From 223eb41fd068a842164a1dd41d3711d928a226ae Mon Sep 17 00:00:00 2001
From: Andrew Poelstra <apoelstra@wpsoftware.net>
Date: Tue, 6 Nov 2018 22:04:02 +0000
Subject: [PATCH] remove context object from ECDH

---
 src/ecdh.rs | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/ecdh.rs b/src/ecdh.rs
index 9da25a3..aec2dbc 100644
--- a/src/ecdh.rs
+++ b/src/ecdh.rs
@@ -18,7 +18,6 @@
 
 use std::{ops, ptr};
 
-use super::Secp256k1;
 use key::{SecretKey, PublicKey};
 use ffi;
 
@@ -29,11 +28,11 @@ pub struct SharedSecret(ffi::SharedSecret);
 impl SharedSecret {
     /// Creates a new shared secret from a pubkey and secret key
     #[inline]
-    pub fn new<C>(secp: &Secp256k1<C>, point: &PublicKey, scalar: &SecretKey) -> SharedSecret {
+    pub fn new(point: &PublicKey, scalar: &SecretKey) -> SharedSecret {
         unsafe {
             let mut ss = ffi::SharedSecret::blank();
             let res = ffi::secp256k1_ecdh(
-                secp.ctx,
+                ffi::secp256k1_context_no_precomp,
                 &mut ss,
                 point.as_ptr(),
                 scalar.as_ptr(),
@@ -109,9 +108,9 @@ mod tests {
         let (sk1, pk1) = s.generate_keypair(&mut thread_rng());
         let (sk2, pk2) = s.generate_keypair(&mut thread_rng());
 
-        let sec1 = SharedSecret::new(&s, &pk1, &sk2);
-        let sec2 = SharedSecret::new(&s, &pk2, &sk1);
-        let sec_odd = SharedSecret::new(&s, &pk1, &sk1);
+        let sec1 = SharedSecret::new(&pk1, &sk2);
+        let sec2 = SharedSecret::new(&pk2, &sk1);
+        let sec_odd = SharedSecret::new(&pk1, &sk1);
         assert_eq!(sec1, sec2);
         assert!(sec_odd != sec2);
     }
@@ -132,7 +131,7 @@ mod benches {
 
         let s = Secp256k1::new();
         bh.iter( || {
-            let res = SharedSecret::new(&s, &pk, &sk);
+            let res = SharedSecret::new(&pk, &sk);
             black_box(res);
         });
     }