webrick/httpauth/digestauth: stream req.body

WARNING! WARNING! WARNING!  LIKELY BROKEN CHANGE

Pass a proc to WEBrick::HTTPRequest#body to avoid reading a
potentially large request body into memory during
authentication.

WARNING! this will break apps completely which want to do
something with the body besides calculating the MD5 digest
of it.

Also, keep in mind that probably nobody uses "auth-int".
Servers such as Apache, lighttpd, nginx don't seem to
support it; nor does curl when using POST/PUT bodies;
and we didn't have tests for it until now...

* lib/webrick/httpauth/digestauth.rb (_authenticate): stream req.body

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62965 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/webrick/httpauth/digestauth.rb

@@ -235,9 +235,11 @@ module WEBrick
           ha2 = hexdigest(req.request_method, auth_req['uri'])
           ha2_res = hexdigest("", auth_req['uri'])
         elsif auth_req['qop'] == "auth-int"
-          ha2 = hexdigest(req.request_method, auth_req['uri'],
-                          hexdigest(req.body))
-          ha2_res = hexdigest("", auth_req['uri'], hexdigest(res.body))
+          body_digest = @h.new
+          req.body { |chunk| body_digest.update(chunk) }
+          body_digest = body_digest.hexdigest
+          ha2 = hexdigest(req.request_method, auth_req['uri'], body_digest)
+          ha2_res = hexdigest("", auth_req['uri'], body_digest)
         end
 
         if auth_req['qop'] == "auth" || auth_req['qop'] == "auth-int"