From 1b9c4477fb542cddbb05012a52c602eb203b2d83 Mon Sep 17 00:00:00 2001
From: Joey Hess <joey@kitenet.net>
Date: Tue, 1 Mar 2011 17:07:15 -0400
Subject: [PATCH] New backends: SHA512 SHA384 SHA256 SHA224

---
 Backend/SHA224.hs | 14 ++++++++++++++
 Backend/SHA256.hs | 14 ++++++++++++++
 Backend/SHA384.hs | 14 ++++++++++++++
 Backend/SHA512.hs | 14 ++++++++++++++
 BackendList.hs    |  8 ++++++++
 configure.hs      | 10 ++++++++--
 debian/changelog  |  1 +
 doc/backends.mdwn |  3 +++
 8 files changed, 76 insertions(+), 2 deletions(-)
 create mode 100644 Backend/SHA224.hs
 create mode 100644 Backend/SHA256.hs
 create mode 100644 Backend/SHA384.hs
 create mode 100644 Backend/SHA512.hs

diff --git a/Backend/SHA224.hs b/Backend/SHA224.hs
new file mode 100644
index 0000000000..614f31c4b8
--- /dev/null
+++ b/Backend/SHA224.hs
@@ -0,0 +1,14 @@
+{- git-annex "SHA224" backend
+ -
+ - Copyright 2011 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Backend.SHA224 (backend) where
+
+import Types
+import Backend.SHA
+
+backend :: Backend Annex
+backend = genBackend 224
diff --git a/Backend/SHA256.hs b/Backend/SHA256.hs
new file mode 100644
index 0000000000..42d3d48c7d
--- /dev/null
+++ b/Backend/SHA256.hs
@@ -0,0 +1,14 @@
+{- git-annex "SHA256" backend
+ -
+ - Copyright 2011 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Backend.SHA256 (backend) where
+
+import Types
+import Backend.SHA
+
+backend :: Backend Annex
+backend = genBackend 256
diff --git a/Backend/SHA384.hs b/Backend/SHA384.hs
new file mode 100644
index 0000000000..0cf77ea647
--- /dev/null
+++ b/Backend/SHA384.hs
@@ -0,0 +1,14 @@
+{- git-annex "SHA384" backend
+ -
+ - Copyright 2011 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Backend.SHA384 (backend) where
+
+import Types
+import Backend.SHA
+
+backend :: Backend Annex
+backend = genBackend 384
diff --git a/Backend/SHA512.hs b/Backend/SHA512.hs
new file mode 100644
index 0000000000..aed8bbcedf
--- /dev/null
+++ b/Backend/SHA512.hs
@@ -0,0 +1,14 @@
+{- git-annex "SHA512" backend
+ -
+ - Copyright 2011 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Backend.SHA512 (backend) where
+
+import Types
+import Backend.SHA
+
+backend :: Backend Annex
+backend = genBackend 512
diff --git a/BackendList.hs b/BackendList.hs
index 5ae78bcc7f..4279b69fc9 100644
--- a/BackendList.hs
+++ b/BackendList.hs
@@ -10,6 +10,10 @@ module BackendList (allBackends) where
 -- When adding a new backend, import it here and add it to the list.
 import qualified Backend.WORM
 import qualified Backend.SHA1
+import qualified Backend.SHA256
+import qualified Backend.SHA512
+import qualified Backend.SHA224
+import qualified Backend.SHA384
 import qualified Backend.URL
 import Types
 
@@ -17,5 +21,9 @@ allBackends :: [Backend Annex]
 allBackends = 
 	[ Backend.WORM.backend
 	, Backend.SHA1.backend
+	, Backend.SHA256.backend
+	, Backend.SHA512.backend
+	, Backend.SHA224.backend
+	, Backend.SHA384.backend
 	, Backend.URL.backend
 	]
diff --git a/configure.hs b/configure.hs
index b5437ec1a5..772ba54899 100644
--- a/configure.hs
+++ b/configure.hs
@@ -11,11 +11,17 @@ tests = [
 	, testCp "cp_p" "-p"
 	, testCp "cp_reflink_auto" "--reflink=auto"
 	, TestCase "uuid generator" $ selectCmd "uuid" ["uuid", "uuidgen"]
-	, TestCase "sha1sum" $ requireCmd "sha1sum" "sha1sum </dev/null"
 	, TestCase "xargs -0" $ requireCmd "xargs_0" "xargs -0 </dev/null"
 	, TestCase "rsync" $ requireCmd "rsync" "rsync --version >/dev/null"
 	, TestCase "unicode FilePath support" $ unicodeFilePath
-	]
+	] ++ shaTestCases [1, 256, 512, 224, 384]
+
+shaTestCases :: [Int] -> [TestCase]
+shaTestCases l = map make l
+	where
+		make n = 
+			let cmd = "sha" ++ show n ++ "sum"
+			in TestCase cmd $ requireCmd cmd (cmd ++ " </dev/null")
 
 tmpDir :: String
 tmpDir = "tmp"
diff --git a/debian/changelog b/debian/changelog
index d634223245..8d7dd46e5c 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -8,6 +8,7 @@ git-annex (0.22) UNRELEASED; urgency=low
   * Support filenames that start with a dash; when such a file is passed
     to a utility it will be escaped to avoid it being interpreted as an
     option.
+  * New backends: SHA512 SHA384 SHA256 SHA224
 
  -- Joey Hess <joeyh@debian.org>  Sun, 13 Feb 2011 00:48:02 -0400
 
diff --git a/doc/backends.mdwn b/doc/backends.mdwn
index 3e605e4b15..5d02ad3a1c 100644
--- a/doc/backends.mdwn
+++ b/doc/backends.mdwn
@@ -19,6 +19,9 @@ can use different backends for different files.
   allows modifications of files to be tracked. Its need to generate checksums
   can make it slower for large files.
   for use.
+* `SHA512`, `SHA384`, `SHA256`, `SHA224` -- Like SHA1, but larger
+  checksums. Mostly useful for the very paranoid, or anyone who is
+  researching checksum collisions and wants to annex their colliding data. ;)
 * `URL` -- This backend downloads the file's content from an external URL.
 
 The `annex.backends` git-config setting can be used to list the backends