"crypto/internal/fips140deps/byteorder" "errors" ) // fieldElement is an integer modulo q, an element of ℤ_q. It is always reduced. type fieldElement uint16 // fieldCheckReduced checks that a value a is < q. func fieldCheckReduced(a uint16) (fieldElement, error) { if a >= q { return 0, errors.New("unreduced field element") } return fieldElement(a), nil } // fieldReduceOnce reduces a value a < 2q. func fieldReduceOnce(a uint16) fieldElement { x := a - q // If x underflowed, then x >= 2¹⁶ - q > 2¹⁵,...