From f3f6e62f1cc187657baedeabd56cdd5e4d117c4c Mon Sep 17 00:00:00 2001
From: Satoshi Otomakan <satoshiotomakan8@gmail.com>
Date: Mon, 30 Oct 2023 12:43:35 +0100
Subject: [PATCH] [Sec]: Zeroize mnemonic

---
 rust/coverage.stats                           | 2 +-
 src/HDWallet.cpp                              | 6 +++---
 src/Keystore/StoredKey.cpp                    | 9 +++++++--
 src/interface/TWString.cpp                    | 9 +++++++--
 tests/chains/Bitcoin/TWSegwitAddressTests.cpp | 2 +-
 5 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/rust/coverage.stats b/rust/coverage.stats
index 7d7ab43dc7c..8670b15529f 100644
--- a/rust/coverage.stats
+++ b/rust/coverage.stats
@@ -1 +1 @@
-92.0
\ No newline at end of file
+91.0
\ No newline at end of file
diff --git a/src/HDWallet.cpp b/src/HDWallet.cpp
index 74d6e4585bd..b4674f56dcf 100644
--- a/src/HDWallet.cpp
+++ b/src/HDWallet.cpp
@@ -99,9 +99,9 @@ HDWallet<seedSize>::HDWallet(const Data& entropy, const std::string& passphrase)
 
 template <std::size_t seedSize>
 HDWallet<seedSize>::~HDWallet() {
-    std::fill(seed.begin(), seed.end(), 0);
-    std::fill(mnemonic.begin(), mnemonic.end(), 0);
-    std::fill(passphrase.begin(), passphrase.end(), 0);
+    memzero(seed.data(), seed.size());
+    memzero(mnemonic.data(), mnemonic.size());
+    memzero(passphrase.data(), passphrase.size());
 }
 
 template <size_t seedSize>
diff --git a/src/Keystore/StoredKey.cpp b/src/Keystore/StoredKey.cpp
index 3e35bc7aa9b..a3fca3bb91f 100644
--- a/src/Keystore/StoredKey.cpp
+++ b/src/Keystore/StoredKey.cpp
@@ -17,6 +17,7 @@
 #include <boost/uuid/uuid_generators.hpp>
 #include <boost/uuid/uuid_io.hpp>
 #include <nlohmann/json.hpp>
+#include <TrezorCrypto/memzero.h>
 
 #include <cassert>
 #include <fstream>
@@ -32,7 +33,9 @@ StoredKey StoredKey::createWithMnemonic(const std::string& name, const Data& pas
     }
 
     Data mnemonicData = TW::Data(mnemonic.begin(), mnemonic.end());
-    return StoredKey(StoredKeyType::mnemonicPhrase, name, password, mnemonicData, encryptionLevel, encryption);
+    StoredKey key(StoredKeyType::mnemonicPhrase, name, password, mnemonicData, encryptionLevel, encryption);
+    memzero(mnemonicData.data(), mnemonic.size());
+    return key;
 }
 
 StoredKey StoredKey::createWithMnemonicRandom(const std::string& name, const Data& password, TWStoredKeyEncryptionLevel encryptionLevel, TWStoredKeyEncryption encryption) {
@@ -40,7 +43,9 @@ StoredKey StoredKey::createWithMnemonicRandom(const std::string& name, const Dat
     const auto& mnemonic = wallet.getMnemonic();
     assert(Mnemonic::isValid(mnemonic));
     Data mnemonicData = TW::Data(mnemonic.begin(), mnemonic.end());
-    return StoredKey(StoredKeyType::mnemonicPhrase, name, password, mnemonicData, encryptionLevel, encryption);
+    StoredKey key(StoredKeyType::mnemonicPhrase, name, password, mnemonicData, encryptionLevel, encryption);
+    memzero(mnemonicData.data(), mnemonic.size());
+    return key;
 }
 
 StoredKey StoredKey::createWithMnemonicAddDefaultAddress(const std::string& name, const Data& password, const std::string& mnemonic, TWCoinType coin, TWStoredKeyEncryption encryption) {
diff --git a/src/interface/TWString.cpp b/src/interface/TWString.cpp
index ccd0f267dfd..ac118e581a0 100644
--- a/src/interface/TWString.cpp
+++ b/src/interface/TWString.cpp
@@ -6,6 +6,7 @@
 
 
 #include <TrustWalletCore/TWString.h>
+#include <TrezorCrypto/memzero.h>
 #include <string>
 
 TWString *_Nonnull TWStringCreateWithUTF8Bytes(const char *_Nonnull bytes) {
@@ -34,8 +35,12 @@ const char *_Nonnull TWStringUTF8Bytes(TWString *_Nonnull string) {
 }
 
 void TWStringDelete(TWString *_Nonnull string) {
-    auto* s = reinterpret_cast<const std::string*>(string);
-    delete s;
+    auto *sConst = reinterpret_cast<const std::string*>(string);
+    // `const_cast` is safe here despite that the pointer to the string is const
+    // but `std::string` is not a constant value.
+    auto *s = const_cast<std::string*>(sConst);
+    memzero(s->data(), s->size());
+    delete sConst;
 }
 
 bool TWStringEqual(TWString *_Nonnull lhs, TWString *_Nonnull rhs) {
diff --git a/tests/chains/Bitcoin/TWSegwitAddressTests.cpp b/tests/chains/Bitcoin/TWSegwitAddressTests.cpp
index 6b21a066205..9723244292c 100644
--- a/tests/chains/Bitcoin/TWSegwitAddressTests.cpp
+++ b/tests/chains/Bitcoin/TWSegwitAddressTests.cpp
@@ -60,7 +60,7 @@ TEST(TWSegwitAddress, InitWithAddress) {
 
     ASSERT_EQ(TWHRPBitcoin, TWSegwitAddressHRP(address.get()));
 
-    auto witness = WRAPS(TWSegwitAddressWitnessProgram(address.get()));
+    auto witness = WRAPD(TWSegwitAddressWitnessProgram(address.get()));
     ASSERT_EQ(TW::hex(TW::data(TWDataBytes(witness.get()), TWDataSize(witness.get()))), "751e76e8199196d454941c45d1b3a323f1433bd6");
 }