Ability to force the Entropy module to use SHA-256 as its basis
By default the SHA-512 module is used if both are available. On some
systems, SHA-256 is the better choice.
Contributed by: Gergely Budai
diff --git a/include/polarssl/entropy.h b/include/polarssl/entropy.h
index 2b824ef..c4d4955 100644
--- a/include/polarssl/entropy.h
+++ b/include/polarssl/entropy.h
@@ -31,7 +31,7 @@
#include "config.h"
-#if defined(POLARSSL_SHA512_C)
+#if defined(POLARSSL_SHA512_C) && !defined(POLARSSL_FORCE_ENTROPY_SHA256)
#include "sha512.h"
#define POLARSSL_ENTROPY_SHA512_ACCUMULATOR
#else