diff --git a/ChangeLog b/ChangeLog
index c0b9ae662d..d604b1fa01 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Sep 14 14:37:45 2006  Tanaka Akira  <akr@fsij.org>
+
+	* ext/digest/lib/digest.rb (Digest::Base.file): new method.
+	  [ruby-dev:29572]
+
 Thu Sep 14 08:30:02 2006  Tanaka Akira  <akr@fsij.org>
 
 	* ext/digest/digest.c (rb_digest_base_inspect): new method.
diff --git a/ext/digest/lib/digest.rb b/ext/digest/lib/digest.rb
index b550f94c3e..7703faa8eb 100644
--- a/ext/digest/lib/digest.rb
+++ b/ext/digest/lib/digest.rb
@@ -5,4 +5,17 @@ module Digest
   autoload "SHA256", "digest/sha2"
   autoload "SHA384", "digest/sha2"
   autoload "SHA512", "digest/sha2"
+
+  class Base
+    def self.file(name)
+      digest = self.new
+      File.open(name) {|f|
+        buf = ""
+        while f.read(16384, buf)
+          digest.update buf
+        end
+      }
+      digest
+    end
+  end
 end