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path: root/src/backend/libpq/auth.c
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* More use of getpwuid_r() directlyPeter Eisentraut2024-09-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove src/port/user.c, call getpwuid_r() directly. This reduces some complexity and allows better control of the error behavior. For example, the old code would in some circumstances silently truncate the result string, or produce error message strings that the caller wouldn't use. src/port/user.c used to be called src/port/thread.c and contained various portability complications to support thread-safety. These are all obsolete, and all but the user-lookup functions have already been removed. This patch completes this by also removing the user-lookup functions. Also convert src/backend/libpq/auth.c to use getpwuid_r() for thread-safety. Originally, I tried to be overly correct by using sysconf(_SC_GETPW_R_SIZE_MAX) to get the buffer size for getpwuid_r(), but that doesn't work on FreeBSD. All the OS where I could find the source code internally use 1024 as the suggested buffer size, so I just ended up hardcoding that. The previous code used BUFSIZ, which is an unrelated constant from stdio.h, so its use seemed inappropriate. Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://www.postgresql.org/message-id/flat/5f293da9-ceb4-4937-8e52-82c25db8e4d3%40eisentraut.org
* Remove unused #include's from backend .c filesPeter Eisentraut2024-03-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | as determined by include-what-you-use (IWYU) While IWYU also suggests to *add* a bunch of #include's (which is its main purpose), this patch does not do that. In some cases, a more specific #include replaces another less specific one. Some manual adjustments of the automatic result: - IWYU currently doesn't know about includes that provide global variable declarations (like -Wmissing-variable-declarations), so those includes are being kept manually. - All includes for port(ability) headers are being kept for now, to play it safe. - No changes of catalog/pg_foo.h to catalog/pg_foo_d.h, to keep the patch from exploding in size. Note that this patch touches just *.c files, so nothing declared in header files changes in hidden ways. As a small example, in src/backend/access/transam/rmgr.c, some IWYU pragma annotations are added to handle a special case there. Discussion: https://www.postgresql.org/message-id/flat/af837490-6b2f-46df-ba05-37ea6a6653fc%40eisentraut.org
* Update copyright for 2024Bruce Momjian2024-01-03
| | | | | | | | Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
* Avoid masking EOF (no-password-supplied) conditions in auth.c.Tom Lane2024-01-03
| | | | | | | | | | | | | | | CheckPWChallengeAuth() would return STATUS_ERROR if the user does not exist or has no password assigned, even if the client disconnected without responding to the password challenge (as libpq often will, for example). We should return STATUS_EOF in that case, and the lower-level functions do, but this code level got it wrong since the refactoring done in 7ac955b34. This breaks the intent of not logging anything for EOF cases (cf. comments in auth_failed()) and might also confuse users of ClientAuthentication_hook. Per report from Liu Lang. Back-patch to all supported versions. Discussion: https://postgr.es/m/b725238c-539d-cb09-2bff-b5e6cb2c069c@esgyn.cn
* Generate new LOG for "trust" connections under log_connectionsMichael Paquier2023-08-26
| | | | | | | | | | | | | | | Adding an extra LOG for connections that have not set an authn ID, like when the "trust" authentication method is used, is useful for audit purposes. A couple of TAP tests for SSL and authentication need to be tweaked to adapt to this new LOG generated, as some scenarios expected no logs but they now get a hit. Reported-by: Shaun Thomas Author: Jacob Champion Reviewed-by: Robert Haas, Michael Paquier Discussion: https://postgr.es/m/CAFdbL1N7-GF-ZXKaB3XuGA+CkSmnjFvqb8hgjMnDfd+uhL2u-A@mail.gmail.com
* Introduce macros for protocol characters.Nathan Bossart2023-08-22
| | | | | | | | | | | This commit introduces descriptively-named macros for the identifiers used in wire protocol messages. These new macros are placed in a new header file so that they can be easily used by third-party code. Author: Dave Cramer Reviewed-by: Alvaro Herrera, Tatsuo Ishii, Peter Smith, Robert Haas, Tom Lane, Peter Eisentraut, Michael Paquier Discussion: https://postgr.es/m/CADK3HHKbBmK-PKf1bPNFoMC%2BoBt%2BpD9PH8h5nvmBQskEHm-Ehw%40mail.gmail.com
* Remove db_user_namespace.Nathan Bossart2023-07-17
| | | | | | | | | | | This feature was intended to be a temporary measure to support per-database user names. A better one hasn't materialized in the ~21 years since it was added, and nobody claims to be using it, so let's just remove it. Reviewed-by: Michael Paquier, Magnus Hagander Discussion: https://postgr.es/m/20230630200509.GA2830328%40nathanxps13 Discussion: https://postgr.es/m/20230630215608.GD2941194%40nathanxps13
* Message wording improvementsPeter Eisentraut2023-07-10
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* Remove unnecessary unbind in LDAP search+bind modePeter Eisentraut2023-07-09
| | | | | | | | | | | | | | | | | | | | | | | | Comments in src/backend/libpq/auth.c say: (after successfully finding the final DN to check the user-supplied password against) /* Unbind and disconnect from the LDAP server */ and later /* * Need to re-initialize the LDAP connection, so that we can bind to * it with a different username. */ But the protocol actually permits multiple subsequent authentications ("binds") over a single connection. So, it seems like the whole connection re-initialization thing was just a confusion and can be safely removed, thus saving quite a few network round-trips, especially for the case of ldaps/starttls. Author: Anatoly Zaretsky <anatoly.zaretsky@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/CALbq6kmJ-1+58df4B51ctPfTOSyPbY8Qi2=ct8oR=i4TamkUoQ@mail.gmail.com
* rename "gss_accept_deleg" to "gss_accept_delegation".Bruce Momjian2023-05-20
| | | | | | This is more consistent with existing GUC spelling. Discussion: https://postgr.es/m/ZGdnEsGtNj7+fZoa@momjian.us
* Explicitly require MIT Kerberos for GSSAPIStephen Frost2023-04-13
| | | | | | | | | | 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
* De-Revert "Add support for Kerberos credential delegation"Stephen Frost2023-04-13
| | | | | | | | | | | | | | | | | | 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
* Revert "Add support for Kerberos credential delegation"Stephen Frost2023-04-08
| | | | | | | | | | | This reverts commit 3d4fa227bce4294ce1cc214b4a9d3b7caa3f0454. 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
* Add support for Kerberos credential delegationStephen Frost2023-04-07
| | | | | | | | | | | | | | | | | | | 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
* Add a hook for modifying the ldapbind passwordAndrew Dunstan2023-03-15
| | | | | | | | | | | 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
* Update copyright for 2023Bruce Momjian2023-01-02
| | | | Backpatch-through: 11
* Refactor code handling the names of files loaded in hba.cMichael Paquier2022-10-26
| | | | | | | | | | | | | | | | | | | | | | | | 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
* Replace loading of ldap_start_tls_sA() by direct function callMichael Paquier2022-09-12
| | | | | | | | | | | | | | | 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
* Free correctly LDAPMessage returned by ldap_search_s() in auth.cMichael Paquier2022-09-10
| | | | | | | | | | | | | | | | 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
* Replace load of functions by direct calls for some WIN32Michael Paquier2022-09-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Remove configure probe for sockaddr_in6 and require AF_INET6.Thomas Munro2022-08-26
| | | | | | | | | | | | | | | | | SUSv3 <netinet/in.h> defines struct sockaddr_in6, and all targeted Unix systems have it. Windows has it in <ws2ipdef.h>. Remove the configure probe, the macro and a small amount of dead code. Also remove a mention of IPv6-less builds from the documentation, since there aren't any. This is similar to commits f5580882 and 077bf2f2 for Unix sockets. Even though AF_INET6 is an "optional" component of SUSv3, there are no known modern operating system without it, and it seems even less likely to be omitted from future systems than AF_UNIX. Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CA+hUKGKErNfhmvb_H0UprEmp4LPzGN06yR2_0tYikjzB-2ECMw@mail.gmail.com
* More -Wshadow=compatible-local warning fixesDavid Rowley2022-08-26
| | | | | | | | | | | | In a similar effort to f01592f91, here we're targetting fixing the warnings where we've deemed the shadowing variable to serve a close enough purpose to the shadowed variable just to reuse the shadowed version and not declare the shadowing variable at all. By my count, this takes the warning count from 106 down to 71. Author: Justin Pryzby Discussion: https://postgr.es/m/20220825020839.GT2342@telsasoft.com
* Allow parallel workers to retrieve some data from PortMichael Paquier2022-08-24
| | | | | | | | | | | | | | | | | | | | | | | | | This commit moves authn_id into a new global structure called ClientConnectionInfo (mapping to a MyClientConnectionInfo for each backend) which is intended to hold all the client information that should be shared between the backend and any of its parallel workers, access for extensions and triggers being the primary use case. There is no need to push all the data of Port to the workers, and authn_id is quite a generic concept so using a separate structure provides the best balance (the name of the structure has been suggested by Robert Haas). While on it, and per discussion as this would be useful for a potential SYSTEM_USER that can be accessed through parallel workers, a second field is added for the authentication method, copied directly from Port. ClientConnectionInfo is serialized and restored using a new parallel key and a structure tracks the length of the authn_id, making the addition of more fields straight-forward. Author: Jacob Champion Reviewed-by: Bertrand Drouvot, Stephen Frost, Robert Haas, Tom Lane, Michael Paquier, Julien Rouhaud Discussion: https://postgr.es/m/793d990837ae5c06a558d58d62de9378ab525d83.camel@vmware.com
* Avoid using list_length() to test for empty list.Tom Lane2022-08-17
| | | | | | | | | | | | | | | | | | | | | | | | The standard way to check for list emptiness is to compare the List pointer to NIL; our list code goes out of its way to ensure that that is the only representation of an empty list. (An acceptable alternative is a plain boolean test for non-null pointer, but explicit mention of NIL is usually preferable.) Various places didn't get that memo and expressed the condition with list_length(), which might not be so bad except that there were such a variety of ways to check it exactly: equal to zero, less than or equal to zero, less than one, yadda yadda. In the name of code readability, let's standardize all those spellings as "list == NIL" or "list != NIL". (There's probably some microscopic efficiency gain too, though few of these look to be at all performance-critical.) A very small number of cases were left as-is because they seemed more consistent with other adjacent list_length tests that way. Peter Smith, with bikeshedding from a number of us Discussion: https://postgr.es/m/CAHut+PtQYe+ENX5KrONMfugf0q6NHg4hR5dAhqEXEc2eefFeig@mail.gmail.com
* Remove replacement code for getaddrinfo.Thomas Munro2022-08-14
| | | | | | | | | | SUSv3, all targeted Unixes and modern Windows have getaddrinfo() and related interfaces. Drop the replacement implementation, and adjust some headers slightly to make sure that the APIs are visible everywhere using standard POSIX headers and names. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/CA%2BhUKG%2BL_3brvh%3D8e0BW_VfX9h7MtwgN%3DnFHP5o7X2oZucY9dg%40mail.gmail.com
* Remove configure probe for sys/select.h.Thomas Munro2022-08-14
| | | | | | | | | <sys/select.h> is in SUSv3 and every targeted Unix system has it. Provide an empty header in src/include/port/win32 so that we can include it unguarded even on Windows. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/CA%2BhUKG%2BL_3brvh%3D8e0BW_VfX9h7MtwgN%3DnFHP5o7X2oZucY9dg%40mail.gmail.com
* Remove redundant null pointer checks before free()Peter Eisentraut2022-07-03
| | | | | | | | | | Per applicable standards, free() with a null pointer is a no-op. Systems that don't observe that are ancient and no longer relevant. Some PostgreSQL code already required this behavior, so this change does not introduce any new requirements, just makes the code more consistent. Discussion: https://www.postgresql.org/message-id/flat/dac5d2d0-98f5-94d9-8e69-46da2413593d%40enterprisedb.com
* Clean up messy API for src/port/thread.c.Tom Lane2022-01-11
| | | | | | | | | | | | | | | | | | | | | | | The point of this patch is to reduce inclusion spam by not needing to #include <netdb.h> or <pwd.h> in port.h (which is read by every compile in our tree). To do that, we must remove port.h's declarations of pqGetpwuid and pqGethostbyname. pqGethostbyname is only used, and is only ever likely to be used, in src/port/getaddrinfo.c --- which isn't even built on most platforms, making pqGethostbyname dead code for most people. Hence, deal with that by just moving it into getaddrinfo.c. To clean up pqGetpwuid, invent a couple of simple wrapper functions with less-messy APIs. This allows removing some duplicate error-handling code, too. In passing, remove thread.c from the MSVC build, since it contains nothing we use on Windows. Noted while working on 376ce3e40. Discussion: https://postgr.es/m/1634252654444.90107@mit.edu
* Improve error handling of cryptohash computationsMichael Paquier2022-01-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing cryptohash facility was causing problems in some code paths related to MD5 (frontend and backend) that relied on the fact that the only type of error that could happen would be an OOM, as the MD5 implementation used in PostgreSQL ~13 (the in-core implementation is used when compiling with or without OpenSSL in those older versions), could fail only under this circumstance. The new cryptohash facilities can fail for reasons other than OOMs, like attempting MD5 when FIPS is enabled (upstream OpenSSL allows that up to 1.0.2, Fedora and Photon patch OpenSSL 1.1.1 to allow that), so this would cause incorrect reports to show up. This commit extends the cryptohash APIs so as callers of those routines can fetch more context when an error happens, by using a new routine called pg_cryptohash_error(). The error states are stored within each implementation's internal context data, so as it is possible to extend the logic depending on what's suited for an implementation. The default implementation requires few error states, but OpenSSL could report various issues depending on its internal state so more is needed in cryptohash_openssl.c, and the code is shaped so as we are always able to grab the necessary information. The core code is changed to adapt to the new error routine, painting more "const" across the call stack where the static errors are stored, particularly in authentication code paths on variables that provide log details. This way, any future changes would warn if attempting to free these strings. The MD5 authentication code was also a bit blurry about the handling of "logdetail" (LOG sent to the postmaster), so improve the comments related that, while on it. The origin of the problem is 87ae969, that introduced the centralized cryptohash facility. Extra changes are done for pgcrypto in v14 for the non-OpenSSL code path to cope with the improvements done by this commit. Reported-by: Michael Mühlbeyer Author: Michael Paquier Reviewed-by: Tom Lane Discussion: https://postgr.es/m/89B7F072-5BBE-4C92-903E-D83E865D9367@trivadis.com Backpatch-through: 14
* Update copyright for 2022Bruce Momjian2022-01-07
| | | | Backpatch-through: 10
* Remove check for accept() argument typesPeter Eisentraut2021-11-09
| | | | | | | | | | | This check was used to accommodate a staggering variety in particular in the type of the third argument of accept(). This is no longer of concern on currently supported systems. We can just use socklen_t in the code and put in a simple check that substitutes int for socklen_t if it's missing, to cover the few stragglers. Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/3538f4c4-1886-64f2-dcff-aaad8267fb82@enterprisedb.com
* Message style improvementsPeter Eisentraut2021-09-16
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* Fix incorrect format placeholdersPeter Eisentraut2021-09-08
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* Refactor SASL code with a generic interface for its mechanismsMichael Paquier2021-07-07
| | | | | | | | | | | | | | | | | | | | | | The code of SCRAM and SASL have been tightly linked together since SCRAM exists in the core code, making hard to apprehend the addition of new SASL mechanisms, but these are by design different facilities, with SCRAM being an option for SASL. This refactors the code related to both so as the backend and the frontend use a set of callbacks for SASL mechanisms, documenting while on it what is expected by anybody adding a new SASL mechanism. The separation between both layers is neat, using two sets of callbacks for the frontend and the backend to mark the frontier between both facilities. The shape of the callbacks is now directly inspired from the routines used by SCRAM, so the code change is straight-forward, and the SASL code is moved into its own set of files. These will likely change depending on how and if new SASL mechanisms get added in the future. Author: Jacob Champion Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/3d2a6f5d50e741117d6baf83eb67ebf1a8a35a11.camel@vmware.com
* Don't assume GSSAPI result strings are null-terminated.Tom Lane2021-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | Our uses of gss_display_status() and gss_display_name() assumed that the gss_buffer_desc strings returned by those functions are null-terminated. It appears that they generally are, given the lack of field complaints up to now. However, the available documentation does not promise this, and some man pages for gss_display_status() show examples that rely on the gss_buffer_desc.length field instead of expecting null termination. Also, we now have a report that on some implementations, clang's address sanitizer is of the opinion that the byte after the specified length is undefined. Hence, change the code to rely on the length field instead. This might well be cosmetic rather than fixing any real bug, but it's hard to be sure, so back-patch to all supported branches. While here, also back-patch the v12 changes that made pg_GSS_error deal honestly with multiple messages available from gss_display_status. Per report from Sudheer H R. Discussion: https://postgr.es/m/5372B6D4-8276-42C0-B8FB-BD0918826FC3@tekenlight.com
* Initial pgindent and pgperltidy run for v14.Tom Lane2021-05-12
| | | | | | | | Also "make reformat-dat-files". The only change worthy of note is that pgindent messed up the formatting of launcher.c's struct LogicalRepWorkerId, which led me to notice that that struct wasn't used at all anymore, so I just took it out.
* Add heuristic incoming-message-size limits in the server.Tom Lane2021-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We had a report of confusing server behavior caused by a client bug that sent junk to the server: the server thought the junk was a very long message length and waited patiently for data that would never come. We can reduce the risk of that by being less trusting about message lengths. For a long time, libpq has had a heuristic rule that it wouldn't believe large message size words, except for a small number of message types that are expected to be (potentially) long. This provides some defense against loss of message-boundary sync and other corrupted-data cases. The server does something similar, except that up to now it only limited the lengths of messages received during the connection authentication phase. Let's do the same as in libpq and put restrictions on the allowed length of all messages, while distinguishing between message types that are expected to be long and those that aren't. I used a limit of 10000 bytes for non-long messages. (libpq's corresponding limit is 30000 bytes, but given the asymmetry of the FE/BE protocol, there's no good reason why the numbers should be the same.) Experimentation suggests that this is at least a factor of 10, maybe a factor of 100, more than we really need; but plenty of daylight seems desirable to avoid false positives. In any case we can adjust the limit based on beta-test results. For long messages, set a limit of MaxAllocSize - 1, which is the most that we can absorb into the StringInfo buffer that the message is collected in. This just serves to make sure that a bogus message size is reported as such, rather than as a confusing gripe about not being able to enlarge a string buffer. While at it, make sure that non-mainline code paths (such as COPY FROM STDIN) are as paranoid as SocketBackend is, and validate the message type code before believing the message length. This provides an additional guard against getting stuck on corrupted input. Discussion: https://postgr.es/m/2003757.1619373089@sss.pgh.pa.us
* Refactor hba_authnameMagnus Hagander2021-04-07
| | | | | | | | | | | The previous implementation (from 9afffcb833) had an unnecessary check on the boundaries of the enum which trigtered compile warnings. To clean it up, move the pre-existing static assert to a central location and call that. Reported-By: Erik Rijkers Reviewed-By: Michael Paquier Discussion: https://postgr.es/m/1056399262.13159.1617793249020@webmailclassic.xs4all.nl
* Add some information about authenticated identity via log_connectionsMichael Paquier2021-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "authenticated identity" is the string used by an authentication method to identify a particular user. In many common cases, this is the same as the PostgreSQL username, but for some third-party authentication methods, the identifier in use may be shortened or otherwise translated (e.g. through pg_ident user mappings) before the server stores it. To help administrators see who has actually interacted with the system, this commit adds the capability to store the original identity when authentication succeeds within the backend's Port, and generates a log entry when log_connections is enabled. The log entries generated look something like this (where a local user named "foouser" is connecting to the database as the database user called "admin"): LOG: connection received: host=[local] LOG: connection authenticated: identity="foouser" method=peer (/data/pg_hba.conf:88) LOG: connection authorized: user=admin database=postgres application_name=psql Port->authn_id is set according to the authentication method: bsd: the PostgreSQL username (aka the local username) cert: the client's Subject DN gss: the user principal ident: the remote username ldap: the final bind DN pam: the PostgreSQL username (aka PAM username) password (and all pw-challenge methods): the PostgreSQL username peer: the peer's pw_name radius: the PostgreSQL username (aka the RADIUS username) sspi: either the down-level (SAM-compatible) logon name, if compat_realm=1, or the User Principal Name if compat_realm=0 The trust auth method does not set an authenticated identity. Neither does clientcert=verify-full. Port->authn_id could be used for other purposes, like a superuser-only extra column in pg_stat_activity, but this is left as future work. PostgresNode::connect_{ok,fails}() have been modified to let tests check the backend log files for required or prohibited patterns, using the new log_like and log_unlike parameters. This uses a method based on a truncation of the existing server log file, like issues_sql_like(). Tests are added to the ldap, kerberos, authentication and SSL test suites. Author: Jacob Champion Reviewed-by: Stephen Frost, Magnus Hagander, Tom Lane, Michael Paquier Discussion: https://postgr.es/m/c55788dd1773c521c862e8e0dddb367df51222be.camel@vmware.com
* Allow matching the DN of a client certificate for authenticationAndrew Dunstan2021-03-29
| | | | | | | | | | | | | | | | | | | Currently we only recognize the Common Name (CN) of a certificate's subject to be matched against the user name. Thus certificates with subjects '/OU=eng/CN=fred' and '/OU=sales/CN=fred' will have the same connection rights. This patch provides an option to match the whole Distinguished Name (DN) instead of just the CN. On any hba line using client certificate identity, there is an option 'clientname' which can have values of 'DN' or 'CN'. The default is 'CN', the current procedure. The DN is matched against the RFC2253 formatted DN, which looks like 'CN=fred,OU=eng'. This facility of probably best used in conjunction with an ident map. Discussion: https://postgr.es/m/92e70110-9273-d93c-5913-0bccb6562740@dunslane.net Reviewed-By: Michael Paquier, Daniel Gustafsson, Jacob Champion
* Remove server and libpq support for old FE/BE protocol version 2.Heikki Linnakangas2021-03-04
| | | | | | | | | | | | | | | | | Protocol version 3 was introduced in PostgreSQL 7.4. There shouldn't be many clients or servers left out there without version 3 support. But as a courtesy, I kept just enough of the old protocol support that we can still send the "unsupported protocol version" error in v2 format, so that old clients can display the message properly. Likewise, libpq still understands v2 ErrorResponse messages when establishing a connection. The impetus to do this now is that I'm working on a patch to COPY FROM, to always prefetch some data. We cannot do that safely with the old protocol, because it requires parsing the input one byte at a time to detect the end-of-copy marker. Reviewed-by: Tom Lane, Alvaro Herrera, John Naylor Discussion: https://www.postgresql.org/message-id/9ec25819-0a8a-d51a-17dc-4150bb3cca3b%40iki.fi
* Change the error message for logical replication authentication failure.Amit Kapila2021-02-23
| | | | | | | | | | | The authentication failure error message wasn't distinguishing whether it is a physical replication or logical replication connection failure and was giving incomplete information on what led to failure in case of logical replication connection. Author: Paul Martinez and Amit Kapila Reviewed-by: Euler Taveira and Amit Kapila Discussion: https://postgr.es/m/CACqFVBYahrAi2OPdJfUA3YCvn3QMzzxZdw0ibSJ8wouWeDtiyQ@mail.gmail.com
* Update copyright for 2021Bruce Momjian2021-01-02
| | | | Backpatch-through: 9.5
* Fix up usage of krb_server_keyfile GUC parameter.Tom Lane2020-12-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | secure_open_gssapi() installed the krb_server_keyfile setting as KRB5_KTNAME unconditionally, so long as it's not empty. However, pg_GSS_recvauth() only installed it if KRB5_KTNAME wasn't set already, leading to a troubling inconsistency: in theory, clients could see different sets of server principal names depending on whether they use GSSAPI encryption. Always using krb_server_keyfile seems like the right thing, so make both places do that. Also fix up secure_open_gssapi()'s lack of a check for setenv() failure --- it's unlikely, surely, but security-critical actions are no place to be sloppy. Also improve the associated documentation. This patch does nothing about secure_open_gssapi()'s use of setenv(), and indeed causes pg_GSS_recvauth() to use it too. That's nominally against project portability rules, but since this code is only built with --with-gssapi, I do not feel a need to do something about this in the back branches. A fix will be forthcoming for HEAD though. Back-patch to v12 where GSSAPI encryption was introduced. The dubious behavior in pg_GSS_recvauth() goes back further, but it didn't have anything to be inconsistent with, so let it be. Discussion: https://postgr.es/m/2187460.1609263156@sss.pgh.pa.us
* Improve log messages related to pg_hba.conf not matching a connection.Tom Lane2020-12-28
| | | | | | | | | | Include details on whether GSS encryption has been activated; since we added "hostgssenc" type HBA entries, that's relevant info. Kyotaro Horiguchi and Tom Lane. Back-patch to v12 where GSS encryption was introduced. Discussion: https://postgr.es/m/e5b0b6ed05764324a2f3fe7acfc766d5@smhi.se
* Fix assorted issues in backend's GSSAPI encryption support.Tom Lane2020-12-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unrecoverable errors detected by GSSAPI encryption can't just be reported with elog(ERROR) or elog(FATAL), because attempting to send the error report to the client is likely to lead to infinite recursion or loss of protocol sync. Instead make this code do what the SSL encryption code has long done, which is to just report any such failure to the server log (with elevel COMMERROR), then pretend we've lost the connection by returning errno = ECONNRESET. Along the way, fix confusion about whether message translation is done by pg_GSS_error() or its callers (the latter should do it), and make the backend version of that function work more like the frontend version. Avoid allocating the port->gss struct until it's needed; we surely don't need to allocate it in the postmaster. Improve logging of "connection authorized" messages with GSS enabled. (As part of this, I back-patched the code changes from dc11f31a1.) Make BackendStatusShmemSize() account for the GSS-related space that will be allocated by CreateSharedBackendStatus(). This omission could possibly cause out-of-shared-memory problems with very high max_connections settings. Remove arbitrary, pointless restriction that only GSS authentication can be used on a GSS-encrypted connection. Improve documentation; notably, document the fact that libpq now prefers GSS encryption over SSL encryption if both are possible. Per report from Mikael Gustavsson. Back-patch to v12 where this code was introduced. Discussion: https://postgr.es/m/e5b0b6ed05764324a2f3fe7acfc766d5@smhi.se
* Convert elog(LOG) calls to ereport() where appropriatePeter Eisentraut2020-12-04
| | | | | | | | | | | User-visible log messages should go through ereport(), so they are subject to translation. Many remaining elog(LOG) calls are really debugging calls. Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Noah Misch <noah@leadboat.com> Discussion: https://www.postgresql.org/message-id/flat/92d6f545-5102-65d8-3c87-489f71ea0a37%40enterprisedb.com
* Fix -Wcast-function-type warnings on Windows/MinGWPeter Eisentraut2020-10-21
| | | | | | | | After de8feb1f3a23465b5737e8a8c160e8ca62f61339, some warnings remained that were only visible when using GCC on Windows. Fix those as well. Note that the ecpg test source files don't use the full pg_config.h, so we can't use pg_funcptr_t there but have to do it the long way.
* Remove arbitrary restrictions on password length.Tom Lane2020-09-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch started out with the goal of harmonizing various arbitrary limits on password length, but after awhile a better idea emerged: let's just get rid of those fixed limits. recv_password_packet() has an arbitrary limit on the packet size, which we don't really need, so just drop it. (Note that this doesn't really affect anything for MD5 or SCRAM password verification, since those will hash the user's password to something shorter anyway. It does matter for auth methods that require a cleartext password.) Likewise remove the arbitrary error condition in pg_saslprep(). The remaining limits are mostly in client-side code that prompts for passwords. To improve those, refactor simple_prompt() so that it allocates its own result buffer that can be made as big as necessary. Actually, it proves best to make a separate routine pg_get_line() that has essentially the semantics of fgets(), except that it allocates a suitable result buffer and hence will never return a truncated line. (pg_get_line has a lot of potential applications to replace randomly-sized fgets buffers elsewhere, but I'll leave that for another patch.) I built pg_get_line() atop stringinfo.c, which requires moving that code to src/common/; but that seems fine since it was a poor fit for src/port/ anyway. This patch is mostly mine, but it owes a good deal to Nathan Bossart who pressed for a solution to the password length problem and created a predecessor patch. Also thanks to Peter Eisentraut and Stephen Frost for ideas and discussion. Discussion: https://postgr.es/m/09512C4F-8CB9-4021-B455-EF4C4F0D55A0@amazon.com
* Dial back -Wimplicit-fallthrough to level 3Alvaro Herrera2020-05-13
| | | | | | | | | The additional pain from level 4 is excessive for the gain. Also revert all the source annotation changes to their original wordings, to avoid back-patching pain. Discussion: https://postgr.es/m/31166.1589378554@sss.pgh.pa.us