initialized // by newCShake function and stores concatenation of N followed by S, encoded // by the method specified in 3.3 of [1]. // It is stored here in order for Reset() to be able to put context into // initial state. initBlock []byte } func bytepad(data []byte, rate int) []byte { out := make([]byte, 0, 9+len(data)+rate-1) out = append(out, leftEncode(uint64(rate))...) out = append(out, data...) if padlen := rate - len(out)%rate; padlen < rate { out = append(out, make([]byte, padlen)...) } return...