SSL: enabled TLSv1.3 with BoringSSL. BoringSSL currently requires SSL_CTX_set_max_proto_version(TLS1_3_VERSION) to be able to enable TLS 1.3. This is because by default max protocol version is set to TLS 1.2, and the SSL_OP_NO_* options are merely used as a blacklist within the version range specified using the SSL_CTX_set_min_proto_version() and SSL_CTX_set_max_proto_version() functions. With this change, we now call SSL_CTX_set_max_proto_version() with an explicit maximum version set. This enables TLS 1.3 with BoringSSL. As a side effect, this change also limits maximum protocol version to the newest protocol we know about, TLS 1.3. This seems to be a good change, as enabling unknown protocols might have unexpected results. Additionally, we now explicitly call SSL_CTX_set_min_proto_version() with 0. This is expected to help with Debian system-wide default of MinProtocol set to TLSv1.2, see http://mailman.nginx.org/pipermail/nginx-ru/2017-October/060411.html. Note that there is no SSL_CTX_set_min_proto_version macro in BoringSSL, so we call SSL_CTX_set_min_proto_version() and SSL_CTX_set_max_proto_version() as long as the TLS1_3_VERSION macro is defined.

# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


echo $ngx_n "checking for system byte ordering ...$ngx_c"

cat << END >> $NGX_AUTOCONF_ERR

----------------------------------------
checking for system byte ordering

END


cat << END > $NGX_AUTOTEST.c

int main(void) {
    int i = 0x11223344;
    char *p;

    p = (char *) &i;
    if (*p == 0x44) return 0;
    return 1;
}

END

ngx_test="$CC $CC_TEST_FLAGS $CC_AUX_FLAGS \
          -o $NGX_AUTOTEST $NGX_AUTOTEST.c $NGX_LD_OPT $ngx_feature_libs"

eval "$ngx_test >> $NGX_AUTOCONF_ERR 2>&1"

if [ -x $NGX_AUTOTEST ]; then
    if $NGX_AUTOTEST >/dev/null 2>&1; then
        echo " little endian"
        have=NGX_HAVE_LITTLE_ENDIAN . auto/have
    else
        echo " big endian"
    fi

    rm -rf $NGX_AUTOTEST*

else
    rm -rf $NGX_AUTOTEST*

    echo
    echo "$0: error: cannot detect system byte ordering"
    exit 1
fi