image: Avoid erroneous double byte-swap in CRC value

The hash algorithm selection was streamlined in commit 92055e138f
("image: Drop if/elseif hash selection in calculate_hash()"). Said
commit kept the call to cpu_to_uimage() to convert the CRC to big
endian format.

This would have been correct when calling crc32_wd(). However, the
->hash_func_ws member of crc32 points to crc32_wd_buf(), which already
converts the CRC to big endian. On a little endian host, doing both
conversions results in a little-endian CRC. This is incorrect.

To remedy this, simply drop the call to cpu_to_uimage(), thus only
doing the byte-order conversion once.

Fixes: 92055e138f ("image: Drop if/elseif hash selection in
       calculate_hash()")
Tested-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
This commit is contained in:
Alexandru Gagniuc 2021-09-14 15:53:33 -05:00 committed by Tom Rini
parent c6eac9122f
commit 1ac7580a22

View file

@ -1193,12 +1193,6 @@ int fit_set_timestamp(void *fit, int noffset, time_t timestamp)
return 0;
}
static void crc32_uimage_fixup(void *value)
{
/* TODO: In C, this type punning is undefined behavior: */
*((uint32_t *)value) = cpu_to_uimage(*((uint32_t *)value));
}
/**
* calculate_hash - calculate and return hash for provided input data
* @data: pointer to the input data
@ -1232,9 +1226,6 @@ int calculate_hash(const void *data, int data_len, const char *name,
algo->hash_func_ws(data, data_len, value, algo->chunk_size);
*value_len = algo->digest_size;
if (!strcmp(name, "crc32"))
crc32_uimage_fixup(value);
return 0;
}