az) } else { b = b.ShiftRightVarTime(bz) } gcd, err := bigmod.NewNat().GCDVarTime(a, b) if err != nil { return nil, err } if gcd.IsOdd() == 0 { return nil, errors.New("rsa: internal error: gcd(a, b) is even") } // To avoid implementing multiple-precision division, we just try again if // the divisor doesn't fit in a single word. This would have a chance of // 2⁻⁶⁴ on 64-bit platforms, and 2⁻³² on 32-bit platforms, but testing 2⁻⁶⁴ // edge cases is impractical, and we'd rather not behave differently...