Fix FALLBACK_SCSV parsing
Fixed a bug in ssl_srv.c when parsing TLS_FALLBACK_SCSV in the
ciphersuite list that caused it to miss it sometimes. Reported by Hugo
Leisink as issue #810. Fix initially by @andreasag01; this commit
isolates the bug fix and adds a non-regression test.
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 24b0fff..21a4ab7 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -17,11 +17,13 @@
: ${OPENSSL_CMD:=openssl} # OPENSSL would conflict with the build system
: ${GNUTLS_CLI:=gnutls-cli}
: ${GNUTLS_SERV:=gnutls-serv}
+: ${PERL:=perl}
O_SRV="$OPENSSL_CMD s_server -www -cert data_files/server5.crt -key data_files/server5.key"
O_CLI="echo 'GET / HTTP/1.0' | $OPENSSL_CMD s_client"
G_SRV="$GNUTLS_SERV --x509certfile data_files/server5.crt --x509keyfile data_files/server5.key"
G_CLI="echo 'GET / HTTP/1.0' | $GNUTLS_CLI --x509cafile data_files/test-ca_cat12.crt"
+TCP_CLIENT="$PERL scripts/tcp_client.pl"
TESTS=0
FAILS=0
@@ -898,6 +900,37 @@
-s "received FALLBACK_SCSV" \
-S "inapropriate fallback"
+## ClientHello generated with
+## "openssl s_client -CAfile tests/data_files/test-ca.crt -tls1_1 -connect localhost:4433 -cipher ..."
+## then manually twiddling the ciphersuite list.
+## The ClientHello content is spelled out below as a hex string as
+## "prefix ciphersuite1 ciphersuite2 ciphersuite3 ciphersuite4 suffix".
+## The expected response is an inappropriate_fallback alert.
+requires_openssl_with_fallback_scsv
+run_test "Fallback SCSV: beginning of list" \
+ "$P_SRV debug_level=2" \
+ "$TCP_CLIENT localhost $SRV_PORT '160301003e0100003a03022aafb94308dc22ca1086c65acc00e414384d76b61ecab37df1633b1ae1034dbe000008 5600 0031 0032 0033 0100000900230000000f000101' '15030200020256'" \
+ 0 \
+ -s "received FALLBACK_SCSV" \
+ -s "inapropriate fallback"
+
+requires_openssl_with_fallback_scsv
+run_test "Fallback SCSV: end of list" \
+ "$P_SRV debug_level=2" \
+ "$TCP_CLIENT localhost $SRV_PORT '160301003e0100003a03022aafb94308dc22ca1086c65acc00e414384d76b61ecab37df1633b1ae1034dbe000008 0031 0032 0033 5600 0100000900230000000f000101' '15030200020256'" \
+ 0 \
+ -s "received FALLBACK_SCSV" \
+ -s "inapropriate fallback"
+
+## Here the expected response is a valid ServerHello prefix, up to the random.
+requires_openssl_with_fallback_scsv
+run_test "Fallback SCSV: not in list" \
+ "$P_SRV debug_level=2" \
+ "$TCP_CLIENT localhost $SRV_PORT '160301003e0100003a03022aafb94308dc22ca1086c65acc00e414384d76b61ecab37df1633b1ae1034dbe000008 0056 0031 0032 0033 0100000900230000000f000101' '16030200300200002c0302'" \
+ 0 \
+ -S "received FALLBACK_SCSV" \
+ -S "inapropriate fallback"
+
# Tests for CBC 1/n-1 record splitting
run_test "CBC Record splitting: TLS 1.2, no splitting" \