Use OpenSSL in compat.sh on Travis, except DTLS

Less heavy-handed than skipping all OpenSSL interop

.travis.yml

@@ -7,7 +7,7 @@ script:
 - cmake -D CMAKE_BUILD_TYPE:String="Check" .
 - make
 - make test
-- tests/compat.sh -p mbedtls
+- OSSL_NO_DTLS=1 tests/compat.sh
 - tests/ssl-opt.sh -e '\(DTLS\|SCSV\).*openssl'
 - tests/scripts/test-ref-configs.pl
 env:

tests/compat.sh

@@ -6,7 +6,7 @@
 # with and without client authentication.
 #
 # Peer version requirements:
-# - OpenSSL 1.0.1e 11 Feb 2013 (probably since 1.0.1, tested with 1.0.1e)
+# - OpenSSL 1.0.1e 11 Feb 2013 (probably NOT since 1.0.1, tested with 1.0.1e)
 # - GnuTLS 3.2.15 (probably works since 3.2.12 but tested only with 3.2.15)
 
 set -u
@@ -54,6 +54,10 @@ VERBOSE=""
 MEMCHECK=0
 PEERS="OpenSSL$PEER_GNUTLS mbedTLS"
 
+# hidden option: skip DTLS with OpenSSL
+# (travis CI has a version that doesn't work for us)
+: ${OSSL_NO_DTLS:=0}
+
 print_usage() {
     echo "Usage: $0"
     printf "  -h|--help\tPrint this help.\n"
@@ -1122,6 +1126,10 @@ for VERIFY in $VERIFIES; do
 
                 [Oo]pen*)
 
+                    if test "$OSSL_NO_DTLS" -gt 0 && is_dtls "$MODE"; then
+                        continue;
+                    fi
+
                     reset_ciphersuites
                     add_common_ciphersuites
                     add_openssl_ciphersuites