Mac OS 10.6.8 breaks OpenSSL dev compatibility

Update (2011-07-29): Globus Toolkit devs have told me that this is a frequent problem with Mac OS updates. Thanks Apple. So they recommend running with the --without-openssl-header-check flag if you don't want to go to the trouble of actually installing compatible headers.

If you are trying to build anything that requires OpenSSL on Mac OS 10.6 and have updated to 10.6.8, you may run into the following complaint:

checking OpenSSL header version... 9080cf (OpenSSL 0.9.8l 5 Nov 2009)
checking OpenSSL library version... 90812f (OpenSSL 0.9.8r 8 Feb 2011)
checking whether OpenSSL's headers match the library... no
configure: error: Your OpenSSL headers do not match your library. Check config.log for details.
If you are sure your installation is consistent, you can disable the check by running "./configure --without-openssl-header-check".
Also see contrib/findssl.sh for help identifying header/library mismatches.

For some reason, when Apple upgraded to OpenSSL 0.9.8r to address security issues they failed to update the headers, so now there is a version mismatch (i.e. header version is 0.9.8l but library version is 0.9.8r).

If you want to track this issue in more detail, you can find a copy of the findssl.sh script, either on your system somewhere or just find it online. If you download it online, you will probably have to hack the script to find Mac's .dylib shared library files instead of the Linux standard .so files. Alternatively, just try these commands:

locate opensslv.h
locate libcrypto.dylib

That should show you where the different versions of headers and libs are respectively. Then you can look inside the opensslv.h file in /usr/include and confirm that it is 0.9.8l instead of 0.9.8r.

In any case, the solution seems to be:

1. Get OpenSSL 0.9.8r from http://www.openssl.org/source/
2. Untar, copy the include/openssl directory to somewhere like /usr/include/openssl-0.9.8r
3. Point your build to these new headers. I decided to just blast the incompatible headers, so I moved my old /usr/include/openssl to /usr/include/openssl-0.9.8l and then symlinked openssl to openssl-0.9.8r.
4. Now it builds!