hash: Add a way to calculate a hash for any algortihm
Rather than needing to call one of many hashing algorithms in U-Boot,
provide a function hash_block() which handles this, and can support all
available hash algorithms.
Once we have md5 supported within hashing, we can use this function in
the FIT image code.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/hash.h b/include/hash.h
index 2dbbd9b..c402067 100644
--- a/include/hash.h
+++ b/include/hash.h
@@ -71,4 +71,26 @@
int hash_command(const char *algo_name, int flags, cmd_tbl_t *cmdtp, int flag,
int argc, char * const argv[]);
+/**
+ * hash_block() - Hash a block according to the requested algorithm
+ *
+ * The caller probably knows the hash length for the chosen algorithm, but
+ * in order to provide a general interface, and output_size parameter is
+ * provided.
+ *
+ * @algo_name: Hash algorithm to use
+ * @data: Data to hash
+ * @len: Lengh of data to hash in bytes
+ * @output: Place to put hash value
+ * @output_size: On entry, pointer to the number of bytes available in
+ * output. On exit, pointer to the number of bytes used.
+ * If NULL, then it is assumed that the caller has
+ * allocated enough space for the hash. This is possible
+ * since the caller is selecting the algorithm.
+ * @return 0 if ok, -ve on error: -EPROTONOSUPPORT for an unknown algorithm,
+ * -ENOSPC if the output buffer is not large enough.
+ */
+int hash_block(const char *algo_name, const void *data, unsigned int len,
+ uint8_t *output, int *output_size);
+
#endif