From 5854b092a88c37b5aa7e48cdfd641ba11e43d440 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Olivier=20Ch=C3=A9ron?= <ocheron@users.noreply.github.com>
Date: Sun, 28 Aug 2016 16:38:04 +0200
Subject: [PATCH] Fix ECDH when scalar and coordinate bit sizes differ

---
 Crypto/PubKey/ECC/Types.hs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Crypto/PubKey/ECC/Types.hs b/Crypto/PubKey/ECC/Types.hs
index 4f100f9..57ea9a9 100644
--- a/Crypto/PubKey/ECC/Types.hs
+++ b/Crypto/PubKey/ECC/Types.hs
@@ -164,7 +164,8 @@ curvesOIDs =
 
 -- | get the size of the curve in bits
 curveSizeBits :: Curve -> Int
-curveSizeBits = numBits . ecc_n . common_curve
+curveSizeBits (CurveFP  c) = numBits (ecc_p  c)
+curveSizeBits (CurveF2m c) = numBits (ecc_fx c) - 1
 
 -- | Get the curve definition associated with a recommended known curve name.
 getCurveByName :: CurveName -> Curve