o read global SSL configuration file
o add GUC "ssl_ciphers" to control allowed ciphers
o add libpq environment variable PGSSLKEY to control SSL hardware keys
Victor B. Wagner
Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
Also update two error messages mentioned in the documenation to match.
more, and standard_conforming_strings less, because in the future non-E
strings will not treat backslashes specially.
Also use E'' strings where backslashes are used in examples. (The
existing examples would have drawn warnings.)
Backpatch to 8.2.X.
and standard_conforming_strings. The encoding changes are needed for proper
escaping in multibyte encodings, as per the SQL-injection vulnerabilities
noted in CVE-2006-2313 and CVE-2006-2314. Concurrent fixes are being applied
to the server to ensure that it rejects queries that may have been corrupted
by attempted SQL injection, but this merely guarantees that unpatched clients
will fail rather than allow injection. An actual fix requires changing the
client-side code. While at it we have also fixed these routines to understand
about standard_conforming_strings, so that the upcoming changeover to SQL-spec
string syntax can be somewhat transparent to client code.
Since the existing API of PQescapeString and PQescapeBytea provides no way to
inform them which settings are in use, these functions are now deprecated in
favor of new functions PQescapeStringConn and PQescapeByteaConn. The new
functions take the PGconn to which the string will be sent as an additional
parameter, and look inside the connection structure to determine what to do.
So as to provide some functionality for clients using the old functions,
libpq stores the latest encoding and standard_conforming_strings values
received from the backend in static variables, and the old functions consult
these variables. This will work reliably in clients using only one Postgres
connection at a time, or even multiple connections if they all use the same
encoding and string syntax settings; which should cover many practical
scenarios.
Clients that use homebrew escaping methods, such as PHP's addslashes()
function or even hardwired regexp substitution, will require extra effort
to fix :-(. It is strongly recommended that such code be replaced by use of
PQescapeStringConn/PQescapeByteaConn if at all feasible.
compatibility for release 7.2 and earlier. I have not altered any
mentions of release 7.3 or later. The release notes were not modified,
so the changes are still documented, just not in the main docs.
PQregisterThreadLock().
I also remove the crypt() mention in the libpq threading section and
added a single sentence in the client-auth manual page under crypt().
Crypt authentication is so old now that a separate paragraph about it
seemed unwise.
I also added a comment about our use of locking around pqGetpwuid().
a parameter in binary format. Also, add a TIP explaining how to use casts
in the query text to avoid needing to specify parameter types by OID.
Also fix bogus spacing --- apparently somebody expanded the tabs in the
example programs to 8 spaces instead of 4 when transposing them into SGML.
with main, avoid using a SQL-defined SQLSTATE for what is most definitely
not a SQL-compatible error condition, fix documentation omissions,
adhere to message style guidelines, don't use two GUC_REPORT variables
when one is sufficient. Nothing done about pg_dump issues.
unlike template0 and template1 does not have any special status in
terms of backend functionality. However, all external utilities such
as createuser and createdb now connect to "postgres" instead of
template1, and the documentation is changed to encourage people to use
"postgres" instead of template1 as a play area. This should fix some
longstanding gotchas involving unexpected propagation of database
objects by createdb (when you used template1 without understanding
the implications), as well as ameliorating the problem that CREATE
DATABASE is unhappy if anyone else is connected to template1.
Patch by Dave Page, minor editing by Tom Lane. All per recent
pghackers discussions.
patch adds missing checks to the call sites of malloc(), strdup(),
PQmakeEmptyPGresult(), pqResultAlloc(), and pqResultStrdup(), and updates
the documentation. Per original report from Volkan Yazici about
PQmakeEmptyPGresult() not checking for malloc() failure.
postgresql.conf.
---------------------------------------------------------------------------
Here's an updated version of the patch, with the following changes:
1) No longer uses "service name" as "application version". It's instead
hardcoded as "postgres". It could be argued that this part should be
backpatched to 8.0, but it doesn't make a big difference until you can
start changing it with GUC / connection parameters. This change only
affects kerberos 5, not 4.
2) Now downcases kerberos usernames when the client is running on win32.
3) Adds guc option for "krb_caseins_users" to make the server ignore
case mismatch which is required by some KDCs such as Active Directory.
Off by default, per discussion with Tom. This change only affects
kerberos 5, not 4.
4) Updated so it doesn't conflict with the rendevouz/bonjour patch
already in ;-)
Magnus Hagander
! authentication. Use of this environment variable is not
! recommended for security reasons (some operating systems
! allow non-root users to see process environment variables via
! <application>ps</>); instead consider using the
! <filename>~/.pgpass</> file (see <xref linkend="libpq-pgpass">).
discussion on pgsql-hackers-win32 list. Documentation still needs to
be tweaked --- I'm not sure how to refer to the APPDATA folder in
user documentation.
Use this new function in psql. Implement query cancellation in psql for
Windows. Code by Magnus Hagander, documentation and minor editorialization
by Tom Lane.
I haven't mentioned any of
~/.postgresql/{root.crt,postgresql.crt,postresql.key} even though they
are checked for in the code, since they do not appear to be supported. I
base this on discussions in pgsql-hackers.
Dominic Mitchell
environment variable processing to libpq.
The patch also adds code to our client apps so we set the environment
variable directly based on our binary location, unless it is already
set. This will allow our applications to emit proper locale messages
that are generated in libpq.
to handle memory management for char pointers returned by libpq functions.
Original patch by Gavin Sherry, some tweaking and consistency improvements
by Neil Conway.
ignore SIGPIPE from send() in libpq, but terminate on any other SIGPIPE,
unless the user installs their own signal handler.
This is a minor fix because the only time you get SIGPIPE from libpq's
send() is when the backend dies.
will downcase the supplied field name unless it is double-quoted. Also,
upgrade the routine's handling of double quotes to match the backend,
in particular support doubled double quotes within quoted identifiers.
Per pgsql-interfaces discussion a couple weeks ago.
libpq, talking to an old server, should assume SQL_ASCII as the default
client encoding, because that is what the server will actually use (not
the server encoding).
libpq users to perform Bind/Execute of previously prepared statements.
Per yesterday's discussion, this offers enough performance improvement
to justify bending the 'no new features during beta' rule.
modes (and replace the requiressl boolean). The four options were first
spelled out by Magnus Hagander <mha@sollentuna.net> on 2000-08-23 in email
to pgsql-hackers, archived here:
http://archives.postgresql.org/pgsql-hackers/2000-08/msg00639.php
My original less-flexible patch and the ensuing thread are archived at:
http://dbforums.com/t623845.html
Attached is a new patch, including documentation.
To sum up, there's a new client parameter "sslmode" and environment
variable "PGSSLMODE", with these options:
sslmode description
------- -----------
disable Unencrypted non-SSL only
allow Negotiate, prefer non-SSL
prefer Negotiate, prefer SSL (default)
require Require SSL
The only change to the server is a new pg_hba.conf line type,
"hostnossl", for specifying connections that are not allowed to use SSL
(for example, to prevent servers on a local network from accidentally
using SSL and wasting cycles). Thus the 3 pg_hba.conf line types are:
pg_hba.conf line types
----------------------
host applies to either SSL or regular connections
hostssl applies only to SSL connections
hostnossl applies only to regular connections
These client and server options, the postgresql.conf ssl = false option,
and finally the possibility of compiling with no SSL support at all,
make quite a range of combinations to test. I threw together a test
script to try many of them out. It's in a separate tarball with its
config files, a patch to psql so it'll announce SSL connections even in
absence of a tty, and the test output. The test is especially informative
when run on the same tty the postmaster was started on, so the FATAL:
errors during negotiation are interleaved with the psql client output.
I saw Tom write that new submissions for 7.4 have to be in before midnight
local time, and since I'm on the east coast in the US, this just makes it
in before the bell. :)
Jon Jensen
only remnant of this failed experiment is that the server will take
SET AUTOCOMMIT TO ON. Still TODO: provide some client-side autocommit
logic in libpq.
have length words. COPY OUT reimplemented per new protocol: it doesn't
need \. anymore, thank goodness. COPY BINARY to/from frontend works,
at least as far as the backend is concerned --- libpq's PQgetline API
is not up to snuff, and will have to be replaced with something that is
null-safe. libpq uses message length words for performance improvement
(no cycles wasted rescanning long messages), but not yet for error
recovery.
with variable-width fields. No more truncation of long user names.
Also, libpq can now send its environment-variable-driven SET commands
as part of the startup packet, saving round trips to server.
including:
- replacing all the appropriate usages of <citetitle>PostgreSQL
...</citetitle> with &cite-user;, &cite-admin;, and so on
- fix an omission in the EXECUTE documentation
- add some more text to the EXPLAIN documentation
- improve the PL/PgSQL RETURN NEXT documentation (more work to do here)
- minor markup fixes
Neil Conway
Chapter 1. libpq - C Library
1.3. Command Execution Functions
1.3.3. Escaping binary strings for inclusion in SQL queries
I found the line
"The result string length does not include the terminating zero byte of the result."
is not right.
The result string length does indeed include the terminating zero byte.
Christoph Haller
PGPASSWORDFILE environment variable. I have modified libpq to make use
of this variable. I present the first cut here.
Currently the format for the file should be
host:port:database:user:password
Alvaro Herrera
libpq.sgml
I was trying (but gave up) to cross-reference back to the input escape
table in the User's Guide, but could not get the documentation to
compile with a cross-book xref (missing IDREF error). Can a cross-book
xref be done?
Joe Conway
discussion on pgsql-hackers (especially the frightening memory dump in
<12273.999562219@sss.pgh.pa.us>), we decided that it is best not to
use identifiers from an untrusted source at all. Therefore, all
claims of the suitability of PQescapeString() for identifiers have
been removed.
Florian Weimer
Client headers are no longer in a subdirectory, since they have been made
namespace-clean.
Internal libpq headers are in a private subdirectory.
Server headers are in a private subdirectory. pg_config has a new option
to point there.
hosting product, on both shared and dedicated machines. We currently
offer Oracle and MySQL, and it would be a nice middle-ground.
However, as shipped, PostgreSQL lacks the following features we need
that MySQL has:
1. The ability to listen only on a particular IP address. Each
hosting customer has their own IP address, on which all of their
servers (http, ftp, real media, etc.) run.
2. The ability to place the Unix-domain socket in a mode 700 directory.
This allows us to automatically create an empty database, with an
empty DBA password, for new or upgrading customers without having
to interactively set a DBA password and communicate it to (or from)
the customer. This in turn cuts down our install and upgrade times.
3. The ability to connect to the Unix-domain socket from within a
change-rooted environment. We run CGI programs chrooted to the
user's home directory, which is another reason why we need to be
able to specify where the Unix-domain socket is, instead of /tmp.
4. The ability to, if run as root, open a pid file in /var/run as
root, and then setuid to the desired user. (mysqld -u can almost
do this; I had to patch it, too).
The patch below fixes problem 1-3. I plan to address #4, also, but
haven't done so yet. These diffs are big enough that they should give
the PG development team something to think about in the meantime :-)
Also, I'm about to leave for 2 weeks' vacation, so I thought I'd get
out what I have, which works (for the problems it tackles), now.
With these changes, we can set up and run PostgreSQL with scripts the
same way we can with apache or proftpd or mysql.
In summary, this patch makes the following enhancements:
1. Adds an environment variable PGUNIXSOCKET, analogous to MYSQL_UNIX_PORT,
and command line options -k --unix-socket to the relevant programs.
2. Adds a -h option to postmaster to set the hostname or IP address to
listen on instead of the default INADDR_ANY.
3. Extends some library interfaces to support the above.
4. Fixes a few memory leaks in PQconnectdb().
The default behavior is unchanged from stock 7.0.2; if you don't use
any of these new features, they don't change the operation.
David J. MacKenzie
I hope I didn't mess the SGML up too bad, but somebody should definitly
look that over. I tried to steal as much as I could from around :-)
This patch updates:
* Installation instructions (paragraph on how to compile with openssl)
* Documentation of pg_hba.conf (added "hostssl" record docs)
* Libpq documentation (added connection option, documentation of
PQgetssl() function)
* Add section on SSL to "Server Runtime Environment"
If you beleive any particular area needs more attention, please let me know.
//Magnus
I hope I didn't mess the SGML up too bad, but somebody should definitly
look that over. I tried to steal as much as I could from around :-)
This patch updates:
* Installation instructions (paragraph on how to compile with openssl)
* Documentation of pg_hba.conf (added "hostssl" record docs)
* Libpq documentation (added connection option, documentation of
PQgetssl() function)
* Add section on SSL to "Server Runtime Environment"
If you beleive any particular area needs more attention, please let me know.
//Magnus
it in a separate object. There's no value in keeping the state separate,
and it creates dangling-pointer problems. Also, remove PQsetenv routines
from public API, until and unless they are redesigned to have a safer
interface. Since they were never part of the documented API before 7.0,
it's unlikely that anyone is calling them.
accesses versus sequential accesses, a (very crude) estimate of the
effects of caching on random page accesses, and cost to evaluate WHERE-
clause expressions. Export critical parameters for this model as SET
variables. Also, create SET variables for the planner's enable flags
(enable_seqscan, enable_indexscan, etc) so that these can be controlled
more conveniently than via PGOPTIONS.
Planner now estimates both startup cost (cost before retrieving
first tuple) and total cost of each path, so it can optimize queries
with LIMIT on a reasonable basis by interpolating between these costs.
Same facility is a win for EXISTS(...) subqueries and some other cases.
Redesign pathkey representation to achieve a major speedup in planning
(I saw as much as 5X on a 10-way join); also minor changes in planner
to reduce memory consumption by recycling discarded Path nodes and
not constructing unnecessary lists.
Minor cleanups to display more-plausible costs in some cases in
EXPLAIN output.
Initdb forced by change in interface to index cost estimation
functions.
Initdb help correction
Changed end/abort to commit/rollback and changed related notices
Commented out way old printing functions in libpq
Fixed a typo in alter table / alter column
in libpq --- mostly, poor response to error conditions. You now actually
get to see the postmaster's 'The Data Base System is starting up' message,
which you didn't before. I suspect the SSL code is still broken though.
PQconnectStart
PQconnectPoll
PQresetStart
PQresetPoll
PQsetenvStart
PQsetenvPoll
PQsetenvAbort
and brings into the published interface
PQsetenv.
The first four are asynchronous analogues of PQconnectdb and PQreset -
they allow an application to connect to the DB without blocking on
remote I/O.
The PQsetenv functions perform an environment negotiation with the
server.
Internal to libpq, pqReadReady and pqWriteReady have been made available
across the library (they were previously static functions inside
fe-misc.c). A lot of internal rearrangement has been necessary to
support these changes.
The API documentation has been updated also.
Caveats:
o The Windows code does not default to using non-blocking sockets,
since I have no documentation: Define WIN32_NON_BLOCKING_CONNECTIONS to
do that.
o The SSL code still blocks.
Ewan Mellor.
on connection. This patch changes it to use PQconnectdb rather than
{fe_setauthsvc,PQsetdb}. This still isn't the complete solution, as
there
is no provision for user,password in class PgEnv, but it does get rid of
the error message. Tested with gcc version egcs-2.91.60 19981201
(egcs-1.1.1 release) under NetBSD-1.3K/i386.
Cheers,
Patrick Welche
Add new bibliographic references from Paul Aoki.
Include libpq++ docs from the old man page in the Programmer's Guide.
Update Unix installation info for ODBC.
Attached are diffs (from current cvs sources) to bring libpq.sgml
and libpq.3 up to date.
It appears that at various times in the past, people have made edits to
one or the other of these files but not both. I propagated some changes
from each into the other, but I don't think I caught every
inconsistency. It'd be real nice if the man pages could be
automatically generated from the SGML...
1. Rewritten libpq to allow asynchronous clients.
2. Implemented client side of cancel protocol in library,
and patched psql.c to send a cancel request upon SIGINT. The
backend doesn't notice it yet :-(
3. Implemented 'Z' protocol message addition and renaming of
copy in/out start messages. These are implemented conditionally,
ie, the client protocol version is checked; so the code should
still work with 1.0 clients.
4. Revised protocol and libpq sgml documents (don't have an SGML
compiler, though, so there may be some markup glitches here).
What remains to be done:
1. Implement addition of atttypmod field to RowDescriptor messages.
The client-side code is there but ifdef'd out. I have no idea
what to change on the backend side. The field should be sent
only if protocol >= 2.0, of course.
2. Implement backend response to cancel requests received as OOB
messages. (This prolly need not be conditional on protocol
version; just do it if you get SIGURG.)
3. Update libpq.3. (I'm hoping this can be generated mechanically
from libpq.sgml... if not, will do it by hand.) Is there any
other doco to fix?
4. Update non-libpq interfaces as necessary. I patched libpgtcl
so that it would compile, but haven't tested it. Dunno what
needs to be done with the other interfaces.
Have at it!
Tom Lane
Bruce Momjian
Tom Lane
Andrew Dunstan
Peter Eisentraut
Neil Conway
PostgreSQL Daemon
Thomas G. Lockhart
Marc G. Fournier