WIP converting S3 special remote from hS3 to aws library

Currently, initremote works, but not the other operations. They should be
fairly easy to add from this base.

Also, https://github.com/aristidb/aws/issues/119 blocks internet archive
support.

Note that since http-conduit is used, this also adds https support to S3.
Although git-annex encrypts everything anyway, so that may not be extremely
useful. It is not enabled by default, because existing S3 special remotes
have port=80 in their config. Setting port=443 will enable it.

This commit was sponsored by Daniel Brockman.

Remote/Helper/AWS.hs

@@ -1,6 +1,6 @@
 {- Amazon Web Services common infrastructure.
  -
- - Copyright 2011,2012 Joey Hess <joey@kitenet.net>
+ - Copyright 2011-2014 Joey Hess <joey@kitenet.net>
  -
  - Licensed under the GNU GPL version 3 or higher.
  -}
@@ -12,8 +12,14 @@ module Remote.Helper.AWS where
 import Common.Annex
 import Creds
 
+import qualified Aws
+import qualified Aws.S3 as S3
 import qualified Data.Map as M
+import qualified Data.ByteString as B
+import qualified Data.Text as T
+import Data.Text.Encoding (encodeUtf8)
 import Data.Text (Text)
+import Data.IORef
 
 creds :: UUID -> CredPairStorage
 creds u = CredPairStorage
@@ -22,6 +28,13 @@ creds u = CredPairStorage
 	, credPairRemoteKey = Just "s3creds"
 	}
 
+genCredentials :: CredPair -> IO Aws.Credentials
+genCredentials (keyid, secret) = Aws.Credentials
+	<$> pure (encodeUtf8 (T.pack keyid))
+	<*> pure (encodeUtf8 (T.pack secret))
+	<*> newIORef []
+	<*> pure Nothing
+
 data Service = S3 | Glacier
 	deriving (Eq)
 
@@ -33,9 +46,10 @@ regionMap = M.fromList . regionInfo
 defaultRegion :: Service -> Region
 defaultRegion = snd . Prelude.head . regionInfo
 
-{- S3 and Glacier use different names for some regions. Ie, "us-east-1"
- - cannot be used with S3, while "US" cannot be used with Glacier. Dunno why.
- - Also, Glacier is not yet available in all regions. -}
+data ServiceRegion = BothRegion Region | S3Region Region | GlacierRegion Region
+
+{- The "US" and "EU" names are used as location constraints when creating a
+ - S3 bucket. -}
 regionInfo :: Service -> [(Text, Region)]
 regionInfo service = map (\(t, r) -> (t, fromServiceRegion r)) $ 
 	filter (matchingService . snd) $
@@ -60,4 +74,14 @@ regionInfo service = map (\(t, r) -> (t, fromServiceRegion r)) $
 	matchingService (S3Region _) = service == S3
 	matchingService (GlacierRegion _) = service == Glacier
 
-data ServiceRegion = BothRegion Region | S3Region Region | GlacierRegion Region
+s3HostName :: Region -> B.ByteString
+s3HostName "US" = "s3.amazonaws.com"
+s3HostName "EU" = "s3-eu-west-1.amazonaws.com"
+s3HostName r = encodeUtf8 $ T.concat ["s3-", r, ".amazonaws.com"]
+
+s3DefaultHost :: String
+s3DefaultHost = "s3.amazonaws.com"
+
+mkLocationConstraint :: Region -> S3.LocationConstraint
+mkLocationConstraint "US" = S3.locationUsClassic
+mkLocationConstraint r = r