- Proper building of shared lib when SHARED defined

diff --git a/library/Makefile b/library/Makefile
index f9e5062..603f5d1 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -53,7 +53,11 @@
 
 .SILENT:
 
+ifndef SHARED
 all: static
+else
+all: shared
+endif
 
 static: libpolarssl.a