Merge #9662: Add createwallet "disableprivatekeys" option: a sane mode for watchonly-wallets

a3fa4d6a6acf19d640a1d5879a00aa1f059e2380 QA: Fix bug in -usecli logic that converts booleans to non-lowercase strings (Jonas Schnelli)
4704e5f074e57782d058404a594a7313cf170cf0 [QA] add createwallet disableprivatekey test (Jonas Schnelli)
c7b8f343e99d9d53ea353ddce9a977f1886caf30 [Qt] Disable creating receive addresses when private keys are disabled (Jonas Schnelli)
2f15c2bc20d583b4c1788da78c9c635c36e03ed0 Add disable privatekeys option to createwallet (Jonas Schnelli)
cebefba0855cee7fbcb9474b34e6779369e8e9ce Add option to disable private keys during internal wallet creation (Jonas Schnelli)
9995a602a639b64a749545b7c3bafbf67f97324f Add facility to store wallet flags (64 bits) (Jonas Schnelli)

Pull request description:

  This mode ('createwallet {"disableprivatekeys": true}') is intended for a sane pure watch-only mode, ideal for a use-case where one likes to use Bitcoin-Core in conjunction with a hardware-wallet or another solutions for cold-storage.

  Since we have support for custom change addresses in `fundrawtransaction`, pure watch-only wallets including coin-selection are possible and do make sense for some use cases.

  This new mode disables all forms of private key generation and ensure that no mix between hot and cold keys are possible.

Tree-SHA512: 3ebe7e8d54c4d4e5f790c348d4c292d456f573960a5b04d69ca5ef43a9217c7e7671761c6968cdc56f9a8bc235f3badd358576651af9f10855a0eb731f3fc508

1 files changed, 18 insertions, 4 deletions

diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index 9c25ee7d76..67fcaa725b 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -510,7 +510,14 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
                 strErr = "Error reading wallet database: SetHDChain failed";
                 return false;
             }
-        } else if (strType != "bestblock" && strType != "bestblock_nomerkle"){
+        } else if (strType == "flags") {
+            uint64_t flags;
+            ssValue >> flags;
+            if (!pwallet->SetWalletFlags(flags, true)) {
+                strErr = "Error reading wallet database: Unknown non-tolerable wallet flags found";
+                return false;
+            }
+        } else if (strType != "bestblock" && strType != "bestblock_nomerkle") {
             wss.m_unknown_records++;
         }
     } catch (...)
@@ -570,10 +577,12 @@ DBErrors WalletBatch::LoadWallet(CWallet* pwallet)
             {
                 // losing keys is considered a catastrophic error, anything else
                 // we assume the user can live with:
-                if (IsKeyType(strType) || strType == "defaultkey")
+                if (IsKeyType(strType) || strType == "defaultkey") {
                     result = DBErrors::CORRUPT;
-                else
-                {
+                } else if(strType == "flags") {
+                    // reading the wallet flags can only fail if unknown flags are present
+                    result = DBErrors::TOO_NEW;
+                } else {
                     // Leave other errors alone, if we try to fix them we might make things worse.
                     fNoncriticalErrors = true; // ... but do warn the user there is something wrong.
                     if (strType == "tx")
@@ -840,6 +849,11 @@ bool WalletBatch::WriteHDChain(const CHDChain& chain)
     return WriteIC(std::string("hdchain"), chain);
 }
 
+bool WalletBatch::WriteWalletFlags(const uint64_t flags)
+{
+    return WriteIC(std::string("flags"), flags);
+}
+
 bool WalletBatch::TxnBegin()
 {
     return m_batch.TxnBegin();