Entropy collector and CTR-DRBG now also work on SHA-256 if SHA-512 not available
diff --git a/include/polarssl/ctr_drbg.h b/include/polarssl/ctr_drbg.h
index b47d389..4c0fc17 100644
--- a/include/polarssl/ctr_drbg.h
+++ b/include/polarssl/ctr_drbg.h
@@ -43,7 +43,11 @@
/**< The seed length (counter + AES key) */
#if !defined(POLARSSL_CONFIG_OPTIONS)
-#define CTR_DRBG_ENTROPY_LEN 48 /**< Amount of entropy used per seed by default */
+#if defined(POLARSSL_SHA512_C)
+#define CTR_DRBG_ENTROPY_LEN 48 /**< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) */
+#else
+#define CTR_DRBG_ENTROPY_LEN 32 /**< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) */
+#endif
#define CTR_DRBG_RESEED_INTERVAL 10000 /**< Interval before reseed is performed by default */
#define CTR_DRBG_MAX_INPUT 256 /**< Maximum number of additional input bytes */
#define CTR_DRBG_MAX_REQUEST 1024 /**< Maximum number of requested bytes per call */