The in-core equivalents can make use of built-in functions if the
compiler supports this option, making optimizations possible. 0ba99c8
replaced all existing calls in the code base at this time, but b0b39f7
(GSSAPI encryption) has forgotten to do the switch.
Discussion: https://postgr.es/m/20201014055303.GG3349@paquier.xyz
Both the backend and libpq leaked buffers containing encrypted data
to be transmitted, so that the process size would grow roughly as
the total amount of data sent.
There were also far-less-critical leaks of the same sort in GSSAPI
session establishment.
Oversight in commit b0b39f72b, which I failed to notice while
reviewing the code in 2c0cdc818.
Per complaint from pmc@citylink.
Back-patch to v12 where this code was introduced.
Discussion: https://postgr.es/m/20200504115649.GA77072@gate.oper.dinoex.org
Fix assorted bugs in handling of non-blocking I/O when using GSSAPI
encryption. The encryption layer could return the wrong status
information to its caller, resulting in effectively dropping some data
(or possibly in aborting a not-broken connection), or in a "livelock"
situation where data remains to be sent but the upper layers think
transmission is done and just go to sleep. There were multiple small
thinkos contributing to that, as well as one big one (failure to think
through what to do when a send fails after having already transmitted
data). Note that these errors could cause failures whether the client
application asked for non-blocking I/O or not, since both libpq and
the backend always run things in non-block mode at this level.
Also get rid of use of static variables for GSSAPI inside libpq;
that's entirely not okay given that multiple connections could be
open at once inside a single client process.
Also adjust a bunch of random small discrepancies between the frontend
and backend versions of the send/receive functions -- except for error
handling, they should be identical, and now they are.
Also extend the Kerberos TAP tests to exercise cases where nontrivial
amounts of data need to be pushed through encryption. Before, those
tests didn't provide any useful coverage at all for the cases of
interest here. (They still might not, depending on timing, but at
least there's a chance.)
Per complaint from pmc@citylink and subsequent investigation.
Back-patch to v12 where this code was introduced.
Discussion: https://postgr.es/m/20200109181822.GA74698@gate.oper.dinoex.org
Make the error messages around GSSAPI encryption a bit clearer. Tweak
some messages to avoid plural problems.
Also make a code change for clarity. Using "conf" for "confidential"
is quite confusing. Using "conf_state" is perhaps not much better but
that's what the GSSAPI documentation uses, so there is at least some
hope of understanding it.
The file has been introduced in src/backend/libpq/ as of b0b39f72, but
all backend-side headers of libpq are located in src/include/libpq/.
Note that the identification path on top of the file referred to
src/include/libpq/ from the start.
Author: Michael Paquier
Reviewed-by: Stephen Frost
Discussion: https://postgr.es/m/20190607043415.GE1736@paquier.xyz
I noted that some buildfarm members were complaining about %ld being
used to format values that are (probably) declared size_t. Use %zu
instead, and insert a cast just in case some versions of the GSSAPI
API declare the length field differently. While at it, clean up
gratuitous differences in wording of equivalent messages, show
the complained-of length in all relevant messages not just some,
include trailing newline where needed, adjust random deviations
from project-standard code layout and message style, etc.
On both the frontend and backend, prepare for GSSAPI encryption
support by moving common code for error handling into a separate file.
Fix a TODO for handling multiple status messages in the process.
Eliminate the OIDs, which have not been needed for some time.
Add frontend and backend encryption support functions. Keep the
context initiation for authentication-only separate on both the
frontend and backend in order to avoid concerns about changing the
requested flags to include encryption support.
In postmaster, pull GSSAPI authorization checking into a shared
function. Also share the initiator name between the encryption and
non-encryption codepaths.
For HBA, add "hostgssenc" and "hostnogssenc" entries that behave
similarly to their SSL counterparts. "hostgssenc" requires either
"gss", "trust", or "reject" for its authentication.
Similarly, add a "gssencmode" parameter to libpq. Supported values are
"disable", "require", and "prefer". Notably, negotiation will only be
attempted if credentials can be acquired. Move credential acquisition
into its own function to support this behavior.
Add a simple pg_stat_gssapi view similar to pg_stat_ssl, for monitoring
if GSSAPI authentication was used, what principal was used, and if
encryption is being used on the connection.
Finally, add documentation for everything new, and update existing
documentation on connection security.
Thanks to Michael Paquier for the Windows fixes.
Author: Robbie Harwood, with changes to the read/write functions by me.
Reviewed in various forms and at different times by: Michael Paquier,
Andres Freund, David Steele.
Discussion: https://www.postgresql.org/message-id/flat/jlg1tgq1ktm.fsf@thriss.redhat.com
Michael Paquier
Tom Lane
Bruce Momjian
Peter Eisentraut
Thomas Munro
Stephen Frost