Allow smart contract verification

src/neo/SmartContract/ApplicationEngine.Runtime.cs

@@ -21,7 +21,7 @@ partial class ApplicationEngine
         public static readonly InteropDescriptor System_Runtime_GetExecutingScriptHash = Register("System.Runtime.GetExecutingScriptHash", nameof(CurrentScriptHash), 0_00000400, CallFlags.None, true);
         public static readonly InteropDescriptor System_Runtime_GetCallingScriptHash = Register("System.Runtime.GetCallingScriptHash", nameof(CallingScriptHash), 0_00000400, CallFlags.None, true);
         public static readonly InteropDescriptor System_Runtime_GetEntryScriptHash = Register("System.Runtime.GetEntryScriptHash", nameof(EntryScriptHash), 0_00000400, CallFlags.None, true);
-        public static readonly InteropDescriptor System_Runtime_CheckWitness = Register("System.Runtime.CheckWitness", nameof(CheckWitness), 0_00030000, CallFlags.AllowStates, true);
+        public static readonly InteropDescriptor System_Runtime_CheckWitness = Register("System.Runtime.CheckWitness", nameof(CheckWitness), 0_00030000, CallFlags.None, true);
         public static readonly InteropDescriptor System_Runtime_GetInvocationCounter = Register("System.Runtime.GetInvocationCounter", nameof(GetInvocationCounter), 0_00000400, CallFlags.None, true);
         public static readonly InteropDescriptor System_Runtime_Log = Register("System.Runtime.Log", nameof(RuntimeLog), 0_01000000, CallFlags.AllowNotify, false);
         public static readonly InteropDescriptor System_Runtime_Notify = Register("System.Runtime.Notify", nameof(RuntimeNotify), 0_01000000, CallFlags.AllowNotify, false);
@@ -109,7 +109,7 @@ internal bool CheckWitnessInternal(UInt160 hash)
                 if (signer.Scopes == WitnessScope.Global) return true;
                 if (signer.Scopes.HasFlag(WitnessScope.CalledByEntry))
                 {
-                    if (CallingScriptHash == EntryScriptHash)
+                    if (CallingScriptHash == null || CallingScriptHash == EntryScriptHash)
                         return true;
                 }
                 if (signer.Scopes.HasFlag(WitnessScope.CustomContracts))
@@ -119,6 +119,11 @@ internal bool CheckWitnessInternal(UInt160 hash)
                 }
                 if (signer.Scopes.HasFlag(WitnessScope.CustomGroups))
                 {
+                    // Check allow state callflag
+
+                    if (!CurrentContext.GetState<ExecutionContextState>().CallFlags.HasFlag(CallFlags.AllowStates))
+                        throw new InvalidOperationException($"Cannot call this SYSCALL without the flag AllowStates.");
+
                     var contract = Snapshot.Contracts[CallingScriptHash];
                     // check if current group is the required one
                     if (contract.Manifest.Groups.Select(p => p.PubKey).Intersect(signer.AllowedGroups).Any())
@@ -127,6 +132,11 @@ internal bool CheckWitnessInternal(UInt160 hash)
                 return false;
             }
 
+            // Check allow state callflag
+
+            if (!CurrentContext.GetState<ExecutionContextState>().CallFlags.HasFlag(CallFlags.AllowStates))
+                throw new InvalidOperationException($"Cannot call this SYSCALL without the flag AllowStates.");
+
             // only for non-Transaction types (Block, etc)
 
             var hashes_for_verifying = ScriptContainer.GetScriptHashesForVerifying(Snapshot);

src/neo/SmartContract/ContractParametersContext.cs

@@ -9,7 +9,6 @@
 using System.IO;
 using System.Linq;
 using System.Reflection;
-using System.Text;
 
 namespace Neo.SmartContract
 {

src/neo/SmartContract/DeployedContract.cs

@@ -0,0 +1,24 @@
+using Neo.Ledger;
+using Neo.SmartContract.Manifest;
+using System;
+using System.Linq;
+
+namespace Neo.SmartContract
+{
+    public class DeployedContract : Contract
+    {
+        public override UInt160 ScriptHash { get; }
+
+        public DeployedContract(ContractState contract)
+        {
+            if (contract is null) throw new ArgumentNullException(nameof(contract));
+
+            Script = null;
+            ScriptHash = contract.ScriptHash;
+            ContractMethodDescriptor descriptor = contract.Manifest.Abi.GetMethod("verify");
+            if (descriptor is null) throw new NotSupportedException("The smart contract haven't got verify method.");
+
+            ParameterList = descriptor.Parameters.Select(u => u.Type).ToArray();
+        }
+    }
+}

src/neo/SmartContract/Helper.cs

@@ -147,6 +147,7 @@ internal static bool VerifyWitnesses(this IVerifiable verifiable, StoreView snap
             for (int i = 0; i < hashes.Length; i++)
             {
                 int offset;
+                ContractMethodDescriptor init = null;
                 byte[] verification = verifiable.Witnesses[i].VerificationScript;
                 if (verification.Length == 0)
                 {
@@ -156,6 +157,7 @@ internal static bool VerifyWitnesses(this IVerifiable verifiable, StoreView snap
                     if (md is null) return false;
                     verification = cs.Script;
                     offset = md.Offset;
+                    init = cs.Manifest.Abi.GetMethod("_initialize");
                 }
                 else
                 {
@@ -165,6 +167,7 @@ internal static bool VerifyWitnesses(this IVerifiable verifiable, StoreView snap
                 using (ApplicationEngine engine = ApplicationEngine.Create(TriggerType.Verification, verifiable, snapshot.Clone(), gas))
                 {
                     engine.LoadScript(verification, CallFlags.None).InstructionPointer = offset;
+                    if (init != null) engine.LoadClonedContext(init.Offset);
                     engine.LoadScript(verifiable.Witnesses[i].InvocationScript, CallFlags.None);
                     if (engine.Execute() == VMState.FAULT) return false;
                     if (engine.ResultStack.Count != 1 || !engine.ResultStack.Pop().GetBoolean()) return false;

src/neo/Wallets/Wallet.cs

@@ -4,6 +4,7 @@
 using Neo.Network.P2P.Payloads;
 using Neo.Persistence;
 using Neo.SmartContract;
+using Neo.SmartContract.Manifest;
 using Neo.SmartContract.Native;
 using Neo.VM;
 using System;
@@ -240,7 +241,7 @@ public virtual WalletAccount Import(string nep2, string passphrase, int N = 1638
             return account;
         }
 
-        public Transaction MakeTransaction(TransferOutput[] outputs, UInt160 from = null)
+        public Transaction MakeTransaction(TransferOutput[] outputs, UInt160 from = null, Signer[] cosigners = null)
         {
             UInt160[] accounts;
             if (from is null)
@@ -250,12 +251,12 @@ public Transaction MakeTransaction(TransferOutput[] outputs, UInt160 from = null
             else
             {
                 if (!Contains(from))
-                    throw new ArgumentException($"The address {from.ToString()} was not found in the wallet");
+                    throw new ArgumentException($"The address {from} was not found in the wallet");
                 accounts = new[] { from };
             }
             using (SnapshotView snapshot = Blockchain.Singleton.GetSnapshot())
             {
-                HashSet<UInt160> cosignerList = new HashSet<UInt160>();
+                Dictionary<UInt160, Signer> cosignerList = cosigners?.ToDictionary(p => p.Account) ?? new Dictionary<UInt160, Signer>();
                 byte[] script;
                 List<(UInt160 Account, BigInteger Value)> balances_gas = null;
                 using (ScriptBuilder sb = new ScriptBuilder())
@@ -282,9 +283,21 @@ public Transaction MakeTransaction(TransferOutput[] outputs, UInt160 from = null
                         {
                             balances = balances.OrderBy(p => p.Value).ToList();
                             var balances_used = FindPayingAccounts(balances, output.Value.Value);
-                            cosignerList.UnionWith(balances_used.Select(p => p.Account));
                             foreach (var (account, value) in balances_used)
                             {
+                                if (cosignerList.TryGetValue(account, out Signer signer))
+                                {
+                                    if (signer.Scopes != WitnessScope.Global)
+                                        signer.Scopes |= WitnessScope.CalledByEntry;
+                                }
+                                else
+                                {
+                                    cosignerList.Add(account, new Signer
+                                    {
+                                        Account = account,
+                                        Scopes = WitnessScope.CalledByEntry
+                                    });
+                                }
                                 sb.EmitAppCall(output.AssetId, "transfer", account, output.ScriptHash, value);
                                 sb.Emit(OpCode.ASSERT);
                             }
@@ -297,14 +310,7 @@ public Transaction MakeTransaction(TransferOutput[] outputs, UInt160 from = null
                 if (balances_gas is null)
                     balances_gas = accounts.Select(p => (Account: p, Value: NativeContract.GAS.BalanceOf(snapshot, p))).Where(p => p.Value.Sign > 0).ToList();
 
-                var cosigners = cosignerList.Select(p => new Signer()
-                {
-                    // default access for transfers should be valid only for first invocation
-                    Scopes = WitnessScope.CalledByEntry,
-                    Account = p
-                }).ToArray();
-
-                return MakeTransaction(snapshot, script, cosigners, Array.Empty<TransactionAttribute>(), balances_gas);
+                return MakeTransaction(snapshot, script, cosignerList.Values.ToArray(), Array.Empty<TransactionAttribute>(), balances_gas);
             }
         }
 
@@ -353,49 +359,66 @@ private Transaction MakeTransaction(StoreView snapshot, byte[] script, Signer[]
                     tx.SystemFee = engine.GasConsumed;
                 }
 
-                UInt160[] hashes = tx.GetScriptHashesForVerifying(snapshot);
-
-                // base size for transaction: includes const_header + signers + attributes + script + hashes
-                int size = Transaction.HeaderSize + tx.Signers.GetVarSize() + tx.Attributes.GetVarSize() + script.GetVarSize() + IO.Helper.GetVarSize(hashes.Length);
-
-                foreach (UInt160 hash in hashes)
-                {
-                    byte[] witness_script = GetAccount(hash)?.Contract?.Script ?? snapshot.Contracts.TryGet(hash)?.Script;
-                    if (witness_script is null) continue;
-                    tx.NetworkFee += CalculateNetworkFee(witness_script, ref size);
-                }
-                tx.NetworkFee += size * NativeContract.Policy.GetFeePerByte(snapshot);
+                tx.NetworkFee = CalculateNetworkFee(snapshot, tx);
                 if (value >= tx.SystemFee + tx.NetworkFee) return tx;
             }
             throw new InvalidOperationException("Insufficient GAS");
         }
 
-        public static long CalculateNetworkFee(byte[] witness_script, ref int size)
+        public long CalculateNetworkFee(StoreView snapshot, Transaction tx)
         {
-            long networkFee = 0;
+            UInt160[] hashes = tx.GetScriptHashesForVerifying(snapshot);
 
-            if (witness_script.IsSignatureContract())
-            {
-                size += 67 + witness_script.GetVarSize();
-                networkFee += ApplicationEngine.OpCodePrices[OpCode.PUSHDATA1] + ApplicationEngine.OpCodePrices[OpCode.PUSHDATA1] + ApplicationEngine.OpCodePrices[OpCode.PUSHNULL] + ApplicationEngine.ECDsaVerifyPrice;
-            }
-            else if (witness_script.IsMultiSigContract(out int m, out int n))
-            {
-                int size_inv = 66 * m;
-                size += IO.Helper.GetVarSize(size_inv) + size_inv + witness_script.GetVarSize();
-                networkFee += ApplicationEngine.OpCodePrices[OpCode.PUSHDATA1] * m;
-                using (ScriptBuilder sb = new ScriptBuilder())
-                    networkFee += ApplicationEngine.OpCodePrices[(OpCode)sb.EmitPush(m).ToArray()[0]];
-                networkFee += ApplicationEngine.OpCodePrices[OpCode.PUSHDATA1] * n;
-                using (ScriptBuilder sb = new ScriptBuilder())
-                    networkFee += ApplicationEngine.OpCodePrices[(OpCode)sb.EmitPush(n).ToArray()[0]];
-                networkFee += ApplicationEngine.OpCodePrices[OpCode.PUSHNULL] + ApplicationEngine.ECDsaVerifyPrice * n;
-            }
-            else
+            // base size for transaction: includes const_header + signers + attributes + script + hashes
+            int size = Transaction.HeaderSize + tx.Signers.GetVarSize() + tx.Attributes.GetVarSize() + tx.Script.GetVarSize() + IO.Helper.GetVarSize(hashes.Length);
+            long networkFee = 0;
+            foreach (UInt160 hash in hashes)
             {
-                //We can support more contract types in the future.
+                byte[] witness_script = GetAccount(hash)?.Contract?.Script;
+                if (witness_script is null)
+                {
+                    var contract = snapshot.Contracts.TryGet(hash);
+                    if (contract is null) continue;
+
+                    // Empty invocation and verification scripts
+                    size += Array.Empty<byte>().GetVarSize() * 2;
+
+                    // Check verify cost
+                    ContractMethodDescriptor verify = contract.Manifest.Abi.GetMethod("verify");
+                    if (verify is null) throw new ArgumentException($"The smart contract {contract.ScriptHash} haven't got verify method");
+                    ContractMethodDescriptor init = contract.Manifest.Abi.GetMethod("_initialize");
+                    using ApplicationEngine engine = ApplicationEngine.Create(TriggerType.Verification, tx, snapshot.Clone(), 0, testMode: true);
+                    engine.LoadScript(contract.Script, CallFlags.None).InstructionPointer = verify.Offset;
+                    if (init != null) engine.LoadClonedContext(init.Offset);
+                    engine.LoadScript(Array.Empty<byte>(), CallFlags.None);
+                    if (engine.Execute() == VMState.FAULT) throw new ArgumentException($"Smart contract {contract.ScriptHash} verification fault.");
+                    if (engine.ResultStack.Count != 1 || !engine.ResultStack.Pop().GetBoolean()) throw new ArgumentException($"Smart contract {contract.ScriptHash} returns false.");
+
+                    networkFee += engine.GasConsumed;
+                }
+                else if (witness_script.IsSignatureContract())
+                {
+                    size += 67 + witness_script.GetVarSize();
+                    networkFee += ApplicationEngine.OpCodePrices[OpCode.PUSHDATA1] + ApplicationEngine.OpCodePrices[OpCode.PUSHDATA1] + ApplicationEngine.OpCodePrices[OpCode.PUSHNULL] + ApplicationEngine.ECDsaVerifyPrice;
+                }
+                else if (witness_script.IsMultiSigContract(out int m, out int n))
+                {
+                    int size_inv = 66 * m;
+                    size += IO.Helper.GetVarSize(size_inv) + size_inv + witness_script.GetVarSize();
+                    networkFee += ApplicationEngine.OpCodePrices[OpCode.PUSHDATA1] * m;
+                    using (ScriptBuilder sb = new ScriptBuilder())
+                        networkFee += ApplicationEngine.OpCodePrices[(OpCode)sb.EmitPush(m).ToArray()[0]];
+                    networkFee += ApplicationEngine.OpCodePrices[OpCode.PUSHDATA1] * n;
+                    using (ScriptBuilder sb = new ScriptBuilder())
+                        networkFee += ApplicationEngine.OpCodePrices[(OpCode)sb.EmitPush(n).ToArray()[0]];
+                    networkFee += ApplicationEngine.OpCodePrices[OpCode.PUSHNULL] + ApplicationEngine.ECDsaVerifyPrice * n;
+                }
+                else
+                {
+                    //We can support more contract types in the future.
+                }
             }
-
+            networkFee += size * NativeContract.Policy.GetFeePerByte(snapshot);
             return networkFee;
         }
 
@@ -405,38 +428,56 @@ public bool Sign(ContractParametersContext context)
             foreach (UInt160 scriptHash in context.ScriptHashes)
             {
                 WalletAccount account = GetAccount(scriptHash);
-                if (account is null) continue;
 
-                // Try to sign self-contained multiSig
+                if (account != null)
+                {
+                    // Try to sign self-contained multiSig
 
-                Contract multiSigContract = account.Contract;
+                    Contract multiSigContract = account.Contract;
 
-                if (multiSigContract != null &&
-                    multiSigContract.Script.IsMultiSigContract(out int m, out ECPoint[] points))
-                {
-                    foreach (var point in points)
+                    if (multiSigContract != null &&
+                        multiSigContract.Script.IsMultiSigContract(out int m, out ECPoint[] points))
+                    {
+                        foreach (var point in points)
+                        {
+                            account = GetAccount(point);
+                            if (account?.HasKey != true) continue;
+                            KeyPair key = account.GetKey();
+                            byte[] signature = context.Verifiable.Sign(key);
+                            fSuccess |= context.AddSignature(multiSigContract, key.PublicKey, signature);
+                            if (fSuccess) m--;
+                            if (context.Completed || m <= 0) break;
+                        }
+                        continue;
+                    }
+                    else if (account.HasKey)
                     {
-                        account = GetAccount(point);
-                        if (account?.HasKey != true) continue;
+                        // Try to sign with regular accounts
                         KeyPair key = account.GetKey();
                         byte[] signature = context.Verifiable.Sign(key);
-                        fSuccess |= context.AddSignature(multiSigContract, key.PublicKey, signature);
-                        if (fSuccess) m--;
-                        if (context.Completed || m <= 0) break;
+                        fSuccess |= context.AddSignature(account.Contract, key.PublicKey, signature);
+                        continue;
                     }
                 }
-                else
+
+                // Try Smart contract verification
+
+                using var snapshot = Blockchain.Singleton.GetSnapshot();
+                var contract = snapshot.Contracts.TryGet(scriptHash);
+
+                if (contract != null)
                 {
-                    // Try to sign with regular accounts
+                    var deployed = new DeployedContract(contract);
 
-                    if (account.HasKey)
+                    // Only works with verify without parameters
+
+                    if (deployed.ParameterList.Length == 0)
                     {
-                        KeyPair key = account.GetKey();
-                        byte[] signature = context.Verifiable.Sign(key);
-                        fSuccess |= context.AddSignature(account.Contract, key.PublicKey, signature);
+                        fSuccess |= context.Add(deployed);
                     }
                 }
             }
+
             return fSuccess;
         }
 

tests/neo.UnitTests/Extensions/Nep5NativeContractExtensions.cs

@@ -4,7 +4,6 @@
 using Neo.SmartContract;
 using Neo.SmartContract.Native;
 using Neo.VM;
-using System;
 using System.IO;
 using System.Numerics;
 
@@ -16,14 +15,10 @@ internal class ManualWitness : IVerifiable
         {
             private readonly UInt160[] _hashForVerify;
 
-            public Witness[] Witnesses
-            {
-                get => throw new NotImplementedException();
-                set => throw new NotImplementedException();
-            }
-
             public int Size => 0;
 
+            public Witness[] Witnesses { get; set; }
+
             public ManualWitness(params UInt160[] hashForVerify)
             {
                 _hashForVerify = hashForVerify ?? new UInt160[0];