On Sun, Dec 8, 2019 at 9:02 AM Tom Lane <t...@sss.pgh.pa.us> wrote:
>
> Andrew Dunstan <andrew.duns...@2ndquadrant.com> writes:
> > Well that pretty much brings us back to the patch as submitted :-)
>
> Yeah, pretty nearly. Taking a quick look over the v3 patch, my
> only quibble is that it doesn't provide any convenient way for the
> external module to make decisions about how to interact with
> ssl_passphrase_command --- in particular, if it would like to allow
> that to take precedence, it can't because there's no way for it to
> invoke the static function ssl_external_passwd_cb.
>
> But rather than expose that globally, maybe the theory ought to be
> "set up the state as we'd normally do, then let loadable modules
> choose to override it". So I'm tempted to propose a hook function
> with the signature
>
> void openssl_tls_init_hook(SSL_CTX *context, bool isServerStart);
>
> and invoke that somewhere in be_tls_init --- maybe fairly late,
> so that it can override other settings if it wants, not only the
> SSL_CTX_set_default_passwd_cb setting.
>
Not sure if the placement is what you want, but maybe something like this?
cheers
andrew
--
Andrew Dunstan https://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 0cc59f1be1..af9f1f71d5 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -45,6 +45,9 @@
#include "tcop/tcopprot.h"
#include "utils/memutils.h"
+/* default init hook can be overridden by a shared library */
+static void default_openssl_tls_init(SSL_CTX *context, bool isServerStart);
+openssl_tls_init_hook_typ openssl_tls_init_hook = default_openssl_tls_init;
static int my_sock_read(BIO *h, char *buf, int size);
static int my_sock_write(BIO *h, const char *buf, int size);
@@ -116,27 +119,10 @@ be_tls_init(bool isServerStart)
SSL_CTX_set_mode(context, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
/*
- * Set password callback
+ * Call init hook (usually to set password callback)
*/
- if (isServerStart)
- {
- if (ssl_passphrase_command[0])
- SSL_CTX_set_default_passwd_cb(context, ssl_external_passwd_cb);
- }
- else
- {
- if (ssl_passphrase_command[0] && ssl_passphrase_command_supports_reload)
- SSL_CTX_set_default_passwd_cb(context, ssl_external_passwd_cb);
- else
+ (* openssl_tls_init_hook)(context, isServerStart);
- /*
- * If reloading and no external command is configured, override
- * OpenSSL's default handling of passphrase-protected files,
- * because we don't want to prompt for a passphrase in an
- * already-running server.
- */
- SSL_CTX_set_default_passwd_cb(context, dummy_ssl_passwd_cb);
- }
/* used by the callback */
ssl_is_server_start = isServerStart;
@@ -1310,3 +1296,27 @@ ssl_protocol_version_to_openssl(int v, const char *guc_name, int loglevel)
GetConfigOption(guc_name, false, false))));
return -1;
}
+
+
+static void
+default_openssl_tls_init(SSL_CTX *context, bool isServerStart)
+{
+ if (isServerStart)
+ {
+ if (ssl_passphrase_command[0])
+ SSL_CTX_set_default_passwd_cb(context, ssl_external_passwd_cb);
+ }
+ else
+ {
+ if (ssl_passphrase_command[0] && ssl_passphrase_command_supports_reload)
+ SSL_CTX_set_default_passwd_cb(context, ssl_external_passwd_cb);
+ else
+ /*
+ * If reloading and no external command is configured, override
+ * OpenSSL's default handling of passphrase-protected files,
+ * because we don't want to prompt for a passphrase in an
+ * already-running server.
+ */
+ SSL_CTX_set_default_passwd_cb(context, dummy_ssl_passwd_cb);
+ }
+}
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 7a92dac525..9e2777c896 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -972,17 +972,6 @@ PostmasterMain(int argc, char *argv[])
*/
LocalProcessControlFile(false);
- /*
- * Initialize SSL library, if specified.
- */
-#ifdef USE_SSL
- if (EnableSSL)
- {
- (void) secure_initialize(true);
- LoadedSSL = true;
- }
-#endif
-
/*
* Register the apply launcher. Since it registers a background worker,
* it needs to be called before InitializeMaxBackends(), and it's probably
@@ -996,6 +985,17 @@ PostmasterMain(int argc, char *argv[])
*/
process_shared_preload_libraries();
+ /*
+ * Initialize SSL library, if specified.
+ */
+#ifdef USE_SSL
+ if (EnableSSL)
+ {
+ (void) secure_initialize(true);
+ LoadedSSL = true;
+ }
+#endif
+
/*
* Now that loadable modules have had their chance to register background
* workers, calculate MaxBackends.
diff --git a/src/include/libpq/libpq-be.h b/src/include/libpq/libpq-be.h
index 82e57afc64..90f80bb33a 100644
--- a/src/include/libpq/libpq-be.h
+++ b/src/include/libpq/libpq-be.h
@@ -287,6 +287,10 @@ extern void be_tls_get_peer_serial(Port *port, char *ptr, size_t len);
extern char *be_tls_get_certificate_hash(Port *port, size_t *len);
#endif
+/* init hook for SSL, the default sets the passwor callback if appropriate */
+typedef void(* openssl_tls_init_hook_typ)(SSL_CTX *context, bool isServerStart);
+extern openssl_tls_init_hook_typ openssl_tls_init_hook;
+
#endif /* USE_SSL */
#ifdef ENABLE_GSS
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index b2eaef3bff..5f975ebcba 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -25,4 +25,9 @@ SUBDIRS = \
unsafe_tests \
worker_spi
+ifeq ($(with_openssl),yes)
+SUBDIRS += ssl_passphrase_callback
+endif
+
+
$(recurse)
diff --git a/src/test/modules/ssl_passphrase_callback/.gitignore b/src/test/modules/ssl_passphrase_callback/.gitignore
new file mode 100644
index 0000000000..1dbadf7baf
--- /dev/null
+++ b/src/test/modules/ssl_passphrase_callback/.gitignore
@@ -0,0 +1 @@
+tmp_check
diff --git a/src/test/modules/ssl_passphrase_callback/Makefile b/src/test/modules/ssl_passphrase_callback/Makefile
new file mode 100644
index 0000000000..e2d19f131a
--- /dev/null
+++ b/src/test/modules/ssl_passphrase_callback/Makefile
@@ -0,0 +1,24 @@
+# ssl_passphrase Makefile
+
+export with_openssl
+
+MODULE_big = ssl_passphrase_func
+OBJS = ssl_passphrase_func.o $(WIN32RES)
+PGFILEDESC = "callback function to provide a passphrase"
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/ssl_passphrase_callback
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
+
+check: prove-check
+
+prove-check: ssl_passphrase_func$(DLSUFFIX) | temp-install
+ @echo running prove ...
+ $(prove_check)
diff --git a/src/test/modules/ssl_passphrase_callback/ssl_passphrase_func.c b/src/test/modules/ssl_passphrase_callback/ssl_passphrase_func.c
new file mode 100644
index 0000000000..0964ba3508
--- /dev/null
+++ b/src/test/modules/ssl_passphrase_callback/ssl_passphrase_func.c
@@ -0,0 +1,82 @@
+/*-------------------------------------------------------------------------
+ *
+ * ssl_passphrase_func.c
+ *
+ * Loadable PostgreSQL module fetch an ssl passphrase for the server cert.
+ * instead of calling an external program. This implementation just hands
+ * back the configured password rot13'd.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include <float.h>
+#include <stdio.h>
+
+#include "libpq/libpq-be.h"
+#include "utils/guc.h"
+
+PG_MODULE_MAGIC;
+
+void _PG_init(void);
+void _PG_fini(void);
+
+static char *ssl_passphrase = NULL;
+
+/* callback function */
+static int rot13_passphrase(char *buf, int size, int rwflag, void *userdata);
+/* hook function to set the callback */
+static void set_rot13(SSL_CTX *context, bool isServerStart);
+/*
+ * Module load callback
+ */
+void
+_PG_init(void)
+{
+ /* Define custom GUC variable. */
+ DefineCustomStringVariable("ssl_passphrase.passphrase",
+ "passphrase before transformation",
+ NULL,
+ &ssl_passphrase,
+ NULL,
+ PGC_SIGHUP,
+ 0, /* no flags required */
+ NULL,
+ NULL,
+ NULL);
+ if (ssl_passphrase)
+ openssl_tls_init_hook = set_rot13;
+}
+
+void
+_PG_fini(void)
+{
+ /* do nothing yet */
+}
+
+static void
+set_rot13(SSL_CTX *context, bool isServerStart)
+{
+ SSL_CTX_set_default_passwd_cb(context, rot13_passphrase);
+}
+
+static int
+rot13_passphrase(char *buf, int size, int rwflag, void *userdata)
+{
+
+ Assert(ssl_passphrase != NULL);
+ StrNCpy(buf, ssl_passphrase, size);
+ for (char *p = buf; *p; p++)
+ {
+ char c = *p;
+
+ if ((c >= 'a' && c <= 'm') || (c >= 'A' && c <= 'M'))
+ *p = c + 13;
+ else if ((c >= 'n' && c <= 'z') || (c >= 'N' && c <= 'Z'))
+ *p = c - 13;
+ }
+
+ return strlen(buf);
+
+}
diff --git a/src/test/modules/ssl_passphrase_callback/t/001_testfunc.pl b/src/test/modules/ssl_passphrase_callback/t/001_testfunc.pl
new file mode 100644
index 0000000000..715d635c58
--- /dev/null
+++ b/src/test/modules/ssl_passphrase_callback/t/001_testfunc.pl
@@ -0,0 +1,67 @@
+
+use strict;
+use warnings;
+
+use File::Copy;
+
+use TestLib;
+use Test::More;
+use PostgresNode;
+
+unless ( ($ENV{with_openssl} || 'no') eq 'yes')
+{
+ plan skip_all => 'SSL not supported by this build';
+}
+
+my $clearpass = "FooBaR1";
+my $rot13pass = "SbbOnE1";
+
+# self-signed cert was generated like this:
+# system('openssl req -new -x509 -days 3650 -nodes -text -out server.crt -keyout server.ckey -subj "/CN=localhost"');
+# add the cleartext passphrase to the key, remove the unprotected key
+# system("openssl rsa -aes256 -in server.ckey -out server.key -passout pass:$clearpass");
+# unlink "server.ckey";
+
+
+my $node = get_new_node('main');
+$node->init;
+$node->append_conf('postgresql.conf',
+ "ssl_passphrase.passphrase = '$rot13pass'");
+$node->append_conf('postgresql.conf',
+ "shared_preload_libraries = 'ssl_passphrase_func'");
+$node->append_conf('postgresql.conf',
+ "listen_addresses = 'localhost'");
+$node->append_conf('postgresql.conf',
+ "ssl = 'on'");
+
+my $ddir = $node->data_dir;
+
+# install certificate and protected key
+move("server.crt", $ddir);
+move("server.key", $ddir);
+chmod 0600, "$ddir/server.key";
+
+$node->start;
+
+# if the server is running we must had successfully transformed the passphrase
+ok(-e "$ddir/postmaster.pid","postgres started");
+
+$node->stop('fast');
+
+# set the wrong passphrase
+$node->append_conf('postgresql.conf',
+ "ssl_passphrase.passphrase = 'blurfl'");
+
+# try to start the server again
+my $ret = TestLib::system_log('pg_ctl', '-D', $node->data_dir, '-l',
+ $node->logfile, 'start');
+
+
+# with a bad passphrase the server should not start
+ok($ret, "pg_ctl fails with bad passphrase");
+ok(! -e "$ddir/postmaster.pid","postgres not started with bad passphrase");
+
+# just in case
+$node->stop('fast');
+
+done_testing();
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index c735d529ca..2eb0311a14 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -429,7 +429,7 @@ sub mkvcbuild
if (!$solution->{options}->{openssl})
{
- push @contrib_excludes, 'sslinfo';
+ push @contrib_excludes, 'sslinfo', 'ssl_passphrase_callback';
}
if (!$solution->{options}->{uuid})
