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.
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.
protocol 3, then falls back to 2 if postmaster rejects the startup packet
with an old-format error message. A side benefit of the rewrite is that
SSL-encrypted connections can now be made without blocking. (I think,
anyway, but do not have a good way to test.)
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.
problems in applications that may have a large number of files open,
such that libpq's socket number exceeds the range supported by fd_set.
From Chris Brown.
that tv_sec is signed; return a useful error message on timeout failure;
honor PGCONNECT_TIMEOUT environment variable in PQsetdbLogin; make code
obey documentation statement that timeout=0 means no timeout.
client
utilities (libpq.dll and psql.exe) for win32 (missing defines,
adjustments to
includes, pedantic casting, non-existent functions) per:
http://developer.postgresql.org/docs/postgres/install-win32.html.
It compiles cleanly under Windows 2000 using Visual Studio .net. Also
compiles clean and passes all regression tests (regular and contrib)
under Linux.
In addition to a review by the usual suspects, it would be very
desirable for someone well versed in the peculiarities of win32 to take
a look.
Joe Conway
files rather than a header file where they belong. Pay some modicum
of attention to picking global routine names that aren't likely to
conflict with surrounding applications.
I am no longer pursuing a total non-blocking implementation. I haven't
found a good way to test it with the type of work that I do with
PostgreSQL. I do use blocking SSL sockets with this mod and have had no
problem whatsoever. The bug that I fixed in this patch is exceptionally
hard to reproduce reliably.
Jack Bates
Attached are a revised set of SSL patches. Many of these patches
are motivated by security concerns, it's not just bug fixes. The key
differences (from stock 7.2.1) are:
*) almost all code that directly uses the OpenSSL library is in two
new files,
src/interfaces/libpq/fe-ssl.c
src/backend/postmaster/be-ssl.c
in the long run, it would be nice to merge these two files.
*) the legacy code to read and write network data have been
encapsulated into read_SSL() and write_SSL(). These functions
should probably be renamed - they handle both SSL and non-SSL
cases.
the remaining code should eliminate the problems identified
earlier, albeit not very cleanly.
*) both front- and back-ends will send a SSL shutdown via the
new close_SSL() function. This is necessary for sessions to
work properly.
(Sessions are not yet fully supported, but by cleanly closing
the SSL connection instead of just sending a TCP FIN packet
other SSL tools will be much happier.)
*) The client certificate and key are now expected in a subdirectory
of the user's home directory. Specifically,
- the directory .postgresql must be owned by the user, and
allow no access by 'group' or 'other.'
- the file .postgresql/postgresql.crt must be a regular file
owned by the user.
- the file .postgresql/postgresql.key must be a regular file
owned by the user, and allow no access by 'group' or 'other'.
At the current time encrypted private keys are not supported.
There should also be a way to support multiple client certs/keys.
*) the front-end performs minimal validation of the back-end cert.
Self-signed certs are permitted, but the common name *must*
match the hostname used by the front-end. (The cert itself
should always use a fully qualified domain name (FDQN) in its
common name field.)
This means that
psql -h eris db
will fail, but
psql -h eris.example.com db
will succeed. At the current time this must be an exact match;
future patches may support any FQDN that resolves to the address
returned by getpeername(2).
Another common "problem" is expiring certs. For now, it may be
a good idea to use a very-long-lived self-signed cert.
As a compile-time option, the front-end can specify a file
containing valid root certificates, but it is not yet required.
*) the back-end performs minimal validation of the client cert.
It allows self-signed certs. It checks for expiration. It
supports a compile-time option specifying a file containing
valid root certificates.
*) both front- and back-ends default to TLSv1, not SSLv3/SSLv2.
*) both front- and back-ends support DSA keys. DSA keys are
moderately more expensive on startup, but many people consider
them preferable than RSA keys. (E.g., SSH2 prefers DSA keys.)
*) if /dev/urandom exists, both client and server will read 16k
of randomization data from it.
*) the server can read empheral DH parameters from the files
$DataDir/dh512.pem
$DataDir/dh1024.pem
$DataDir/dh2048.pem
$DataDir/dh4096.pem
if none are provided, the server will default to hardcoded
parameter files provided by the OpenSSL project.
Remaining tasks:
*) the select() clauses need to be revisited - the SSL abstraction
layer may need to absorb more of the current code to avoid rare
deadlock conditions. This also touches on a true solution to
the pg_eof() problem.
*) the SIGPIPE signal handler may need to be revisited.
*) support encrypted private keys.
*) sessions are not yet fully supported. (SSL sessions can span
multiple "connections," and allow the client and server to avoid
costly renegotiations.)
*) makecert - a script that creates back-end certs.
*) pgkeygen - a tool that creates front-end certs.
*) the whole protocol issue, SASL, etc.
*) certs are fully validated - valid root certs must be available.
This is a hassle, but it means that you *can* trust the identity
of the server.
*) the client library can handle hardcoded root certificates, to
avoid the need to copy these files.
*) host name of server cert must resolve to IP address, or be a
recognized alias. This is more liberal than the previous
iteration.
*) the number of bytes transferred is tracked, and the session
key is periodically renegotiated.
*) basic cert generation scripts (mkcert.sh, pgkeygen.sh). The
configuration files have reasonable defaults for each type
of use.
Bear Giles
are motivated by security concerns, it's not just bug fixes. The key
differences (from stock 7.2.1) are:
*) almost all code that directly uses the OpenSSL library is in two
new files,
src/interfaces/libpq/fe-ssl.c
src/backend/postmaster/be-ssl.c
in the long run, it would be nice to merge these two files.
*) the legacy code to read and write network data have been
encapsulated into read_SSL() and write_SSL(). These functions
should probably be renamed - they handle both SSL and non-SSL
cases.
the remaining code should eliminate the problems identified
earlier, albeit not very cleanly.
*) both front- and back-ends will send a SSL shutdown via the
new close_SSL() function. This is necessary for sessions to
work properly.
(Sessions are not yet fully supported, but by cleanly closing
the SSL connection instead of just sending a TCP FIN packet
other SSL tools will be much happier.)
*) The client certificate and key are now expected in a subdirectory
of the user's home directory. Specifically,
- the directory .postgresql must be owned by the user, and
allow no access by 'group' or 'other.'
- the file .postgresql/postgresql.crt must be a regular file
owned by the user.
- the file .postgresql/postgresql.key must be a regular file
owned by the user, and allow no access by 'group' or 'other'.
At the current time encrypted private keys are not supported.
There should also be a way to support multiple client certs/keys.
*) the front-end performs minimal validation of the back-end cert.
Self-signed certs are permitted, but the common name *must*
match the hostname used by the front-end. (The cert itself
should always use a fully qualified domain name (FDQN) in its
common name field.)
This means that
psql -h eris db
will fail, but
psql -h eris.example.com db
will succeed. At the current time this must be an exact match;
future patches may support any FQDN that resolves to the address
returned by getpeername(2).
Another common "problem" is expiring certs. For now, it may be
a good idea to use a very-long-lived self-signed cert.
As a compile-time option, the front-end can specify a file
containing valid root certificates, but it is not yet required.
*) the back-end performs minimal validation of the client cert.
It allows self-signed certs. It checks for expiration. It
supports a compile-time option specifying a file containing
valid root certificates.
*) both front- and back-ends default to TLSv1, not SSLv3/SSLv2.
*) both front- and back-ends support DSA keys. DSA keys are
moderately more expensive on startup, but many people consider
them preferable than RSA keys. (E.g., SSH2 prefers DSA keys.)
*) if /dev/urandom exists, both client and server will read 16k
of randomization data from it.
*) the server can read empheral DH parameters from the files
$DataDir/dh512.pem
$DataDir/dh1024.pem
$DataDir/dh2048.pem
$DataDir/dh4096.pem
if none are provided, the server will default to hardcoded
parameter files provided by the OpenSSL project.
Remaining tasks:
*) the select() clauses need to be revisited - the SSL abstraction
layer may need to absorb more of the current code to avoid rare
deadlock conditions. This also touches on a true solution to
the pg_eof() problem.
*) the SIGPIPE signal handler may need to be revisited.
*) support encrypted private keys.
*) sessions are not yet fully supported. (SSL sessions can span
multiple "connections," and allow the client and server to avoid
costly renegotiations.)
*) makecert - a script that creates back-end certs.
*) pgkeygen - a tool that creates front-end certs.
*) the whole protocol issue, SASL, etc.
*) certs are fully validated - valid root certs must be available.
This is a hassle, but it means that you *can* trust the identity
of the server.
*) the client library can handle hardcoded root certificates, to
avoid the need to copy these files.
*) host name of server cert must resolve to IP address, or be a
recognized alias. This is more liberal than the previous
iteration.
*) the number of bytes transferred is tracked, and the session
key is periodically renegotiated.
*) basic cert generation scripts (mkcert.sh, pgkeygen.sh). The
configuration files have reasonable defaults for each type
of use.
Bear Giles
work on all win9x machines, so i made it go thru a l ookup table
instead, using the DLL as last resort. I also moved this out of the
fe-misc.c file because of the size of the lookup ta ble. Who knows, we
might add more other win32 specific code there in the future.
I also fixed a small typo in the pg_config.h.win32 that made the
compiler compla in about the gnu snprintf declaration.
I tried to make this patch with psql coding style. I've successfully
tested this on win2k and win98 and it works fine (i.e. the mes sage
shows on win98 too, it didn't with the old implementation).
Magnus Naeslund
In summary, if a software writer implements timer events or other events
which generate a signal with a timing fast enough to occur while libpq
is inside connect(), then connect returns -EINTR. The code following
the connect call does not handle this and generates an error message.
The sum result is that the pg_connect() fails. If the timer or other
event is right on the window of the connect() completion time, the
pg_connect() may appear to work sporadically. If the event is too slow,
pg_connect() will appear to always work and if the event is too fast,
pg_connect() will always fail.
David Ford
Bruce Momjian