So is there any actual evidence being presented of Russia doing the hacking or are we just to accept it on faith that the CIA wouldn't lie?
Well the CIA lies, pretty sure that's in their job description
I believe the evidence is the signatures that point to the groups performing the hack that the CIA has been monitoring as probably RIS, and one of the key figures is suspected of being a Russian agent. But the bulk is spies talking to contacts on the ground, and for obvious reasons that isn't likely to come out for a good long time.
The CIA is unlikely to deceive the world as a means to support the DNC and there probably isn't overt profit in upsetting Russia but then - they are sneaky bastards and they may have a completely different game plan in mind.
Or they may be making mistakes or falling for evidence someone wanted them to find.