[AWS|Signaturev4] canonicalize . and .. in path

lib/fog/aws/signaturev4.rb

@@ -36,7 +36,7 @@ module Fog
       def signature_components(params, date, body_sha)
         canonical_request = <<-DATA
 #{params[:method].to_s.upcase}
-#{params[:path]}
+#{canonical_path(params[:path])}
 #{canonical_query_string(params[:query])}
 #{canonical_headers(params[:headers])}
 #{signed_headers(params[:headers])}
@@ -78,6 +78,20 @@ DATA
 
       protected
 
+      def canonical_path(path)
+        components = path.split('/')
+        path = components.inject([]) do |acc, component|
+          case component
+          when '.'   #canonicalize by removing .
+          when '..' then acc.pop#canonicalize by reducing ..
+          else
+            acc << component
+          end
+          acc
+        end.join('/')
+        path.empty? ? '/' : path
+      end
+
       def canonical_query_string(query)
         canonical_query_string = []
         for key in (query || {}).keys.sort_by {|k| k.to_s}

tests/aws/signaturev4_tests.rb

@@ -38,6 +38,18 @@ Shindo.tests('AWS | signaturev4', ['aws']) do
     end
   end
 
+  tests('get with relative path') do
+    returns(@signer.sign({:query => {}, :headers => {'Host' => 'host.foo.com', 'Date' => 'Mon, 09 Sep 2011 23:36:00 GMT'}, :method => :get, :path => '/foo/bar/../..'}, @now)) do
+      'AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=date;host, Signature=b27ccfbfa7df52a200ff74193ca6e32d4b48b8856fab7ebf1c595d0670a7e470'
+    end
+  end
+
+  tests('get with pointless .') do
+    returns(@signer.sign({:query => {}, :headers => {'Host' => 'host.foo.com', 'Date' => 'Mon, 09 Sep 2011 23:36:00 GMT'}, :method => :get, :path => '/./foo'}, @now)) do
+      'AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=date;host, Signature=910e4d6c9abafaf87898e1eb4c929135782ea25bb0279703146455745391e63a'
+    end
+  end
+
   tests('get signature as components') do 
     returns(@signer.signature_parameters({:query => {'a' => 'foo', 'b' => 'foo'}, :headers => {'Host' => 'host.foo.com', 'Date' => 'Mon, 09 Sep 2011 23:36:00 GMT'}, :method => :get, :path => '/'}, @now)) do
       {