Remove one use of IDENT_USERNAME_MAX
It seems to me that using IDENT_USERNAME_MAX for peer authentication is
some kind of historical leftover and not really appropriate or useful,
so I propose the attached cleanup.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Attachments:
0001-Remove-one-use-of-IDENT_USERNAME_MAX.patchtext/plain; charset=UTF-8; name=0001-Remove-one-use-of-IDENT_USERNAME_MAX.patch; x-mac-creator=0; x-mac-type=0Download+7-6
Hello.
At Sat, 26 Oct 2019 08:55:03 +0200, Peter Eisentraut <peter.eisentraut@2ndquadrant.com> wrote in
IDENT_USERNAME_MAX is the maximum length of the information returned
by an ident server, per RFC 1413. Using it as the buffer size in peer
authentication is inappropriate. It was done here because of the
historical relationship between peer and ident authentication. But
since it's also completely useless code-wise, remove it.
In think one of the reasons for the coding is the fact that *pw is
described to be placed in the static area, which can be overwritten by
succeeding calls to getpw*() functions. I think we can believe
check_usermap() never calls them but I suppose that some comments
needed..
regards.
--
Kyotaro Horiguchi
NTT Open Source Software Center
Kyotaro Horiguchi <horikyota.ntt@gmail.com> writes:
At Sat, 26 Oct 2019 08:55:03 +0200, Peter Eisentraut <peter.eisentraut@2ndquadrant.com> wrote in
IDENT_USERNAME_MAX is the maximum length of the information returned
by an ident server, per RFC 1413. Using it as the buffer size in peer
authentication is inappropriate. It was done here because of the
historical relationship between peer and ident authentication. But
since it's also completely useless code-wise, remove it.
In think one of the reasons for the coding is the fact that *pw is
described to be placed in the static area, which can be overwritten by
succeeding calls to getpw*() functions.
Good point ... so maybe pstrdup instead of using a fixed-size buffer?
regards, tom lane
On 2019-10-28 14:45, Tom Lane wrote:
Kyotaro Horiguchi <horikyota.ntt@gmail.com> writes:
At Sat, 26 Oct 2019 08:55:03 +0200, Peter Eisentraut <peter.eisentraut@2ndquadrant.com> wrote in
IDENT_USERNAME_MAX is the maximum length of the information returned
by an ident server, per RFC 1413. Using it as the buffer size in peer
authentication is inappropriate. It was done here because of the
historical relationship between peer and ident authentication. But
since it's also completely useless code-wise, remove it.In think one of the reasons for the coding is the fact that *pw is
described to be placed in the static area, which can be overwritten by
succeeding calls to getpw*() functions.Good point ... so maybe pstrdup instead of using a fixed-size buffer?
Maybe. Or we just decide that check_usermap() is not allowed to call
getpw*(). It's just a string-matching routine, so it doesn't have any
such business anyway.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:
On 2019-10-28 14:45, Tom Lane wrote:
Kyotaro Horiguchi <horikyota.ntt@gmail.com> writes:
In think one of the reasons for the coding is the fact that *pw is
described to be placed in the static area, which can be overwritten by
succeeding calls to getpw*() functions.
Good point ... so maybe pstrdup instead of using a fixed-size buffer?
Maybe. Or we just decide that check_usermap() is not allowed to call
getpw*(). It's just a string-matching routine, so it doesn't have any
such business anyway.
I'm okay with that as long as you add a comment describing this
assumption.
regards, tom lane
On 2019-10-29 15:34, Tom Lane wrote:
Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:
On 2019-10-28 14:45, Tom Lane wrote:
Kyotaro Horiguchi <horikyota.ntt@gmail.com> writes:
In think one of the reasons for the coding is the fact that *pw is
described to be placed in the static area, which can be overwritten by
succeeding calls to getpw*() functions.Good point ... so maybe pstrdup instead of using a fixed-size buffer?
Maybe. Or we just decide that check_usermap() is not allowed to call
getpw*(). It's just a string-matching routine, so it doesn't have any
such business anyway.I'm okay with that as long as you add a comment describing this
assumption.
Committed with a pstrdup(). That seemed more consistent with other code
in that file.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services