Commits a59c79564 et al. tried to sync libpq's SSL key file
permissions checks with what we've used for years in the backend.
We did not intend to create any new failure cases, but it turns out
we did: restricting the key file's ownership breaks cases where the
client is allowed to read a key file despite not having the identical
UID. In particular a client running as root used to be able to read
someone else's key file; and having seen that I suspect that there are
other, less-dubious use cases that this restriction breaks on some
platforms.
We don't really need an ownership check, since if we can read the key
file despite its having restricted permissions, it must have the right
ownership --- under normal conditions anyway, and the point of this
patch is that any additional corner cases where that works should be
deemed allowable, as they have been historically. Hence, just drop
the ownership check, and rearrange the permissions check to get rid
of its faulty assumption that geteuid() can't be zero. (Note that the
comparable backend-side code doesn't have to cater for geteuid() == 0,
since the server rejects that very early on.)
This does have the end result that the permissions safety check used
for a root user's private key file is weaker than that used for
anyone else's. While odd, root really ought to know what she's doing
with file permissions, so I think this is acceptable.
Per report from Yogendra Suralkar. Like the previous patch,
back-patch to all supported branches.
Discussion: https://postgr.es/m/MW3PR15MB3931DF96896DC36D21AFD47CA3D39@MW3PR15MB3931.namprd15.prod.outlook.com
This change makes libpq apply the same private-key-file ownership
and permissions checks that we have used in the backend since commit
9a83564c5. Namely, that the private key can be owned by either the
current user or root (with different file permissions allowed in the
two cases). This allows system-wide management of key files, which
is just as sensible on the client side as the server, particularly
when the client is itself some application daemon.
Sync the comments about this between libpq and the backend, too.
David Steele
Discussion: https://postgr.es/m/f4b7bc55-97ac-9e69-7398-335e212f7743@pgmasters.net
The patch needs test cases, reorganization, and cfbot testing.
Technically reverts commits 5c31afc49d..e35b2bad1a (exclusive/inclusive)
and 08db7c63f3..ccbe34139b.
Reported-by: Tom Lane, Michael Paquier
Discussion: https://postgr.es/m/E1ktAAG-0002V2-VB@gemulon.postgresql.org
Use the explicit_bzero() function in places where it is important that
security information such as passwords is cleared from memory. There
might be other places where it could be useful; this is just an
initial collection.
For platforms that don't have explicit_bzero(), provide various
fallback implementations. (explicit_bzero() itself isn't standard,
but as Linux/glibc, FreeBSD, and OpenBSD have it, it's the most common
spelling, so it makes sense to make that the invocation point.)
Discussion: https://www.postgresql.org/message-id/flat/42d26bde-5d5b-c90d-87ae-6cab875f73be%402ndquadrant.com
b654714 has reworked the way trailing CR/LF characters are removed from
strings. This commit introduces a new routine in common/string.c and
refactors the code so as the logic is in a single place, mostly.
Author: Michael Paquier
Reviewed-by: Bruce Momjian
Discussion: https://postgr.es/m/20190801031820.GF29334@paquier.xyz
libpq failed to ignore Windows-style newlines in connection service files.
This normally wasn't a problem on Windows itself, because fgets() would
convert \r\n to just \n. But if libpq were running inside a program that
changes the default fopen mode to binary, it would see the \r's and think
they were data. In any case, it's project policy to ignore \r in text
files unconditionally, because people sometimes try to use files with
DOS-style newlines on Unix machines, where the C library won't hide that
from us.
Hence, adjust parseServiceFile() to ignore \r as well as \n at the end of
the line. In HEAD, go a little further and make it ignore all trailing
whitespace, to match what it's always done with leading whitespace.
In HEAD, also run around and fix up everyplace where we have
newline-chomping code to make all those places look consistent and
uniformly drop \r. It is not clear whether any of those changes are
fixing live bugs. Most of the non-cosmetic changes are in places that
are reading popen output, and the jury is still out as to whether popen
on Windows can return \r\n. (The Windows-specific code in pipe_read_line
seems to think so, but our lack of support for this elsewhere suggests
maybe it's not a problem in practice.) Hence, I desisted from applying
those changes to back branches, except in run_ssl_passphrase_command()
which is new enough and little-tested enough that we'd probably not have
heard about any problems there.
Tom Lane and Michael Paquier, per bug #15827 from Jorge Gustavo Rocha.
Back-patch the parseServiceFile() change to all supported branches,
and the run_ssl_passphrase_command() change to v11 where that was added.
Discussion: https://postgr.es/m/15827-e6ba53a3a7ed543c@postgresql.org
Update typedefs.list from current buildfarm results. Adjust pgindent's
typedef blacklist to block some more unfortunate typedef names that have
snuck in since last time. Manually tweak a few places where I didn't
like the initial results of pgindent'ing.
Recent commit 8a3d9425 has introduced be-secure-common.c, which is aimed
at including backend-side APIs that can be used by any SSL
implementation. The purpose is similar to fe-secure-common.c for the
frontend-side APIs.
However, this has forgotten to include check_ssl_key_file_permissions()
in the move, which causes a double dependency between be-secure.c and
be-secure-openssl.c.
Refactor the code in a more logical way. This also puts into light an
API which is usable by future SSL implementations for permissions on SSL
key files.
Author: Michael Paquier <michael@paquier.xyz>
This allows specifying an external command for prompting for or
otherwise obtaining passphrases for SSL key files. This is useful
because in many cases there is no TTY easily available during service
startup.
Also add a setting ssl_passphrase_command_supports_reload, which allows
supporting SSL configuration reload even if SSL files need passphrases.
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
