bf6b9e9444
Some authentication methods allowed it, others did not. In the client-side, libpq does not even try to authenticate with an empty password, which makes using empty passwords hazardous: an administrator might think that an account with an empty password cannot be used to log in, because psql doesn't allow it, and not realize that a different client would in fact allow it. To clear that confusion and to be be consistent, disallow empty passwords in all authentication methods. All the authentication methods that used plaintext authentication over the wire, except for BSD authentication, already checked that the password received from the user was not empty. To avoid forgetting it in the future again, move the check to the recv_password_packet function. That only forbids using an empty password with plaintext authentication, however. MD5 and SCRAM need a different fix: * In stable branches, check that the MD5 hash stored for the user does not not correspond to an empty string. This adds some overhead to MD5 authentication, because the server needs to compute an extra MD5 hash, but it is not noticeable in practice. * In HEAD, modify CREATE and ALTER ROLE to clear the password if an empty string, or a password hash that corresponds to an empty string, is specified. The user-visible behavior is the same as in the stable branches, the user cannot log in, but it seems better to stop the empty password from entering the system in the first place. Secondly, it is fairly expensive to check that a SCRAM hash doesn't correspond to an empty string, because computing a SCRAM hash is much more expensive than an MD5 hash by design, so better avoid doing that on every authentication. We could clear the password on CREATE/ALTER ROLE also in stable branches, but we would still need to check at authentication time, because even if we prevent empty passwords from being stored in pg_authid, there might be existing ones there already. Reported by Jeroen van der Ham, Ben de Graaff and Jelte Fennema. Security: CVE-2017-7546 |
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| recovery | ||
| regress | ||
| ssl | ||
| subscription | ||
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| README | ||
README
PostgreSQL tests ================ This directory contains a variety of test infrastructure as well as some of the tests in PostgreSQL. Not all tests are here -- in particular, there are more in individual contrib/ modules and in src/bin. Not all these tests get run by "make check". Check src/test/Makefile to see which tests get run automatically. authentication/ Tests for authentication examples/ Demonstration programs for libpq that double as regression tests via "make check" isolation/ Tests for concurrent behavior at the SQL level locale/ Sanity checks for locale data, encodings, etc mb/ Tests for multibyte encoding (UTF-8) support modules/ Extensions used only or mainly for test purposes, generally not suitable for installing in production databases perl/ Infrastructure for Perl-based TAP tests recovery/ Test suite for recovery and replication regress/ PostgreSQL's main regression test suite, pg_regress ssl/ Tests to exercise and verify SSL certificate handling subscription/ Tests for logical replication thread/ A thread-safety-testing utility used by configure