Does EVP_MAC_CTX_dup() after the MAC context has been initialised do
what you want?
Pauli
On 5/4/21 10:51 pm, Hal Murray wrote:
It used to take just a ctx. Now it also wants a key+length and a params.
I have some simple/hack code to time 2 cases. The first gives it the key each
time. The second preloads the key. That would require an evp per key, but I
might we willing to make that space/time tradeoff.
The each time mode of my old code put the cipher and key into a params array,
then called
EVP_MAC_CTX_set_params(ctx, params) and then
EVP_MAC_init(ctx)
That's easy to change. I just drop putting the key into a params slot and
drop calling set_parms and add the key and parms to EVP_MAC_init. That worked.
Is there a way to use a preloaded key? I tried using NULL for key and params
when calling EVP_MAC_init. It compiles and runs but doesn't get the right
answer. Is that, or something like it supposed to work?
--------
EVP_MAC_CTX_set_params() seems ugly to me.
My inner loop looks like:
EVP_MAC_CTX_set_params()
EVP_MAC_init()
EVP_MAC_update()
EVP_MAC_final()
I'm trying to make things go fast. It's going to have to do string compares
to figure out what I want to do. I'm working with small blocks of data (48
bytes) so the setup cost is important. Or I think it is, so I'm trying to
measure it.
The case I'm trying to get working is to move the EVP_MAC_CTX_set_params() out
of the loop.
