OpenSSL 1.1.1 and newer versions have added support for RSA-PSS
certificates, which requires the use of a specific routine in OpenSSL to
determine which hash function to use when compiling it when using
channel binding in SCRAM-SHA-256. X509_get_signature_nid(), that is the
original routine the channel binding code has relied on, is not able to
determine which hash algorithm to use for such certificates. However,
X509_get_signature_info(), new to OpenSSL 1.1.1, is able to do it. This
commit switches the channel binding logic to rely on
X509_get_signature_info() over X509_get_signature_nid(), which would be
the choice when building with 1.1.1 or newer.
The error could have been triggered on the client or the server, hence
libpq and the backend need to have their related code paths patched.
Note that attempting to load an RSA-PSS certificate with OpenSSL 1.1.0
or older leads to a failure due to an unsupported algorithm.
The discovery of relying on X509_get_signature_info() comes from Jacob,
the tests have been written by Heikki (with few tweaks from me), while I
have bundled the whole together while adding the bits needed for MSVC
and meson.
This issue exists since channel binding exists, so backpatch all the way
down. Some tests are added in 15~, triggered if compiling with OpenSSL
1.1.1 or newer, where the certificate and key files can easily be
generated for RSA-PSS.
Reported-by: Gunnar "Nick" Bluth
Author: Jacob Champion, Heikki Linnakangas
Discussion: https://postgr.es/m/17760-b6c61e752ec07060@postgresql.org
Backpatch-through: 11
The frontend-side routine in charge of building a SCRAM verifier
mentioned that the restrictions applying to SASLprep on the password
with the encoding are described at the top of fe-auth-scram.c, but this
information is in auth-scram.c.
This is wrong since 8f8b9be, so backpatch all the way down as this is an
important documentation bit.
Spotted while reviewing a different patch.
Backpatch-through: 11
The ECPG preprocessor converted code such as
static varchar str1[10], str2[20], str3[30];
into
static struct varchar_1 { int len; char arr[ 10 ]; } str1 ;
struct varchar_2 { int len; char arr[ 20 ]; } str2 ;
struct varchar_3 { int len; char arr[ 30 ]; } str3 ;
thus losing the storage attribute for the later variables.
Repeat the declaration for each such variable.
(Note that this occurred only for variables declared "varchar"
or "bytea", which may help explain how it escaped detection
for so long.)
Andrey Sokolov
Discussion: https://postgr.es/m/942241662288242@mail.yandex.ru
There's a convention that externally-visible libpq functions should
check for a NULL PGconn pointer, and fail gracefully instead of
crashing. PQflush() and PQisnonblocking() didn't get that memo
though. Also add a similar check to PQdefaultSSLKeyPassHook_OpenSSL;
while it's not clear that ordinary usage could reach that with a
null conn pointer, it's cheap enough to check, so let's be consistent.
Daniele Varrazzo and Tom Lane
Discussion: https://postgr.es/m/CA+mi_8Zm_mVVyW1iNFgyMd9Oh0Nv8-F+7Y3-BqwMgTMHuo_h2Q@mail.gmail.com
Per buildfarm member prairiedog, this platform rejects uninitialized
global variables in shared libraries. Back-patch to v10, like the
addition of the variable.
Reviewed by Tom Lane.
Discussion: https://postgr.es/m/20220703030619.GB2378460@rfd.leadboat.com
ecpglib has been calling it once per SQL query and once per EXEC SQL GET
DESCRIPTOR. Instead, if newlocale() has not succeeded before, call it
while establishing a connection. This mitigates three problems:
- If newlocale() failed in EXEC SQL GET DESCRIPTOR, the command silently
proceeded without the intended locale change.
- On AIX, each newlocale()+freelocale() cycle leaked memory.
- newlocale() CPU usage may have been nontrivial.
Fail the connection attempt if newlocale() fails. Rearrange
ecpg_do_prologue() to validate the connection before its uselocale().
The sort of program that may regress is one running in an environment
where newlocale() fails. If that program establishes connections
without running SQL statements, it will stop working in response to this
change. I'm betting against the importance of such an ECPG use case.
Most SQL execution (any using ECPGdo()) has long required newlocale()
success, so there's little a connection could do without newlocale().
Back-patch to v10 (all supported versions).
Reviewed by Tom Lane. Reported by Guillaume Lelarge.
Discussion: https://postgr.es/m/20220101074055.GA54621@rfd.leadboat.com
If an application executed operations like EXEC SQL PREPARE
without having first established a database connection, it could
get a core dump instead of the expected clean failure. This
occurred because we did "pthread_getspecific(actual_connection_key)"
without ever having initialized the TSD key actual_connection_key.
The results of that are probably platform-specific, but at least
on Linux it often leads to a crash.
To fix, add calls to ecpg_pthreads_init() in the code paths that
might use actual_connection_key uninitialized. It's harmless
(and hopefully inexpensive) to do that more than once.
Per bug #17514 from Okano Naoki. The problem's ancient, so
back-patch to all supported branches.
Discussion: https://postgr.es/m/17514-edd4fad547c5692c@postgresql.org
An error PGresult generated by libpq itself, such as a report of
connection loss, won't have broken-down error fields.
ecpg_raise_backend() blithely assumed that PG_DIAG_MESSAGE_PRIMARY
would always be present, and would end up passing a NULL string
pointer to snprintf when it isn't. That would typically crash
before 3779ac62d, and it would fail to provide a useful error report
in any case. Best practice is to substitute PQerrorMessage(conn)
in such cases, so do that.
Per bug #17421 from Masayuki Hirose. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/17421-790ff887e3188874@postgresql.org
Commits a59c79564 et al. tried to sync libpq's SSL key file
permissions checks with what we've used for years in the backend.
We did not intend to create any new failure cases, but it turns out
we did: restricting the key file's ownership breaks cases where the
client is allowed to read a key file despite not having the identical
UID. In particular a client running as root used to be able to read
someone else's key file; and having seen that I suspect that there are
other, less-dubious use cases that this restriction breaks on some
platforms.
We don't really need an ownership check, since if we can read the key
file despite its having restricted permissions, it must have the right
ownership --- under normal conditions anyway, and the point of this
patch is that any additional corner cases where that works should be
deemed allowable, as they have been historically. Hence, just drop
the ownership check, and rearrange the permissions check to get rid
of its faulty assumption that geteuid() can't be zero. (Note that the
comparable backend-side code doesn't have to cater for geteuid() == 0,
since the server rejects that very early on.)
This does have the end result that the permissions safety check used
for a root user's private key file is weaker than that used for
anyone else's. While odd, root really ought to know what she's doing
with file permissions, so I think this is acceptable.
Per report from Yogendra Suralkar. Like the previous patch,
back-patch to all supported branches.
Discussion: https://postgr.es/m/MW3PR15MB3931DF96896DC36D21AFD47CA3D39@MW3PR15MB3931.namprd15.prod.outlook.com
The target failed, tested $PATH binaries, or tested a stale temporary
installation. Commit c66b438db6 missed
this. Back-patch to v10 (all supported versions).
This change makes libpq apply the same private-key-file ownership
and permissions checks that we have used in the backend since commit
9a83564c5. Namely, that the private key can be owned by either the
current user or root (with different file permissions allowed in the
two cases). This allows system-wide management of key files, which
is just as sensible on the client side as the server, particularly
when the client is itself some application daemon.
Sync the comments about this between libpq and the backend, too.
Back-patch of a59c79564 and 50f03473e into all supported branches.
David Steele
Discussion: https://postgr.es/m/f4b7bc55-97ac-9e69-7398-335e212f7743@pgmasters.net
In libpq and ecpglib, multiple threads can concurrently enter the
initialization logic for message localization. Since we set the
its-done flag before actually doing the work, it'd be possible
for some threads to reach gettext() before anyone has called
bindtextdomain(). Barring bugs in libintl itself, this would not
result in anything worse than failure to localize some early
messages. Nonetheless, it's a bug, and an easy one to fix.
Noted while investigating bug #17299 from Clemens Zeidler
(much thanks to Liam Bowen for followup investigation on that).
It currently appears that that actually *is* a bug in libintl itself,
but that doesn't let us off the hook for this bit.
Back-patch to all supported versions.
Discussion: https://postgr.es/m/17299-7270741958c0b1ab@postgresql.org
Discussion: https://postgr.es/m/CAE7q7Eit4Eq2=bxce=Fm8HAStECjaXUE=WBQc-sDDcgJQ7s7eg@mail.gmail.com
PQcancel() is supposed to be safe to call from a signal handler,
and indeed psql uses it that way. All of the library functions
it uses are specified to be async-signal-safe by POSIX ...
except for strerror. Neither plain strerror nor strerror_r
are considered safe. When this code was written, back in the
dark ages, we probably figured "oh, strerror will just index
into a constant array of strings" ... but in any locale except C,
that's unlikely to be true. Probably the reason we've not heard
complaints is that (a) this error-handling code is unlikely to be
reached in normal use, and (b) in many scenarios, localized error
strings would already have been loaded, after which maybe it's
safe to call strerror here. Still, this is clearly unacceptable.
The best we can do without relying on strerror is to print the
decimal value of errno, so make it do that instead. (This is
probably not much loss of user-friendliness, given that it is
hard to get a failure here.)
Back-patch to all supported branches.
Discussion: https://postgr.es/m/2937814.1641960929@sss.pgh.pa.us
We started to backpatch test infrastructure improvements more aggressively to
make it easier to backpatch test. A proposed isolationtester improvement has a
dependency on b1907d688, backpatch b1907d688 to make it easier to subsequently
backpatch the new proposed isolationtester change.
Discussion: https://postgr.es/m/861977.1639421872@sss.pgh.pa.us
Backpatch: 10-12, the commit already is in 13-HEAD
libpq collects up to a bufferload of data whenever it reads data from
the socket. When SSL or GSS encryption is requested during startup,
any additional data received with the server's yes-or-no reply
remained in the buffer, and would be treated as already-decrypted data
once the encryption handshake completed. Thus, a man-in-the-middle
with the ability to inject data into the TCP connection could stuff
some cleartext data into the start of a supposedly encryption-protected
database session.
This could probably be abused to inject faked responses to the
client's first few queries, although other details of libpq's behavior
make that harder than it sounds. A different line of attack is to
exfiltrate the client's password, or other sensitive data that might
be sent early in the session. That has been shown to be possible with
a server vulnerable to CVE-2021-23214.
To fix, throw a protocol-violation error if the internal buffer
is not empty after the encryption handshake.
Our thanks to Jacob Champion for reporting this problem.
Security: CVE-2021-23222
An out-of-memory failure happening when allocating the structures to
store the connection parameter keywords and values would mess up with
the set of connections saved, as on failure the pthread mutex would
still be hold with the new connection object listed but free()'d.
Rather than just unlocking the mutex, which would leave the static list
of connections into an inconsistent state, move the allocation for the
structures of the connection parameters before beginning the test
manipulation. This ensures that the list of connections and the
connection mutex remain consistent all the time in this code path.
This error is unlikely going to happen, but this could mess up badly
with ECPG clients in surprising ways, so backpatch all the way down.
Reported-by: ryancaicse
Discussion: https://postgr.es/m/17186-b4cfd8f0eb4d1dee@postgresql.org
Backpatch-through: 9.6
In OpenSSL there are two types of BIO's (I/O abstractions):
source/sink and filters. A source/sink BIO is a source and/or
sink of data, ie one acting on a socket or a file. A filter
BIO takes a stream of input from another BIO and transforms it.
In order for BIO_find_type() to be able to traverse the chain
of BIO's and correctly find all BIO's of a certain type they
shall have the type bit set accordingly, source/sink BIO's
(what PostgreSQL implements) use BIO_TYPE_SOURCE_SINK and
filter BIO's use BIO_TYPE_FILTER. In addition to these, file
descriptor based BIO's should have the descriptor bit set,
BIO_TYPE_DESCRIPTOR.
The PostgreSQL implementation didn't set the type bits, which
went unnoticed for a long time as it's only really relevant
for code auditing the OpenSSL installation, or doing similar
tasks. It is required by the API though, so this fixes it.
Backpatch through 9.6 as this has been wrong for a long time.
Author: Itamar Gafni
Discussion: https://postgr.es/m/SN6PR06MB39665EC10C34BB20956AE4578AF39@SN6PR06MB3966.namprd06.prod.outlook.com
Backpatch-through: 9.6
Causing a core dump on out-of-memory seems pretty unfriendly,
and surely is far outside the expected behavior of a general-purpose
library. Just print an error message (as we did already) and return.
These functions unfortunately don't have an error return convention,
but code using them is probably just looking for a quick-n-dirty
print method and wouldn't bother to check anyway.
Although these functions are semi-deprecated, it still seems
appropriate to back-patch this. In passing, also back-patch
b90e6cef1, just to reduce cosmetic differences between the
branches.
Discussion: https://postgr.es/m/3122443.1624735363@sss.pgh.pa.us
Our uses of gss_display_status() and gss_display_name() assumed
that the gss_buffer_desc strings returned by those functions are
null-terminated. It appears that they generally are, given the
lack of field complaints up to now. However, the available
documentation does not promise this, and some man pages
for gss_display_status() show examples that rely on the
gss_buffer_desc.length field instead of expecting null
termination. Also, we now have a report that on some
implementations, clang's address sanitizer is of the opinion
that the byte after the specified length is undefined.
Hence, change the code to rely on the length field instead.
This might well be cosmetic rather than fixing any real bug, but
it's hard to be sure, so back-patch to all supported branches.
While here, also back-patch the v12 changes that made pg_GSS_error
deal honestly with multiple messages available from
gss_display_status.
Per report from Sudheer H R.
Discussion: https://postgr.es/m/5372B6D4-8276-42C0-B8FB-BD0918826FC3@tekenlight.com
An incorrectly-encoded multibyte character near the end of a string
could cause various processing loops to run past the string's
terminating NUL, with results ranging from no detectable issue to
a program crash, depending on what happens to be in the following
memory.
This isn't an issue in the server, because we take care to verify
the encoding of strings before doing any interesting processing
on them. However, that lack of care leaked into client-side code
which shouldn't assume that anyone has validated the encoding of
its input.
Although this is certainly a bug worth fixing, the PG security team
elected not to regard it as a security issue, primarily because
any untrusted text should be sanitized by PQescapeLiteral or
the like before being incorporated into a SQL or psql command.
(If an app fails to do so, the same technique can be used to
cause SQL injection, with probably much more dire consequences
than a mere client-program crash.) Those functions were already
made proof against this class of problem, cf CVE-2006-2313.
To fix, invent PQmblenBounded() which is like PQmblen() except it
won't return more than the number of bytes remaining in the string.
In HEAD we can make this a new libpq function, as PQmblen() is.
It seems imprudent to change libpq's API in stable branches though,
so in the back branches define PQmblenBounded as a macro in the files
that need it. (Note that just changing PQmblen's behavior would not
be a good idea; notably, it would completely break the escaping
functions' defense against this exact problem. So we just want a
version for those callers that don't have any better way of handling
this issue.)
Per private report from houjingyi. Back-patch to all supported branches.
Commit 92785dac2 copied some logic related to advancement of inStart
from pqParseInput3 into getRowDescriptions and getAnotherTuple,
because it wanted to allow user-defined row processor callbacks to
potentially longjmp out of the library, and inStart would have to be
updated before that happened to avoid an infinite loop. We later
decided that that API was impossibly fragile and reverted it, but
we didn't undo all of the related code changes, and this bit of
messiness survived. Undo it now so that there's just one place in
pqParseInput3's processing where inStart is advanced; this will
simplify addition of better tracing support.
getParamDescriptions had grown similar processing somewhere along
the way (not in 92785dac2; I didn't track down just when), but it's
actually buggy because its handling of corrupt-message cases seems to
have been copied from the v2 logic where we lacked a known message
length. The cases where we "goto not_enough_data" should not simply
return EOF, because then we won't consume the message, potentially
creating an infinite loop. That situation now represents a
definitively corrupt message, and we should report it as such.
Although no field reports of getParamDescriptions getting stuck in
a loop have been seen, it seems appropriate to back-patch that fix.
I chose to back-patch all of this to keep the logic looking more alike
in supported branches.
Discussion: https://postgr.es/m/2217283.1615411989@sss.pgh.pa.us
We had "short *mdy" in the extern declarations, but "short mdy[3]"
in the actual function definitions. Per C99 these are equivalent,
but recent versions of gcc have started to issue warnings about
the inconsistency. Clean it up before the warnings get any more
widespread.
Back-patch, in case anyone wants to build older PG versions with
bleeding-edge compilers.
Discussion: https://postgr.es/m/2401575.1611764534@sss.pgh.pa.us
We must not set the "done" flag until after we've executed the
initialization function. Otherwise, other threads can fall through
the initial unlocked test before initialization is really complete.
This has been seen to cause rare failures of ecpg's thread/descriptor
test, and it could presumably cause other sorts of misbehavior in
threaded ECPG-using applications, since ecpglib relies on
pthread_once() in several places.
Diagnosis and patch by me, based on investigation by Alexander Lakhin.
Back-patch to all supported branches (the bug dates to 2007).
Discussion: https://postgr.es/m/16685-d6cd241872c101d3@postgresql.org
The Windows documentation insists that every WSAStartup call should
have a matching WSACleanup call. However, if that ever had actual
relevance, it wasn't in this century. Every remotely-modern Windows
kernel is capable of cleaning up when a process exits without doing
that, and must be so to avoid resource leaks in case of a process
crash. Moreover, Postgres backends have done WSAStartup without
WSACleanup since commit 4cdf51e64 in 2004, and we've never seen any
indication of a problem with that.
libpq's habit of doing WSAStartup during connection start and
WSACleanup during shutdown is also rather inefficient, since a
series of non-overlapping connection requests leads to repeated,
quite expensive DLL unload/reload cycles. We document a workaround
for that (having the application call WSAStartup for itself), but
that's just a kluge. It's also worth noting that it's far from
uncommon for applications to exit without doing PQfinish, and
we've not heard reports of trouble from that either.
However, the real reason for acting on this is that recent
experiments by Alexander Lakhin show that calling WSACleanup
during PQfinish is triggering the symptom we occasionally see
that a process using libpq fails to emit expected stdio output.
Therefore, let's change libpq so that it calls WSAStartup only
once per process, during the first connection attempt, and never
calls WSACleanup at all.
While at it, get rid of the only other WSACleanup call in our code
tree, in pg_dump/parallel.c; that presumably is equally useless.
Back-patch of HEAD commit 7d00a6b2d.
Discussion: https://postgr.es/m/ac976d8c-03df-d6b8-025c-15a2de8d9af1@postgrespro.ru
Historically there's been a hard-wired assumption here that no line of
a .pgpass file could be as long as NAMEDATALEN*5 bytes. That's a bit
shaky to start off with, because (a) there's no reason to suppose that
host names fit in NAMEDATALEN, and (b) this figure fails to allow for
backslash escape characters. However, it fails completely if someone
wants to use a very long password, and we're now hearing reports of
people wanting to use "security tokens" that can run up to several
hundred bytes. Another angle is that the file is specified to allow
comment lines, but there's no reason to assume that long comment lines
aren't possible.
Rather than guessing at what might be a more suitable limit, let's
replace the fixed-size buffer with an expansible PQExpBuffer. That
adds one malloc/free cycle to the typical use-case, but that's surely
pretty cheap relative to the I/O this code has to do.
Also, add TAP test cases to exercise this code, because there was no
test coverage before.
This reverts most of commit 2eb3bc588, as there's no longer a need for
a warning message about overlength .pgpass lines. (I kept the explicit
check for comment lines, though.)
In HEAD and v13, this also fixes an oversight in 74a308cf5: there's not
much point in explicit_bzero'ing the line buffer if we only do so in two
of the three exit paths.
Back-patch to all supported branches, except that the test case only
goes back to v10 where src/test/authentication/ was added.
Discussion: https://postgr.es/m/4187382.1598909041@sss.pgh.pa.us
A couple of test cases had connect_timeout=14, a value that seems
to have been plucked from a hat. While it's more than sufficient
for normal cases, slow/overloaded buildfarm machines can get a timeout
failure here, as per recent report from "sungazer". Increase to 180
seconds, which is in line with our typical timeouts elsewhere in
the regression tests.
Back-patch to 9.6; the code looks different in 9.5, and this doesn't
seem to be quite worth the effort to adapt to that.
Report: https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=sungazer&dt=2020-08-04%2007%3A12%3A22
Michael Paquier
Tom Lane
Peter Eisentraut
Alvaro Herrera
Noah Misch
Andres Freund
Daniel Gustafsson
John Naylor
Bruce Momjian