Merge #12493: [wallet] Reopen CDBEnv after encryption instead of shutting down

c1dde3a949b36ce9c2155777b3fa1372e7ed97d8 No longer shutdown after encrypting the wallet (Andrew Chow)
d7637c5a3f1d62922594cdfb6272e30dacf60ce9 After encrypting the wallet, reload the database environment (Andrew Chow)
5d296ac810755dc47f105eb95b52b7e2bcb8aea8 Add function to close all Db's and reload the databae environment (Andrew Chow)
a769461d5e37ddcb771ae836254fdc69177a28c4 Move BerkeleyEnvironment deletion from internal method to callsite (Andrew Chow)

Pull request description:

  This is the replacement for #11678 which implements @ryanofsky's [suggestion](https://github.com/bitcoin/bitcoin/pull/11678#pullrequestreview-76464511).

  Shutting down the software was to prevent the BDB environment from writing unencrypted private keys to disk in the database log files, as was noted [here](https://bitcointalk.org/index.php?topic=51474.msg616068#msg616068). This PR replaces the shutdown behavior with a CDBEnv flush, close, and reopen which achieves the same effect: everything is cleanly flushed and closed, the log files are removed, and then the environment reopened to continue normal operation.

  To ensure that no unencrypted private keys are in the log files after encrypting the wallet, I wrote [this script](https://gist.github.com/achow101/7f7143e6c3d3fdc034d3470e72823e9d) to pull private keys from the original wallet file and searches for these keys in the log files (note that you will have to change your file paths to make it work on your own machine).

  As for concerns about private keys being written to slack space or being kept in memory, these behaviors no longer exist after the original wallet encryption PR and the shutting down solution from 2011.

  cc @ryanofsky

Tree-SHA512: 34b894283b0677a873d06dee46dff8424dec85a2973009ac9b84bcf3d22d05f227c494168c395219d9aee3178e420cf70d4b3eeacc9785aa86b6015d25758e75

6 files changed, 6 insertions, 21 deletions

diff --git a/test/functional/rpc_fundrawtransaction.py b/test/functional/rpc_fundrawtransaction.py
index daa890ab15..0c61e9ab62 100755
--- a/test/functional/rpc_fundrawtransaction.py
+++ b/test/functional/rpc_fundrawtransaction.py
@@ -478,10 +478,8 @@ class RawTransactionsTest(BitcoinTestFramework):
 
         ############################################################
         # locked wallet test
-        self.stop_node(0)
-        self.nodes[1].node_encrypt_wallet("test")
-        self.stop_node(2)
-        self.stop_node(3)
+        self.nodes[1].encryptwallet("test")
+        self.stop_nodes()
 
         self.start_nodes()
         # This test is not meant to test fee estimation and we'd like
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
index 3d114c4077..c267f7f24f 100755
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -305,14 +305,6 @@ class TestNode():
                     assert_msg = "bitcoind should have exited with expected error " + expected_msg
                 self._raise_assertion_error(assert_msg)
 
-    def node_encrypt_wallet(self, passphrase):
-        """"Encrypts the wallet.
-
-        This causes bitcoind to shutdown, so this method takes
-        care of cleaning up resources."""
-        self.encryptwallet(passphrase)
-        self.wait_until_stopped()
-
     def add_p2p_connection(self, p2p_conn, *, wait_for_verack=True, **kwargs):
         """Add a p2p connection to the node.
 
diff --git a/test/functional/wallet_bumpfee.py b/test/functional/wallet_bumpfee.py
index 2ea72896bb..67ee00871d 100755
--- a/test/functional/wallet_bumpfee.py
+++ b/test/functional/wallet_bumpfee.py
@@ -42,8 +42,7 @@ class BumpFeeTest(BitcoinTestFramework):
 
     def run_test(self):
         # Encrypt wallet for test_locked_wallet_fails test
-        self.nodes[1].node_encrypt_wallet(WALLET_PASSPHRASE)
-        self.start_node(1)
+        self.nodes[1].encryptwallet(WALLET_PASSPHRASE)
         self.nodes[1].walletpassphrase(WALLET_PASSPHRASE, WALLET_PASSPHRASE_TIMEOUT)
 
         connect_nodes_bi(self.nodes, 0, 1)
diff --git a/test/functional/wallet_dump.py b/test/functional/wallet_dump.py
index 125e114b2c..b1db1e4ab9 100755
--- a/test/functional/wallet_dump.py
+++ b/test/functional/wallet_dump.py
@@ -132,8 +132,7 @@ class WalletDumpTest(BitcoinTestFramework):
         assert_equal(witness_addr_ret, witness_addr)  # p2sh-p2wsh address added to the first key
 
         #encrypt wallet, restart, unlock and dump
-        self.nodes[0].node_encrypt_wallet('test')
-        self.start_node(0)
+        self.nodes[0].encryptwallet('test')
         self.nodes[0].walletpassphrase('test', 10)
         # Should be a no-op:
         self.nodes[0].keypoolrefill()
diff --git a/test/functional/wallet_encryption.py b/test/functional/wallet_encryption.py
index d8c27b09d9..ab9ebed8d4 100755
--- a/test/functional/wallet_encryption.py
+++ b/test/functional/wallet_encryption.py
@@ -33,8 +33,7 @@ class WalletEncryptionTest(BitcoinTestFramework):
         assert_equal(len(privkey), 52)
 
         # Encrypt the wallet
-        self.nodes[0].node_encrypt_wallet(passphrase)
-        self.start_node(0)
+        self.nodes[0].encryptwallet(passphrase)
 
         # Test that the wallet is encrypted
         assert_raises_rpc_error(-13, "Please enter the wallet passphrase with walletpassphrase first", self.nodes[0].dumpprivkey, address)
diff --git a/test/functional/wallet_keypool.py b/test/functional/wallet_keypool.py
index acc336e4d5..51afa0cb1a 100755
--- a/test/functional/wallet_keypool.py
+++ b/test/functional/wallet_keypool.py
@@ -25,9 +25,7 @@ class KeyPoolTest(BitcoinTestFramework):
         assert(addr_before_encrypting_data['hdseedid'] == wallet_info_old['hdseedid'])
 
         # Encrypt wallet and wait to terminate
-        nodes[0].node_encrypt_wallet('test')
-        # Restart node 0
-        self.start_node(0)
+        nodes[0].encryptwallet('test')
         # Keep creating keys
         addr = nodes[0].getnewaddress()
         addr_data = nodes[0].getaddressinfo(addr)