From 6c039ec5260c61c5edca7a6ddc8867c34a806f96 Mon Sep 17 00:00:00 2001
From: Tyler Neely <t@jujit.su>
Date: Wed, 25 Nov 2020 12:35:24 +0100
Subject: [PATCH] Speed up compilation by avoiding zeroize_derive

---
 Cargo.toml    |  2 +-
 src/secret.rs | 17 +++++++++++++----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 21fc1a4..df69515 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -30,7 +30,7 @@ rand_core = { version = "0.6", default-features = false, optional = true }
 serde_crate = { package = "serde", version = "1.0", default-features = false, optional = true }
 serde_bytes = { version = "0.11", default-features = false, optional = true }
 sha2 = { version = "0.10", default-features = false }
-zeroize = { version = "1", default-features = false, features = ["zeroize_derive"] }
+zeroize = { version = "1", default-features = false }
 
 [dev-dependencies]
 hex = "^0.4"
diff --git a/src/secret.rs b/src/secret.rs
index fbb2145..80c2002 100644
--- a/src/secret.rs
+++ b/src/secret.rs
@@ -40,10 +40,14 @@ use crate::signature::*;
 ///
 /// Instances of this secret are automatically overwritten with zeroes when they
 /// fall out of scope.
-#[derive(Zeroize)]
-#[zeroize(drop)] // Overwrite secret key material with null bytes when it goes out of scope.
 pub struct SecretKey(pub(crate) [u8; SECRET_KEY_LENGTH]);
 
+impl Drop for SecretKey {
+    fn drop(&mut self) {
+        self.0.zeroize()
+    }
+}
+
 impl Debug for SecretKey {
     fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result {
         write!(f, "SecretKey: {:?}", &self.0[..])
@@ -235,13 +239,18 @@ impl<'d> Deserialize<'d> for SecretKey {
 // same signature scheme, and which both fail in exactly the same way.  For a
 // better-designed, Schnorr-based signature scheme, see Trevor Perrin's work on
 // "generalised EdDSA" and "VXEdDSA".
-#[derive(Zeroize)]
-#[zeroize(drop)] // Overwrite secret key material with null bytes when it goes out of scope.
 pub struct ExpandedSecretKey {
     pub(crate) key: Scalar,
     pub(crate) nonce: [u8; 32],
 }
 
+impl Drop for ExpandedSecretKey {
+    fn drop(&mut self) {
+        self.key.zeroize();
+        self.nonce.zeroize()
+    }
+}
+
 impl<'a> From<&'a SecretKey> for ExpandedSecretKey {
     /// Construct an `ExpandedSecretKey` from a `SecretKey`.
     ///