mgomes/api_auth — pull request #11 by jlwebster (2012-10-09 05:46:20+00:00)
Title: Added check for HTTP_CONTENT_MD5 in the ActionController driver

I found that this was required. I am passing Content-MD5 from a node.js app and it's ending up as HTTP_CONTENT_MD5 in Rails 3.2.8. It looks like other header fields have a check for the field name starting with HTTP_ as well, so it should make sense here as well.