Simon Josefsson simon@josefsson.org writes:
+void +salsa20_core (uint8_t *dst,
const uint8_t *src,unsigned rounds)is not ideal -- the reason is that the Salsa20 core is not defined with a parametrised number of rounds, so the interface is somewhat of a bastardisation.
Naming is difficult, it's awkward to use the prefix "salsa20" for a function which is "salsa20, but not really 20"... In sed syntax it would be salsa20_sx20xrx ;-)
In my work space, I have used the namespace 'salsa20r_core' instead. This opens up for later addition of a true 'salsa20_core' function which would use the official 20 rounds.
What do you think?
I have no better suggestions for naming. But if we think of salsa20r_core as mostly for internal use, maybe we don't need it?
If I understood you correctly, your primary use case is scrypt, which you intend to implement in Nettle? Then maybe you would be better off without an extra wrapper function around _salsa20_core? If nothing else, you could then make sure you have proper alignment so you don't need an extra memcpy.
I hesitate a bit to add, document and support a new "obscure" function until there's a clear external use case.
Regards, /Niels