lib: Rename rsa-checksum.c to hash-checksum.c

rsa-checksum.c sontains the hash_calculate() implementations. Despite
the "rsa-" file prefix, this function is useful for other algorithms.

To prevent confusion, move this file to lib/, and rename it to
hash-checksum.c, to give it a more "generic" feel.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

lib/hash-checksum.c

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2013, Andreas Oetken.
+ */
+
+#ifndef USE_HOSTCC
+#include <common.h>
+#include <fdtdec.h>
+#include <asm/byteorder.h>
+#include <linux/errno.h>
+#include <asm/unaligned.h>
+#include <hash.h>
+#else
+#include "fdt_host.h"
+#endif
+#include <hash.h>
+#include <image.h>
+
+int hash_calculate(const char *name,
+		    const struct image_region region[],
+		    int region_count, uint8_t *checksum)
+{
+	struct hash_algo *algo;
+	int ret = 0;
+	void *ctx;
+	uint32_t i;
+	i = 0;
+
+	ret = hash_progressive_lookup_algo(name, &algo);
+	if (ret)
+		return ret;
+
+	ret = algo->hash_init(algo, &ctx);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < region_count - 1; i++) {
+		ret = algo->hash_update(algo, ctx, region[i].data,
+					region[i].size, 0);
+		if (ret)
+			return ret;
+	}
+
+	ret = algo->hash_update(algo, ctx, region[i].data, region[i].size, 1);
+	if (ret)
+		return ret;
+	ret = algo->hash_finish(algo, ctx, checksum, algo->digest_size);
+	if (ret)
+		return ret;
+
+	return 0;
+}