Add sha256 and sha512 checksums

That should suffice...

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/sha512.h b/sha512.h
new file mode 100644
index 0000000..46e10cb
--- /dev/null
+++ b/sha512.h
@@ -0,0 +1,14 @@
+#ifndef FIO_SHA512_H
+#define FIO_SHA512_H
+
+struct sha512_ctx {
+	uint64_t state[8];
+	uint32_t count[4];
+	uint8_t *buf;
+	uint64_t W[80];
+};
+
+void sha512_init(struct sha512_ctx *);
+void sha512_update(struct sha512_ctx *, const uint8_t *, unsigned int);
+
+#endif