width types and varlena types, since with the introduction of CSTRING as
a more-or-less-real type, these concepts aren't identical. I've tried to
use varlena consistently to denote datatypes with typlen = -1, ie, they
have a length word and are potentially TOASTable; while the term variable
width covers both varlena and cstring (and, perhaps, someday other types
with other rules for computing the actual width). No code changes in this
commit except for renaming a couple macros.
on the server, if DebugLvl >= 2.
The patch also includes a late addition to the last patch
(X509_check_private_key()). I'm not sure why it the currect
revision wasn't tagged.
Bear Giles
If the user has certificates in $HOME/.postgresql/postgresql.crt
and $HOME/.postgresql/postgresql.key exist, they are provided
to the server. The certificate used to sign this cert must be
known to the server, in $DataDir/root.crt. If successful, the
cert's "common name" is logged.
Client certs are not used for authentication, but they could be
via the port->peer (X509 *), port->peer_dn (char *) or
port->peer_cn (char *) fields. Or any other function could be
used, e.g., many sites like the issuer + serial number hash.
Bear Giles
In order to reduce the risk of cryptanalysis during extended
sessions (or brief ones involving a substantial amount of data),
this patch renegotiates the session key after 64kib has been
transferred.
Bear Giles
As the comment headers in be-secure.c discusses, EPH preserves
confidentiality even if the static private key (which is usually
kept unencrypted) is compromised.
Because of the value of this, common default values are hard-coded
to protect the confidentiality of the data even if an attacker
successfully deletes or modifies the external file.
Bear Giles
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
As proof of concept, provide an alternate implementation based on POSIX
semaphores. Also push the SysV shared-memory implementation into a
separate file so that it can be replaced conveniently.
A new pg_hba.conf column, USER
Allow specifiction of lists of users separated by commas
Allow group names specified by +
Allow include files containing lists of users specified by @
Allow lists of databases, and database files
Allow samegroup in database column to match group name matching dbname
Removal of secondary password files
Remove pg_passwd utility
Lots of code cleanup in user.c and hba.c
New data/global/pg_pwd format
New data/global/pg_group file
o Change all current CVS messages of NOTICE to WARNING. We were going
to do this just before 7.3 beta but it has to be done now, as you will
see below.
o Change current INFO messages that should be controlled by
client_min_messages to NOTICE.
o Force remaining INFO messages, like from EXPLAIN, VACUUM VERBOSE, etc.
to always go to the client.
o Remove INFO from the client_min_messages options and add NOTICE.
Seems we do need three non-ERROR elog levels to handle the various
behaviors we need for these messages.
Regression passed.
when to send what to which, prevent recursion by introducing new COMMERROR
elog level for client-communication problems, get rid of direct writes
to stderr in backend/libpq files, prevent non-error elogs from going to
client during the authentication cycle.
now just below FATAL in server_min_messages. Added more text to
highlight ordering difference between it and client_min_messages.
---------------------------------------------------------------------------
REALLYFATAL => PANIC
STOP => PANIC
New INFO level the prints to client by default
New LOG level the prints to server log by default
Cause VACUUM information to print only to the client
NOTICE => INFO where purely information messages are sent
DEBUG => LOG for purely server status messages
DEBUG removed, kept as backward compatible
DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1 added
DebugLvl removed in favor of new DEBUG[1-5] symbols
New server_min_messages GUC parameter with values:
DEBUG[5-1], INFO, NOTICE, ERROR, LOG, FATAL, PANIC
New client_min_messages GUC parameter with values:
DEBUG[5-1], LOG, INFO, NOTICE, ERROR, FATAL, PANIC
Server startup now logged with LOG instead of DEBUG
Remove debug_level GUC parameter
elog() numbers now start at 10
Add test to print error message if older elog() values are passed to elog()
Bootstrap mode now has a -d that requires an argument, like postmaster
> and that the right fix is to make each of the subsequent calls be in
> this same pattern, not to try to emulate their nonsensical style.
Dominic J. Eidson
to use and significantly faster. This tweak saves 25% (!) of the runtime
of COPY IN in a test with 8000-character lines. I wouldn't normally
commit a performance improvement this late in the cycle, but 25% got
my attention...
postmaster children before client auth step. Postmaster now rereads
pg_pwd on receipt of SIGHUP, the same way that pg_hba.conf is handled.
No cycles need be expended to validate password cache validity during
connection startup.
authentication failed' and a 'send() failed: Broken pipe' message
on every connection from psql in password auth mode. Problem is
that psql doesn't ask user for a password until it sees a password
challenge failure, and libpq just closes the connection unceremoniously
if it's challenged for a password when it hasn't got one to send.
Accordingly, EOF from the client after asking for a password is
normal behavior and should not result in postmaster log entries.
a hung client or lost connection can't indefinitely block a postmaster
child (not to mention the possibility of deliberate DoS attacks).
Timeout is controlled by new authentication_timeout GUC variable,
which I set to 60 seconds by default ... does that seem reasonable?
We will no longer try to send elog messages to the client before we have
initialized backend libpq (oops); however, reporting bogus commandline
switches via elog does work now (not irrelevant, because of PGOPTIONS).
Fix problem with inappropriate sending of checkpoint-process messages
to stderr.
> pam_strerror() should be used a few more times, rather than just saying
> "Error!". Also, the configure.in snippet seems wrong. You add
> -I$pam_prefix/include/security to $INCLUDES and then you #include
> <security/pam_appl.h>. This whole thing is probably unnecessary, since
> PAM is a system library on the systems where it exists, so the headers
> and libraries are found automatically, unlike OpenSSL and
> Kerberos.
See attached revised patch. (I'm sure the configure.in stuff can be done
right/better, I'm just not enough of a autoconf guru to know what to
change it to.)
Dominic J. Eidson
Allow pg_shadow to be MD5 encrypted.
Add ENCRYPTED/UNENCRYPTED option to CREATE/ALTER user.
Add password_encryption postgresql.conf option.
Update wire protocol version to 2.1.
that call is not needed to prepare for SO_PEERCRED. Also, simplify code
so that #ifdef SO_PEERCRED appears in only one place, to make it easier
to support other platforms with variants of this capability.
points out how silly it is to use Autoconf to test for a preprocessor
symbol, when one can equally easily #ifdef on the symbol itself.
Accordingly, revert configure to prior state and do it that way.
system supports SO_PEERCRED requests for Unix sockets. This is an
amalgamation of patches submitted by Helge Bahmann and Oliver Elphick,
with some editorializing by yours truly.
number in the data structure so that we can give at least a minimally
useful idea of where the mistake is when we issue syntax error messages.
Move the ClientAuthentication() call to where it should have been in
the first place, so that postmaster memory releasing can happen in a
reasonable place also. Update obsolete comments, correct one real bug
(auth_argument was not picked up correctly).
Bruce Momjian
Tom Lane
Tatsuo Ishii
Peter Eisentraut
Jan Wieck