Previously, lookups of non-existent user names could return "Success";
it will now return "User does not exist" by resetting errno. This also
centralizes the user name lookup code in libpgport.
Report and analysis by Nicolas Marchildon; patch by me
This sets up ECDH key exchange, when compiling against OpenSSL that
supports EC. Then the ECDHE-RSA and ECDHE-ECDSA cipher suites can be
used for SSL connections. The latter one means that EC keys are now
usable.
The reason for EC key exchange is that it's faster than DHE and it
allows to go to higher security levels where RSA will be horribly slow.
There is also new GUC option ssl_ecdh_curve that specifies the curve
name used for ECDH. It defaults to "prime256v1", which is the most
common curve in use in HTTPS.
From: Marko Kreen <markokr@gmail.com>
Reviewed-by: Adrian Klaver <adrian.klaver@gmail.com>
By default, OpenSSL (and SSL/TLS in general) lets the client cipher
order take priority. This is OK for browsers where the ciphers were
tuned, but few PostgreSQL client libraries make the cipher order
configurable. So it makes sense to have the cipher order in
postgresql.conf take priority over client defaults.
This patch adds the setting "ssl_prefer_server_ciphers" that can be
turned on so that server cipher order is preferred. Per discussion,
this now defaults to on.
From: Marko Kreen <markokr@gmail.com>
Reviewed-by: Adrian Klaver <adrian.klaver@gmail.com>
Current OpenSSL code includes a BIO_clear_retry_flags() step in the
sock_write() function. Either we failed to copy the code correctly, or
they added this since we copied it. In any case, lack of the clear step
appears to be the cause of the server lockup after connection loss reported
in bug #8647 from Valentine Gogichashvili. Assume that this is correct
coding for all OpenSSL versions, and hence back-patch to all supported
branches.
Diagnosis and patch by Alexander Kukushkin.
These functions must be careful that they return the intended value of
errno to their callers. There were several scenarios where this might
not happen:
1. The recent SSL renegotiation patch added a hunk of code that would
execute after setting errno. In the first place, it's doubtful that we
should consider renegotiation to be successfully completed after a failure,
and in the second, there's no real guarantee that the called OpenSSL
routines wouldn't clobber errno. Fix by not executing that hunk except
during success exit.
2. errno was left in an unknown state in case of an unrecognized return
code from SSL_get_error(). While this is a "can't happen" case, it seems
like a good idea to be sure we know what would happen, so reset errno to
ECONNRESET in such cases. (The corresponding code in libpq's fe-secure.c
already did this.)
3. There was an (undocumented) assumption that client_read_ended() wouldn't
change errno. While true in the current state of the code, this seems less
than future-proof. Add explicit saving/restoring of errno to make sure
that changes in the called functions won't break things.
I see no need to back-patch, since #1 is new code and the other two issues
are mostly hypothetical.
Per discussion with Amit Kapila.
With these, one need no longer manipulate large object descriptors and
extract numeric constants from header files in order to read and write
large object contents from SQL.
Pavel Stehule, reviewed by Rushabh Lathia.
asprintf(), aside from not being particularly portable, has a fundamentally
badly-designed API; the psprintf() function that was added in passing in
the previous patch has a much better API choice. Moreover, the NetBSD
implementation that was borrowed for the previous patch doesn't work with
non-C99-compliant vsnprintf, which is something we still have to cope with
on some platforms; and it depends on va_copy which isn't all that portable
either. Get rid of that code in favor of an implementation similar to what
we've used for many years in stringinfo.c. Also, move it into libpgcommon
since it's not really libpgport material.
I think this patch will be enough to turn the buildfarm green again, but
there's still cosmetic work left to do, namely get rid of pg_asprintf()
in favor of using psprintf(). That will come in a followon patch.
Add asprintf(), pg_asprintf(), and psprintf() to simplify string
allocation and composition. Replacement implementations taken from
NetBSD.
Reviewed-by: Álvaro Herrera <alvherre@2ndquadrant.com>
Reviewed-by: Asif Naeem <anaeem.it@gmail.com>
The existing renegotiation code was home for several bugs: it might
erroneously report that renegotiation had failed; it might try to
execute another renegotiation while the previous one was pending; it
failed to terminate the connection if the renegotiation never actually
took place; if a renegotiation was started, the byte count was reset,
even if the renegotiation wasn't completed (this isn't good from a
security perspective because it means continuing to use a session that
should be considered compromised due to volume of data transferred.)
The new code is structured to avoid these pitfalls: renegotiation is
started a little earlier than the limit has expired; the handshake
sequence is retried until it has actually returned successfully, and no
more than that, but if it fails too many times, the connection is
closed. The byte count is reset only when the renegotiation has
succeeded, and if the renegotiation byte count limit expires, the
connection is terminated.
This commit only touches the master branch, because some of the changes
are controversial. If everything goes well, a back-patch might be
considered.
Per discussion started by message
20130710212017.GB4941@eldon.alvh.no-ip.org
We had two copies of this function in the backend and libpq, which was
already pretty bogus, but it turns out that we need it in some other
programs that don't use libpq (such as pg_test_fsync). So put it where
it probably should have been all along. The signal-mask-initialization
support in src/backend/libpq/pqsignal.c stays where it is, though, since
we only need that in the backend.
Instead of just reporting which user failed to log in, log both the
line number in the active pg_hba.conf file (which may not match reality
in case the file has been edited and not reloaded) and the contents of
the matching line (which will always be correct), to make it easier
to debug incorrect pg_hba.conf files.
The message to the client remains unchanged and does not include this
information, to prevent leaking security sensitive information.
Reviewed by Tom Lane and Dean Rasheed
The length of a socket path name is constrained by the size of struct
sockaddr_un, and there's not a lot we can do about it since that is a
kernel API. However, it would be a good thing if we produced an
intelligible error message when the user specifies a socket path that's too
long --- and getaddrinfo's standard API is too impoverished to do this in
the natural way. So insert explicit tests at the places where we construct
a socket path name. Now you'll get an error that makes sense and even
tells you what the limit is, rather than something generic like
"Non-recoverable failure in name resolution".
Per trouble report from Jeremy Drake and a fix idea from Andrew Dunstan.
Files opened with BasicOpenFile or PathNameOpenFile are not automatically
cleaned up on error. That puts unnecessary burden on callers that only want
to keep the file open for a short time. There is AllocateFile, but that
returns a buffered FILE * stream, which in many cases is not the nicest API
to work with. So add function called OpenTransientFile, which returns a
unbuffered fd that's cleaned up like the FILE* returned by AllocateFile().
This plugs a few rare fd leaks in error cases:
1. copy_file() - fixed by by using OpenTransientFile instead of BasicOpenFile
2. XLogFileInit() - fixed by adding close() calls to the error cases. Can't
use OpenTransientFile here because the fd is supposed to persist over
transaction boundaries.
3. lo_import/lo_export - fixed by using OpenTransientFile instead of
PathNameOpenFile.
In addition to plugging those leaks, this replaces many BasicOpenFile() calls
with OpenTransientFile() that were not leaking, because the code meticulously
closed the file on error. That wasn't strictly necessary, but IMHO it's good
for robustness.
The same leaks exist in older versions, but given the rarity of the issues,
I'm not backpatching this. Not yet, anyway - it might be good to backpatch
later, after this mechanism has had some more testing in master branch.
Do read/write permissions checks at most once per large object descriptor,
not once per lo_read or lo_write call as before. The repeated tests were
quite useless in the read case since the snapshot-based tests were
guaranteed to produce the same answer every time. In the write case,
the extra tests could in principle detect revocation of write privileges
after a series of writes has started --- but there's a race condition there
anyway, since we'd check privileges before performing and certainly before
committing the write. So there's no real advantage to checking every
single time, and we might as well redefine it as "only check the first
time".
On the same reasoning, remove the LargeObjectExists checks in inv_write
and inv_truncate. We already checked existence when the descriptor was
opened, and checking again doesn't provide any real increment of safety
that would justify the cost.
Fix broken-on-bigendian-machines byte-swapping functions, add missed update
of alternate regression expected file, improve error reporting, remove some
unnecessary code, sync testlo64.c with current testlo.c (it seems to have
been cloned from a very old copy of that), assorted cosmetic improvements.
4TB large objects (standard 8KB BLCKSZ case). For this purpose new
libpq API lo_lseek64, lo_tell64 and lo_truncate64 are added. Also
corresponding new backend functions lo_lseek64, lo_tell64 and
lo_truncate64 are added. inv_api.c is changed to handle 64-bit
offsets.
Patch contributed by Nozomi Anzai (backend side) and Yugo Nagata
(frontend side, docs, regression tests and example program). Reviewed
by Kohei Kaigai. Committed by Tatsuo Ishii with minor editings.
Similar changes were done to pg_hba.conf earlier already, this commit makes
pg_ident.conf to behave the same as pg_hba.conf.
This has two user-visible effects. First, if pg_ident.conf contains multiple
errors, the whole file is parsed at postmaster startup time and all the
errors are immediately reported. Before this patch, the file was parsed and
the errors were reported only when someone tries to connect using an
authentication method that uses the file, and the parsing stopped on first
error. Second, if you SIGHUP to reload the config files, and the new
pg_ident.conf file contains an error, the error is logged but the old file
stays in effect.
Also, regular expressions in pg_ident.conf are now compiled only once when
the file is loaded, rather than every time the a user is authenticated. That
should speed up authentication if you have a lot of regexps in the file.
Amit Kapila
Replace unix_socket_directory with unix_socket_directories, which is a list
of socket directories, and adjust postmaster's code to allow zero or more
Unix-domain sockets to be created.
This is mostly a straightforward change, but since the Unix sockets ought
to be created after the TCP/IP sockets for safety reasons (better chance
of detecting a port number conflict), AddToDataDirLockFile needs to be
fixed to support out-of-order updates of data directory lockfile lines.
That's a change that had been foreseen to be necessary someday anyway.
Honza Horak, reviewed and revised by Tom Lane
The Solaris Studio compiler warns about these instances, unlike more
mainstream compilers such as gcc. But manual inspection showed that
the code is clearly not reachable, and we hope no worthy compiler will
complain about removing this code.
rc should be an int here, not a pgsocket. Fairly harmless as long as
pgsocket is an integer type, but nonetheless wrong. Error introduced
in commit 87091cb1f1.
For those variables only used when asserts are enabled, use a new
macro PG_USED_FOR_ASSERTS_ONLY, which expands to
__attribute__((unused)) when asserts are not enabled.
Both libpq and the backend would truncate a common name extracted from a
certificate at 32 bytes. Replace that fixed-size buffer with dynamically
allocated string so that there is no hard limit. While at it, remove the
code for extracting peer_dn, which we weren't using for anything; and
don't bother to store peer_cn longer than we need it in libpq.
This limit was not so terribly unreasonable when the code was written,
because we weren't using the result for anything critical, just logging it.
But now that there are options for checking the common name against the
server host name (in libpq) or using it as the user's name (in the server),
this could result in undesirable failures. In the worst case it even seems
possible to spoof a server name or user name, if the correct name is
exactly 32 bytes and the attacker can persuade a trusted CA to issue a
certificate in which that string is a prefix of the certificate's common
name. (To exploit this for a server name, he'd also have to send the
connection astray via phony DNS data or some such.) The case that this is
a realistic security threat is a bit thin, but nonetheless we'll treat it
as one.
Back-patch to 8.4. Older releases contain the faulty code, but it's not
a security problem because the common name wasn't used for anything
interesting.
Reported and patched by Heikki Linnakangas
Security: CVE-2012-0867
This allows changing the location of the files that were previously
hard-coded to server.crt, server.key, root.crt, root.crl.
server.crt and server.key continue to be the default settings and are
thus required to be present by default if SSL is enabled. But the
settings for the server-side CA and CRL are now empty by default, and
if they are set, the files are required to be present. This replaces
the previous behavior of ignoring the functionality if the files were
not found.
In e5e2fc842c, blank lines were removed
after a comment block, which now looks as though the comment refers to
the immediately following code, but it actually refers to the
preceding code. So put the blank lines back.
lost. The only way we detect that at the moment is when write() fails when
we try to write to the socket.
Florian Pflug with small changes by me, reviewed by Greg Jaskiewicz.
