5 ms·

Another case of poorly chosen defaults leading to bugs, leading to security issues. Also a case of violating the Principle of Least Astonishment [0]. How many

Another case of poorly chosen defaults leading to bugs, leading to security issues. Also a case of violating the Principle of Least Astonishment [0]. How many people would expect that when you write a file you would also have specify that you want it truncated? [0] https://en.wikipedia.org/wiki/Principle_of_least_astonishment https://en.wikipedia.org/wiki/Principle_of_least_astonishmen...

jandrese 4y ago
It's notable that in practically every other programming language on every platform the default is to truncate the file to 0 bytes when opened in write (not append) mode. This isn't one of those things where there are two schools of thought where people take sides. It's a completely baffling decision to buck all convention vs. common sense.
- Someone 4y ago
  > It's notable that in practically every other programming language on every platform the default is to truncate the file to 0 bytes when opened in write (not append) mode Examples of ‘Open’ calls that require setting a bit in the ‘flags’ argument to truncate an existing file: - https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-openfile https://learn.microsoft.com/en-us/windows/win32/api/winbase/... - https://man.freebsd.org/cgi/man.cgi?query=open&sektion=2&n=1 https://man.freebsd.org/cgi/man.cgi?query=open&sektion=2&n=1
  - okanat 4y ago
    You're comparing system call interfaces to higher level standard API defaults. Not really an apples to apples comparison. System calls are special low-level interfaces. The requirement for reading their docs carefully and general care is expected at that level. A higher level API shouldn't contain gotchas like this.
  - moefh 4y ago
    Wow, that Win32 OpenFile function is truly cursed: - If you don't specify a directory, Windows will look for the file in a bunch of directories, but the current directory is not the first place searched. - The lpReOpenBuff is annotated as [out], but is an input when uStyle contains the OF_REOPEN flag. - The function is named OpenFile, but can be used to delete a file. Even better, the documentation is not clear what to do with the return value on success: is it a valid file handle that must be passed to CloseHandle, or just a dummy non-error file handle? - You can also use it to check the existence of the file -- the documentation says it will open and then close the file. What's the return value in that case? Is it a stale file handle, a dummy, or do you still have to close it?
    - Someone 4y ago
      You’re forgetting this one: you can specify a flag that makes the call display a dialog box if a requested file does not exist. Yes, this call to open a file can run an event loop that lets the user create directories, rename files, possibly even format floppy disks, etc. If you want a prime example of a layer violation, this is it. Its replacement “CreateFile” (https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea https://learn.microsoft.com/en-us/windows/win32/api/fileapi/...) is a lot saner, but still has this: “If you rename or delete a file and then restore it shortly afterward, the system searches the cache for file information to restore. Cached information includes its short/long name pair and creation time.” That’s intended to make it easier for “Save” operations in document-based applications to keep the short name of the file, creation time and file flags around.
deleted 4y ago
[deleted]
intelVISA 4y ago
Some say certain agencies wanted it this way.
- jmull 4y ago
  Some are yet naive. “Never attribute to malice that which is adequately explained by stupidity.”
  - account42 4y ago
    Are you trying to volunteer yourself as an example of naivety.
- bagels 4y ago
  Who says this?
  - dylan604 4y ago
    They and them. Don't confuse the pronouns as being more than one person.
- rozab 4y ago
  This would be the stupidest possible way of conducting mass surveillance

jandrese 4y ago

It's notable that in practically every other programming language on every platform the default is to truncate the file to 0 bytes when opened in write (not append) mode. This isn't one of those things where there are two schools of thought where people take sides. It's a completely baffling decision to buck all convention vs. common sense.

Someone 4y ago
> It's notable that in practically every other programming language on every platform the default is to truncate the file to 0 bytes when opened in write (not append) mode Examples of ‘Open’ calls that require setting a bit in the ‘flags’ argument to truncate an existing file: - https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-openfile https://learn.microsoft.com/en-us/windows/win32/api/winbase/... - https://man.freebsd.org/cgi/man.cgi?query=open&sektion=2&n=1 https://man.freebsd.org/cgi/man.cgi?query=open&sektion=2&n=1
- okanat 4y ago
  You're comparing system call interfaces to higher level standard API defaults. Not really an apples to apples comparison. System calls are special low-level interfaces. The requirement for reading their docs carefully and general care is expected at that level. A higher level API shouldn't contain gotchas like this.
- moefh 4y ago
  Wow, that Win32 OpenFile function is truly cursed: - If you don't specify a directory, Windows will look for the file in a bunch of directories, but the current directory is not the first place searched. - The lpReOpenBuff is annotated as [out], but is an input when uStyle contains the OF_REOPEN flag. - The function is named OpenFile, but can be used to delete a file. Even better, the documentation is not clear what to do with the return value on success: is it a valid file handle that must be passed to CloseHandle, or just a dummy non-error file handle? - You can also use it to check the existence of the file -- the documentation says it will open and then close the file. What's the return value in that case? Is it a stale file handle, a dummy, or do you still have to close it?
  - Someone 4y ago
    You’re forgetting this one: you can specify a flag that makes the call display a dialog box if a requested file does not exist. Yes, this call to open a file can run an event loop that lets the user create directories, rename files, possibly even format floppy disks, etc. If you want a prime example of a layer violation, this is it. Its replacement “CreateFile” (https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea https://learn.microsoft.com/en-us/windows/win32/api/fileapi/...) is a lot saner, but still has this: “If you rename or delete a file and then restore it shortly afterward, the system searches the cache for file information to restore. Cached information includes its short/long name pair and creation time.” That’s intended to make it easier for “Save” operations in document-based applications to keep the short name of the file, creation time and file flags around.

deleted 4y ago

[deleted]

intelVISA 4y ago

Some say certain agencies wanted it this way.

jmull 4y ago
Some are yet naive. “Never attribute to malice that which is adequately explained by stupidity.”
- account42 4y ago
  Are you trying to volunteer yourself as an example of naivety.
bagels 4y ago
Who says this?
- dylan604 4y ago
  They and them. Don't confuse the pronouns as being more than one person.
rozab 4y ago
This would be the stupidest possible way of conducting mass surveillance