diff --git a/src/scalar.rs b/src/scalar.rs index 7e23699..b700368 100644 --- a/src/scalar.rs +++ b/src/scalar.rs @@ -535,6 +535,32 @@ impl Scalar { /// # Returns /// /// The multiplicative inverse of the this `Scalar`. + /// + /// # Example + /// + /// ``` + /// use curve25519_dalek::scalar::Scalar; + /// + /// // x = 2238329342913194256032495932344128051776374960164957527413114840482143558222 + /// let X: Scalar = Scalar::from_bytes_mod_order([ + /// 0x4e, 0x5a, 0xb4, 0x34, 0x5d, 0x47, 0x08, 0x84, + /// 0x59, 0x13, 0xb4, 0x64, 0x1b, 0xc2, 0x7d, 0x52, + /// 0x52, 0xa5, 0x85, 0x10, 0x1b, 0xcc, 0x42, 0x44, + /// 0xd4, 0x49, 0xf4, 0xa8, 0x79, 0xd9, 0xf2, 0x04, + /// ]); + /// // 1/x = 6859937278830797291664592131120606308688036382723378951768035303146619657244 + /// let XINV: Scalar = Scalar::from_bytes_mod_order([ + /// 0x1c, 0xdc, 0x17, 0xfc, 0xe0, 0xe9, 0xa5, 0xbb, + /// 0xd9, 0x24, 0x7e, 0x56, 0xbb, 0x01, 0x63, 0x47, + /// 0xbb, 0xba, 0x31, 0xed, 0xd5, 0xa9, 0xbb, 0x96, + /// 0xd5, 0x0b, 0xcd, 0x7a, 0x3f, 0x96, 0x2a, 0x0f, + /// ]); + /// + /// let inv_X: Scalar = X.invert(); + /// assert!(XINV == inv_X); + /// let should_be_one: Scalar = &inv_X * &X; + /// assert!(should_be_one == Scalar::one()); + /// ``` pub fn invert(&self) -> Scalar { self.unpack().invert().pack() }