Add note about P256 encoding of point-at-infinity

2017-07-04 21:39:01 +02:00 · 2017-07-04 21:39:01 +02:00 · aec6af5de4
commit aec6af5de4
parent adc192ac17
1 changed files with 2 additions and 1 deletions
--- a/Crypto/PubKey/ECC/P256.hs
+++ b/Crypto/PubKey/ECC/P256.hs
@ -114,7 +114,8 @@ pointMul scalar p = withNewPoint $ \dx dy ->
    withScalar scalar $ \n -> withPoint p $ \px py -> withScalarZero $ \nzero ->
        ccryptonite_p256_points_mul_vartime nzero n px py dx dy

-- | Similar to 'pointMul', serializing the x coordinate as binary
+-- | Similar to 'pointMul', serializing the x coordinate as binary.
+-- When scalar is multiple of point order the result is all zero.
 pointDh :: ByteArray binary => Scalar -> Point -> binary
 pointDh scalar p =
    B.unsafeCreate scalarSize $ \dst -> withTempPoint $ \dx dy -> do