&& len(S) == 0 { *c = *NewShake128() return c } return newCShake(c, N, S, rateK256, 32, dsbyteCShake) } // NewCShake256 creates a new cSHAKE256 XOF. // // N is used to define functions based on cSHAKE, it can be empty when plain // cSHAKE is desired. S is a customization byte string used for domain // separation. When N and S are both empty, this is equivalent to NewShake256. func NewCShake256(N, S []byte) *SHAKE { // The actual logic is in a separate function to outline this allocation. c := &SHAKE{}...