add sha224sum and sha384sum

Signed-off-by: Mattias Andrée <maandree@kth.se>

sha384.h

@@ -0,0 +1,16 @@
+/* public domain sha512 implementation based on fips180-3 */
+
+#include "sha512.h"
+
+#define sha384  sha512  /*struct*/
+
+enum { SHA384_DIGEST_LENGTH = 48 };
+
+/* reset state */
+void sha384_init(void *ctx);
+/* process message */
+#define sha384_update  sha512_update
+/* get message digest */
+/* state is ruined after sum, keep a copy if multiple sum is needed */
+/* part of the message might be left in s, zero it if secrecy is needed */
+void sha384_sum(void *ctx, uint8_t md[SHA384_DIGEST_LENGTH]);