I get the same error on Linux Mint 64Bit (execpt the path's are "64bit")
/usr/bin/ld: build.Linux/src/cwc.o: undefined reference to symbol 'MD5_Final@@OPENSSL_1.0.0'
/usr/bin/ld: note: 'MD5_Final@@OPENSSL_1.0.0' is defined in DSO //usr/lib64/libcrypto.so.1.0.0 so try adding it to the linker command line
//usr/lib64/libcrypto.so.1.0.0: could not read symbols: Invalid operation
collect2: ld returned 1 exit status
make:* [build.Linux/tvheadend] Error 1
Adding /usr/lib64/ to /etc/ld.so.conf.d/x86_64-linux-gnu.conf seems to works a workaround for me.