Merge #11403: SegWit wallet support

b224a47a1 Add address_types test (Pieter Wuille)
7ee54fd7c Support downgrading after recovered keypool witness keys (Pieter Wuille)
940a21932 SegWit wallet support (Pieter Wuille)
f37c64e47 Implicitly know about P2WPKH redeemscripts (Pieter Wuille)
57273f2b3 [test] Serialize CTransaction with witness by default (Pieter Wuille)
cf2c0b6f5 Support P2WPKH and P2SH-P2WPKH in dumpprivkey (Pieter Wuille)
37c03d3e0 Support P2WPKH addresses in create/addmultisig (Pieter Wuille)
3eaa003c8 Extend validateaddress information for P2SH-embedded witness (Pieter Wuille)
30a27dc5b Expose method to find key for a single-key destination (Pieter Wuille)
985c79552 Improve witness destination types and use them more (Pieter Wuille)
cbe197470 [refactor] GetAccount{PubKey,Address} -> GetAccountDestination (Pieter Wuille)
0c8ea6380 Abstract out IsSolvable from Witnessifier (Pieter Wuille)

Pull request description:

  This implements a minimum viable implementation of SegWit wallet support, based on top of #11389, and includes part of the functionality from #11089.

  Two new configuration options are added:
  * `-addresstype`, with options `legacy`, `p2sh`, and `bech32`. It controls what kind of addresses are produced by `getnewaddress`, `getaccountaddress`, and `createmultisigaddress`.
  * `-changetype`, with the same options, and by default equal to `-addresstype`, that controls what kind of change is used.

  All wallet private and public keys can be used for any type of address. Support for address types dependent on different derivation paths will need a major overhaul of how our internal detection of outputs work. I expect that that will happen for a next major version.

  The above also applies to imported keys, as having a distinction there but not for normal operations is a disaster for testing, and probably for comprehension of users. This has some ugly effects, like needing to associate the provided label to `importprivkey` with each style address for the corresponding key.

  To deal with witness outputs requiring a corresponding redeemscript in wallet, three approaches are used:
  * All SegWit addresses created through `getnewaddress` or multisig RPCs explicitly get their redeemscripts added to the wallet file. This means that downgrading after creating a witness address will work, as long as the wallet file is up to date.
  * All SegWit keys in the wallet get an _implicit_ redeemscript added, without it being written to the file. This means recovery of an old backup will work, as long as you use new software.
  * All keypool keys that are seen used in transactions explicitly get their redeemscripts added to the wallet files. This means that downgrading after recovering from a backup that includes a witness address will work.

  These approaches correspond to solutions 3a, 1a, and 5a respectively from https://gist.github.com/sipa/125cfa1615946d0c3f3eec2ad7f250a2. As argued there, there is no full solution for dealing with the case where you both downgrade and restore a backup, so that's also not implemented.

  `dumpwallet`, `importwallet`, `importmulti`, `signmessage` and `verifymessage` don't work with SegWit addresses yet. They're remaining TODOs, for this PR or a follow-up. Because of that, several tests unexpectedly run with `-addresstype=legacy` for now.

Tree-SHA512: d425dbe517c0422061ab8dacdc3a6ae47da071450932ed992c79559d922dff7b2574a31a8c94feccd3761c1dffb6422c50055e6dca8e3cf94a169bc95e39e959

1 files changed, 46 insertions, 34 deletions

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index df9bdd39bb..e307623fd5 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -136,14 +136,15 @@ UniValue getnewaddress(const JSONRPCRequest& request)
         return NullUniValue;
     }
 
-    if (request.fHelp || request.params.size() > 1)
+    if (request.fHelp || request.params.size() > 2)
         throw std::runtime_error(
-            "getnewaddress ( \"account\" )\n"
+            "getnewaddress ( \"account\" \"address_type\" )\n"
             "\nReturns a new Bitcoin address for receiving payments.\n"
             "If 'account' is specified (DEPRECATED), it is added to the address book \n"
             "so payments received with the address will be credited to 'account'.\n"
             "\nArguments:\n"
             "1. \"account\"        (string, optional) DEPRECATED. The account name for the address to be linked to. If not provided, the default account \"\" is used. It can also be set to the empty string \"\" to represent the default account. The account does not need to exist, it will be created if there is no account by the given name.\n"
+            "2. \"address_type\"   (string, optional) The address type to use. Options are \"legacy\", \"p2sh\", and \"bech32\". Default is set by -addresstype.\n"
             "\nResult:\n"
             "\"address\"    (string) The new bitcoin address\n"
             "\nExamples:\n"
@@ -158,6 +159,14 @@ UniValue getnewaddress(const JSONRPCRequest& request)
     if (!request.params[0].isNull())
         strAccount = AccountFromValue(request.params[0]);
 
+    OutputType output_type = g_address_type;
+    if (!request.params[1].isNull()) {
+        output_type = ParseOutputType(request.params[1].get_str(), g_address_type);
+        if (output_type == OUTPUT_TYPE_NONE) {
+            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Unknown address type '%s'", request.params[1].get_str()));
+        }
+    }
+
     if (!pwallet->IsLocked()) {
         pwallet->TopUpKeyPool();
     }
@@ -167,22 +176,23 @@ UniValue getnewaddress(const JSONRPCRequest& request)
     if (!pwallet->GetKeyFromPool(newKey)) {
         throw JSONRPCError(RPC_WALLET_KEYPOOL_RAN_OUT, "Error: Keypool ran out, please call keypoolrefill first");
     }
-    CKeyID keyID = newKey.GetID();
+    pwallet->LearnRelatedScripts(newKey, output_type);
+    CTxDestination dest = GetDestinationForKey(newKey, output_type);
 
-    pwallet->SetAddressBook(keyID, strAccount, "receive");
+    pwallet->SetAddressBook(dest, strAccount, "receive");
 
-    return EncodeDestination(keyID);
+    return EncodeDestination(dest);
 }
 
 
-CTxDestination GetAccountAddress(CWallet* const pwallet, std::string strAccount, bool bForceNew=false)
+CTxDestination GetAccountDestination(CWallet* const pwallet, std::string strAccount, bool bForceNew=false)
 {
-    CPubKey pubKey;
-    if (!pwallet->GetAccountPubkey(pubKey, strAccount, bForceNew)) {
+    CTxDestination dest;
+    if (!pwallet->GetAccountDestination(dest, strAccount, bForceNew)) {
         throw JSONRPCError(RPC_WALLET_KEYPOOL_RAN_OUT, "Error: Keypool ran out, please call keypoolrefill first");
     }
 
-    return pubKey.GetID();
+    return dest;
 }
 
 UniValue getaccountaddress(const JSONRPCRequest& request)
@@ -214,7 +224,7 @@ UniValue getaccountaddress(const JSONRPCRequest& request)
 
     UniValue ret(UniValue::VSTR);
 
-    ret = EncodeDestination(GetAccountAddress(pwallet, strAccount));
+    ret = EncodeDestination(GetAccountDestination(pwallet, strAccount));
     return ret;
 }
 
@@ -226,11 +236,13 @@ UniValue getrawchangeaddress(const JSONRPCRequest& request)
         return NullUniValue;
     }
 
-    if (request.fHelp || request.params.size() > 0)
+    if (request.fHelp || request.params.size() > 1)
         throw std::runtime_error(
-            "getrawchangeaddress\n"
+            "getrawchangeaddress ( \"address_type\" )\n"
             "\nReturns a new Bitcoin address, for receiving change.\n"
             "This is for use with raw transactions, NOT normal use.\n"
+            "\nArguments:\n"
+            "1. \"address_type\"           (string, optional) The address type to use. Options are \"legacy\", \"p2sh\", and \"bech32\". Default is set by -changetype.\n"
             "\nResult:\n"
             "\"address\"    (string) The address\n"
             "\nExamples:\n"
@@ -244,6 +256,14 @@ UniValue getrawchangeaddress(const JSONRPCRequest& request)
         pwallet->TopUpKeyPool();
     }
 
+    OutputType output_type = g_change_type;
+    if (!request.params[0].isNull()) {
+        output_type = ParseOutputType(request.params[0].get_str(), g_change_type);
+        if (output_type == OUTPUT_TYPE_NONE) {
+            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Unknown address type '%s'", request.params[0].get_str()));
+        }
+    }
+
     CReserveKey reservekey(pwallet);
     CPubKey vchPubKey;
     if (!reservekey.GetReservedKey(vchPubKey, true))
@@ -251,9 +271,10 @@ UniValue getrawchangeaddress(const JSONRPCRequest& request)
 
     reservekey.KeepKey();
 
-    CKeyID keyID = vchPubKey.GetID();
+    pwallet->LearnRelatedScripts(vchPubKey, output_type);
+    CTxDestination dest = GetDestinationForKey(vchPubKey, output_type);
 
-    return EncodeDestination(keyID);
+    return EncodeDestination(dest);
 }
 
 
@@ -292,8 +313,8 @@ UniValue setaccount(const JSONRPCRequest& request)
         // Detect when changing the account of an address that is the 'unused current key' of another account:
         if (pwallet->mapAddressBook.count(dest)) {
             std::string strOldAccount = pwallet->mapAddressBook[dest].name;
-            if (dest == GetAccountAddress(pwallet, strOldAccount)) {
-                GetAccountAddress(pwallet, strOldAccount, true);
+            if (dest == GetAccountDestination(pwallet, strOldAccount)) {
+                GetAccountDestination(pwallet, strOldAccount, true);
             }
         }
         pwallet->SetAddressBook(dest, strAccount, "receive");
@@ -1188,11 +1209,12 @@ UniValue addmultisigaddress(const JSONRPCRequest& request)
 
     // Construct using pay-to-script-hash:
     CScript inner = _createmultisig_redeemScript(pwallet, request.params);
-    CScriptID innerID(inner);
     pwallet->AddCScript(inner);
 
-    pwallet->SetAddressBook(innerID, strAccount, "send");
-    return EncodeDestination(innerID);
+    CTxDestination dest = pwallet->AddAndGetDestinationForScript(inner, g_address_type);
+
+    pwallet->SetAddressBook(dest, strAccount, "send");
+    return EncodeDestination(dest);
 }
 
 class Witnessifier : public boost::static_visitor<bool>
@@ -1208,12 +1230,7 @@ public:
         if (pwallet) {
             CScript basescript = GetScriptForDestination(keyID);
             CScript witscript = GetScriptForWitness(basescript);
-            SignatureData sigs;
-            // This check is to make sure that the script we created can actually be solved for and signed by us
-            // if we were to have the private keys. This is just to make sure that the script is valid and that,
-            // if found in a transaction, we would still accept and relay that transaction.
-            if (!ProduceSignature(DummySignatureCreator(pwallet), witscript, sigs) ||
-                !VerifyScript(sigs.scriptSig, witscript, &sigs.scriptWitness, MANDATORY_SCRIPT_VERIFY_FLAGS | SCRIPT_VERIFY_WITNESS_PUBKEYTYPE, DummySignatureCreator(pwallet).Checker())) {
+            if (!IsSolvable(*pwallet, witscript)) {
                 return false;
             }
             return ExtractDestination(witscript, result);
@@ -1232,12 +1249,7 @@ public:
                 return true;
             }
             CScript witscript = GetScriptForWitness(subscript);
-            SignatureData sigs;
-            // This check is to make sure that the script we created can actually be solved for and signed by us
-            // if we were to have the private keys. This is just to make sure that the script is valid and that,
-            // if found in a transaction, we would still accept and relay that transaction.
-            if (!ProduceSignature(DummySignatureCreator(pwallet), witscript, sigs) ||
-                !VerifyScript(sigs.scriptSig, witscript, &sigs.scriptWitness, MANDATORY_SCRIPT_VERIFY_FLAGS | SCRIPT_VERIFY_WITNESS_PUBKEYTYPE, DummySignatureCreator(pwallet).Checker())) {
+            if (!IsSolvable(*pwallet, witscript)) {
                 return false;
             }
             return ExtractDestination(witscript, result);
@@ -1321,7 +1333,7 @@ UniValue addwitnessaddress(const JSONRPCRequest& request)
             throw JSONRPCError(RPC_WALLET_ERROR, "Cannot convert between witness address types");
         }
     } else {
-        pwallet->AddCScript(witprogram);
+        pwallet->AddCScript(witprogram); // Implicit for single-key now, but necessary for multisig and for compatibility with older software
         pwallet->SetAddressBook(w.result, "", "receive");
     }
 
@@ -3466,8 +3478,8 @@ static const CRPCCommand commands[] =
     { "wallet",             "getaccount",               &getaccount,               {"address"} },
     { "wallet",             "getaddressesbyaccount",    &getaddressesbyaccount,    {"account"} },
     { "wallet",             "getbalance",               &getbalance,               {"account","minconf","include_watchonly"} },
-    { "wallet",             "getnewaddress",            &getnewaddress,            {"account"} },
-    { "wallet",             "getrawchangeaddress",      &getrawchangeaddress,      {} },
+    { "wallet",             "getnewaddress",            &getnewaddress,            {"account","address_type"} },
+    { "wallet",             "getrawchangeaddress",      &getrawchangeaddress,      {"address_type"} },
     { "wallet",             "getreceivedbyaccount",     &getreceivedbyaccount,     {"account","minconf"} },
     { "wallet",             "getreceivedbyaddress",     &getreceivedbyaddress,     {"address","minconf"} },
     { "wallet",             "gettransaction",           &gettransaction,           {"txid","include_watchonly"} },