Unrecoverable errors detected by GSSAPI encryption can't just be
reported with elog(ERROR) or elog(FATAL), because attempting to
send the error report to the client is likely to lead to infinite
recursion or loss of protocol sync. Instead make this code do what
the SSL encryption code has long done, which is to just report any
such failure to the server log (with elevel COMMERROR), then pretend
we've lost the connection by returning errno = ECONNRESET.
Along the way, fix confusion about whether message translation is done
by pg_GSS_error() or its callers (the latter should do it), and make
the backend version of that function work more like the frontend
version.
Avoid allocating the port->gss struct until it's needed; we surely
don't need to allocate it in the postmaster.
Improve logging of "connection authorized" messages with GSS enabled.
(As part of this, I back-patched the code changes from dc11f31a1.)
Make BackendStatusShmemSize() account for the GSS-related space that
will be allocated by CreateSharedBackendStatus(). This omission
could possibly cause out-of-shared-memory problems with very high
max_connections settings.
Remove arbitrary, pointless restriction that only GSS authentication
can be used on a GSS-encrypted connection.
Improve documentation; notably, document the fact that libpq now
prefers GSS encryption over SSL encryption if both are possible.
Per report from Mikael Gustavsson. Back-patch to v12 where
this code was introduced.
Discussion: https://postgr.es/m/e5b0b6ed05764324a2f3fe7acfc766d5@smhi.se
User-visible log messages should go through ereport(), so they are
subject to translation. Many remaining elog(LOG) calls are really
debugging calls.
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://www.postgresql.org/message-id/flat/92d6f545-5102-65d8-3c87-489f71ea0a37%40enterprisedb.com
After de8feb1f3a23465b5737e8a8c160e8ca62f61339, some warnings remained
that were only visible when using GCC on Windows. Fix those as well.
Note that the ecpg test source files don't use the full pg_config.h,
so we can't use pg_funcptr_t there but have to do it the long way.
This patch started out with the goal of harmonizing various arbitrary
limits on password length, but after awhile a better idea emerged:
let's just get rid of those fixed limits.
recv_password_packet() has an arbitrary limit on the packet size,
which we don't really need, so just drop it. (Note that this doesn't
really affect anything for MD5 or SCRAM password verification, since
those will hash the user's password to something shorter anyway.
It does matter for auth methods that require a cleartext password.)
Likewise remove the arbitrary error condition in pg_saslprep().
The remaining limits are mostly in client-side code that prompts
for passwords. To improve those, refactor simple_prompt() so that
it allocates its own result buffer that can be made as big as
necessary. Actually, it proves best to make a separate routine
pg_get_line() that has essentially the semantics of fgets(), except
that it allocates a suitable result buffer and hence will never
return a truncated line. (pg_get_line has a lot of potential
applications to replace randomly-sized fgets buffers elsewhere,
but I'll leave that for another patch.)
I built pg_get_line() atop stringinfo.c, which requires moving
that code to src/common/; but that seems fine since it was a poor
fit for src/port/ anyway.
This patch is mostly mine, but it owes a good deal to Nathan Bossart
who pressed for a solution to the password length problem and
created a predecessor patch. Also thanks to Peter Eisentraut and
Stephen Frost for ideas and discussion.
Discussion: https://postgr.es/m/09512C4F-8CB9-4021-B455-EF4C4F0D55A0@amazon.com
The additional pain from level 4 is excessive for the gain.
Also revert all the source annotation changes to their original
wordings, to avoid back-patching pain.
Discussion: https://postgr.es/m/31166.1589378554@sss.pgh.pa.us
Use it at level 4, a bit more restrictive than the default level, and
tweak our commanding comments to FALLTHROUGH.
(However, leave zic.c alone, since it's external code; to avoid the
warnings that would appear there, change CFLAGS for that file in the
Makefile.)
Author: Julien Rouhaud <rjuju123@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20200412081825.qyo5vwwco3fv4gdo@nol
Discussion: https://postgr.es/m/flat/E1fDenm-0000C8-IJ@gemulon.postgresql.org
This fixes and updates a couple of comments related to outdated Windows
versions. Particularly, src/common/exec.c had a fallback implementation
to read a file's line from a pipe because stdin/stdout/stderr does not
exist in Windows 2000 that is removed to simplify src/common/ as there
are unlikely versions of Postgres running on such platforms.
Author: Michael Paquier
Reviewed-by: Kyotaro Horiguchi, Juan José Santamaría Flecha
Discussion: https://postgr.es/m/20191219021526.GC4202@paquier.xyz
We used to strategically place newlines after some function call left
parentheses to make pgindent move the argument list a few chars to the
left, so that the whole line would fit under 80 chars. However,
pgindent no longer does that, so the newlines just made the code
vertically longer for no reason. Remove those newlines, and reflow some
of those lines for some extra naturality.
Reviewed-by: Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/20200129200401.GA6303@alvherre.pgsql
The leaks have been detected by a Coverity run on Windows. No backpatch
is done as the leaks are minor.
While on it, make restricted token creation more consistent in its error
handling by logging an error instead of a warning if missing
advapi32.dll, which was missing in the NT4 days. Any modern platform
should have this DLL around. Now, if the library is not there, an error
is still reported back to the caller, and nothing is done do there is no
behavior change done in this commit.
Author: Ranier Vilela
Discussion: https://postgr.es/m/CAEudQApa9MG0foPkgPX87fipk=vhnF2Xfg+CfUyR08h4R7Mywg@mail.gmail.com
The getpeereid() uses have so far been protected by HAVE_UNIX_SOCKETS,
so they didn't ever care about Windows support. But in anticipation
of Unix-domain socket support on Windows, that needs to be handled
differently.
Windows doesn't support getpeereid() at this time, so we use the
existing not-supported code path. We let configure do its usual thing
of picking up the replacement from libpgport, instead of the custom
overrides that it was doing before.
But then Windows doesn't have struct passwd, so this patch sprinkles
some additional #ifdef WIN32 around to make it work. This is similar
to existing code that deals with this issue.
Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/5974caea-1267-7708-40f2-6009a9d653b0@2ndquadrant.com
For a long time (since commit aed378e8d) we have had a policy to log
nothing about a connection if the client disconnects when challenged
for a password. This is because libpq-using clients will typically
do that, and then come back for a new connection attempt once they've
collected a password from their user, so that logging the abandoned
connection attempt will just result in log spam. However, this did
not work well for PAM authentication: the bottom-level function
pam_passwd_conv_proc() was on board with it, but we logged messages
at higher levels anyway, for lack of any reporting mechanism.
Add a flag and tweak the logic so that the case is silent, as it is
for other password-using auth mechanisms.
Per complaint from Yoann La Cancellera. It's been like this for awhile,
so back-patch to all supported branches.
Discussion: https://postgr.es/m/CACP=ajbrFFYUrLyJBLV8=q+eNCapa1xDEyvXhMoYrNphs-xqPw@mail.gmail.com
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. To
reduce confusion between the two authenticaton methods and disentangle
their code, use a dynamically allocated buffer instead.
Discussion: https://www.postgresql.org/message-id/flat/c798fba5-8b71-4f27-c78e-37714037ea31%402ndquadrant.com
For historical reasons, the functions for peer authentication were
grouped under ident authentication. But they are really completely
separate, so give them their own section headings.
Within the context of SCRAM, "verifier" has a specific meaning in the
protocol, per RFCs. The existing code used "verifier" differently, to
mean whatever is or would be stored in pg_auth.rolpassword.
Fix this by using the term "secret" for this, following RFC 5803.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/flat/be397b06-6e4b-ba71-c7fb-54cae84a7e18%402ndquadrant.com
These were introduced by pgindent due to fixe to broken
indentation (c.f. 8255c7a5eeba8). Previously the mis-indentation of
function prototypes was creatively used to reduce indentation in a few
places.
As that formatting only exists in master and REL_12_STABLE, it seems
better to fix it in both, rather than having some odd indentation in
v12 that somebody might copy for future patches or such.
Author: Andres Freund
Discussion: https://postgr.es/m/20190728013754.jwcbe5nfyt3533vx@alap3.anarazel.de
Backpatch: 12-
Originally, Postgres Lists were a more or less exact reimplementation of
Lisp lists, which consist of chains of separately-allocated cons cells,
each having a value and a next-cell link. We'd hacked that once before
(commit d0b4399d8) to add a separate List header, but the data was still
in cons cells. That makes some operations -- notably list_nth() -- O(N),
and it's bulky because of the next-cell pointers and per-cell palloc
overhead, and it's very cache-unfriendly if the cons cells end up
scattered around rather than being adjacent.
In this rewrite, we still have List headers, but the data is in a
resizable array of values, with no next-cell links. Now we need at
most two palloc's per List, and often only one, since we can allocate
some values in the same palloc call as the List header. (Of course,
extending an existing List may require repalloc's to enlarge the array.
But this involves just O(log N) allocations not O(N).)
Of course this is not without downsides. The key difficulty is that
addition or deletion of a list entry may now cause other entries to
move, which it did not before.
For example, that breaks foreach() and sister macros, which historically
used a pointer to the current cons-cell as loop state. We can repair
those macros transparently by making their actual loop state be an
integer list index; the exposed "ListCell *" pointer is no longer state
carried across loop iterations, but is just a derived value. (In
practice, modern compilers can optimize things back to having just one
loop state value, at least for simple cases with inline loop bodies.)
In principle, this is a semantics change for cases where the loop body
inserts or deletes list entries ahead of the current loop index; but
I found no such cases in the Postgres code.
The change is not at all transparent for code that doesn't use foreach()
but chases lists "by hand" using lnext(). The largest share of such
code in the backend is in loops that were maintaining "prev" and "next"
variables in addition to the current-cell pointer, in order to delete
list cells efficiently using list_delete_cell(). However, we no longer
need a previous-cell pointer to delete a list cell efficiently. Keeping
a next-cell pointer doesn't work, as explained above, but we can improve
matters by changing such code to use a regular foreach() loop and then
using the new macro foreach_delete_current() to delete the current cell.
(This macro knows how to update the associated foreach loop's state so
that no cells will be missed in the traversal.)
There remains a nontrivial risk of code assuming that a ListCell *
pointer will remain good over an operation that could now move the list
contents. To help catch such errors, list.c can be compiled with a new
define symbol DEBUG_LIST_MEMORY_USAGE that forcibly moves list contents
whenever that could possibly happen. This makes list operations
significantly more expensive so it's not normally turned on (though it
is on by default if USE_VALGRIND is on).
There are two notable API differences from the previous code:
* lnext() now requires the List's header pointer in addition to the
current cell's address.
* list_delete_cell() no longer requires a previous-cell argument.
These changes are somewhat unfortunate, but on the other hand code using
either function needs inspection to see if it is assuming anything
it shouldn't, so it's not all bad.
Programmers should be aware of these significant performance changes:
* list_nth() and related functions are now O(1); so there's no
major access-speed difference between a list and an array.
* Inserting or deleting a list element now takes time proportional to
the distance to the end of the list, due to moving the array elements.
(However, it typically *doesn't* require palloc or pfree, so except in
long lists it's probably still faster than before.) Notably, lcons()
used to be about the same cost as lappend(), but that's no longer true
if the list is long. Code that uses lcons() and list_delete_first()
to maintain a stack might usefully be rewritten to push and pop at the
end of the list rather than the beginning.
* There are now list_insert_nth...() and list_delete_nth...() functions
that add or remove a list cell identified by index. These have the
data-movement penalty explained above, but there's no search penalty.
* list_concat() and variants now copy the second list's data into
storage belonging to the first list, so there is no longer any
sharing of cells between the input lists. The second argument is
now declared "const List *" to reflect that it isn't changed.
This patch just does the minimum needed to get the new implementation
in place and fix bugs exposed by the regression tests. As suggested
by the foregoing, there's a fair amount of followup work remaining to
do.
Also, the ENABLE_LIST_COMPAT macros are finally removed in this
commit. Code using those should have been gone a dozen years ago.
Patch by me; thanks to David Rowley, Jesper Pedersen, and others
for review.
Discussion: https://postgr.es/m/11587.1550975080@sss.pgh.pa.us
The file has been introduced in src/backend/libpq/ as of b0b39f72, but
all backend-side headers of libpq are located in src/include/libpq/.
Note that the identification path on top of the file referred to
src/include/libpq/ from the start.
Author: Michael Paquier
Reviewed-by: Stephen Frost
Discussion: https://postgr.es/m/20190607043415.GE1736@paquier.xyz
This is still using the 2.0 version of pg_bsd_indent.
I thought it would be good to commit this separately,
so as to document the differences between 2.0 and 2.1 behavior.
Discussion: https://postgr.es/m/16296.1558103386@sss.pgh.pa.us
On both the frontend and backend, prepare for GSSAPI encryption
support by moving common code for error handling into a separate file.
Fix a TODO for handling multiple status messages in the process.
Eliminate the OIDs, which have not been needed for some time.
Add frontend and backend encryption support functions. Keep the
context initiation for authentication-only separate on both the
frontend and backend in order to avoid concerns about changing the
requested flags to include encryption support.
In postmaster, pull GSSAPI authorization checking into a shared
function. Also share the initiator name between the encryption and
non-encryption codepaths.
For HBA, add "hostgssenc" and "hostnogssenc" entries that behave
similarly to their SSL counterparts. "hostgssenc" requires either
"gss", "trust", or "reject" for its authentication.
Similarly, add a "gssencmode" parameter to libpq. Supported values are
"disable", "require", and "prefer". Notably, negotiation will only be
attempted if credentials can be acquired. Move credential acquisition
into its own function to support this behavior.
Add a simple pg_stat_gssapi view similar to pg_stat_ssl, for monitoring
if GSSAPI authentication was used, what principal was used, and if
encryption is being used on the connection.
Finally, add documentation for everything new, and update existing
documentation on connection security.
Thanks to Michael Paquier for the Windows fixes.
Author: Robbie Harwood, with changes to the read/write functions by me.
Reviewed in various forms and at different times by: Michael Paquier,
Andres Freund, David Steele.
Discussion: https://www.postgresql.org/message-id/flat/jlg1tgq1ktm.fsf@thriss.redhat.com
LDAP servers can be advertised on a network with RFC 2782 DNS SRV
records. The OpenLDAP command-line tools automatically try to find
servers that way, if no server name is provided by the user. Teach
PostgreSQL to do the same using OpenLDAP's support functions, when
building with OpenLDAP.
For now, we assume that HAVE_LDAP_INITIALIZE (an OpenLDAP extension
available since OpenLDAP 2.0 and also present in Apple LDAP) implies
that you also have ldap_domain2hostlist() (which arrived in the same
OpenLDAP version and is also present in Apple LDAP).
Author: Thomas Munro
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/CAEepm=2hAnSfhdsd6vXsM6VZVN0br-FbAZ-O+Swk18S5HkCP=A@mail.gmail.com
This allows a login to require both that the cn of the certificate
matches (like authentication type cert) *and* that another
authentication method (such as password or kerberos) succeeds as well.
The old value of clientcert=1 maps to the new clientcert=verify-ca,
clientcert=0 maps to the new clientcert=no-verify, and the new option
erify-full will add the validation of the CN.
Author: Julian Markwort, Marius Timmer
Reviewed by: Magnus Hagander, Thomas Munro
This removes a portion of infrastructure introduced by fe0a0b5 to allow
compilation of Postgres in environments where no strong random source is
available, meaning that there is no linking to OpenSSL and no
/dev/urandom (Windows having its own CryptoAPI). No systems shipped
this century lack /dev/urandom, and the buildfarm is actually not
testing this switch at all, so just remove it. This simplifies
particularly some backend code which included a fallback implementation
using shared memory, and removes a set of alternate regression output
files from pgcrypto.
Author: Michael Paquier
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/20181230063219.GG608@paquier.xyz
Since commit 2f1d2b7a we have set PAM_RHOST to "[local]" for Unix
sockets. This caused Linux PAM's libaudit integration to make DNS
requests for that name. It's not exactly clear what value PAM_RHOST
should have in that case, but it seems clear that we shouldn't set it
to an unresolvable name, so don't do that.
Back-patch to 9.6. Bug #15520.
Author: Thomas Munro
Reviewed-by: Peter Eisentraut
Reported-by: Albert Schabhuetl
Discussion: https://postgr.es/m/15520-4c266f986998e1c5%40postgresql.org
Commit 35c0754f failed to handle space-separated lists of alternative
hostnames in ldapserver, when building a URI for ldap_initialize()
(OpenLDAP). Such lists need to be expanded to space-separated URIs.
Repair. Back-patch to 11, to fix bug report #15495.
Author: Thomas Munro
Reported-by: Renaud Navarro
Discussion: https://postgr.es/m/15495-2c39fc196c95cd72%40postgresql.org
While we generally don't sweat too much about "may be used uninitialized"
warnings from older compilers, I noticed that there's a fair number of
buildfarm animals that are producing such a warning *only* for this
variable. So it seems worth silencing.
While monitoring the code, a couple of issues related to string
translation has showed up:
- Some routines for auto-updatable views return an error string, which
sometimes missed the shot. A comment regarding string translation is
added for each routine to help with future features.
- GSSAPI authentication missed two translations.
- vacuumdb handles non-translated strings.
- GetConfigOptionByNum should translate strings. This part is not
back-patched as after a minor upgrade this could be surprising for
users.
Reported-by: Kyotaro Horiguchi
Author: Kyotaro Horiguchi
Reviewed-by: Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/20180810.152131.31921918.horiguchi.kyotaro@lab.ntt.co.jp
Backpatch-through: 9.3
There are some problems with the tls-unique channel binding type. It's not
supported by all SSL libraries, and strictly speaking it's not defined for
TLS 1.3 at all, even though at least in OpenSSL, the functions used for it
still seem to work with TLS 1.3 connections. And since we had no
mechanism to negotiate what channel binding type to use, there would be
awkward interoperability issues if a server only supported some channel
binding types. tls-server-end-point seems feasible to support with any SSL
library, so let's just stick to that.
This removes the scram_channel_binding libpq option altogether, since there
is now only one supported channel binding type.
This also removes all the channel binding tests from the SSL test suite.
They were really just testing the scram_channel_binding option, which
is now gone. Channel binding is used if both client and server support it,
so it is used in the existing tests. It would be good to have some tests
specifically for channel binding, to make sure it really is used, and the
different combinations of a client and a server that support or doesn't
support it. The current set of settings we have make it hard to write such
tests, but I did test those things manually, by disabling
HAVE_BE_TLS_GET_CERTIFICATE_HASH and/or
HAVE_PGTLS_GET_PEER_CERTIFICATE_HASH.
I also removed the SCRAM_CHANNEL_BINDING_TLS_END_POINT constant. This is a
matter of taste, but IMO it's more readable to just use the
"tls-server-end-point" string.
Refactor the checks on whether the SSL library supports the functions
needed for tls-server-end-point channel binding. Now the server won't
advertise, and the client won't choose, the SCRAM-SHA-256-PLUS variant, if
compiled with an OpenSSL version too old to support it.
In the passing, add some sanity checks to check that the chosen SASL
mechanism, SCRAM-SHA-256 or SCRAM-SHA-256-PLUS, matches whether the SCRAM
exchange used channel binding or not. For example, if the client selects
the non-channel-binding variant SCRAM-SHA-256, but in the SCRAM message
uses channel binding anyway. It's harmless from a security point of view,
I believe, and I'm not sure if there are some other conditions that would
cause the connection to fail, but it seems better to be strict about these
things and check explicitly.
Discussion: https://www.postgresql.org/message-id/ec787074-2305-c6f4-86aa-6902f98485a4%40iki.fi
This is the converse of the unsafe-usage-of-%m problem: the reason
ereport/elog provide that format code is mainly to dodge the hazard
of errno getting changed before control reaches functions within the
arguments of the macro. I only found one instance of this hazard,
but it's been there since 9.4 :-(.
pg_hba_file_rules erroneously reported this as scram-sha256. Fix that.
To avoid future errors and confusion, also adjust documentation links
and internal symbols to have a separator between "sha" and "256".
Reported-by: Christophe Courtois <christophe.courtois@dalibo.com>
Author: Michael Paquier <michael.paquier@gmail.com>
As things stand now, channel binding data is fetched from OpenSSL and
saved into the SCRAM exchange context for any SSL connection attempted
for a SCRAM authentication, resulting in data fetched but not used if no
channel binding is used or if a different channel binding type is used
than what the data is here for.
Refactor the code in such a way that binding data is fetched from the
SSL stack only when a specific channel binding is used for both the
frontend and the backend. In order to achieve that, save the libpq
connection context directly in the SCRAM exchange state, and add a
dependency to SSL in the low-level SCRAM routines.
This makes the interface in charge of initializing the SCRAM context
cleaner as all its data comes from either PGconn* (for frontend) or
Port* (for the backend).
Author: Michael Paquier <michael.paquier@gmail.com>
Some versions of Windows don't define LDAPS_PORT.
Also, Windows' ldap_sslinit() is documented to use LDAPS even if you
said secure=0 when the port number happens to be 636 or 3269. Let's
avoid using the port number to imply that you want LDAPS, so that
connection strings have the same meaning on Windows and Unix.
Author: Thomas Munro
Discussion: https://postgr.es/m/CAEepm%3D23B7GV4AUz3MYH1TKpTv030VHxD2Sn%2BLYWDv8d-qWxww%40mail.gmail.com
While ldaptls=1 provides an RFC 4513 conforming way to do LDAP
authentication with TLS encryption, there was an earlier de facto
standard way to do LDAP over SSL called LDAPS. Even though it's not
enshrined in a standard, it's still widely used and sometimes required
by organizations' network policies. There seems to be no reason not to
support it when available in the client library. Therefore, add support
when using OpenLDAP 2.4+ or Windows. It can be configured with
ldapscheme=ldaps or ldapurl=ldaps://...
Add tests for both ways of requesting LDAPS and a test for the
pre-existing ldaptls=1. Modify the 001_auth.pl test for "diagnostic
messages", which was previously relying on the server rejecting
ldaptls=1.
Author: Thomas Munro
Reviewed-By: Peter Eisentraut
Discussion: https://postgr.es/m/CAEepm=1s+pA-LZUjQ-9GQz0Z4rX_eK=DFXAF1nBQ+ROPimuOYQ@mail.gmail.com
Mechanism names for SCRAM and channel binding names have been included
in scram.h by the libpq frontend code, and this header references a set
of routines which are only used by the backend. scram-common.h is on
the contrary usable by both the backend and libpq, so getting those
names from there seems more reasonable.
Author: Michael Paquier <michael.paquier@gmail.com>
This is the basic feature set using OpenSSL to support the feature. In
order to allow the frontend and the backend to fetch the sent and
expected TLS Finished messages, a PG-like API is added to be able to
make the interface pluggable for other SSL implementations.
This commit also adds a infrastructure to facilitate the addition of
future channel binding types as well as libpq parameters to control the
SASL mechanism names and channel binding names. Those will be added by
upcoming commits.
Some tests are added to the SSL test suite to test SCRAM authentication
with channel binding.
Author: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
An LDAP URL without a host name such as "ldap://" or without a base DN
such as "ldap://localhost" would cause a crash when reading pg_hba.conf.
If no binddn is configured, an error message might end up trying to print a
null pointer, which could crash on some platforms.
Author: Thomas Munro <thomas.munro@enterprisedb.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
