sikkienl/dash
1
0
Fork 0
mirror of https://github.com/dashpay/dash.git synced 2024-12-25 03:52:49 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity

Merge bitcoin/bitcoin#28774: wallet: avoid returning a reference to vMasterKey after releasing the mutex that guards it

Browse Source 
32a9f13cb805ecf6aebb5cf4e5d92b8a47c4548b wallet: avoid returning a reference to vMasterKey after releasing the mutex that guards it (Vasil Dimov)

Pull request description:

  `CWallet::GetEncryptionKey()` would return a reference to the internal
  `CWallet::vMasterKey`, guarded by `CWallet::cs_wallet`, which is unsafe.

  Returning a copy would be a shorter solution, but could have security
  implications of the master key remaining somewhere in the memory even
  after `CWallet::Lock()` (the current calls to
  `CWallet::GetEncryptionKey()` are safe, but that is not future proof).

  So, instead of `EncryptSecret(m_storage.GetEncryptionKey(), ...)`
  change the `GetEncryptionKey()` method to provide the encryption
  key to a given callback:
  `m_storage.WithEncryptionKey([](const CKeyingMaterial& k) { EncryptSecret(k, ...); })`

  This silences the following (clang 18):

  ```
  wallet/wallet.cpp:3520:12: error: returning variable 'vMasterKey' by reference requires holding mutex 'cs_wallet' [-Werror,-Wthread-safety-reference-return]
   3520 |     return vMasterKey;
        |            ^
  ```

  ---
  _Previously this PR modified both ArgsManager and wallet code. But the ArgsManager commit 856c88776f was merged in https://github.com/bitcoin/bitcoin/pull/29040 so now this only affects wallet code. The previous PR description was:_

  Avoid this unsafe pattern from `ArgsManager` and `CWallet`:

  ```cpp
  class A
  {
      Mutex mutex;
      Foo member GUARDED_BY(mutex);
      const Foo& Get()
      {
          LOCK(mutex);
          return member;
      } // callers of `Get()` will have access to `member` without owning the mutex.
  ```

ACKs for top commit:
  achow101:
    ACK 32a9f13cb805ecf6aebb5cf4e5d92b8a47c4548b
  ryanofsky:
    Code review ACK 32a9f13cb805ecf6aebb5cf4e5d92b8a47c4548b. This seems like a potentially real race condition, and the fix here is pretty simple.
  furszy:
    ACK 32a9f13c

Tree-SHA512: 133da84691642afc1a73cf14ad004a7266cb4be1a6a3ec634d131dca5dbcdef52522c1d5eb04f5b6c4e06e1fc3e6ac57315f8fe1e207b464ca025c2b4edefdc1
This commit is contained in:
Ava Chow 2024-01-23 14:50:58 -05:00 committed by Konstantin Akimov
parent 6d452845dc
commit 898282d620
No known key found for this signature in database
GPG Key ID: 2176C4A5D01EA524
4 changed files with 36 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
src/wallet/scriptpubkeyman.cpp
View File

@ -342,8 +342,11 @@ void LegacyScriptPubKeyMan::UpgradeKeyMetadata()
CHDChain hdChainCurrent;
if (!GetHDChain(hdChainCurrent))
throw std::runtime_error(std::string(__func__) + ": GetHDChain failed");
if (!DecryptHDChain(m_storage.GetEncryptionKey(), hdChainCurrent))
if (!m_storage.WithEncryptionKey([&](const CKeyingMaterial& encryption_key) {
return DecryptHDChain(encryption_key, hdChainCurrent);
})) {
throw std::runtime_error(std::string(__func__) + ": DecryptHDChain failed");
}
CExtKey masterKey;
SecureVector vchSeed = hdChainCurrent.GetSeed();
@ -474,8 +477,11 @@ bool LegacyScriptPubKeyMan::GetDecryptedHDChain(CHDChain& hdChainRet)
return false;
}
if (!DecryptHDChain(m_storage.GetEncryptionKey(), hdChainTmp))
if (!m_storage.WithEncryptionKey([&](const CKeyingMaterial& encryption_key) {
return DecryptHDChain(encryption_key, hdChainTmp);
})) {
return false;
}
// make sure seed matches this chain
if (hdChainTmp.GetID() != hdChainTmp.GetSeedHash())
@ -911,7 +917,9 @@ bool LegacyScriptPubKeyMan::AddKeyPubKeyInner(const CKey& key, const CPubKey &pu
std::vector<unsigned char> vchCryptedSecret;
CKeyingMaterial vchSecret(key.begin(), key.end());
if (!EncryptSecret(m_storage.GetEncryptionKey(), vchSecret, pubkey.GetHash(), vchCryptedSecret)) {
if (!m_storage.WithEncryptionKey([&](const CKeyingMaterial& encryption_key) {
return EncryptSecret(encryption_key, vchSecret, pubkey.GetHash(), vchCryptedSecret);
})) {
return false;
}
@ -933,7 +941,9 @@ bool LegacyScriptPubKeyMan::GetKeyInner(const CKeyID &address, CKey& keyOut) con
{
const CPubKey &vchPubKey = (*mi).second.first;
const std::vector<unsigned char> &vchCryptedSecret = (*mi).second.second;
return DecryptKey(m_storage.GetEncryptionKey(), vchCryptedSecret, vchPubKey, keyOut);
return m_storage.WithEncryptionKey([&](const CKeyingMaterial& encryption_key) {
return DecryptKey(encryption_key, vchCryptedSecret, vchPubKey, keyOut);
});
}
return false;
}
@ -1164,8 +1174,11 @@ bool LegacyScriptPubKeyMan::GetKey(const CKeyID &address, CKey& keyOut) const
CHDChain hdChainCurrent;
if (!GetHDChain(hdChainCurrent))
throw std::runtime_error(std::string(__func__) + ": GetHDChain failed");
if (!DecryptHDChain(m_storage.GetEncryptionKey(), hdChainCurrent))
if (!m_storage.WithEncryptionKey([&](const CKeyingMaterial& encryption_key) {
return DecryptHDChain(encryption_key, hdChainCurrent);
})) {
throw std::runtime_error(std::string(__func__) + ": DecryptHDChain failed");
}
// make sure seed matches this chain
if (hdChainCurrent.GetID() != hdChainCurrent.GetSeedHash())
throw std::runtime_error(std::string(__func__) + ": Wrong HD chain!");
@ -1276,8 +1289,11 @@ void LegacyScriptPubKeyMan::DeriveNewChildKey(WalletBatch &batch, CKeyMetadata&
throw std::runtime_error(std::string(__func__) + ": GetHDChain failed");
}
if (!DecryptHDChain(m_storage.GetEncryptionKey(), hdChainTmp))
if (!m_storage.WithEncryptionKey([&](const CKeyingMaterial& encryption_key) {
return DecryptHDChain(encryption_key, hdChainTmp);
})) {
throw std::runtime_error(std::string(__func__) + ": DecryptHDChain failed");
}
// make sure seed matches this chain
if (hdChainTmp.GetID() != hdChainTmp.GetSeedHash())
throw std::runtime_error(std::string(__func__) + ": Wrong HD chain!");
@ -1897,7 +1913,9 @@ std::map<CKeyID, CKey> DescriptorScriptPubKeyMan::GetKeys() const
const CPubKey& pubkey = key_pair.second.first;
const std::vector<unsigned char>& crypted_secret = key_pair.second.second;
CKey key;
DecryptKey(m_storage.GetEncryptionKey(), crypted_secret, pubkey, key);
m_storage.WithEncryptionKey([&](const CKeyingMaterial& encryption_key) {
return DecryptKey(encryption_key, crypted_secret, pubkey, key);
});
keys[pubkey.GetID()] = key;
}
return keys;
@ -2010,7 +2028,9 @@ bool DescriptorScriptPubKeyMan::AddDescriptorKeyWithDB(WalletBatch& batch, const
std::vector<unsigned char> crypted_secret;
CKeyingMaterial secret(key.begin(), key.end());
if (!EncryptSecret(m_storage.GetEncryptionKey(), secret, pubkey.GetHash(), crypted_secret)) {
if (!m_storage.WithEncryptionKey([&](const CKeyingMaterial& encryption_key) {
return EncryptSecret(encryption_key, secret, pubkey.GetHash(), crypted_secret);
})) {
return false;
}

4
src/wallet/scriptpubkeyman.h
View File

@ -21,6 +21,7 @@
#include <boost/signals2/signal.hpp>
#include <functional>
#include <optional>
// Wallet storage things that ScriptPubKeyMans need in order to be able to store things to the wallet database.
@ -38,7 +39,8 @@ public:
virtual void UnsetBlankWalletFlag(WalletBatch&) = 0;
virtual bool CanSupportFeature(enum WalletFeature) const = 0;
virtual void SetMinVersion(enum WalletFeature, WalletBatch* = nullptr) = 0;
virtual const CKeyingMaterial& GetEncryptionKey() const = 0;
//! Pass the encryption key to cb().
virtual bool WithEncryptionKey(std::function<bool (const CKeyingMaterial&)> cb) const = 0;
virtual bool HasEncryptionKeys() const = 0;
virtual bool IsLocked(bool fForMixing) const = 0;

5
src/wallet/wallet.cpp
View File

@ -5743,9 +5743,10 @@ void CWallet::SetupLegacyScriptPubKeyMan()
m_spk_managers[spk_manager->GetID()] = std::move(spk_manager);
}
const CKeyingMaterial& CWallet::GetEncryptionKey() const
bool CWallet::WithEncryptionKey(std::function<bool (const CKeyingMaterial&)> cb) const
{
return vMasterKey;
LOCK(cs_wallet);
return cb(vMasterKey);
}
bool CWallet::HasEncryptionKeys() const

3
src/wallet/wallet.h
View File

@ -1468,7 +1468,8 @@ public:
//! Make a LegacyScriptPubKeyMan and set it for all types, internal, and external.
void SetupLegacyScriptPubKeyMan();
const CKeyingMaterial& GetEncryptionKey() const override;
bool WithEncryptionKey(std::function<bool (const CKeyingMaterial&)> cb) const override;
bool HasEncryptionKeys() const override;
/** Get last block processed height */