New createmultisig rpc command

This is to support the signrawtransaction API call; given the public
keys involved in a multisig transaction, this gives back the redeemScript
needed to sign it.

1 files changed, 48 insertions, 15 deletions

diff --git a/src/rpcwallet.cpp b/src/rpcwallet.cpp
index 6f8728e979..cd91f650a8 100644
--- a/src/rpcwallet.cpp
+++ b/src/rpcwallet.cpp
@@ -702,22 +702,13 @@ Value sendmany(const Array& params, bool fHelp)
     return wtx.GetHash().GetHex();
 }
 
-Value addmultisigaddress(const Array& params, bool fHelp)
+//
+// Used by addmultisigaddress / createmultisig:
+//
+static CScript _createmultisig(const Array& params)
 {
-    if (fHelp || params.size() < 2 || params.size() > 3)
-    {
-        string msg = "addmultisigaddress <nrequired> <'[\"key\",\"key\"]'> [account]\n"
-            "Add a nrequired-to-sign multisignature address to the wallet\"\n"
-            "each key is a Bitcoin address or hex-encoded public key\n"
-            "If [account] is specified, assign address to [account].";
-        throw runtime_error(msg);
-    }
-
     int nRequired = params[0].get_int();
     const Array& keys = params[1].get_array();
-    string strAccount;
-    if (params.size() > 2)
-        strAccount = AccountFromValue(params[2]);
 
     // Gather public keys
     if (nRequired < 1)
@@ -760,10 +751,28 @@ Value addmultisigaddress(const Array& params, bool fHelp)
             throw runtime_error(" Invalid public key: "+ks);
         }
     }
+    CScript result;
+    result.SetMultisig(nRequired, pubkeys);
+    return result;
+}
+
+Value addmultisigaddress(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() < 2 || params.size() > 3)
+    {
+        string msg = "addmultisigaddress <nrequired> <'[\"key\",\"key\"]'> [account]\n"
+            "Add a nrequired-to-sign multisignature address to the wallet\"\n"
+            "each key is a Bitcoin address or hex-encoded public key\n"
+            "If [account] is specified, assign address to [account].";
+        throw runtime_error(msg);
+    }
+
+    string strAccount;
+    if (params.size() > 2)
+        strAccount = AccountFromValue(params[2]);
 
     // Construct using pay-to-script-hash:
-    CScript inner;
-    inner.SetMultisig(nRequired, pubkeys);
+    CScript inner = _createmultisig(params);
     CScriptID innerID = inner.GetID();
     pwalletMain->AddCScript(inner);
 
@@ -771,6 +780,30 @@ Value addmultisigaddress(const Array& params, bool fHelp)
     return CBitcoinAddress(innerID).ToString();
 }
 
+Value createmultisig(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() < 2 || params.size() > 2)
+    {
+        string msg = "createmultisig <nrequired> <'[\"key\",\"key\"]'>\n"
+            "Creates a multi-signature address and returns a json object\n"
+            "with keys:\n"
+            "address : bitcoin address\n"
+            "redeemScript : hex-encoded redemption script";
+        throw runtime_error(msg);
+    }
+
+    // Construct using pay-to-script-hash:
+    CScript inner = _createmultisig(params);
+    CScriptID innerID = inner.GetID();
+    CBitcoinAddress address(innerID);
+
+    Object result;
+    result.push_back(Pair("address", address.ToString()));
+    result.push_back(Pair("redeemScript", HexStr(inner.begin(), inner.end())));
+
+    return result;
+}
+
 
 struct tallyitem
 {