@Osiris The -devel package (for any package) contains just include files, only needed to build other packages depending on this one, not needed for regular operations. You can safely remove them.
@alan3188 The dependency failures are because on CentOS 7 (where we took the spec file from), the openssl package is split into "openssl" and "openssl-libs", but on CentOS 6 you had only "openssl". So you need to explicitly install the -libs package at the same time.
(which is why I suggested to merge them back into one, but that's another bit more work on the spec file. once you get it installed, it doesn't matter anymore.)