Merge #16227: Refactor CWallet's inheritance chain

93ce4a0b6fb54efb1f424a71dfc09cc33307e5b9 Move WatchOnly stuff from SigningProvider to CWallet (Andrew Chow)
8f5b81e6edae9cb22559545de63f391d97c15701 Remove CCryptoKeyStore and move all of it's functionality into CWallet (Andrew Chow)
37a79a4fccbf6cd65a933594e24e59d36e674653 Move various SigningProviders to signingprovider.{cpp,h} (Andrew Chow)
16f8096e911e4d59292240a17e2d4004f0500b9e Move KeyOriginInfo to its own header file (Andrew Chow)
d9becff4e13da8e182631baa79b9794c03d44434 scripted-diff: rename CBasicKeyStore to FillableSigningProvider (Andrew Chow)
a913e3f2fbeb1352fc66f334d4f5f7332ea89ad7 Move HaveKey static function from keystore to rpcwallet where it is used (Andrew Chow)
c7797ec65544bd23a2e571b2892e1bf512f2a485 Remove CKeyStore and squash into CBasicKeyStore (Andrew Chow)
1b699a5083b435c2b79f3951f94ac9f967d24f6c Add HaveKey and HaveCScript to SigningProvider (Andrew Chow)

Pull request description:

  This PR compresses the `CWallet` chain of inheritance from 5 classes to 3 classes. `CBasicKeyStore` is renamed to `FillableSigningProvider` and some parts of it (the watchonly parts) are moved into `CWallet`. `CKeyStore` and `CCrypoKeyStore` are completely removed. `CKeyStore`'s `Have*` functions are moved into `SigningProvider` and the `Add*` moved into `FillableSigningProvider`, thus allowing it to go away entirely. `CCryptoKeyStore`'s functionality is moved into `CWallet`. The new inheritance chain is:

  ```
  SigningProvider -> FillableSigningProvider -> CWallet
  ```

  `SigningProvider` now is the class the provides keys and scripts and indicates whether keys and scripts are present. `FillableSigningProvider` allows keys and scripts to be added to the signing provider via `Add*` functions. `CWallet` handles all of the watchonly stuff (`AddWatchOnly`, `HaveWatchOnly`, `RemoveWatchOnly` which were previously in `CKeyStore`) and key encryption (previously in `CCryptoKeyStore`).

  Implements the 2nd [prerequisite](https://github.com/bitcoin-core/bitcoin-devwiki/wiki/Wallet-Class-Structure-Changes#cwallet-subclass-stack) from the wallet restructure.

ACKs for top commit:
  Sjors:
    re-ACK 93ce4a0; it keeps `EncryptSecret`, `DecryptSecret` and `DecryptKey` in `wallet/crypter.cpp`, but makes them not static. It improves alphabetical includes, reorders some function definitions, fixes commit message, brings back lost code comment.
  instagibbs:
    utACK https://github.com/bitcoin/bitcoin/pull/16227/commits/93ce4a0b6fb54efb1f424a71dfc09cc33307e5b9

Tree-SHA512: 393dfd0623ad2dac38395eb89b862424318d6072f0b7083c92a0d207fd032c48b284f5f2cb13bc492f34557de350c5fee925da02e47daf011c5c6930a721b6d3

1 files changed, 262 insertions, 13 deletions

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index e53b433ca8..07fc8c35d5 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -13,13 +13,13 @@
 #include <interfaces/wallet.h>
 #include <key.h>
 #include <key_io.h>
-#include <keystore.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <script/descriptor.h>
 #include <script/script.h>
+#include <script/signingprovider.h>
 #include <util/bip32.h>
 #include <util/error.h>
 #include <util/fees.h>
@@ -358,14 +358,14 @@ bool CWallet::AddKeyPubKeyWithDB(WalletBatch& batch, const CKey& secret, const C
     // Make sure we aren't adding private keys to private key disabled wallets
     assert(!IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS));
 
-    // CCryptoKeyStore has no concept of wallet databases, but calls AddCryptedKey
+    // FillableSigningProvider has no concept of wallet databases, but calls AddCryptedKey
     // which is overridden below.  To avoid flushes, the database handle is
     // tunneled through to it.
     bool needsDB = !encrypted_batch;
     if (needsDB) {
         encrypted_batch = &batch;
     }
-    if (!CCryptoKeyStore::AddKeyPubKey(secret, pubkey)) {
+    if (!AddKeyPubKeyInner(secret, pubkey)) {
         if (needsDB) encrypted_batch = nullptr;
         return false;
     }
@@ -400,7 +400,7 @@ bool CWallet::AddKeyPubKey(const CKey& secret, const CPubKey &pubkey)
 bool CWallet::AddCryptedKey(const CPubKey &vchPubKey,
                             const std::vector<unsigned char> &vchCryptedSecret)
 {
-    if (!CCryptoKeyStore::AddCryptedKey(vchPubKey, vchCryptedSecret))
+    if (!AddCryptedKeyInner(vchPubKey, vchCryptedSecret))
         return false;
     {
         LOCK(cs_wallet);
@@ -468,7 +468,7 @@ void CWallet::UpgradeKeyMetadata()
 
 bool CWallet::LoadCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret)
 {
-    return CCryptoKeyStore::AddCryptedKey(vchPubKey, vchCryptedSecret);
+    return AddCryptedKeyInner(vchPubKey, vchCryptedSecret);
 }
 
 /**
@@ -495,7 +495,7 @@ bool CWallet::AddCScript(const CScript& redeemScript)
 
 bool CWallet::AddCScriptWithDB(WalletBatch& batch, const CScript& redeemScript)
 {
-    if (!CCryptoKeyStore::AddCScript(redeemScript))
+    if (!FillableSigningProvider::AddCScript(redeemScript))
         return false;
     if (batch.WriteCScript(Hash160(redeemScript), redeemScript)) {
         UnsetWalletFlagWithDB(batch, WALLET_FLAG_BLANK_WALLET);
@@ -516,12 +516,40 @@ bool CWallet::LoadCScript(const CScript& redeemScript)
         return true;
     }
 
-    return CCryptoKeyStore::AddCScript(redeemScript);
+    return FillableSigningProvider::AddCScript(redeemScript);
+}
+
+static bool ExtractPubKey(const CScript &dest, CPubKey& pubKeyOut)
+{
+    //TODO: Use Solver to extract this?
+    CScript::const_iterator pc = dest.begin();
+    opcodetype opcode;
+    std::vector<unsigned char> vch;
+    if (!dest.GetOp(pc, opcode, vch) || !CPubKey::ValidSize(vch))
+        return false;
+    pubKeyOut = CPubKey(vch);
+    if (!pubKeyOut.IsFullyValid())
+        return false;
+    if (!dest.GetOp(pc, opcode, vch) || opcode != OP_CHECKSIG || dest.GetOp(pc, opcode, vch))
+        return false;
+    return true;
+}
+
+bool CWallet::AddWatchOnlyInMem(const CScript &dest)
+{
+    LOCK(cs_KeyStore);
+    setWatchOnly.insert(dest);
+    CPubKey pubKey;
+    if (ExtractPubKey(dest, pubKey)) {
+        mapWatchKeys[pubKey.GetID()] = pubKey;
+        ImplicitlyLearnRelatedKeyScripts(pubKey);
+    }
+    return true;
 }
 
 bool CWallet::AddWatchOnlyWithDB(WalletBatch &batch, const CScript& dest)
 {
-    if (!CCryptoKeyStore::AddWatchOnly(dest))
+    if (!AddWatchOnlyInMem(dest))
         return false;
     const CKeyMetadata& meta = m_script_metadata[CScriptID(dest)];
     UpdateTimeFirstKey(meta.nCreateTime);
@@ -554,8 +582,17 @@ bool CWallet::AddWatchOnly(const CScript& dest, int64_t nCreateTime)
 bool CWallet::RemoveWatchOnly(const CScript &dest)
 {
     AssertLockHeld(cs_wallet);
-    if (!CCryptoKeyStore::RemoveWatchOnly(dest))
-        return false;
+    {
+        LOCK(cs_KeyStore);
+        setWatchOnly.erase(dest);
+        CPubKey pubKey;
+        if (ExtractPubKey(dest, pubKey)) {
+            mapWatchKeys.erase(pubKey.GetID());
+        }
+        // Related CScripts are not removed; having superfluous scripts around is
+        // harmless (see comment in ImplicitlyLearnRelatedKeyScripts).
+    }
+
     if (!HaveWatchOnly())
         NotifyWatchonlyChanged(false);
     if (!WalletBatch(*database).EraseWatchOnly(dest))
@@ -566,7 +603,19 @@ bool CWallet::RemoveWatchOnly(const CScript &dest)
 
 bool CWallet::LoadWatchOnly(const CScript &dest)
 {
-    return CCryptoKeyStore::AddWatchOnly(dest);
+    return AddWatchOnlyInMem(dest);
+}
+
+bool CWallet::HaveWatchOnly(const CScript &dest) const
+{
+    LOCK(cs_KeyStore);
+    return setWatchOnly.count(dest) > 0;
+}
+
+bool CWallet::HaveWatchOnly() const
+{
+    LOCK(cs_KeyStore);
+    return (!setWatchOnly.empty());
 }
 
 bool CWallet::Unlock(const SecureString& strWalletPassphrase, bool accept_no_keys)
@@ -582,7 +631,7 @@ bool CWallet::Unlock(const SecureString& strWalletPassphrase, bool accept_no_key
                 return false;
             if (!crypter.Decrypt(pMasterKey.second.vchCryptedKey, _vMasterKey))
                 continue; // try another master key
-            if (CCryptoKeyStore::Unlock(_vMasterKey, accept_no_keys)) {
+            if (Unlock(_vMasterKey, accept_no_keys)) {
                 // Now that we've unlocked, upgrade the key metadata
                 UpgradeKeyMetadata();
                 return true;
@@ -608,7 +657,7 @@ bool CWallet::ChangeWalletPassphrase(const SecureString& strOldWalletPassphrase,
                 return false;
             if (!crypter.Decrypt(pMasterKey.second.vchCryptedKey, _vMasterKey))
                 return false;
-            if (CCryptoKeyStore::Unlock(_vMasterKey))
+            if (Unlock(_vMasterKey))
             {
                 int64_t nStartTime = GetTimeMillis();
                 crypter.SetKeyFromPassphrase(strNewWalletPassphrase, pMasterKey.second.vchSalt, pMasterKey.second.nDeriveIterations, pMasterKey.second.nDerivationMethod);
@@ -4681,3 +4730,203 @@ bool CWallet::AddKeyOriginWithDB(WalletBatch& batch, const CPubKey& pubkey, cons
     mapKeyMetadata[pubkey.GetID()].hdKeypath = WriteHDKeypath(info.path);
     return batch.WriteKeyMetadata(mapKeyMetadata[pubkey.GetID()], pubkey, true);
 }
+
+bool CWallet::SetCrypted()
+{
+    LOCK(cs_KeyStore);
+    if (fUseCrypto)
+        return true;
+    if (!mapKeys.empty())
+        return false;
+    fUseCrypto = true;
+    return true;
+}
+
+bool CWallet::IsLocked() const
+{
+    if (!IsCrypted()) {
+        return false;
+    }
+    LOCK(cs_KeyStore);
+    return vMasterKey.empty();
+}
+
+bool CWallet::Lock()
+{
+    if (!SetCrypted())
+        return false;
+
+    {
+        LOCK(cs_KeyStore);
+        vMasterKey.clear();
+    }
+
+    NotifyStatusChanged(this);
+    return true;
+}
+
+bool CWallet::Unlock(const CKeyingMaterial& vMasterKeyIn, bool accept_no_keys)
+{
+    {
+        LOCK(cs_KeyStore);
+        if (!SetCrypted())
+            return false;
+
+        bool keyPass = mapCryptedKeys.empty(); // Always pass when there are no encrypted keys
+        bool keyFail = false;
+        CryptedKeyMap::const_iterator mi = mapCryptedKeys.begin();
+        for (; mi != mapCryptedKeys.end(); ++mi)
+        {
+            const CPubKey &vchPubKey = (*mi).second.first;
+            const std::vector<unsigned char> &vchCryptedSecret = (*mi).second.second;
+            CKey key;
+            if (!DecryptKey(vMasterKeyIn, vchCryptedSecret, vchPubKey, key))
+            {
+                keyFail = true;
+                break;
+            }
+            keyPass = true;
+            if (fDecryptionThoroughlyChecked)
+                break;
+        }
+        if (keyPass && keyFail)
+        {
+            LogPrintf("The wallet is probably corrupted: Some keys decrypt but not all.\n");
+            throw std::runtime_error("Error unlocking wallet: some keys decrypt but not all. Your wallet file may be corrupt.");
+        }
+        if (keyFail || (!keyPass && !accept_no_keys))
+            return false;
+        vMasterKey = vMasterKeyIn;
+        fDecryptionThoroughlyChecked = true;
+    }
+    NotifyStatusChanged(this);
+    return true;
+}
+
+bool CWallet::HaveKey(const CKeyID &address) const
+{
+    LOCK(cs_KeyStore);
+    if (!IsCrypted()) {
+        return FillableSigningProvider::HaveKey(address);
+    }
+    return mapCryptedKeys.count(address) > 0;
+}
+
+bool CWallet::GetKey(const CKeyID &address, CKey& keyOut) const
+{
+    LOCK(cs_KeyStore);
+    if (!IsCrypted()) {
+        return FillableSigningProvider::GetKey(address, keyOut);
+    }
+
+    CryptedKeyMap::const_iterator mi = mapCryptedKeys.find(address);
+    if (mi != mapCryptedKeys.end())
+    {
+        const CPubKey &vchPubKey = (*mi).second.first;
+        const std::vector<unsigned char> &vchCryptedSecret = (*mi).second.second;
+        return DecryptKey(vMasterKey, vchCryptedSecret, vchPubKey, keyOut);
+    }
+    return false;
+}
+
+bool CWallet::GetWatchPubKey(const CKeyID &address, CPubKey &pubkey_out) const
+{
+    LOCK(cs_KeyStore);
+    WatchKeyMap::const_iterator it = mapWatchKeys.find(address);
+    if (it != mapWatchKeys.end()) {
+        pubkey_out = it->second;
+        return true;
+    }
+    return false;
+}
+
+bool CWallet::GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const
+{
+    LOCK(cs_KeyStore);
+    if (!IsCrypted()) {
+        if (!FillableSigningProvider::GetPubKey(address, vchPubKeyOut)) {
+            return GetWatchPubKey(address, vchPubKeyOut);
+        }
+        return true;
+    }
+
+    CryptedKeyMap::const_iterator mi = mapCryptedKeys.find(address);
+    if (mi != mapCryptedKeys.end())
+    {
+        vchPubKeyOut = (*mi).second.first;
+        return true;
+    }
+    // Check for watch-only pubkeys
+    return GetWatchPubKey(address, vchPubKeyOut);
+}
+
+std::set<CKeyID> CWallet::GetKeys() const
+{
+    LOCK(cs_KeyStore);
+    if (!IsCrypted()) {
+        return FillableSigningProvider::GetKeys();
+    }
+    std::set<CKeyID> set_address;
+    for (const auto& mi : mapCryptedKeys) {
+        set_address.insert(mi.first);
+    }
+    return set_address;
+}
+
+bool CWallet::EncryptKeys(CKeyingMaterial& vMasterKeyIn)
+{
+    LOCK(cs_KeyStore);
+    if (!mapCryptedKeys.empty() || IsCrypted())
+        return false;
+
+    fUseCrypto = true;
+    for (const KeyMap::value_type& mKey : mapKeys)
+    {
+        const CKey &key = mKey.second;
+        CPubKey vchPubKey = key.GetPubKey();
+        CKeyingMaterial vchSecret(key.begin(), key.end());
+        std::vector<unsigned char> vchCryptedSecret;
+        if (!EncryptSecret(vMasterKeyIn, vchSecret, vchPubKey.GetHash(), vchCryptedSecret))
+            return false;
+        if (!AddCryptedKey(vchPubKey, vchCryptedSecret))
+            return false;
+    }
+    mapKeys.clear();
+    return true;
+}
+
+bool CWallet::AddKeyPubKeyInner(const CKey& key, const CPubKey &pubkey)
+{
+    LOCK(cs_KeyStore);
+    if (!IsCrypted()) {
+        return FillableSigningProvider::AddKeyPubKey(key, pubkey);
+    }
+
+    if (IsLocked()) {
+        return false;
+    }
+
+    std::vector<unsigned char> vchCryptedSecret;
+    CKeyingMaterial vchSecret(key.begin(), key.end());
+    if (!EncryptSecret(vMasterKey, vchSecret, pubkey.GetHash(), vchCryptedSecret)) {
+        return false;
+    }
+
+    if (!AddCryptedKey(pubkey, vchCryptedSecret)) {
+        return false;
+    }
+    return true;
+}
+
+
+bool CWallet::AddCryptedKeyInner(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret)
+{
+    LOCK(cs_KeyStore);
+    if (!SetCrypted()) {
+        return false;
+    }
+
+    mapCryptedKeys[vchPubKey.GetID()] = make_pair(vchPubKey, vchCryptedSecret);
+    ImplicitlyLearnRelatedKeyScripts(vchPubKey);
+    return true;
+}