From 3eab8112754c484c192248afe64055d40a231f7b Mon Sep 17 00:00:00 2001
From: Noah Misch <noah@leadboat.com>
Date: Mon, 8 May 2017 07:24:24 -0700
Subject: [PATCH] Restore PGREQUIRESSL recognition in libpq.
Commit 65c3bf19fd3e1f6a591618e92eb4c54d0b217564 moved handling of the,
already then, deprecated requiressl parameter into conninfo_storeval().
The default PGREQUIRESSL environment variable was however lost in the
change resulting in a potentially silent accept of a non-SSL connection
even when set. Its documentation remained. Restore its implementation.
Also amend the documentation to mark PGREQUIRESSL as deprecated for
those not following the link to requiressl. Back-patch to 9.3, where
commit 65c3bf1 first appeared.
Behavior has been more complex when the user provides both deprecated
and non-deprecated settings. Before commit 65c3bf1, libpq operated
according to the first of these found:
requiressl=1
PGREQUIRESSL=1
sslmode=*
PGSSLMODE=*
(Note requiressl=0 didn't override sslmode=*; it would only suppress
PGREQUIRESSL=1 or a previous requiressl=1. PGREQUIRESSL=0 had no effect
whatsoever.) Starting with commit 65c3bf1, libpq ignored PGREQUIRESSL,
and order of precedence changed to this:
last of requiressl=* or sslmode=*
PGSSLMODE=*
Starting now, adopt the following order of precedence:
last of requiressl=* or sslmode=*
PGSSLMODE=*
PGREQUIRESSL=1
This retains the 65c3bf1 behavior for connection strings that contain
both requiressl=* and sslmode=*. It retains the 65c3bf1 change that
either connection string option overrides both environment variables.
For the first time, PGSSLMODE has precedence over PGREQUIRESSL; this
avoids reducing security of "PGREQUIRESSL=1 PGSSLMODE=verify-full"
configurations originating under v9.3 and later.
Daniel Gustafsson
Security: CVE-2017-7485
---
doc/src/sgml/libpq.sgml | 3 +++
src/interfaces/libpq/fe-connect.c | 24 ++++++++++++++++++++++++
2 files changed, 27 insertions(+)
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index c39a2273ce3..ebaf4ea0513 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -6710,6 +6710,9 @@ myEventProc(PGEventId evtId, void *evtInfo, void *passThrough)
</indexterm>
<envar>PGREQUIRESSL</envar> behaves the same as the <xref
linkend="libpq-connect-requiressl"> connection parameter.
+ This environment variable is deprecated in favor of the
+ <envar>PGSSLMODE</envar> variable; setting both variables suppresses the
+ effect of this one.
</para>
</listitem>
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 0748c00ac9f..9e813d6f000 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -4608,6 +4608,30 @@ conninfo_add_defaults(PQconninfoOption *options, PQExpBuffer errorMessage)
}
}
+ /*
+ * Interpret the deprecated PGREQUIRESSL environment variable. Per
+ * tradition, translate values starting with "1" to sslmode=require,
+ * and ignore other values. Given both PGREQUIRESSL=1 and PGSSLMODE,
+ * PGSSLMODE takes precedence; the opposite was true before v9.3.
+ */
+ if (strcmp(option->keyword, "sslmode") == 0)
+ {
+ const char *requiresslenv = getenv("PGREQUIRESSL");
+
+ if (requiresslenv != NULL && requiresslenv[0] == '1')
+ {
+ option->val = strdup("require");
+ if (!option->val)
+ {
+ if (errorMessage)
+ printfPQExpBuffer(errorMessage,
+ libpq_gettext("out of memory\n"));
+ return false;
+ }
+ continue;
+ }
+ }
+
/*
* No environment variable specified or the variable isn't set - try
* compiled-in default