From 57cc136282c38825e97bbf85728df4bdf1ccc648 Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter@wuille.net>
Date: Thu, 17 Aug 2023 15:37:41 -0400
Subject: [PATCH] crypto: make ChaCha20::SetKey wipe buffer

---
 src/crypto/chacha20.cpp | 7 +++++++
 src/crypto/chacha20.h   | 6 +-----
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/crypto/chacha20.cpp b/src/crypto/chacha20.cpp
index 143179f905a..a3cc87e81b3 100644
--- a/src/crypto/chacha20.cpp
+++ b/src/crypto/chacha20.cpp
@@ -335,6 +335,13 @@ ChaCha20::~ChaCha20()
     memory_cleanse(m_buffer.data(), m_buffer.size());
 }
 
+void ChaCha20::SetKey(Span<const std::byte> key) noexcept
+{
+    m_aligned.SetKey(key);
+    m_bufleft = 0;
+    memory_cleanse(m_buffer.data(), m_buffer.size());
+}
+
 FSChaCha20::FSChaCha20(Span<const std::byte> key, uint32_t rekey_interval) noexcept :
     m_chacha20(key), m_rekey_interval(rekey_interval)
 {
diff --git a/src/crypto/chacha20.h b/src/crypto/chacha20.h
index 4d169616097..5f0f1ff64ba 100644
--- a/src/crypto/chacha20.h
+++ b/src/crypto/chacha20.h
@@ -95,11 +95,7 @@ public:
     ~ChaCha20();
 
     /** Set 32-byte key, and seek to nonce 0 and block position 0. */
-    void SetKey(Span<const std::byte> key) noexcept
-    {
-        m_aligned.SetKey(key);
-        m_bufleft = 0;
-    }
+    void SetKey(Span<const std::byte> key) noexcept;
 
     /** 96-bit nonce type. */
     using Nonce96 = ChaCha20Aligned::Nonce96;