From 463921bb649d644f79f9d7f0f96f10aa0d165f76 Mon Sep 17 00:00:00 2001
From: Jonas Schnelli <dev@jonasschnelli.ch>
Date: Mon, 13 Aug 2018 20:18:25 +0200
Subject: [PATCH] CKey: add method to negate the key

---
 src/key.cpp | 6 ++++++
 src/key.h   | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/src/key.cpp b/src/key.cpp
index 9d982fc44..c17f6a0ae 100644
--- a/src/key.cpp
+++ b/src/key.cpp
@@ -163,6 +163,12 @@ void CKey::MakeNewKey(bool fCompressedIn) {
     fCompressed = fCompressedIn;
 }
 
+bool CKey::Negate()
+{
+    assert(fValid);
+    return secp256k1_ec_privkey_negate(secp256k1_context_sign, keydata.data());
+}
+
 CPrivKey CKey::GetPrivKey() const {
     assert(fValid);
     CPrivKey privkey;
diff --git a/src/key.h b/src/key.h
index 0f695c07b..67e2cfc09 100644
--- a/src/key.h
+++ b/src/key.h
@@ -98,6 +98,9 @@ public:
     //! Generate a new private key using a cryptographic PRNG.
     void MakeNewKey(bool fCompressed);
 
+    //! Negate private key
+    bool Negate();
+
     /**
      * Convert the private key to a CPrivKey (serialized OpenSSL private key data).
      * This is expensive.