Example #1
0
        internal static bool VerifyWitnesses(this IVerifiable verifiable, StoreView snapshot, long gas, WitnessFlag filter = WitnessFlag.All)
        {
            if (gas < 0)
            {
                return(false);
            }
            if (gas > MaxVerificationGas)
            {
                gas = MaxVerificationGas;
            }

            UInt160[] hashes;
            try
            {
                hashes = verifiable.GetScriptHashesForVerifying(snapshot);
            }
            catch (InvalidOperationException)
            {
                return(false);
            }
            if (hashes.Length != verifiable.Witnesses.Length)
            {
                return(false);
            }
            for (int i = 0; i < hashes.Length; i++)
            {
                WitnessFlag flag = verifiable.Witnesses[i].StateDependent ? WitnessFlag.StateDependent : WitnessFlag.StateIndependent;
                if (!filter.HasFlag(flag))
                {
                    gas -= verifiable.Witnesses[i].GasConsumed;
                    if (gas < 0)
                    {
                        return(false);
                    }
                    continue;
                }

                using (ApplicationEngine engine = ApplicationEngine.Create(TriggerType.Verification, verifiable, snapshot?.Clone(), gas))
                {
                    CallFlags callFlags    = verifiable.Witnesses[i].StateDependent ? CallFlags.AllowStates : CallFlags.None;
                    byte[]    verification = verifiable.Witnesses[i].VerificationScript;

                    if (verification.Length == 0)
                    {
                        ContractState cs = snapshot.Contracts.TryGet(hashes[i]);
                        if (cs is null)
                        {
                            return(false);
                        }
                        if (engine.LoadContract(cs, "verify", callFlags, true) is null)
                        {
                            return(false);
                        }
                    }
                    else
                    {
                        if (NativeContract.IsNative(hashes[i]))
                        {
                            return(false);
                        }
                        if (hashes[i] != verifiable.Witnesses[i].ScriptHash)
                        {
                            return(false);
                        }
                        engine.LoadScript(verification, callFlags, hashes[i], 0);
                    }

                    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);
                    }
                    gas -= engine.GasConsumed;
                    verifiable.Witnesses[i].GasConsumed = engine.GasConsumed;
                }
            }
            return(true);
        }
Example #2
0
        internal static bool VerifyWitnesses(this IVerifiable verifiable, StoreView snapshot, long gas, WitnessFlag filter = WitnessFlag.All)
        {
            if (gas < 0)
            {
                return(false);
            }
            if (gas > MaxVerificationGas)
            {
                gas = MaxVerificationGas;
            }

            UInt160[] hashes;
            try
            {
                hashes = verifiable.GetScriptHashesForVerifying(snapshot);
            }
            catch (InvalidOperationException)
            {
                return(false);
            }
            if (hashes.Length != verifiable.Witnesses.Length)
            {
                return(false);
            }
            for (int i = 0; i < hashes.Length; i++)
            {
                WitnessFlag flag = verifiable.Witnesses[i].StateDependent ? WitnessFlag.StateDependent : WitnessFlag.StateIndependent;
                if (!filter.HasFlag(flag))
                {
                    gas -= verifiable.Witnesses[i].GasConsumed;
                    if (gas < 0)
                    {
                        return(false);
                    }
                    continue;
                }

                int offset;
                ContractMethodDescriptor init = null;
                byte[] verification           = verifiable.Witnesses[i].VerificationScript;
                if (verification.Length == 0)
                {
                    ContractState cs = snapshot.Contracts.TryGet(hashes[i]);
                    if (cs is null)
                    {
                        return(false);
                    }
                    ContractMethodDescriptor md = cs.Manifest.Abi.GetMethod("verify");
                    if (md is null)
                    {
                        return(false);
                    }
                    verification = cs.Script;
                    offset       = md.Offset;
                    init         = cs.Manifest.Abi.GetMethod("_initialize");
                }
                else
                {
                    if (NativeContract.IsNative(hashes[i]))
                    {
                        return(false);
                    }
                    if (hashes[i] != verifiable.Witnesses[i].ScriptHash)
                    {
                        return(false);
                    }
                    offset = 0;
                }
                using (ApplicationEngine engine = ApplicationEngine.Create(TriggerType.Verification, verifiable, snapshot?.Clone(), gas))
                {
                    CallFlags        callFlags = verifiable.Witnesses[i].StateDependent ? CallFlags.AllowStates : CallFlags.None;
                    ExecutionContext context   = engine.LoadScript(verification, callFlags, offset);
                    if (NativeContract.IsNative(hashes[i]))
                    {
                        using ScriptBuilder sb = new ScriptBuilder();
                        sb.Emit(OpCode.DEPTH, OpCode.PACK);
                        sb.EmitPush("verify");
                        engine.LoadScript(sb.ToArray(), CallFlags.None);
                    }
                    else if (init != null)
                    {
                        engine.LoadContext(context.Clone(init.Offset), false);
                    }
                    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);
                    }
                    gas -= engine.GasConsumed;
                    verifiable.Witnesses[i].GasConsumed = engine.GasConsumed;
                }
            }
            return(true);
        }