Jamie Dornan said the following in a recent interview with the Guardian:

On a more serious point, Dornan describes himself as a feminist – is he worried that the film will glorify sexual violence against women? “I think it’s very hard to argue that when it is all consensual. Half the book is about making contracts. Permission and agreement that this be done. There’s no rape, no forced sexual situations.”

There’s a lot that can be said about that short quote, but for the record: Ana never signed the BDSM contract. It’s important to appreciate that consent is important in the whole of a relationship – and whereas I’ll say that Ana did consent to some things, to say that she consents to everything is doubtful. There are numerous consent violations throughout the books and here’s a post on the 50shadesabuse blog (formerly: 50shadesisdomesticabuse.webs.com) that lists a number of them.