[Info-vax] The best VMS features, was: Re: openvms renaming file

[Johnny Billquist]

On 2018-05-28 22:33, Simon Clubley wrote:
> On 2018-05-28, Johnny Billquist <bqt at softjar.se> wrote:
>> On 2018-05-28 21:15, Simon Clubley wrote:
>>> On 2018-05-28, Arne Vajhøj <arne at vajhoej.dk> wrote:
>>>> On 5/28/2018 1:56 AM, Simon Clubley wrote:
>>>>>
>>>>> For one obvious example, what exactly is the point of having both
>>>>> CMEXEC and CMKRNL privileges on VMS, given how VMS is designed ?
>>>>>
>>>>> Because of that design, CMEXEC is completely and utterly redundant
>>>>> and is just artifical complexity (and a false sense of security).
>>>>
>>>> I don't think it is.
>>>>
>>>> It was never intended to be a security feature where getting from EXEC
>>>> to KRNL required something special.
>>>>
>>>> But it did and still does provide two levels of access for code,
>>>> that protects against coding errors (but not against malicious code).
>>>>
>>>
>>> All you need to do is to give the user or program CMKRNL privilege and
>>> let the program switch into executive mode instead because when you
>>> give the user or program CMEXEC privilege, what you are really giving
>>> them is CMKRNL privilege.
>>>
>>> CMEXEC is utterly redundant within VMS as currently implemented.
>>
>> How about you actually listen and understand what someone said? The use
>> case Arne brought up is perfectly valid.
>>
> 
> I understood what Arne said - he's missed what I am saying. You don't
> need CMEXEC privilege to get into executive mode. You can do it with
> CMKRNL privilege:
> 
> http://h41379.www4.hpe.com/doc/84final/4527/4527pro_017.html
> 
> and further more, if you can switch into executive mode with CMEXEC
> privilege you can also get into kernel mode without needing CMKRNL
> privilege. From the above URL:
> 
> |For example, $CMKRNL bypasses the check for CMKRNL privilege that is normally
> |required when $CMKRNL is called from executive mode, and $SETPRV calls are
> |processed without SETPRV privilege when called from executive or kernel mode.
> 
> Like I said, CMEXEC privilege is completely and utterly redundant
> within VMS as currently implemented.

So you did not understand what Arne said after all. No need to repeat that.

   Johnny

-- 
Johnny Billquist                  || "I'm on a bus
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