remove CNumScript from pegin witness logic

Author: instagibbs

qa/rpc-tests/pegging.py

@@ -153,7 +153,7 @@ def sync_all(sidechain, sidechain2):
         pegtxid = sidechain.claimpegin(raw, proof, sidechain.getnewaddress())
         raise Exception("Peg-in with non-matching claim_script should fail.")
     except JSONRPCException as e:
-        assert("Given claim_script is not a valid v0 witness program" in e.error["message"])
+        assert("Given claim_script does not match the given Bitcoin transaction." in e.error["message"])
         pass
 
     # 12 confirms allows in mempool

src/script/script.h

@@ -325,12 +325,6 @@ class CScriptNum
         return m_value;
     }
 
-    // Only used for peg-in witness values
-    int64_t getint64() const
-    {
-        return m_value;
-    }
-
     std::vector<unsigned char> getvch() const
     {
         return serialize(m_value);

src/validation.cpp

@@ -2375,8 +2375,17 @@ bool IsValidPeginWitness(const CScriptWitness& pegin_witness, const COutPoint& p
         return false;
     }
 
-    // Get output value. Special 8 byte length to capture possible bitcoin values
-    CAmount value = CScriptNum(stack[0], true, 8).getint64();
+    CDataStream stream(stack[0], SER_NETWORK, PROTOCOL_VERSION);
+    CAmount value;
+    try {
+        stream >> value;
+    } catch (...) {
+        return false;
+    }
+
+    if (!MoneyRange(value)) {
+        return false;
+    }
 
     // Get asset type
     if (stack[1].size() != 32) {
@@ -2473,7 +2482,11 @@ bool IsValidPeginWitness(const CScriptWitness& pegin_witness, const COutPoint& p
 
 // Constructs unblinded output to be used in amount and scriptpubkey checks during pegin
 CTxOut GetPeginOutputFromWitness(const CScriptWitness& pegin_witness) {
-    return CTxOut(CAsset(pegin_witness.stack[1]), CScriptNum(pegin_witness.stack[0], true, 8).getint64(), CScript(pegin_witness.stack[3].begin(), pegin_witness.stack[3].end()));
+	CDataStream stream(pegin_witness.stack[0], SER_NETWORK, PROTOCOL_VERSION);
+    CAmount value;
+    stream >> value;
+
+	return CTxOut(CAsset(pegin_witness.stack[1]), value, CScript(pegin_witness.stack[3].begin(), pegin_witness.stack[3].end()));
 }
 
 // Protected by cs_main

src/wallet/rpcwallet.cpp

@@ -3579,6 +3579,9 @@ UniValue createrawpegin(const JSONRPCRequest& request)
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Given claim_script is not a valid v0 witness program.");
         }
         nOut = GetPeginTxnOutputIndex(txBTC, witnessProgScript);
+        if (nOut == txBTC.vout.size()) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Given claim_script does not match the given Bitcoin transaction.");
+        }
     }
     else {
         // Look through address book for pegin contract value by extracting the unlderlying witness program from p2sh-p2wpkh
@@ -3611,6 +3614,17 @@ UniValue createrawpegin(const JSONRPCRequest& request)
 
     CAmount value = txBTC.vout[nOut].nValue;
 
+    CDataStream stream(0, 0);
+    try {
+        stream << value;
+    } catch (...) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Amount serialization is invalid.");
+    }
+    // Need to reinterpret bytes as unsigned chars before adding to witness
+    char* buf = stream.data();
+    unsigned char* membuf = reinterpret_cast<unsigned char*>(buf);
+    std::vector<unsigned char> value_bytes(membuf, membuf + stream.size());
+
     uint256 genesisBlockHash = Params().ParentGenesisBlockHash();
 
     // Manually construct peg-in transaction, sign it, and send it off.
@@ -3639,7 +3653,7 @@ UniValue createrawpegin(const JSONRPCRequest& request)
     // Construct pegin proof
     CScriptWitness pegin_witness;
     std::vector<std::vector<unsigned char> >& stack = pegin_witness.stack;
-    stack.push_back(CScriptNum::serialize(value));
+    stack.push_back(value_bytes);
     stack.push_back(std::vector<unsigned char>(Params().GetConsensus().pegged_asset.begin(), Params().GetConsensus().pegged_asset.end()));
     stack.push_back(std::vector<unsigned char>(genesisBlockHash.begin(), genesisBlockHash.end()));
     stack.push_back(std::vector<unsigned char>(witnessProgScript.begin(), witnessProgScript.end()));