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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2020-12-30 11:38:42 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2020-12-30 11:38:42 -0500 |
| commit | 3ca19490b4f8875c802999a62a207f9dabe813b2 (patch) | |
| tree | 6bcac8c1144ea025051097aac282f288176b2cbb /src/backend/libpq/be-secure-gssapi.c | |
| parent | 635140ace0b84aa5f177bddc368acb64f56a8e59 (diff) | |
| download | postgresql-3ca19490b4f8875c802999a62a207f9dabe813b2.tar.gz postgresql-3ca19490b4f8875c802999a62a207f9dabe813b2.zip | |
Fix up usage of krb_server_keyfile GUC parameter.
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
Diffstat (limited to 'src/backend/libpq/be-secure-gssapi.c')
| -rw-r--r-- | src/backend/libpq/be-secure-gssapi.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/src/backend/libpq/be-secure-gssapi.c b/src/backend/libpq/be-secure-gssapi.c index fe0a39c7ca5..211634fd5b7 100644 --- a/src/backend/libpq/be-secure-gssapi.c +++ b/src/backend/libpq/be-secure-gssapi.c @@ -525,8 +525,16 @@ secure_open_gssapi(Port *port) * Use the configured keytab, if there is one. Unfortunately, Heimdal * doesn't support the cred store extensions, so use the env var. */ - if (pg_krb_server_keyfile != NULL && strlen(pg_krb_server_keyfile) > 0) - setenv("KRB5_KTNAME", pg_krb_server_keyfile, 1); + if (pg_krb_server_keyfile != NULL && pg_krb_server_keyfile[0] != '\0') + { + if (setenv("KRB5_KTNAME", pg_krb_server_keyfile, 1) != 0) + { + /* The only likely failure cause is OOM, so use that errcode */ + ereport(FATAL, + (errcode(ERRCODE_OUT_OF_MEMORY), + errmsg("could not set environment: %m"))); + } + } while (true) { |