, but as Bob mentioned, wouldn't a variable do the same thing? put ";delete hard drive;put " into x do x vs: do "put " && quote & ";delete hard drive;put " & quote && "into x" This actually came up way back in MetaCard where it was pointed out that the engine was about as secure as it gets as long as you validate all user input when using "do" or (I think) "value". In the first example above, input needs to be examined before the "do" command is issued. So I think there's a line or two missing in there somewhere. ;) On 3/30/18 12:15 PM, Mark Waddingham via use-livecode wrote: Think about the string that can be constructed in the quoted version - user input could be "; ...;put " where ... is any code you would like... Sent from my iPhone On 30 Mar 2018, at 18:09, J. Landman Gay via use-livecode wrote: These look the same to me. Both versions place content into a variable. Is the difference because of how the engine evaluates the input somehow? -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com On March 30, 2018 11:04:54 AM Mark Waddingham via use-livecode wrote: Using do safely is the same as making database queries safe, or URL requests. You 'just' need to make sure that any input from outside is sanitized to ensure that it doesn't change the meaning of the expression you are 'doing'. For example, don't interpolate strings directly in the script using quotes, use a local var instead: put user input into tVar1 do "put tVar1 into x" -- safe Rather than do "put " && quote & user input & quote && "into x" -- not safe Warmest Regards, Mark. Sent from my iPhone On 30 Mar 2018, at 16:43, Tom Glod via use-livecode wrote: Dear Geniuses Sometimes late at night just before falling asleep I think about the dangers of the do command. Is it possible to inject code into this mechanism through malware? I do not have enough understanding of operating systems and their processes ...and the livecode engineto be able to know if its a reasonable question or not. Thanks for any input on this. ___ -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
Couldn't the same be said about tVar? I suppose you mean that you could check the user input before doing it. Bob S > On Mar 30, 2018, at 10:15 , Mark Waddingham via use-livecode > wrote: > > Think about the string that can be constructed in the quoted version - user > input could be "; ...;put " where ... is any code you would like... ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
Think about the string that can be constructed in the quoted version - user input could be "; ...;put " where ... is any code you would like... Sent from my iPhone > On 30 Mar 2018, at 18:09, J. Landman Gay via use-livecode > wrote: > > These look the same to me. Both versions place content into a variable. Is > the difference because of how the engine evaluates the input somehow? > > -- > Jacqueline Landman Gay | jac...@hyperactivesw.com > HyperActive Software | http://www.hyperactivesw.com >> On March 30, 2018 11:04:54 AM Mark Waddingham via use-livecode >> wrote: >> >> Using do safely is the same as making database queries safe, or URL requests. >> >> You 'just' need to make sure that any input from outside is sanitized to >> ensure that it doesn't change the meaning of the expression you are 'doing'. >> >> For example, don't interpolate strings directly in the script using quotes, >> use a local var instead: >> >> put user input into tVar1 >> do "put tVar1 into x" -- safe >> >> Rather than >> >> do "put " && quote & user input & quote && "into x" -- not safe >> >> Warmest Regards, >> >> Mark. >> >> Sent from my iPhone >> >> > On 30 Mar 2018, at 16:43, Tom Glod via use-livecode >> > wrote: >> > >> > Dear Geniuses >> > >> > Sometimes late at night just before falling asleep I think about the >> > dangers of the do command. Is it possible to inject code into this >> > mechanism through malware? >> > >> > I do not have enough understanding of operating systems and their processes >> > ...and the livecode engineto be able to know if its a reasonable >> > question or not. >> > >> > Thanks for any input on this. >> > ___ >> > use-livecode mailing list >> > use-livecode@lists.runrev.com >> > Please visit this url to subscribe, unsubscribe and manage your >> > subscription preferences: >> > http://lists.runrev.com/mailman/listinfo/use-livecode >> >> >> ___ >> use-livecode mailing list >> use-livecode@lists.runrev.com >> Please visit this url to subscribe, unsubscribe and manage your subscription >> preferences: >> http://lists.runrev.com/mailman/listinfo/use-livecode > > > > > ___ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
These look the same to me. Both versions place content into a variable. Is the difference because of how the engine evaluates the input somehow? -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com On March 30, 2018 11:04:54 AM Mark Waddingham via use-livecode wrote: Using do safely is the same as making database queries safe, or URL requests. You 'just' need to make sure that any input from outside is sanitized to ensure that it doesn't change the meaning of the expression you are 'doing'. For example, don't interpolate strings directly in the script using quotes, use a local var instead: put user input into tVar1 do "put tVar1 into x" -- safe Rather than do "put " && quote & user input & quote && "into x" -- not safe Warmest Regards, Mark. Sent from my iPhone > On 30 Mar 2018, at 16:43, Tom Glod via use-livecode wrote: > > Dear Geniuses > > Sometimes late at night just before falling asleep I think about the > dangers of the do command. Is it possible to inject code into this > mechanism through malware? > > I do not have enough understanding of operating systems and their processes > ...and the livecode engineto be able to know if its a reasonable > question or not. > > Thanks for any input on this. > ___ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
your point still applies about not being responsible that the user has allowed malware onto their system. On Fri, Mar 30, 2018 at 12:52 PM, Bob Sneidar via use-livecode < use-livecode@lists.runrev.com> wrote: > Ah I saw command in the subject and thought you were talking about shell > commands. > > Bob S > > > > On Mar 30, 2018, at 09:49 , Tom Glod via use-livecode < > use-livecode@lists.runrev.com> wrote: > > > > Valid point Bob. Thank You. > > > > Useful info, Thanks Mark. I was doing it the right way sometimes. the > > wrong way other times. thank you. > > > ___ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode > ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
Ah I saw command in the subject and thought you were talking about shell commands. Bob S > On Mar 30, 2018, at 09:49 , Tom Glod via use-livecode > wrote: > > Valid point Bob. Thank You. > > Useful info, Thanks Mark. I was doing it the right way sometimes. the > wrong way other times. thank you. ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
Valid point Bob. Thank You. Useful info, Thanks Mark. I was doing it the right way sometimes. the wrong way other times. thank you. On Fri, Mar 30, 2018 at 12:02 PM, Mark Waddingham via use-livecode < use-livecode@lists.runrev.com> wrote: > Using do safely is the same as making database queries safe, or URL > requests. > > You 'just' need to make sure that any input from outside is sanitized to > ensure that it doesn't change the meaning of the expression you are 'doing'. > > For example, don't interpolate strings directly in the script using > quotes, use a local var instead: > > put user input into tVar1 > do "put tVar1 into x" -- safe > > Rather than > > do "put " && quote & user input & quote && "into x" -- not safe > > Warmest Regards, > > Mark. > > Sent from my iPhone > > > On 30 Mar 2018, at 16:43, Tom Glod via use-livecode < > use-livecode@lists.runrev.com> wrote: > > > > Dear Geniuses > > > > Sometimes late at night just before falling asleep I think about the > > dangers of the do command. Is it possible to inject code into this > > mechanism through malware? > > > > I do not have enough understanding of operating systems and their > processes > > ...and the livecode engineto be able to know if its a reasonable > > question or not. > > > > Thanks for any input on this. > > ___ > > use-livecode mailing list > > use-livecode@lists.runrev.com > > Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > > http://lists.runrev.com/mailman/listinfo/use-livecode > > > ___ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode > ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
Using do safely is the same as making database queries safe, or URL requests. You 'just' need to make sure that any input from outside is sanitized to ensure that it doesn't change the meaning of the expression you are 'doing'. For example, don't interpolate strings directly in the script using quotes, use a local var instead: put user input into tVar1 do "put tVar1 into x" -- safe Rather than do "put " && quote & user input & quote && "into x" -- not safe Warmest Regards, Mark. Sent from my iPhone > On 30 Mar 2018, at 16:43, Tom Glod via use-livecode > wrote: > > Dear Geniuses > > Sometimes late at night just before falling asleep I think about the > dangers of the do command. Is it possible to inject code into this > mechanism through malware? > > I do not have enough understanding of operating systems and their processes > ...and the livecode engineto be able to know if its a reasonable > question or not. > > Thanks for any input on this. > ___ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: do. command. safety. ?
Any shell command that can do anything dangerous is typically protected by the host OS. You could not for example install software in a way that would bypass UAC in Windows. You *could* conceivably delete all the files in a folder I suppose, but you couldn't copy files to a protected location. Essentially anything the end user is capable of doing, LC can do, but this is not unique. You can say that about any application. If the IT department has given complete write access to everything to all their users (a common practice I am learning as I interact with our customer IT departments) then it's not up to LC to try to protect themselves from themselves. HTH Bob S > On Mar 30, 2018, at 08:43 , Tom Glod via use-livecode > wrote: > > Dear Geniuses > > Sometimes late at night just before falling asleep I think about the > dangers of the do command. Is it possible to inject code into this > mechanism through malware? > > I do not have enough understanding of operating systems and their processes > ...and the livecode engineto be able to know if its a reasonable > question or not. > > Thanks for any input on this. ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
do. command. safety. ?
Dear Geniuses Sometimes late at night just before falling asleep I think about the dangers of the do command. Is it possible to inject code into this mechanism through malware? I do not have enough understanding of operating systems and their processes ...and the livecode engineto be able to know if its a reasonable question or not. Thanks for any input on this. ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode