Commit Graph

1336 Commits

Author SHA1 Message Date
Peter Eisentraut 803b4a26ca Remove stray mid-sentence tabs in comments 2023-05-19 16:13:16 +02:00
Tom Lane e4d905f772 NULL is not an ideal way to spell bool "false".
Thinko in commit 6633cfb21, detected by buildfarm member hamerkop.
2023-04-14 13:31:51 -04:00
Michael Paquier a282697088 Remove code in charge of freeing regexps generation by Lab.c
bea3d7e has redesigned the regexp engine so as all the allocations go
through palloc() with a dedicated memory context.  hba.c had to cope
with the past memory management logic by going through all the HBA and
ident lines generated, then directly free all the regexps found in
AuthTokens to ensure that no leaks would happen.  Such leaks could
happen for example in the postmaster after a SIGHUP, in the event of
an HBA and/or ident reload failure where all the new content parsed must
be discarded, including all the regexps that may have been compiled.

Now that regexps are palloc()'d in their own memory context,
MemoryContextDelete() is enough to ensure that all the compiled regexps
are properly gone.  Simplifying this logic in hba.c has the effect to
only remove code.  Most of it is new in v16, except the part for regexps
compiled in ident entries for the system username, so doing this cleanup
now rather than when v17 opens for business will reduce future diffs
with the upcoming REL_16_STABLE.

Some comments were incorrect since bea3d7e, now fixed to reflect the
reality.

Reviewed-by: Bertrand Drouvot, Álvaro Herrera
Discussion: https://postgr.es/m/ZDdJ289Ky2qEj4h+@paquier.xyz
2023-04-14 07:27:44 +09:00
Stephen Frost f7431bca8b Explicitly require MIT Kerberos for GSSAPI
WHen building with GSSAPI support, explicitly require MIT Kerberos and
check for gssapi_ext.h in configure.ac and meson.build.  Also add
documentation explicitly stating that we now require MIT Kerberos when
building with GSSAPI support.

Reveiwed by: Johnathan Katz
Discussion: https://postgr.es/m/abcc73d0-acf7-6896-e0dc-f5bc12a61bb1@postgresql.org
2023-04-13 08:55:13 -04:00
Stephen Frost 6633cfb216 De-Revert "Add support for Kerberos credential delegation"
This reverts commit 3d03b24c3 (Revert Add support for Kerberos
credential delegation) which was committed on the grounds of concern
about portability, but on further review and discussion, it's clear that
we are better off explicitly requiring MIT Kerberos as that appears to
be the only GSSAPI library currently that's under proper maintenance
and ongoing development.  The API used for storing credentials was added
to MIT Kerberos over a decade ago while for the other libraries which
appear to be mainly based on Heimdal, which exists explicitly to be a
re-implementation of MIT Kerberos, the API never made it to a released
version (even though it was added to the Heimdal git repo over 5 years
ago..).

This post-feature-freeze change was approved by the RMT.

Discussion: https://postgr.es/m/ZDDO6jaESKaBgej0%40tamriel.snowman.net
2023-04-13 08:55:07 -04:00
Stephen Frost 3d03b24c35 Revert "Add support for Kerberos credential delegation"
This reverts commit 3d4fa227bc.

Per discussion and buildfarm, this depends on APIs that seem to not
be available on at least one platform (NetBSD).  Should be certainly
possible to rework to be optional on that platform if necessary but bit
late for that at this point.

Discussion: https://postgr.es/m/3286097.1680922218@sss.pgh.pa.us
2023-04-08 07:21:35 -04:00
Stephen Frost 3d4fa227bc Add support for Kerberos credential delegation
Support GSSAPI/Kerberos credentials being delegated to the server by a
client.  With this, a user authenticating to PostgreSQL using Kerberos
(GSSAPI) credentials can choose to delegate their credentials to the
PostgreSQL server (which can choose to accept them, or not), allowing
the server to then use those delegated credentials to connect to
another service, such as with postgres_fdw or dblink or theoretically
any other service which is able to be authenticated using Kerberos.

Both postgres_fdw and dblink are changed to allow non-superuser
password-less connections but only when GSSAPI credentials have been
delegated to the server by the client and GSSAPI is used to
authenticate to the remote system.

Authors: Stephen Frost, Peifeng Qiu
Reviewed-By: David Christensen
Discussion: https://postgr.es/m/CO1PR05MB8023CC2CB575E0FAAD7DF4F8A8E29@CO1PR05MB8023.namprd05.prod.outlook.com
2023-04-07 21:58:04 -04:00
Daniel Gustafsson b577743000 Make SCRAM iteration count configurable
Replace the hardcoded value with a GUC such that the iteration
count can be raised in order to increase protection against
brute-force attacks.  The hardcoded value for SCRAM iteration
count was defined to be 4096, which is taken from RFC 7677, so
set the default for the GUC to 4096 to match.  In RFC 7677 the
recommendation is at least 15000 iterations but 4096 is listed
as a SHOULD requirement given that it's estimated to yield a
0.5s processing time on a mobile handset of the time of RFC
writing (late 2015).

Raising the iteration count of SCRAM will make stored passwords
more resilient to brute-force attacks at a higher computational
cost during connection establishment.  Lowering the count will
reduce computational overhead during connections at the tradeoff
of reducing strength against brute-force attacks.

There are however platforms where even a modest iteration count
yields a too high computational overhead, with weaker password
encryption schemes chosen as a result.  In these situations,
SCRAM with a very low iteration count still gives benefits over
weaker schemes like md5, so we allow the iteration count to be
set to one at the low end.

The new GUC is intentionally generically named such that it can
be made to support future SCRAM standards should they emerge.
At that point the value can be made into key:value pairs with
an undefined key as a default which will be backwards compatible
with this.

Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Jonathan S. Katz <jkatz@postgresql.org>
Discussion: https://postgr.es/m/F72E7BC7-189F-4B17-BF47-9735EB72C364@yesql.se
2023-03-27 09:46:29 +02:00
Andrew Dunstan 419a8dd814 Add a hook for modifying the ldapbind password
The hook can be installed by a shared_preload library.

A similar mechanism could be used for radius paswords, for example, and
the type name auth_password_hook_typ has been shosen with that in mind.

John Naylor and Andrew Dunstan

Discussion: https://postgr.es/m/469b06ed-69de-ba59-c13a-91d2372e52a9@dunslane.net
2023-03-15 16:37:28 -04:00
Thomas Munro 1da569ca1f Don't leak descriptors into subprograms.
Open long-lived data and WAL file descriptors with O_CLOEXEC.  This flag
was introduced by SUSv4 (POSIX.1-2008), and by now all of our target
Unix systems have it.  Our open() implementation for Windows already had
that behavior, so provide a dummy O_CLOEXEC flag on that platform.

For now, callers of open() and the "thin" wrappers in fd.c that deal in
raw descriptors need to pass in O_CLOEXEC explicitly if desired.  This
commit does that for WAL files, and automatically for everything
accessed via VFDs including SMgrRelation and BufFile.  (With more
discussion we might decide to turn it on automatically for the thin
open()-wrappers too to avoid risk of missing places that need it, but
these are typically used for short-lived descriptors where we don't
expect to fork/exec, and it's remotely possible that extensions could be
using these APIs and passing descriptors to subprograms deliberately, so
that hasn't been done here.)

Do the same for sockets and the postmaster pipe with FD_CLOEXEC.  (Later
commits might use modern interfaces to remove these extra fcntl() calls
and more where possible, but we'll need them as a fallback for a couple
of systems, so do it that way in this initial commit.)

With this change, subprograms executed for archiving, copying etc will
no longer have access to the server's descriptors, other than the ones
that we decide to pass down.

Reviewed-by: Andres Freund <andres@anarazel.de> (earlier version)
Discussion: https://postgr.es/m/CA%2BhUKGKb6FsAdQWcRL35KJsftv%2B9zXqQbzwkfRf1i0J2e57%2BhQ%40mail.gmail.com
2023-03-03 10:43:33 +13:00
Daniel Gustafsson 7ab1bc2939 Fix outdated references to guc.c
Commit 0a20ff54f split out the GUC variables from guc.c into a new file
guc_tables.c. This updates comments referencing guc.c regarding variables
which are now in guc_tables.c.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/6B50C70C-8C1F-4F9A-A7C0-EEAFCC032406@yesql.se
2023-03-02 13:49:39 +01:00
Michael Paquier 1b43743f11 Add description for new patterns supported in HBA and ident sample files
Support for regexps in database and role entries for pg_hba.conf has
been added in 8fea8683, and efb6f4a has extended support of pg-user in
pg_ident.conf, still both of them have missed a short description about
the new patterns supported in their respective sample files.

This commit closes the gap, by providing a short description of all the
new features supported for each entry type.

Reported-by: Pavel Luzanov
Reviewed-by: Jelte Fennema, Pavel Luzanov
Discussion: https://postgr.es/m/e495112d-8741-e651-64a2-ecb5728f1a56@postgrespro.ru
2023-02-16 07:38:52 +09:00
Michael Paquier 9244c11afe Fix handling of SCRAM-SHA-256's channel binding with RSA-PSS certificates
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
2023-02-15 10:12:16 +09:00
Peter Eisentraut 3b12e68a5c Change argument type of pq_sendbytes from char * to void *
This is a follow-up to 1f605b82ba.  It
allows getting rid of further casts at call sites.

Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://www.postgresql.org/message-id/783a4edb-84f9-6df2-7470-2ef5ccc6607a@enterprisedb.com
2023-02-14 13:32:19 +01:00
Michael Paquier efb6f4a4f9 Support the same patterns for pg-user in pg_ident.conf as in pg_hba.conf
While pg_hba.conf has support for non-literal username matches, and
this commit extends the capabilities that are supported for the
PostgreSQL user listed in an ident entry part of pg_ident.conf, with
support for:
1. The "all" keyword, where all the requested users are allowed.
2. Membership checks using the + prefix.
3. Using a regex to match against multiple roles.

1. is a feature that has been requested by Jelte Fennema, 2. something
that has been mentioned independently by Andrew Dunstan, and 3. is
something I came up with while discussing how to extend the first one,
whose implementation is facilitated by 8fea868.

This allows matching certain system users against many different
postgres users with a single line in pg_ident.conf.  Without this, one
would need one line for each of the postgres users that a system user
can log in as, which can be cumbersome to maintain.

Tests are added to the TAP test of peer authentication to provide
coverage for all that.

Note that this introduces a set of backward-incompatible changes to be
able to detect the new patterns, for the following cases:
- A role named "all".
- A role prefixed with '+' characters, which is something that would not
have worked in HBA entries anyway.
- A role prefixed by a slash character, similarly to 8fea868.
Any of these can be still be handled by using quotes in the Postgres
role defined in an ident entry.

A huge advantage of this change is that the code applies the same checks
for the Postgres roles in HBA and ident entries, via the common routine
check_role().

**This compatibility change should be mentioned in the release notes.**

Author: Jelte Fennema
Discussion: https://postgr.es/m/DBBPR83MB0507FEC2E8965012990A80D0F7FC9@DBBPR83MB0507.EURPRD83.prod.outlook.com
2023-01-20 11:21:55 +09:00
Michael Paquier 02d3448f4f Store IdentLine->pg_user as an AuthToken
While system_user was stored as an AuthToken in IdentLine, pg_user was
stored as a plain string.  This commit changes the code as we start
storing pg_user as an AuthToken too.

This does not have any functional changes, as all the operations on
pg_user only use the string from the AuthToken.  There is no regexp
compiled and no check based on its quoting, yet.  This is in preparation
of more features that intend to extend its capabilities, like support
for regexps and group membership.

Author: Jelte Fennema
Discussion: https://postgr.es/m/CAGECzQRNow4MwkBjgPxywXdJU_K3a9+Pm78JB7De3yQwwkTDew@mail.gmail.com
2023-01-16 13:58:07 +09:00
Michael Paquier 8607630d74 Rename some variables related to ident files in hba.{c,h}
The code that handles authentication for user maps was pretty confusing
with its choice of variable names.  It involves two types of users: a
system user and a Postgres user (well, role), and these were not named
consistently throughout the code that processes the user maps loaded
from pg_ident.conf at authentication.

This commit changes the following things to improve the situation:
- Rename "pg_role" to "pg_user" and "token" to "system_user" in
IndetLine.  These choices are more consistent with the pg_ident.conf
example in the docs, as well.  "token" has been introduced recently in
fc579e1, and it is way worse than the choice before that, "ident_user".
- Switch the order of the fields in IdentLine to map with the order of
the items in the ident files, as of map name, system user and PG user.
- In check_ident_usermap(), rename "regexp_pgrole" to "expanded_pg_user"
when processing a regexp for the system user entry in a user map.  This
variable does not store a regular expression at all: it would be either
a string or a substitution to \1 if the Postgres role is specified as
such.

Author: Jelte Fennema
Discussion: https://postgr.es/m/CAGECzQTkwELHUOAKhvdA+m3tWbUQySHHkExJV8GAZ1pwgbEgXg@mail.gmail.com
2023-01-12 14:23:20 +09:00
Thomas Munro 7389aad636 Use WaitEventSet API for postmaster's event loop.
Switch to a design similar to regular backends, instead of the previous
arrangement where signal handlers did non-trivial state management and
called fork().  The main changes are:

* The postmaster now has its own local latch to wait on.  (For now, we
  don't want other backends setting its latch directly, but that could
  probably be made to work with more research on robustness.)

* The existing signal handlers are cut in two: a handle_pm_XXX() part
  that just sets pending_pm_XXX flags and the latch, and a
  process_pm_XXX() part that runs later when the latch is seen.

* Signal handlers are now installed with the regular pqsignal()
  function rather than the special pqsignal_pm() function; historical
  portability concerns about the effect of SA_RESTART on select() are no
  longer relevant, and we don't need to block signals anymore.

Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA%2BhUKG%2BZ-HpOj1JsO9eWUP%2Bar7npSVinsC_npxSy%2BjdOMsx%3DGg%40mail.gmail.com
2023-01-12 16:32:20 +13:00
Peter Eisentraut c96de2ce17 Common function for percent placeholder replacement
There are a number of places where a shell command is constructed with
percent-placeholders (like %x).  It's cumbersome to have to open-code
this several times.  This factors out this logic into a separate
function.  This also allows us to ensure consistency for and document
some subtle behaviors, such as what to do with unrecognized
placeholders.

The unified handling is now that incorrect and unknown placeholders
are an error, where previously in most cases they were skipped or
ignored.  This affects the following settings:

- archive_cleanup_command
- archive_command
- recovery_end_command
- restore_command
- ssl_passphrase_command

The following settings are part of this refactoring but already had
stricter error handling and should be unchanged in their behavior:

- basebackup_to_shell.command

Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/5238bbed-0b01-83a6-d4b2-7eb0562a054e%40enterprisedb.com
2023-01-11 10:42:35 +01:00
Peter Eisentraut d952373a98 New header varatt.h split off from postgres.h
This new header contains all the variable-length data types support
(TOAST support) from postgres.h, which isn't needed by large parts of
the backend code.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/ddcce239-0f29-6e62-4b47-1f8ca742addf%40enterprisedb.com
2023-01-10 05:54:36 +01:00
Amit Kapila 216a784829 Perform apply of large transactions by parallel workers.
Currently, for large transactions, the publisher sends the data in
multiple streams (changes divided into chunks depending upon
logical_decoding_work_mem), and then on the subscriber-side, the apply
worker writes the changes into temporary files and once it receives the
commit, it reads from those files and applies the entire transaction. To
improve the performance of such transactions, we can instead allow them to
be applied via parallel workers.

In this approach, we assign a new parallel apply worker (if available) as
soon as the xact's first stream is received and the leader apply worker
will send changes to this new worker via shared memory. The parallel apply
worker will directly apply the change instead of writing it to temporary
files. However, if the leader apply worker times out while attempting to
send a message to the parallel apply worker, it will switch to
"partial serialize" mode -  in this mode, the leader serializes all
remaining changes to a file and notifies the parallel apply workers to
read and apply them at the end of the transaction. We use a non-blocking
way to send the messages from the leader apply worker to the parallel
apply to avoid deadlocks. We keep this parallel apply assigned till the
transaction commit is received and also wait for the worker to finish at
commit. This preserves commit ordering and avoid writing to and reading
from files in most cases. We still need to spill if there is no worker
available.

This patch also extends the SUBSCRIPTION 'streaming' parameter so that the
user can control whether to apply the streaming transaction in a parallel
apply worker or spill the change to disk. The user can set the streaming
parameter to 'on/off', or 'parallel'. The parameter value 'parallel' means
the streaming will be applied via a parallel apply worker, if available.
The parameter value 'on' means the streaming transaction will be spilled
to disk. The default value is 'off' (same as current behaviour).

In addition, the patch extends the logical replication STREAM_ABORT
message so that abort_lsn and abort_time can also be sent which can be
used to update the replication origin in parallel apply worker when the
streaming transaction is aborted. Because this message extension is needed
to support parallel streaming, parallel streaming is not supported for
publications on servers < PG16.

Author: Hou Zhijie, Wang wei, Amit Kapila with design inputs from Sawada Masahiko
Reviewed-by: Sawada Masahiko, Peter Smith, Dilip Kumar, Shi yu, Kuroda Hayato, Shveta Mallik
Discussion: https://postgr.es/m/CAA4eK1+wyN6zpaHUkCLorEWNx75MG0xhMwcFhvjqm2KURZEAGw@mail.gmail.com
2023-01-09 07:52:45 +05:30
Bruce Momjian c8e1ba736b Update copyright for 2023
Backpatch-through: 11
2023-01-02 15:00:37 -05:00
Andrew Dunstan 8284cf5f74 Add copyright notices to meson files
Discussion: https://postgr.es/m/222b43a5-2fb3-2c1b-9cd0-375d376c8246@dunslane.net
2022-12-20 07:54:39 -05:00
Michael Paquier b3bb7d12af Remove hardcoded dependency to cryptohash type in the internals of SCRAM
SCRAM_KEY_LEN was a variable used in the internal routines of SCRAM to
size a set of fixed-sized arrays used in the SHA and HMAC computations
during the SASL exchange or when building a SCRAM password.  This had a
hard dependency on SHA-256, reducing the flexibility of SCRAM when it
comes to the addition of more hash methods.  A second issue was that
SHA-256 is assumed as the cryptohash method to use all the time.

This commit renames SCRAM_KEY_LEN to a more generic SCRAM_KEY_MAX_LEN,
which is used as the size of the buffers used by the internal routines
of SCRAM.  This is aimed at tracking centrally the maximum size
necessary for all the hash methods supported by SCRAM.  A global
variable has the advantage of keeping the code in its simplest form,
reducing the need of more alloc/free logic for all the buffers used in
the hash calculations.

A second change is that the key length (SHA digest length) and hash
types are now tracked by the state data in the backend and the frontend,
the common portions being extended to handle these as arguments by the
internal routines of SCRAM.  There are a few RFC proposals floating
around to extend the SCRAM protocol, including some to use stronger
cryptohash algorithms, so this lifts some of the existing restrictions
in the code.

The code in charge of parsing and building SCRAM secrets is extended to
rely on the key length and on the cryptohash type used for the exchange,
assuming currently that only SHA-256 is supported for the moment.  Note
that the mock authentication simply enforces SHA-256.

Author: Michael Paquier
Reviewed-by: Peter Eisentraut, Jonathan Katz
Discussion: https://postgr.es/m/Y5k3Qiweo/1g9CG6@paquier.xyz
2022-12-20 08:53:22 +09:00
Peter Eisentraut 75f49221c2 Static assertions cleanup
Because we added StaticAssertStmt() first before StaticAssertDecl(),
some uses as well as the instructions in c.h are now a bit backwards
from the "native" way static assertions are meant to be used in C.
This updates the guidance and moves some static assertions to better
places.

Specifically, since the addition of StaticAssertDecl(), we can put
static assertions at the file level.  This moves a number of static
assertions out of function bodies, where they might have been stuck
out of necessity, to perhaps better places at the file level or in
header files.

Also, when the static assertion appears in a position where a
declaration is allowed, then using StaticAssertDecl() is more native
than StaticAssertStmt().

Reviewed-by: John Naylor <john.naylor@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/941a04e7-dd6f-c0e4-8cdf-a33b3338cbda%40enterprisedb.com
2022-12-15 10:10:32 +01:00
Michael Paquier 02ac05b4c0 Fix typo in hba.c
Spotted while reading through the git history.
2022-11-26 10:14:18 +09:00
Michael Paquier d13b684117 Introduce variables for initial and max nesting depth on configuration files
The code has been assuming already in a few places that the initial
recursion nesting depth is 0, and the recent changes in hba.c (mainly
783e8c6) have relies on this assumption in more places.  The maximum
recursion nesting level is assumed to be 10 for hba.c and GUCs.

Author: Julien Rouhaud
Discussion: https://postgr.es/m/20221124090724.n7amf5kpdhx6vb76@jrouhaud
2022-11-25 07:40:12 +09:00
Michael Paquier a54b658ce7 Add support for file inclusions in HBA and ident configuration files
pg_hba.conf and pg_ident.conf gain support for three record keywords:
- "include", to include a file.
- "include_if_exists", to include a file, ignoring it if missing.
- "include_dir", to include a directory of files.  These are classified
by name (C locale, mostly) and need to be prefixed by ".conf", hence
following the same rules as GUCs.

This commit relies on the refactoring pieces done in efc9816, ad6c528,
783e8c6 and 1b73d0b, adding a small wrapper to build a list of
TokenizedAuthLines (tokenize_include_file), and the code is shaped to
offer some symmetry with what is done for GUCs with the same options.

pg_hba_file_rules and pg_ident_file_mappings gain a new field called
file_name, to track from which file a record is located, taking
advantage of the addition of rule_number in c591300 to offer an
organized view of the HBA or ident records loaded.

Bump catalog version.

Author: Julien Rouhaud
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/20220223045959.35ipdsvbxcstrhya@jrouhaud
2022-11-24 13:51:34 +09:00
Michael Paquier d46ad72f46 Create memory context for tokenization after opening top-level file in hba.c
The memory context was created before attempting to open the first HBA
or ident file, which would cause it to leak.  This had no consequences
for the system views for HBA and ident files, but this would cause
memory leaks in the postmaster on reload if the initial HBA and/or ident
files are missing, which is a valid behavior while the backend is
running.

Oversight in efc9816.

Author: Ted Yu
Discussion: https://postgr.es/m/CALte62xH6ivgiKKzPRJgfekPZC6FKLB3xbnf3=tZmc_gKj78dw@mail.gmail.com
2022-11-24 10:27:38 +09:00
Michael Paquier d5566fbfeb Add missing initialization in tokenize_expand_file() for output list
This should have been added in efc9816, but it looks like I have found a
way to mess up a bit a patch split.  This should have no consequence in
practice, but let's be clean.

Discussion: https://postgr.es/m/Y324HvGKiWxW2yxe@paquier.xyz
2022-11-24 10:03:11 +09:00
Michael Paquier efc981627a Rework memory contexts in charge of HBA/ident tokenization
The list of TokenizedAuthLines generated at parsing for the HBA and
ident files is now stored in a static context called tokenize_context,
where only all the parsed tokens are stored.  This context is created
when opening the first authentication file of a HBA/ident set (hba_file
or ident_file), and is cleaned up once we are done all the work around
it through a new routine called free_auth_file().  One call of
open_auth_file() should have one matching call of free_auth_file(), the
creation and deletion of the tokenization context is controlled by the
recursion depth of the tokenization.

Rather than having tokenize_auth_file() return a memory context that
includes all the records, the tokenization logic now creates and deletes
one memory context each time this function is called.  This will
simplify recursive calls to this routine for the upcoming inclusion
record logic.

While on it, rename tokenize_inc_file() to tokenize_expand_file() as
this would conflict with the upcoming patch that will add inclusion
records for HBA/ident files.  An '@' file has its tokens added to an
existing list.

Reloading HBA/indent configuration in a tight loop shows no leaks, as of
one type of test done (with and without -DEXEC_BACKEND).

Author: Michael Paquier
Reviewed-by: Julien Rouhaud
Discussion: https://postgr.es/m/Y324HvGKiWxW2yxe@paquier.xyz
2022-11-24 08:21:55 +09:00
Michael Paquier ad6c52846f Add error context callback when tokenizing authentication files
The parsing of the authentication files for HBA and ident entries
happens in two phases:
- Tokenization of the files, creating a list of TokenizedAuthLines.
- Validation of the HBA and ident entries, building a set of HbaLines or
IdentLines.

The second phase doing the validation provides already some error
context about the configuration file and the line where a problem
happens, but there is no such information in the first phase when
tokenizing the files.  This commit adds an ErrorContextCallback in
tokenize_auth_file(), with a context made of the line number and the
configuration file name involved in a problem.  This is useful for files
included in an HBA file for user and database lists, and it will become
much more handy to track problems for files included via a potential
@include[_dir,_if_exists].

The error context is registered so as the full chain of events is
reported when using cascaded inclusions when for example
tokenize_auth_file() recurses over itself on new files, displaying one
context line for each file gone through when tokenizing things.

Author: Michael Paquier
Reviewed-by: Julien Rouhaud
Discussion: https://postgr.es/m/Y2xUBJ+S+Z0zbxRW@paquier.xyz
2022-11-14 11:58:10 +09:00
Michael Paquier 783e8c69cb Invent open_auth_file() in hba.c to refactor authentication file opening
This adds a check on the recursion depth when including authentication
configuration files, something that has never been done when processing
'@' files for database and user name lists in pg_hba.conf.  On HEAD,
this was leading to a rather confusing error, as of:
FATAL:  exceeded maxAllocatedDescs (NN) while trying to open file "/path/blah.conf"

This refactors the code so as the error reported is now the following,
which is the same as for GUCs:
FATAL: could not open file "/path/blah.conf": maximum nesting depth exceeded

This reduces a bit the verbosity of the error message used for files
included in user and database lists, reporting only the file name of
what's failing to load, without mentioning the relative or absolute path
specified after '@' in a HBA file.  The absolute path is built upon what
'@' defines anyway, so there is no actual loss of information.  This
makes the future inclusion logic much simpler.  A follow-up patch will
add an error context to be able to track on which line of which file the
inclusion is failing, to close the loop, providing all the information
needed to know the full chain of events.

This logic has been extracted from a larger patch written by Julien,
rewritten by me to have a unique code path calling AllocateFile() on
authentication files, and is useful on its own.  This new interface
will be used later for authentication files included with
@include[_dir,_if_exists], in a follow-up patch.

Author: Michael Paquier, Julien Rouhaud
Discussion: https://www.postgresql.org/message-id/Y2xUBJ+S+Z0zbxRW@paquier.xyz
2022-11-14 10:21:42 +09:00
Peter Eisentraut afbfc02983 Refactor ownercheck functions
Instead of dozens of mostly-duplicate pg_foo_ownercheck() functions,
write one common function object_ownercheck() that can handle almost
all of them.  We already have all the information we need, such as
which system catalog corresponds to which catalog table and which
column is the owner column.

Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Reviewed-by: Antonin Houska <ah@cybertec.at>
Discussion: https://www.postgresql.org/message-id/flat/95c30f96-4060-2f48-98b5-a4392d3b6066@enterprisedb.com
2022-11-13 08:12:37 +01:00
Peter Eisentraut b4b7ce8061 Add repalloc0 and repalloc0_array
These zero out the space added by repalloc.  This is a common pattern
that is quite hairy to code by hand.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/b66dfc89-9365-cb57-4e1f-b7d31813eeec@enterprisedb.com
2022-11-12 20:34:44 +01:00
Thomas Munro b28ac1d24d Provide sigaction() for Windows.
Commit 9abb2bfc left behind code to block signals inside signal
handlers on Windows, because our signal porting layer didn't have
sigaction().  Provide a minimal implementation that is capable of
blocking signals, to get rid of platform differences.  See also related
commit c94ae9d8.

Discussion: https://postgr.es/m/CA%2BhUKGKKKfcgx6jzok9AYenp2TNti_tfs8FMoJpL8%2B0Gsy%3D%3D_A%40mail.gmail.com
2022-11-09 13:06:31 +13:00
Michael Paquier 6bbd8b7385 Use AbsoluteConfigLocation() when building an included path in hba.c
The code building an absolute path to a file included, as prefixed by
'@' in authentication files, for user and database lists uses the same
logic as for GUCs, except that it has no need to know about DataDir as
there is always a calling file to rely to build the base directory path.
The refactoring done in a1a7bb8 makes this move straight-forward, and
unifies the code used for GUCs and authentication files, and the
intention is to rely also on that for the upcoming patch to be able to
include full files from HBA or ident files.

Note that this gets rid of an inconsistency introduced in 370f909, that
copied the logic coming from GUCs but applied it for files included in
authentication files, where the result buffer given to
join_path_components() must have a size of MAXPGPATH.  Based on a
double-check of the existing code, all the other callers of
join_path_components() already do that, except the code path changed
here.

Discussion: https://postgr.es/m/Y2igk7q8OMpg+Yta@paquier.xyz
2022-11-09 08:47:02 +09:00
Michael Paquier d9d873bac6 Clean up some inconsistencies with GUC declarations
This is similar to 7d25958, and this commit takes care of all the
remaining inconsistencies between the initial value used in the C
variable associated to a GUC and its default value stored in the GUC
tables (as of pg_settings.boot_val).

Some of the initial values of the GUCs updated rely on a compile-time
default.  These are refactored so as the GUC table and its C declaration
use the same values.  This makes everything consistent with other
places, backend_flush_after, bgwriter_flush_after, port,
checkpoint_flush_after doing so already, for example.

Extracted from a larger patch by Peter Smith.  The spots updated in the
modules are from me.

Author: Peter Smith, Michael Paquier
Reviewed-by: Nathan Bossart, Tom Lane, Justin Pryzby
Discussion: https://postgr.es/m/CAHut+PtHE0XSfjjRQ6D4v7+dqzCw=d+1a64ujra4EX8aoc_Z+w@mail.gmail.com
2022-10-31 12:44:48 +09:00
Michael Paquier 37d264478a Fix variable assignment thinko in hba.c
The intention behind 1b73d0b was to limit the use of TokenizedAuthLine,
but I have fat-fingered one location in parse_hba_line() when creating
the HbaLine, where this should use the local variable and not the value
coming from TokenizedAuthLine.  This logic is the exactly the same, but
let's be clean about all that on consistency grounds.

Reported-by: Julien Rouhaud
Discussion: https://postgr.es/m/20221026032730.k3sib5krgm7l6njk@jrouhaud
2022-10-26 12:57:40 +09:00
Michael Paquier 1b73d0b1c3 Refactor code handling the names of files loaded in hba.c
This has the advantage to limit the presence of the GUC values
hba_file and ident_file to the code paths where these files are loaded,
easing the introduction of an upcoming feature aimed at adding inclusion
logic for files and directories in HBA and ident files.

Note that this needs the addition of the source file name to HbaLine, in
addition to the line number, which is something needed by the backend in
two places of auth.c (authentication failure details and auth_id log
when log_connections is enabled).

While on it, adjust a log generated on authentication failure to report
the name of the actual HBA file on which the connection attempt matched,
where the line number and the raw line written in the HBA file were
already included.  This was previously hardcoded as pg_hba.conf, which
would be incorrect when a custom value is used at postmaster startup for
the GUC hba_file.

Extracted from a larger patch by the same author.

Author: Julien Rouhaud
Discussion: https://postgr.es/m/20220223045959.35ipdsvbxcstrhya@jrouhaud
2022-10-26 11:42:13 +09:00
Michael Paquier 8fea86830e Add support for regexps on database and user entries in pg_hba.conf
As of this commit, any database or user entry beginning with a slash (/)
is considered as a regular expression.  This is particularly useful for
users, as now there is no clean way to match pattern on multiple HBA
lines.  For example, a user name mapping with a regular expression needs
first to match with a HBA line, and we would skip the follow-up HBA
entries if the ident regexp does *not* match with what has matched in
the HBA line.

pg_hba.conf is able to handle multiple databases and roles with a
comma-separated list of these, hence individual regular expressions that
include commas need to be double-quoted.

At authentication time, user and database names are now checked in the
following order:
- Arbitrary keywords (like "all", the ones beginning by '+' for
membership check), that we know will never have a regexp.  A fancy case
is for physical WAL senders, we *have* to only match "replication" for
the database.
- Regular expression matching.
- Exact match.
The previous logic did the same, but without the regexp step.

We have discussed as well the possibility to support regexp pattern
matching for host names, but these happen to lead to tricky issues based
on what I understand, particularly with host entries that have CIDRs.

This commit relies heavily on the refactoring done in a903971 and
fc579e1, so as the amount of code required to compile and execute
regular expressions is now minimal.  When parsing pg_hba.conf, all the
computed regexps needs to explicitely free()'d, same as pg_ident.conf.

Documentation and TAP tests are added to cover this feature, including
cases where the regexps use commas (for clarity in the docs, coverage
for the parsing logic in the tests).

Note that this introduces a breakage with older versions, where a
database or user name beginning with a slash are treated as something to
check for an equal match.  Per discussion, we have discarded this as
being much of an issue in practice as it would require a cluster to
have database and/or role names that begin with a slash, as well as HBA
entries using these.  Hence, the consistency gained with regexps in
pg_ident.conf is more appealing in the long term.

**This compatibility change should be mentioned in the release notes.**

Author: Bertrand Drouvot
Reviewed-by: Jacob Champion, Tom Lane, Michael Paquier
Discussion: https://postgr.es/m/fff0d7c1-8ad4-76a1-9db3-0ab6ec338bf7@amazon.com
2022-10-24 11:45:31 +09:00
Michael Paquier a903971351 Refactor more logic for compilation of regular expressions in hba.c
It happens that the parts of hba.conf that are planned to be extended
to support regular expressions would finish by using the same error
message as the one used currently for pg_ident.conf when a regular
expression cannot be compiled, as long as the routine centralizing the
logic, regcomp_auth_token(), knows from which file the regexp comes from
and its line location in the so-said file.

This change makes the follow-up patches slightly simpler, and the logic
remains the same.  I suspect that this makes the proposal to add support
for file inclusions in pg_ident.conf and pg_hba.conf slightly simpler,
as well.

Extracted from a larger patch by the same author.  This is similar to
the refactoring done in fc579e1.

Author: Bertrand Drouvot
Discussion: https://postgr.es/m/fff0d7c1-8ad4-76a1-9db3-0ab6ec338bf7@amazon.com
2022-10-21 09:55:56 +09:00
Michael Paquier fc579e11c6 Refactor regular expression handling in hba.c
AuthToken gains a regular expression, and IdentLine is changed so as it
uses an AuthToken rather than tracking separately the ident user string
used for the regex compilation and its generated regex_t.  In the case
of pg_ident.conf, a set of AuthTokens is built in the pre-parsing phase
of the file, and an extra regular expression is compiled when building
the list of IdentLines, after checking the sanity of the fields in a
pre-parsed entry.

The logic in charge of computing and executing regular expressions is
now done in a new set of routines called respectively
regcomp_auth_token() and regexec_auth_token() that are wrappers around
pg_regcomp() and pg_regexec(), working on AuthTokens.  While on it, this
patch adds a routine able to free an AuthToken, free_auth_token(), to
simplify a bit the logic around the requirement of using a specific free
routine for computed regular expressions.  Note that there are no
functional or behavior changes introduced by this commit.

The goal of this patch is to ease the use of regular expressions with
more items of pg_hba.conf (user list, database list, potentially
hostnames) where AuthTokens are used extensively.  This will be tackled
later in a separate patch.

Author: Bertrand Drouvot, Michael Paquier
Discussion: https://postgr.es/m/fff0d7c1-8ad4-76a1-9db3-0ab6ec338bf7@amazon.com
2022-10-19 10:08:49 +09:00
Andres Freund e6927270cd meson: Add initial version of meson based build system
Autoconf is showing its age, fewer and fewer contributors know how to wrangle
it. Recursive make has a lot of hard to resolve dependency issues and slow
incremental rebuilds. Our home-grown MSVC build system is hard to maintain for
developers not using Windows and runs tests serially. While these and other
issues could individually be addressed with incremental improvements, together
they seem best addressed by moving to a more modern build system.

After evaluating different build system choices, we chose to use meson, to a
good degree based on the adoption by other open source projects.

We decided that it's more realistic to commit a relatively early version of
the new build system and mature it in tree.

This commit adds an initial version of a meson based build system. It supports
building postgres on at least AIX, FreeBSD, Linux, macOS, NetBSD, OpenBSD,
Solaris and Windows (however only gcc is supported on aix, solaris). For
Windows/MSVC postgres can now be built with ninja (faster, particularly for
incremental builds) and msbuild (supporting the visual studio GUI, but
building slower).

Several aspects (e.g. Windows rc file generation, PGXS compatibility, LLVM
bitcode generation, documentation adjustments) are done in subsequent commits
requiring further review. Other aspects (e.g. not installing test-only
extensions) are not yet addressed.

When building on Windows with msbuild, builds are slower when using a visual
studio version older than 2019, because those versions do not support
MultiToolTask, required by meson for intra-target parallelism.

The plan is to remove the MSVC specific build system in src/tools/msvc soon
after reaching feature parity. However, we're not planning to remove the
autoconf/make build system in the near future. Likely we're going to keep at
least the parts required for PGXS to keep working around until all supported
versions build with meson.

Some initial help for postgres developers is at
https://wiki.postgresql.org/wiki/Meson

With contributions from Thomas Munro, John Naylor, Stone Tickle and others.

Author: Andres Freund <andres@anarazel.de>
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Author: Peter Eisentraut <peter@eisentraut.org>
Reviewed-By: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/20211012083721.hvixq4pnh2pixr3j@alap3.anarazel.de
2022-09-21 22:37:17 -07:00
Peter Geoghegan a601366a46 Harmonize more parameter names in bulk.
Make sure that function declarations use names that exactly match the
corresponding names from function definitions in optimizer, parser,
utility, libpq, and "commands" code, as well as in remaining library
code.  Do the same for all code related to frontend programs (with the
exception of pg_dump/pg_dumpall related code).

Like other recent commits that cleaned up function parameter names, this
commit was written with help from clang-tidy.  Later commits will handle
ecpg and pg_dump/pg_dumpall.

Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAH2-WznJt9CMM9KJTMjJh_zbL5hD9oX44qdJ4aqZtjFi-zA3Tg@mail.gmail.com
2022-09-20 13:09:30 -07:00
Tom Lane 0a20ff54f5 Split up guc.c for better build speed and ease of maintenance.
guc.c has grown to be one of our largest .c files, making it
a bottleneck for compilation.  It's also acquired a bunch of
knowledge that'd be better kept elsewhere, because of our not
very good habit of putting variable-specific check hooks here.
Hence, split it up along these lines:

* guc.c itself retains just the core GUC housekeeping mechanisms.
* New file guc_funcs.c contains the SET/SHOW interfaces and some
  SQL-accessible functions for GUC manipulation.
* New file guc_tables.c contains the data arrays that define the
  built-in GUC variables, along with some already-exported constant
  tables.
* GUC check/assign/show hook functions are moved to the variable's
  home module, whenever that's clearly identifiable.  A few hard-
  to-classify hooks ended up in commands/variable.c, which was
  already a home for miscellaneous GUC hook functions.

To avoid cluttering a lot more header files with #include "guc.h",
I also invented a new header file utils/guc_hooks.h and put all
the GUC hook functions' declarations there, regardless of their
originating module.  That allowed removal of #include "guc.h"
from some existing headers.  The fallout from that (hopefully
all caught here) demonstrates clearly why such inclusions are
best minimized: there are a lot of files that, for example,
were getting array.h at two or more levels of remove, despite
not having any connection at all to GUCs in themselves.

There is some very minor code beautification here, such as
renaming a couple of inconsistently-named hook functions
and improving some comments.  But mostly this just moves
code from point A to point B and deals with the ensuing
needs for #include adjustments and exporting a few functions
that previously weren't exported.

Patch by me, per a suggestion from Andres Freund; thanks also
to Michael Paquier for the idea to invent guc_funcs.c.

Discussion: https://postgr.es/m/587607.1662836699@sss.pgh.pa.us
2022-09-13 11:11:45 -04:00
Peter Eisentraut 257eb57b50 Don't reflect unescaped cert data to the logs
Commit 3a0e385048 introduced a new path for unauthenticated bytes from
the client certificate to be printed unescaped to the logs. There are a
handful of these already, but it doesn't make sense to keep making the
problem worse. \x-escape any unprintable bytes.

The test case introduces a revoked UTF-8 certificate. This requires the
addition of the `-utf8` flag to `openssl req`. Since the existing
certificates all use an ASCII subset, this won't modify the existing
certificates' subjects if/when they get regenerated; this was verified
experimentally with

    $ make sslfiles-clean
    $ make sslfiles

Unfortunately the test can't be run in the CI yet due to a test timing
issue; see 55828a6b60.

Author: Jacob Champion <jchampion@timescale.com>
Discussion: https://www.postgresql.org/message-id/CAAWbhmgsvHrH9wLU2kYc3pOi1KSenHSLAHBbCVmmddW6-mc_=w@mail.gmail.com
2022-09-13 16:10:50 +02:00
Michael Paquier c3fb5809ea Replace loading of ldap_start_tls_sA() by direct function call
This change impacts the backend-side code in charge of starting a LDAP
TLS session.  It is a bit sad that it is not possible to unify the WIN32
and non-WIN32 code paths, but the different number of arguments for both
discard this possibility.

This is similar to 47bd0b3, where this replaces the last function
loading that seems worth it, any others being either environment or
version-dependent.

Reported-by: Thomas Munro
Reviewed-by: Thomas Munro
Discussion: https://postgr.es/m/Yx0rxpNgDh8tN4XA@paquier.xyz
2022-09-12 09:07:10 +09:00
Michael Paquier 799437e0bd Free correctly LDAPMessage returned by ldap_search_s() in auth.c
The LDAP wiki states that the search message should be freed regardless
of the return value of ldap_search_s(), but we failed to do so in one
backend code path when searching LDAP with a filter.  This is not
critical in an authentication code path failing in the backend as this
causes such the process to exit promptly, but let's be clean and free
the search message appropriately, as documented by upstream.

All the other code paths failing a LDAP operation do that already, and
somebody looking at this code in the future may miss what LDAP expects
with the search message.

Author: Zhihong Yu
Discussion: https://postgr.es/m/CALNJ-vTf5Y+8RtzZ4GjOGE9qWVHZ8awfhnFYc_qGm8fMLUNRAg@mail.gmail.com
2022-09-10 16:56:07 +09:00
Michael Paquier 47bd0b3fa6 Replace load of functions by direct calls for some WIN32
This commit changes the following code paths to do direct system calls
to some WIN32 functions rather than loading them from an external
library, shaving some code in the process:
- Creation of restricted tokens in pg_ctl.c, introduced by a25cd81.
- QuerySecurityContextToken() in auth.c for SSPI authentication in the
backend, introduced in d602592.
- CreateRestrictedToken() in src/common/.  This change is similar to the
case of pg_ctl.c.

Most of these functions were loaded rather than directly called because,
as mentioned in the code comments, MinGW headers were not declaring
them.  I have double-checked the recent MinGW code, and all the
functions changed here are declared in its headers, so this change
should be safe.  Note that I do not have a MinGW environment at hand so
I have not tested it directly, but that MSVC was fine with the change.
The buildfarm will tell soon enough if this change is appropriate or not
for a much broader set of environments.

A few code paths still use GetProcAddress() to load some functions:
- LDAP authentication for ldap_start_tls_sA(), where I am not confident
that this change would work.
- win32env.c and win32ntdll.c where we have a per-MSVC version
dependency for the name of the library loaded.
- crashdump.c for MiniDumpWriteDump() and EnumDirTree(), where direct
calls were not able to work after testing.

Reported-by: Thomas Munro
Reviewed-by: Justin Prysby
Discussion: https://postgr.es/m/CA+hUKG+BMdcaCe=P-EjMoLTCr3zrrzqbcVE=8h5LyNsSVHKXZA@mail.gmail.com
2022-09-09 10:52:17 +09:00