SSL: logging levels of "unsupported protocol", "version too low". Starting with OpenSSL 1.1.0, SSL_R_UNSUPPORTED_PROTOCOL instead of SSL_R_UNKNOWN_PROTOCOL is reported when a protocol is disabled via an SSL_OP_NO_* option. Additionally, SSL_R_VERSION_TOO_LOW is reported when using MinProtocol or when seclevel checks (as set by @SECLEVEL=n in the cipher string) rejects a protocol, and this is what happens with SSLv3 and @SECLEVEL=1, which is the default. There is also the SSL_R_VERSION_TOO_HIGH error code, but it looks like it is not possible to trigger it.

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


if [ $PCRE != NONE -a $PCRE != NO -a $PCRE != YES ]; then
    . auto/lib/pcre/make
fi

if [ $OPENSSL != NONE -a $OPENSSL != NO -a $OPENSSL != YES ]; then
    . auto/lib/openssl/make
fi

if [ $ZLIB != NONE -a $ZLIB != NO -a $ZLIB != YES ]; then
    . auto/lib/zlib/make
fi

if [ $NGX_LIBATOMIC != NO -a $NGX_LIBATOMIC != YES ]; then
    . auto/lib/libatomic/make
fi

if [ $USE_PERL != NO ]; then
    . auto/lib/perl/make
fi