Merge pull request #3060 from mpg/skip-close-notify-2.16
[backport 2.16] Fix possible close_notify/ClientHello confusion
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index f95ca0c..13d0d17 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -115,6 +115,7 @@
#define DFL_FALLBACK -1
#define DFL_EXTENDED_MS -1
#define DFL_ETM -1
+#define DFL_SKIP_CLOSE_NOTIFY 0
#define GET_REQUEST "GET %s HTTP/1.0\r\nExtra-header: "
#define GET_REQUEST_END "\r\n\r\n"
@@ -278,6 +279,7 @@
" options: 1 (level-triggered, implies nbio=1),\n" \
" read_timeout=%%d default: 0 ms (no timeout)\n" \
" max_resend=%%d default: 0 (no resend on timeout)\n" \
+ " skip_close_notify=%%d default: 0 (send close_notify)\n" \
"\n" \
USAGE_DTLS \
"\n" \
@@ -376,6 +378,7 @@
int dgram_packing; /* allow/forbid datagram packing */
int extended_ms; /* negotiate extended master secret? */
int etm; /* negotiate encrypt then mac? */
+ int skip_close_notify; /* skip sending the close_notify alert */
} opt;
int query_config( const char *config );
@@ -653,6 +656,7 @@
opt.extended_ms = DFL_EXTENDED_MS;
opt.etm = DFL_ETM;
opt.dgram_packing = DFL_DGRAM_PACKING;
+ opt.skip_close_notify = DFL_SKIP_CLOSE_NOTIFY;
for( i = 1; i < argc; i++ )
{
@@ -993,6 +997,12 @@
{
return query_config( q );
}
+ else if( strcmp( p, "skip_close_notify" ) == 0 )
+ {
+ opt.skip_close_notify = atoi( q );
+ if( opt.skip_close_notify < 0 || opt.skip_close_notify > 1 )
+ goto usage;
+ }
else
goto usage;
}
@@ -2032,10 +2042,25 @@
mbedtls_printf( " . Closing the connection..." );
fflush( stdout );
- /* No error checking, the connection might be closed already */
- do ret = mbedtls_ssl_close_notify( &ssl );
- while( ret == MBEDTLS_ERR_SSL_WANT_WRITE );
- ret = 0;
+ /*
+ * Most of the time sending a close_notify before closing is the right
+ * thing to do. However, when the server already knows how many messages
+ * are expected and closes the connection by itself, this alert becomes
+ * redundant. Sometimes with DTLS this redundancy becomes a problem by
+ * leading to a race condition where the server might close the connection
+ * before seeing the alert, and since UDP is connection-less when the
+ * alert arrives it will be seen as a new connection, which will fail as
+ * the alert is clearly not a valid ClientHello. This may cause spurious
+ * failures in tests that use DTLS and resumption with ssl_server2 in
+ * ssl-opt.sh, avoided by enabling skip_close_notify client-side.
+ */
+ if( opt.skip_close_notify == 0 )
+ {
+ /* No error checking, the connection might be closed already */
+ do ret = mbedtls_ssl_close_notify( &ssl );
+ while( ret == MBEDTLS_ERR_SSL_WANT_WRITE );
+ ret = 0;
+ }
mbedtls_printf( " done\n" );
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 3a5cad2..863e5e8 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -1575,7 +1575,7 @@
run_test "Session resume using tickets, DTLS: basic" \
"$P_SRV debug_level=3 dtls=1 tickets=1" \
- "$P_CLI debug_level=3 dtls=1 tickets=1 reconnect=1" \
+ "$P_CLI debug_level=3 dtls=1 tickets=1 reconnect=1 skip_close_notify=1" \
0 \
-c "client hello, adding session ticket extension" \
-s "found session ticket extension" \
@@ -1589,7 +1589,7 @@
run_test "Session resume using tickets, DTLS: cache disabled" \
"$P_SRV debug_level=3 dtls=1 tickets=1 cache_max=0" \
- "$P_CLI debug_level=3 dtls=1 tickets=1 reconnect=1" \
+ "$P_CLI debug_level=3 dtls=1 tickets=1 reconnect=1 skip_close_notify=1" \
0 \
-c "client hello, adding session ticket extension" \
-s "found session ticket extension" \
@@ -1603,7 +1603,7 @@
run_test "Session resume using tickets, DTLS: timeout" \
"$P_SRV debug_level=3 dtls=1 tickets=1 cache_max=0 ticket_timeout=1" \
- "$P_CLI debug_level=3 dtls=1 tickets=1 reconnect=1 reco_delay=2" \
+ "$P_CLI debug_level=3 dtls=1 tickets=1 reconnect=1 skip_close_notify=1 reco_delay=2" \
0 \
-c "client hello, adding session ticket extension" \
-s "found session ticket extension" \
@@ -1735,7 +1735,7 @@
run_test "Session resume using cache, DTLS: tickets enabled on client" \
"$P_SRV dtls=1 debug_level=3 tickets=0" \
- "$P_CLI dtls=1 debug_level=3 tickets=1 reconnect=1" \
+ "$P_CLI dtls=1 debug_level=3 tickets=1 reconnect=1 skip_close_notify=1" \
0 \
-c "client hello, adding session ticket extension" \
-s "found session ticket extension" \
@@ -1749,7 +1749,7 @@
run_test "Session resume using cache, DTLS: tickets enabled on server" \
"$P_SRV dtls=1 debug_level=3 tickets=1" \
- "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1" \
+ "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1 skip_close_notify=1" \
0 \
-C "client hello, adding session ticket extension" \
-S "found session ticket extension" \
@@ -1763,7 +1763,7 @@
run_test "Session resume using cache, DTLS: cache_max=0" \
"$P_SRV dtls=1 debug_level=3 tickets=0 cache_max=0" \
- "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1" \
+ "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1 skip_close_notify=1" \
0 \
-S "session successfully restored from cache" \
-S "session successfully restored from ticket" \
@@ -1772,7 +1772,7 @@
run_test "Session resume using cache, DTLS: cache_max=1" \
"$P_SRV dtls=1 debug_level=3 tickets=0 cache_max=1" \
- "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1" \
+ "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1 skip_close_notify=1" \
0 \
-s "session successfully restored from cache" \
-S "session successfully restored from ticket" \
@@ -1781,7 +1781,7 @@
run_test "Session resume using cache, DTLS: timeout > delay" \
"$P_SRV dtls=1 debug_level=3 tickets=0" \
- "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1 reco_delay=0" \
+ "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1 skip_close_notify=1 reco_delay=0" \
0 \
-s "session successfully restored from cache" \
-S "session successfully restored from ticket" \
@@ -1790,7 +1790,7 @@
run_test "Session resume using cache, DTLS: timeout < delay" \
"$P_SRV dtls=1 debug_level=3 tickets=0 cache_timeout=1" \
- "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1 reco_delay=2" \
+ "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1 skip_close_notify=1 reco_delay=2" \
0 \
-S "session successfully restored from cache" \
-S "session successfully restored from ticket" \
@@ -1799,7 +1799,7 @@
run_test "Session resume using cache, DTLS: no timeout" \
"$P_SRV dtls=1 debug_level=3 tickets=0 cache_timeout=0" \
- "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1 reco_delay=2" \
+ "$P_CLI dtls=1 debug_level=3 tickets=0 reconnect=1 skip_close_notify=1 reco_delay=2" \
0 \
-s "session successfully restored from cache" \
-S "session successfully restored from ticket" \
@@ -3348,19 +3348,19 @@
run_test "Event-driven I/O, DTLS: ticket + client auth + resume" \
"$P_SRV dtls=1 event=1 tickets=1 auth_mode=required" \
- "$P_CLI dtls=1 event=1 tickets=1 reconnect=1" \
+ "$P_CLI dtls=1 event=1 tickets=1 reconnect=1 skip_close_notify=1" \
0 \
-c "Read from server: .* bytes read"
run_test "Event-driven I/O, DTLS: ticket + resume" \
"$P_SRV dtls=1 event=1 tickets=1 auth_mode=none" \
- "$P_CLI dtls=1 event=1 tickets=1 reconnect=1" \
+ "$P_CLI dtls=1 event=1 tickets=1 reconnect=1 skip_close_notify=1" \
0 \
-c "Read from server: .* bytes read"
run_test "Event-driven I/O, DTLS: session-id resume" \
"$P_SRV dtls=1 event=1 tickets=0 auth_mode=none" \
- "$P_CLI dtls=1 event=1 tickets=0 reconnect=1" \
+ "$P_CLI dtls=1 event=1 tickets=0 reconnect=1 skip_close_notify=1" \
0 \
-c "Read from server: .* bytes read"
@@ -3372,7 +3372,7 @@
run_test "Event-driven I/O, DTLS: session-id resume, UDP packing" \
-p "$P_PXY pack=50" \
"$P_SRV dtls=1 event=1 tickets=0 auth_mode=required" \
- "$P_CLI dtls=1 event=1 tickets=0 reconnect=1" \
+ "$P_CLI dtls=1 event=1 tickets=0 reconnect=1 skip_close_notify=1" \
0 \
-c "Read from server: .* bytes read"
@@ -6378,7 +6378,7 @@
key_file=data_files/server8.key \
hs_timeout=10000-60000 \
force_ciphersuite=TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256 \
- mtu=1450 reconnect=1 reco_delay=1" \
+ mtu=1450 reconnect=1 skip_close_notify=1 reco_delay=1" \
0 \
-S "autoreduction" \
-s "found fragmented DTLS handshake message" \
@@ -7225,7 +7225,7 @@
"$P_SRV dtls=1 dgram_packing=0 hs_timeout=500-10000 tickets=0 auth_mode=none \
psk=abc123 debug_level=3" \
"$P_CLI dtls=1 dgram_packing=0 hs_timeout=500-10000 tickets=0 psk=abc123 \
- debug_level=3 reconnect=1 read_timeout=1000 max_resend=10 \
+ debug_level=3 reconnect=1 skip_close_notify=1 read_timeout=1000 max_resend=10 \
force_ciphersuite=TLS-PSK-WITH-AES-128-CCM-8" \
0 \
-s "a session has been resumed" \
@@ -7239,7 +7239,7 @@
"$P_SRV dtls=1 dgram_packing=0 hs_timeout=500-10000 tickets=0 auth_mode=none \
psk=abc123 debug_level=3 nbio=2" \
"$P_CLI dtls=1 dgram_packing=0 hs_timeout=500-10000 tickets=0 psk=abc123 \
- debug_level=3 reconnect=1 read_timeout=1000 max_resend=10 \
+ debug_level=3 reconnect=1 skip_close_notify=1 read_timeout=1000 max_resend=10 \
force_ciphersuite=TLS-PSK-WITH-AES-128-CCM-8 nbio=2" \
0 \
-s "a session has been resumed" \