[U-Boot] [RFC PATCH 27/44] hash: Add a way to calculate a hash for any algortihm

Simon Glass
2013-01-05T01:51:56Z

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>
---
common/hash.c | 22 ++++++++++++++++++++++
include/hash.h | 15 +++++++++++++++
2 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/common/hash.c b/common/hash.c
index 2e0a67b..897b9a3 100644
--- a/common/hash.c
+++ b/common/hash.c
@@ -29,6 +29,7 @@
#include <sha1.h>
#include <sha256.h>
#include <asm/io.h>
+#include <asm/errno.h>

/*
* These are the hash algorithms we support. Chips which support accelerated
@@ -171,6 +172,27 @@ static void show_hash(struct hash_algo *algo, ulong addr, ulong len,
printf("%02x", output[i]);
}

+int hash_block(const char *algo_name, const void *data, int len,
+ uint8_t *output, int *output_size)
+{
+ struct hash_algo *algo;
+
+ algo = find_hash_algo(algo_name);
+ if (!algo) {
+ debug("Unknown hash algorithm '%s'\n", algo_name);
+ return -EPROTONOSUPPORT;
+ }
+ if (output_size && *output_size < algo->digest_size) {
+ debug("Output buffer size %d too small (need %d bytes)",
+ *output_size, algo->digest_size);
+ return -ENOSPC;
+ }
+ *output_size = algo->digest_size;
+ algo->hash_func_ws(data, len, output, algo->chunk_size);
+
+ return 0;
+}
+
int hash_command(const char *algo_name, int verify, cmd_tbl_t *cmdtp, int flag,
int argc, char * const argv[])
{
diff --git a/include/hash.h b/include/hash.h
index ba2ba65..dda6f79 100644
--- a/include/hash.h
+++ b/include/hash.h
@@ -66,4 +66,19 @@ struct hash_algo {
int hash_command(const char *algo_name, int verify, cmd_tbl_t *cmdtp, int flag,
int argc, char * const argv[]);

+/**
+ * hash_block() - Hash a block according to the requested algorithm
+ *
+ * @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, the number of bytes available in output,
+ * On exit, the number of bytes used
+ * @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, int len,
+ uint8_t *output, int *output_size);
+
#endif
--
1.7.7.3