Unaligned access in random_bytes() and rand_get_bytes()

[rw8896]

libspdm/os_stub/cryptlib_mbedtls/rand/rand.c

Line 63 in 631028a

*((uint64 *)output) = temp_rand;

libspdm/os_stub/openssllib/rand_pool.c

Line 48 in 631028a

*((uint64 *)RandBuffer) = temp_rand;

These assignments may cause unaligned access when output or RandBuffer is not at alignment of uint64_t.
Better to use copy_mem() instead.

[steven-bellock]

Part of the issue is the SPDM specification itself, and how fields are laid out within a request or response. There's also endianness issues as well. In the short term we can fix this; in the long term need a strategy on whether to accommodate all alignment issues.

[steven-bellock]

Will defer to STABLE 0.2.

[jyao1]

@rw8896, do you want to propose a fix?

[rw8896]

As @steven-bellock commented, the short term solution is just to avoid the uint64 assignment in these two rand.c files.
We could simply replace it with copy_mem().

I am not sure about the long term strategy to address the alignment and endianness issues though.