segwit support for createmultisig RPC

Author: ajtowns

src/Makefile.am

@@ -226,6 +226,7 @@ libbitcoin_server_a_SOURCES = \
   net.cpp \
   net_processing.cpp \
   noui.cpp \
+  outputtype.cpp \
   policy/fees.cpp \
   policy/policy.cpp \
   policy/rbf.cpp \
@@ -266,7 +267,6 @@ libbitcoin_wallet_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
 libbitcoin_wallet_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libbitcoin_wallet_a_SOURCES = \
   interfaces/wallet.cpp \
-  outputtype.cpp \
   wallet/crypter.cpp \
   wallet/db.cpp \
   wallet/feebumper.cpp \

src/rpc/misc.cpp

@@ -12,6 +12,7 @@
 #include <httpserver.h>
 #include <net.h>
 #include <netbase.h>
+#include <outputtype.h>
 #include <rpc/blockchain.h>
 #include <rpc/server.h>
 #include <rpc/util.h>
@@ -91,9 +92,9 @@ class CWallet;
 
 static UniValue createmultisig(const JSONRPCRequest& request)
 {
-    if (request.fHelp || request.params.size() < 2 || request.params.size() > 2)
+    if (request.fHelp || request.params.size() < 2 || request.params.size() > 3)
     {
-        std::string msg = "createmultisig nrequired [\"key\",...]\n"
+        std::string msg = "createmultisig nrequired [\"key\",...] ( \"address_type\" )\n"
             "\nCreates a multi-signature address with n signature of m keys required.\n"
             "It returns a json object with the address and redeemScript.\n"
             "\nArguments:\n"
@@ -103,6 +104,7 @@ static UniValue createmultisig(const JSONRPCRequest& request)
             "       \"key\"                    (string) The hex-encoded public key\n"
             "       ,...\n"
             "     ]\n"
+            "3. \"address_type\"               (string, optional) The address type to use. Options are \"legacy\", \"p2sh-segwit\", and \"bech32\". Default is legacy.\n"
 
             "\nResult:\n"
             "{\n"
@@ -133,12 +135,21 @@ static UniValue createmultisig(const JSONRPCRequest& request)
         }
     }
 
+    // Get the output type
+    OutputType output_type = OutputType::LEGACY;
+    if (!request.params[2].isNull()) {
+        if (!ParseOutputType(request.params[2].get_str(), output_type)) {
+            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Unknown address type '%s'", request.params[2].get_str()));
+        }
+    }
+
     // Construct using pay-to-script-hash:
-    CScript inner = CreateMultisigRedeemscript(required, pubkeys);
-    CScriptID innerID(inner);
+    const CScript inner = CreateMultisigRedeemscript(required, pubkeys);
+    CBasicKeyStore keystore;
+    const CTxDestination dest = AddAndGetDestinationForScript(keystore, inner, output_type);
 
     UniValue result(UniValue::VOBJ);
-    result.pushKV("address", EncodeDestination(innerID));
+    result.pushKV("address", EncodeDestination(dest));
     result.pushKV("redeemScript", HexStr(inner.begin(), inner.end()));
 
     return result;