Cryptography Reference
In-Depth Information
AESCrypt_l (rstate->XAES, &rstate->RandAESWorksp,
&rstate->RandAESSched, rstate->XAES, 24);
Generation of a random value via application of the function
ψ
(
k, x, i
):=
x/
2
8
·
(23
−
(
i
mod
16))
mod
2
8
ψ
:
S
→
S,
rbyte = rstate->XAES[(rstate->RoundAES)++ & 15];
Key update if the parameter is set and the prescribed number of rounds is reached
if (rstate->UpdateKeyAES)
{
if (0 == (rstate->RoundAES % rstate->UpdateKeyAES))
{
for (i = 0; i < 32; i++)
{
rstate->RandAESKey[i]
ˆ
= rstate->XAES[i];
}
AESInit_l (&rstate->RandAESWorksp, AES_ECB, 192, NULL,
&rstate->RandAESSched, rstate->RandAESKey, 256, AES_ENC);
}
}
return rbyte;
}
Random values
r_l
in the interval
2
l
−
1
≤
r_l
≤
2
l
−
1
are specified with the
function
RandAES_l()
, whose function header is given here:
generation of a random number of type
CLINT
Function:
int
RandAES_1 (CLINT r_l, STATEAES *rstate, int l);
Syntax:
rstate
(internal state of the pseudorandom number generator)
l
(number of binary digits of the number to be generated)
Input:
r_l
(random number in the interval
2
l
−
1
≤
r_l
≤
2
l
−
1
)
Ouput:
E_CLINT_OK
if all O.K.
E_CLING_RIN
if the generator is not initialized
Return:
