Whether --enable-dh is defined or not the stunnel created certificates created during make-install will include DH support. This is because the USE_DH variable in tools/Makefile is undefined which in turn causes the test portion of the install-data-local section of the tools/Makefile below to fail
test $(USE_DH) -eq 0 || $(openssl) gendh $$RND 512 >> stunnel.pem; \ $(openssl) x509 -subject -dates -fingerprint -noout -in stunnel.pem; \ ${INSTALL} -m 600 stunnel.pem $(DESTDIR)$(confdir)/stunnel.pem; \ rm stunnel.pem; \
The test fails with this error message "/bin/bash: test: -eq: unary operator expected" since USE_DH is empty (undefined). I looked at the dh section of the configure script and it appears USE_DH is being set to 1 when --enable-dh is defined. However, USE_DH=1 is only in the DEFS section of tools/Makefile and not actually setting the value of USE_DH variable.
I read in the change notes (from several years ago) that dh was disabled by default. I have been running stunnel for the past 3-4 years but have since I initially installed it back then I have been upgrading and therefore the above section of the tools\Makefile was skipped since I already had certificates defined. I went to install on a new box today and found the above 'problem'. So I am not sure how long this has been like this. Before I tried to figure out what is "wrong" I wanted to see if others have noticed this.
I have seen this on Solaris 9 and in the cygwin 1.5.19.