Remove support for SSL compression

PostgreSQL disabled compression as of e3bdb2d and the documentation
recommends against using it since.  Additionally, SSL compression has
been disabled in OpenSSL since version 1.1.0, and was disabled in many
distributions long before that.  The most recent TLS version, TLSv1.3,
disallows compression at the protocol level.

This commit removes the feature itself, removing support for the libpq
parameter sslcompression (parameter still listed for compatibility
reasons with existing connection strings, just ignored), and removes
the equivalent field in pg_stat_ssl and de facto PgBackendSSLStatus.

Note that, on top of removing the ability to activate compression by
configuration, compression is actively disabled in both frontend and
backend to avoid overrides from local configurations.

A TAP test is added for deprecated SSL parameters to check after
backwards compatibility.

Bump catalog version.

Author: Daniel Gustafsson
Reviewed-by: Peter Eisentraut, Magnus Hagander, Michael Paquier
Discussion:  https://postgr.es/m/7E384D48-11C5-441B-9EC3-F7DB1F8518F6@yesql.se

15 files changed, 57 insertions, 68 deletions

diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index fc94a73a54a..fb1116d09ad 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -863,7 +863,6 @@ CREATE VIEW pg_stat_ssl AS
             S.sslversion AS version,
             S.sslcipher AS cipher,
             S.sslbits AS bits,
-            S.sslcompression AS compression,
             S.ssl_client_dn AS client_dn,
             S.ssl_client_serial AS client_serial,
             S.ssl_issuer_dn AS issuer_dn
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 4c4f025eb1a..8c37381add3 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -245,6 +245,9 @@ be_tls_init(bool isServerStart)
 	/* disallow SSL session caching, too */
 	SSL_CTX_set_session_cache_mode(context, SSL_SESS_CACHE_OFF);
 
+	/* disallow SSL compression */
+	SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
+
 	/* set up ephemeral DH and ECDH keys */
 	if (!initialize_dh(context, isServerStart))
 		goto error;
@@ -1182,15 +1185,6 @@ be_tls_get_cipher_bits(Port *port)
 		return 0;
 }
 
-bool
-be_tls_get_compression(Port *port)
-{
-	if (port->ssl)
-		return (SSL_get_current_compression(port->ssl) != NULL);
-	else
-		return false;
-}
-
 const char *
 be_tls_get_version(Port *port)
 {
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index f75b52719dd..9259dc9d3e1 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -3215,7 +3215,6 @@ pgstat_bestart(void)
 	{
 		lbeentry.st_ssl = true;
 		lsslstatus.ssl_bits = be_tls_get_cipher_bits(MyProcPort);
-		lsslstatus.ssl_compression = be_tls_get_compression(MyProcPort);
 		strlcpy(lsslstatus.ssl_version, be_tls_get_version(MyProcPort), NAMEDATALEN);
 		strlcpy(lsslstatus.ssl_cipher, be_tls_get_cipher(MyProcPort), NAMEDATALEN);
 		be_tls_get_peer_subject_name(MyProcPort, lsslstatus.ssl_client_dn, NAMEDATALEN);
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 62bff52638d..318ce154fd2 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -569,7 +569,7 @@ pg_stat_get_progress_info(PG_FUNCTION_ARGS)
 Datum
 pg_stat_get_activity(PG_FUNCTION_ARGS)
 {
-#define PG_STAT_GET_ACTIVITY_COLS	30
+#define PG_STAT_GET_ACTIVITY_COLS	29
 	int			num_backends = pgstat_fetch_stat_numbackends();
 	int			curr_backend;
 	int			pid = PG_ARGISNULL(0) ? -1 : PG_GETARG_INT32(0);
@@ -708,7 +708,7 @@ pg_stat_get_activity(PG_FUNCTION_ARGS)
 			pfree(clipped_activity);
 
 			/* leader_pid */
-			nulls[29] = true;
+			nulls[28] = true;
 
 			proc = BackendPidGetProc(beentry->st_procpid);
 
@@ -745,8 +745,8 @@ pg_stat_get_activity(PG_FUNCTION_ARGS)
 				 */
 				if (leader && leader->pid != beentry->st_procpid)
 				{
-					values[29] = Int32GetDatum(leader->pid);
-					nulls[29] = false;
+					values[28] = Int32GetDatum(leader->pid);
+					nulls[28] = false;
 				}
 			}
 
@@ -875,44 +875,43 @@ pg_stat_get_activity(PG_FUNCTION_ARGS)
 				values[19] = CStringGetTextDatum(beentry->st_sslstatus->ssl_version);
 				values[20] = CStringGetTextDatum(beentry->st_sslstatus->ssl_cipher);
 				values[21] = Int32GetDatum(beentry->st_sslstatus->ssl_bits);
-				values[22] = BoolGetDatum(beentry->st_sslstatus->ssl_compression);
 
 				if (beentry->st_sslstatus->ssl_client_dn[0])
-					values[23] = CStringGetTextDatum(beentry->st_sslstatus->ssl_client_dn);
+					values[22] = CStringGetTextDatum(beentry->st_sslstatus->ssl_client_dn);
 				else
-					nulls[23] = true;
+					nulls[22] = true;
 
 				if (beentry->st_sslstatus->ssl_client_serial[0])
-					values[24] = DirectFunctionCall3(numeric_in,
+					values[23] = DirectFunctionCall3(numeric_in,
 													 CStringGetDatum(beentry->st_sslstatus->ssl_client_serial),
 													 ObjectIdGetDatum(InvalidOid),
 													 Int32GetDatum(-1));
 				else
-					nulls[24] = true;
+					nulls[23] = true;
 
 				if (beentry->st_sslstatus->ssl_issuer_dn[0])
-					values[25] = CStringGetTextDatum(beentry->st_sslstatus->ssl_issuer_dn);
+					values[24] = CStringGetTextDatum(beentry->st_sslstatus->ssl_issuer_dn);
 				else
-					nulls[25] = true;
+					nulls[24] = true;
 			}
 			else
 			{
 				values[18] = BoolGetDatum(false);	/* ssl */
-				nulls[19] = nulls[20] = nulls[21] = nulls[22] = nulls[23] = nulls[24] = nulls[25] = true;
+				nulls[19] = nulls[20] = nulls[21] = nulls[22] = nulls[23] = nulls[24] = true;
 			}
 
 			/* GSSAPI information */
 			if (beentry->st_gss)
 			{
-				values[26] = BoolGetDatum(beentry->st_gssstatus->gss_auth); /* gss_auth */
-				values[27] = CStringGetTextDatum(beentry->st_gssstatus->gss_princ);
-				values[28] = BoolGetDatum(beentry->st_gssstatus->gss_enc);	/* GSS Encryption in use */
+				values[25] = BoolGetDatum(beentry->st_gssstatus->gss_auth); /* gss_auth */
+				values[26] = CStringGetTextDatum(beentry->st_gssstatus->gss_princ);
+				values[27] = BoolGetDatum(beentry->st_gssstatus->gss_enc);	/* GSS Encryption in use */
 			}
 			else
 			{
-				values[26] = BoolGetDatum(false);	/* gss_auth */
-				nulls[27] = true;	/* No GSS principal */
-				values[28] = BoolGetDatum(false);	/* GSS Encryption not in
+				values[25] = BoolGetDatum(false);	/* gss_auth */
+				nulls[26] = true;	/* No GSS principal */
+				values[27] = BoolGetDatum(false);	/* GSS Encryption not in
 													 * use */
 			}
 		}
@@ -942,7 +941,6 @@ pg_stat_get_activity(PG_FUNCTION_ARGS)
 			nulls[26] = true;
 			nulls[27] = true;
 			nulls[28] = true;
-			nulls[29] = true;
 		}
 
 		tuplestore_putvalues(tupstore, tupdesc, values, nulls);
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index e5965bc517d..7abeccb5362 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -264,11 +264,10 @@ PerformAuthentication(Port *port)
 
 #ifdef USE_SSL
 		if (port->ssl_in_use)
-			appendStringInfo(&logmsg, _(" SSL enabled (protocol=%s, cipher=%s, bits=%d, compression=%s)"),
+			appendStringInfo(&logmsg, _(" SSL enabled (protocol=%s, cipher=%s, bits=%d)"),
 							 be_tls_get_version(port),
 							 be_tls_get_cipher(port),
-							 be_tls_get_cipher_bits(port),
-							 be_tls_get_compression(port) ? _("on") : _("off"));
+							 be_tls_get_cipher_bits(port));
 #endif
 #ifdef ENABLE_GSS
 		if (port->gss)
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index c98e3d31d0c..8d6970a4f34 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -3509,7 +3509,6 @@ printSSLInfo(void)
 	const char *protocol;
 	const char *cipher;
 	const char *bits;
-	const char *compression;
 
 	if (!PQsslInUse(pset.db))
 		return;					/* no SSL */
@@ -3517,13 +3516,11 @@ printSSLInfo(void)
 	protocol = PQsslAttribute(pset.db, "protocol");
 	cipher = PQsslAttribute(pset.db, "cipher");
 	bits = PQsslAttribute(pset.db, "key_bits");
-	compression = PQsslAttribute(pset.db, "compression");
 
-	printf(_("SSL connection (protocol: %s, cipher: %s, bits: %s, compression: %s)\n"),
+	printf(_("SSL connection (protocol: %s, cipher: %s, bits: %s)\n"),
 		   protocol ? protocol : _("unknown"),
 		   cipher ? cipher : _("unknown"),
-		   bits ? bits : _("unknown"),
-		   (compression && strcmp(compression, "off") != 0) ? _("on") : _("off"));
+		   bits ? bits : _("unknown"));
 }
 
 /*
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index e28bbf1317d..81fd68348d5 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202103081
+#define CATALOG_VERSION_NO	202103091
 
 #endif
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index a0fe0851c41..2ccc3e7c7c7 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5249,9 +5249,9 @@
   proname => 'pg_stat_get_activity', prorows => '100', proisstrict => 'f',
   proretset => 't', provolatile => 's', proparallel => 'r',
   prorettype => 'record', proargtypes => 'int4',
-  proallargtypes => '{int4,oid,int4,oid,text,text,text,text,text,timestamptz,timestamptz,timestamptz,timestamptz,inet,text,int4,xid,xid,text,bool,text,text,int4,bool,text,numeric,text,bool,text,bool,int4}',
-  proargmodes => '{i,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
-  proargnames => '{pid,datid,pid,usesysid,application_name,state,query,wait_event_type,wait_event,xact_start,query_start,backend_start,state_change,client_addr,client_hostname,client_port,backend_xid,backend_xmin,backend_type,ssl,sslversion,sslcipher,sslbits,sslcompression,ssl_client_dn,ssl_client_serial,ssl_issuer_dn,gss_auth,gss_princ,gss_enc,leader_pid}',
+  proallargtypes => '{int4,oid,int4,oid,text,text,text,text,text,timestamptz,timestamptz,timestamptz,timestamptz,inet,text,int4,xid,xid,text,bool,text,text,int4,text,numeric,text,bool,text,bool,int4}',
+  proargmodes => '{i,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
+  proargnames => '{pid,datid,pid,usesysid,application_name,state,query,wait_event_type,wait_event,xact_start,query_start,backend_start,state_change,client_addr,client_hostname,client_port,backend_xid,backend_xmin,backend_type,ssl,sslversion,sslcipher,sslbits,ssl_client_dn,ssl_client_serial,ssl_issuer_dn,gss_auth,gss_princ,gss_enc,leader_pid}',
   prosrc => 'pg_stat_get_activity' },
 { oid => '3318',
   descr => 'statistics: information about progress of backends running maintenance command',
diff --git a/src/include/libpq/libpq-be.h b/src/include/libpq/libpq-be.h
index 7be1a67d692..30fb4e613da 100644
--- a/src/include/libpq/libpq-be.h
+++ b/src/include/libpq/libpq-be.h
@@ -266,7 +266,6 @@ extern ssize_t be_tls_write(Port *port, void *ptr, size_t len, int *waitfor);
  * Return information about the SSL connection.
  */
 extern int	be_tls_get_cipher_bits(Port *port);
-extern bool be_tls_get_compression(Port *port);
 extern const char *be_tls_get_version(Port *port);
 extern const char *be_tls_get_cipher(Port *port);
 extern void be_tls_get_peer_subject_name(Port *port, char *ptr, size_t len);
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 724068cf87e..e0c70d221be 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -1135,7 +1135,6 @@ typedef struct PgBackendSSLStatus
 {
 	/* Information about SSL connection */
 	int			ssl_bits;
-	bool		ssl_compression;
 	char		ssl_version[NAMEDATALEN];
 	char		ssl_cipher[NAMEDATALEN];
 	char		ssl_client_dn[NAMEDATALEN];
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index f83af03d0a7..fed06bb038c 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -293,9 +293,12 @@ static const internalPQconninfoOption PQconninfoOptions[] = {
 		"SSL-Mode", "", 12,		/* sizeof("verify-full") == 12 */
 	offsetof(struct pg_conn, sslmode)},
 
-	{"sslcompression", "PGSSLCOMPRESSION", "0", NULL,
-		"SSL-Compression", "", 1,
-	offsetof(struct pg_conn, sslcompression)},
+	/*
+	 * "sslcompression" is no longer used, but keep it present for backwards
+	 * compatibility.
+	 */
+	{"sslcompression", NULL, NULL, NULL,
+	"SSL-Compression", "D", 1, -1},
 
 	{"sslcert", "PGSSLCERT", NULL, NULL,
 		"SSL-Client-Cert", "", 64,
@@ -4080,8 +4083,6 @@ freePGconn(PGconn *conn)
 		free(conn->sslcrl);
 	if (conn->sslcrldir)
 		free(conn->sslcrldir);
-	if (conn->sslcompression)
-		free(conn->sslcompression);
 	if (conn->requirepeer)
 		free(conn->requirepeer);
 	if (conn->ssl_min_protocol_version)
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 0fa10a23b4a..c88dd3a1183 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -1257,13 +1257,8 @@ initialize_SSL(PGconn *conn)
 	if (have_rootcert)
 		SSL_set_verify(conn->ssl, SSL_VERIFY_PEER, verify_cb);
 
-	/*
-	 * Set compression option if necessary.
-	 */
-	if (conn->sslcompression && conn->sslcompression[0] == '0')
-		SSL_set_options(conn->ssl, SSL_OP_NO_COMPRESSION);
-	else
-		SSL_clear_options(conn->ssl, SSL_OP_NO_COMPRESSION);
+	/* disable SSL compression */
+	SSL_set_options(conn->ssl, SSL_OP_NO_COMPRESSION);
 
 	return 0;
 }
@@ -1553,8 +1548,12 @@ PQsslAttribute(PGconn *conn, const char *attribute_name)
 	if (strcmp(attribute_name, "cipher") == 0)
 		return SSL_get_cipher(conn->ssl);
 
+	/*
+	 * SSL compression is disabled, so even if connecting to an older server
+	 * which still supports it, it will not be active.
+	 */
 	if (strcmp(attribute_name, "compression") == 0)
-		return SSL_get_current_compression(conn->ssl) ? "on" : "off";
+		return "off";
 
 	if (strcmp(attribute_name, "protocol") == 0)
 		return SSL_get_version(conn->ssl);
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 8d51e6ed9ff..cca98c14bf8 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -360,7 +360,6 @@ struct pg_conn
 	char	   *keepalives_count;	/* maximum number of TCP keepalive
 									 * retransmits */
 	char	   *sslmode;		/* SSL mode (require,prefer,allow,disable) */
-	char	   *sslcompression; /* SSL compression (0 or 1) */
 	char	   *sslkey;			/* client key filename */
 	char	   *sslcert;		/* client certificate filename */
 	char	   *sslpassword;	/* client key file password */
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index b1c9b7bdfe3..dd5cc9c2213 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1764,7 +1764,7 @@ pg_stat_activity| SELECT s.datid,
     s.backend_xmin,
     s.query,
     s.backend_type
-   FROM ((pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, sslcompression, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid)
+   FROM ((pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid)
      LEFT JOIN pg_database d ON ((s.datid = d.oid)))
      LEFT JOIN pg_authid u ON ((s.usesysid = u.oid)));
 pg_stat_all_indexes| SELECT c.oid AS relid,
@@ -1876,7 +1876,7 @@ pg_stat_gssapi| SELECT s.pid,
     s.gss_auth AS gss_authenticated,
     s.gss_princ AS principal,
     s.gss_enc AS encrypted
-   FROM pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, sslcompression, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid)
+   FROM pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid)
   WHERE (s.client_port IS NOT NULL);
 pg_stat_progress_analyze| SELECT s.pid,
     s.datid,
@@ -2033,7 +2033,7 @@ pg_stat_replication| SELECT s.pid,
     w.sync_priority,
     w.sync_state,
     w.reply_time
-   FROM ((pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, sslcompression, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid)
+   FROM ((pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid)
      JOIN pg_stat_get_wal_senders() w(pid, state, sent_lsn, write_lsn, flush_lsn, replay_lsn, write_lag, flush_lag, replay_lag, sync_priority, sync_state, reply_time) ON ((s.pid = w.pid)))
      LEFT JOIN pg_authid u ON ((s.usesysid = u.oid)));
 pg_stat_replication_slots| SELECT s.slot_name,
@@ -2060,11 +2060,10 @@ pg_stat_ssl| SELECT s.pid,
     s.sslversion AS version,
     s.sslcipher AS cipher,
     s.sslbits AS bits,
-    s.sslcompression AS compression,
     s.ssl_client_dn AS client_dn,
     s.ssl_client_serial AS client_serial,
     s.ssl_issuer_dn AS issuer_dn
-   FROM pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, sslcompression, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid)
+   FROM pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid)
   WHERE (s.client_port IS NOT NULL);
 pg_stat_subscription| SELECT su.oid AS subid,
     su.subname,
diff --git a/src/test/ssl/t/001_ssltests.pl b/src/test/ssl/t/001_ssltests.pl
index 864f6e209f5..ee97f6f0697 100644
--- a/src/test/ssl/t/001_ssltests.pl
+++ b/src/test/ssl/t/001_ssltests.pl
@@ -17,7 +17,7 @@ if ($ENV{with_ssl} ne 'openssl')
 }
 else
 {
-	plan tests => 100;
+	plan tests => 101;
 }
 
 #### Some configuration
@@ -157,6 +157,13 @@ test_connect_fails(
 	qr/root certificate file "invalid" does not exist/,
 	"connect without server root cert sslmode=verify-full");
 
+# Test deprecated SSL parameters, still accepted for backwards
+# compatibility.
+test_connect_ok(
+	$common_connstr,
+	"sslrootcert=invalid sslmode=require sslcompression=1 requiressl=1",
+	"connect with deprecated connection parameters");
+
 # Try with wrong root cert, should fail. (We're using the client CA as the
 # root, but the server's key is signed by the server CA.)
 test_connect_fails($common_connstr,
@@ -376,8 +383,8 @@ command_like(
 		"$common_connstr sslrootcert=invalid", '-c',
 		"SELECT * FROM pg_stat_ssl WHERE pid = pg_backend_pid()"
 	],
-	qr{^pid,ssl,version,cipher,bits,compression,client_dn,client_serial,issuer_dn\r?\n
-				^\d+,t,TLSv[\d.]+,[\w-]+,\d+,f,_null_,_null_,_null_\r?$}mx,
+	qr{^pid,ssl,version,cipher,bits,client_dn,client_serial,issuer_dn\r?\n
+				^\d+,t,TLSv[\d.]+,[\w-]+,\d+,_null_,_null_,_null_\r?$}mx,
 	'pg_stat_ssl view without client certificate');
 
 # Test min/max SSL protocol versions.
@@ -493,8 +500,8 @@ command_like(
 		'-c',
 		"SELECT * FROM pg_stat_ssl WHERE pid = pg_backend_pid()"
 	],
-	qr{^pid,ssl,version,cipher,bits,compression,client_dn,client_serial,issuer_dn\r?\n
-				^\d+,t,TLSv[\d.]+,[\w-]+,\d+,f,/CN=ssltestuser,1,\Q/CN=Test CA for PostgreSQL SSL regression test client certs\E\r?$}mx,
+	qr{^pid,ssl,version,cipher,bits,client_dn,client_serial,issuer_dn\r?\n
+				^\d+,t,TLSv[\d.]+,[\w-]+,\d+,/CN=ssltestuser,1,\Q/CN=Test CA for PostgreSQL SSL regression test client certs\E\r?$}mx,
 	'pg_stat_ssl with client certificate');
 
 # client key with wrong permissions