BIP143: Signing logic

wesgurn · Feb 20, 2018 · 157a5d0 · 157a5d0
1 parent c86a1cb
commit 157a5d0
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Showing 13 changed files with 379 additions and 163 deletions.
diff --git a/src/bitcoin-tx.cpp b/src/bitcoin-tx.cpp
@@ -322,6 +322,18 @@ vector<unsigned char> ParseHexUO(map<string,UniValue>& o, string strKey)
     return ParseHexUV(o[strKey], strKey);
 }
 
+static CAmount AmountFromValue(const UniValue& value)
+{
+    if (!value.isNum() && !value.isStr())
+        throw runtime_error("Amount is not a number or string");
+    CAmount amount;
+    if (!ParseFixedPoint(value.getValStr(), 8, &amount))
+        throw runtime_error("Invalid amount");
+    if (!MoneyRange(amount))
+        throw runtime_error("Amount out of range");
+    return amount;
+}
+
 static void MutateTxSign(CMutableTransaction& tx, const string& flagStr)
 {
     int nHashType = SIGHASH_ALL;
@@ -393,7 +405,10 @@ static void MutateTxSign(CMutableTransaction& tx, const string& flagStr)
                 if ((unsigned int)nOut >= coins->vout.size())
                     coins->vout.resize(nOut+1);
                 coins->vout[nOut].scriptPubKey = scriptPubKey;
-                coins->vout[nOut].nValue = 0; // we don't know the actual output value
+                coins->vout[nOut].nValue = 0;
+                if (prevOut.exists("amount")) {
+                    coins->vout[nOut].nValue = AmountFromValue(prevOut["amount"]);
+                }
             }
 
             // if redeemScript given and private keys given,
@@ -423,15 +438,16 @@ static void MutateTxSign(CMutableTransaction& tx, const string& flagStr)
         const CScript& prevPubKey = coins->vout[txin.prevout.n].scriptPubKey;
         const CAmount& amount = coins->vout[txin.prevout.n].nValue;
 
-        txin.scriptSig.clear();
+        SignatureData sigdata;
         // Only sign SIGHASH_SINGLE if there's a corresponding output:
         if (!fHashSingle || (i < mergedTx.vout.size()))
-            SignSignature(keystore, prevPubKey, mergedTx, i, nHashType);
+            ProduceSignature(MutableTransactionSignatureCreator(&keystore, &mergedTx, i, amount, nHashType), prevPubKey, sigdata);
 
         // ... and merge in other signatures:
-        BOOST_FOREACH(const CTransaction& txv, txVariants) {
-            txin.scriptSig = CombineSignatures(prevPubKey, mergedTx, i, amount, txin.scriptSig, txv.vin[i].scriptSig);
-        }
+        BOOST_FOREACH(const CTransaction& txv, txVariants)
+            sigdata = CombineSignatures(prevPubKey, MutableTransactionSignatureChecker(&mergedTx, i, amount), sigdata, DataFromTransaction(txv, i));
+        UpdateTransaction(mergedTx, i, sigdata);
+
         if (!VerifyScript(txin.scriptSig, prevPubKey, STANDARD_SCRIPT_VERIFY_FLAGS, MutableTransactionSignatureChecker(&mergedTx, i, amount)))
             fComplete = false;
     }

diff --git a/src/rpcrawtransaction.cpp b/src/rpcrawtransaction.cpp
@@ -654,7 +654,8 @@ UniValue signrawtransaction(const UniValue& params, bool fHelp)
             "         \"txid\":\"id\",             (string, required) The transaction id\n"
             "         \"vout\":n,                  (numeric, required) The output number\n"
             "         \"scriptPubKey\": \"hex\",   (string, required) script key\n"
-            "         \"redeemScript\": \"hex\"    (string, required for P2SH) redeem script\n"
+            "         \"redeemScript\": \"hex\",   (string, required for P2SH) redeem script\n"
+            "         \"amount\": value            (numeric, required) The amount spent\n"
             "       }\n"
             "       ,...\n"
             "    ]\n"
@@ -792,7 +793,10 @@ UniValue signrawtransaction(const UniValue& params, bool fHelp)
                 if ((unsigned int)nOut >= coins->vout.size())
                     coins->vout.resize(nOut+1);
                 coins->vout[nOut].scriptPubKey = scriptPubKey;
-                coins->vout[nOut].nValue = 0; // we don't know the actual output value
+                coins->vout[nOut].nValue = 0;
+                if (prevOut.exists("amount")) {
+                    coins->vout[nOut].nValue = AmountFromValue(find_value(prevOut, "amount"));
+                }
             }
 
             // if redeemScript given and not using the local wallet (private keys
@@ -852,15 +856,18 @@ UniValue signrawtransaction(const UniValue& params, bool fHelp)
         const CScript& prevPubKey = coins->vout[txin.prevout.n].scriptPubKey;
         const CAmount& amount = coins->vout[txin.prevout.n].nValue;
 
-        txin.scriptSig.clear();
+        SignatureData sigdata;
         // Only sign SIGHASH_SINGLE if there's a corresponding output:
         if (!fHashSingle || (i < mergedTx.vout.size()))
-            SignSignature(keystore, prevPubKey, mergedTx, i, nHashType);
+            ProduceSignature(MutableTransactionSignatureCreator(&keystore, &mergedTx, i, amount, nHashType), prevPubKey, sigdata);
 
         // ... and merge in other signatures:
         BOOST_FOREACH(const CMutableTransaction& txv, txVariants) {
-            txin.scriptSig = CombineSignatures(prevPubKey, txConst, i, amount, txin.scriptSig, txv.vin[i].scriptSig);
+            sigdata = CombineSignatures(prevPubKey, TransactionSignatureChecker(&txConst, i, amount), sigdata, DataFromTransaction(txv, i));
         }
+
+        UpdateTransaction(mergedTx, i, sigdata);
+
         ScriptError serror = SCRIPT_ERR_OK;
         if (!VerifyScript(txin.scriptSig, prevPubKey, STANDARD_SCRIPT_VERIFY_FLAGS, TransactionSignatureChecker(&txConst, i, amount), &serror)) {
             TxInErrorToJSON(txin, vErrors, ScriptErrorString(serror));