[Masternode] Offline signing endpoints

src/Stratis.Bitcoin.Features.PoA/Voting/JoinFederationRequestModel.cs

@@ -40,4 +40,50 @@ public sealed class JoinFederationRequestModel
         [JsonProperty(PropertyName = "walletAccount")]
         public string WalletAccount { get; set; }
     }
+
+    /// <summary>
+    /// Contains the collateral address for which we want to build the join message for signing.
+    /// </summary>
+    public sealed class GetJoinMessageModel
+    {
+        /// <summary>
+        /// The collateral address.
+        /// </summary>
+        [Required(ErrorMessage = "The collateral address is required.")]
+        [JsonProperty(PropertyName = "collateralAddress")]
+        public string CollateralAddress { get; set; }
+    }
+
+    /// <summary>
+    /// A class containing the necessary parameters for a join federation request with a signed message.
+    /// </summary>
+    public sealed class JoinFederationRequestWithSignature
+    {
+        /// <summary>
+        /// The collateral address.
+        /// </summary>
+        [Required(ErrorMessage = "The collateral address is required.")]
+        [JsonProperty(PropertyName = "collateralAddress")]
+        public string CollateralAddress { get; set; }
+
+        /// <summary>The name of the wallet which will supply the fee on the Cirrus network.</summary>
+        [Required(ErrorMessage = "The fee wallet name is required")]
+        [JsonProperty(PropertyName = "walletName")]
+        public string WalletName { get; set; }
+
+        /// <summary>The password of the wallet which will supply the fee on the Cirrus network.</summary>
+        [Required(ErrorMessage = "The fee wallet password is required")]
+        [JsonProperty(PropertyName = "walletPassword")]
+        public string WalletPassword { get; set; }
+
+        /// <summary>The account of the wallet which will supply the fee on the Cirrus network.</summary>
+        [Required(ErrorMessage = "The fee wallet account is required")]
+        [JsonProperty(PropertyName = "walletAccount")]
+        public string WalletAccount { get; set; }
+
+        /// <summary>The join federation message signature as signed by the collateral address key.</summary>
+        [Required(ErrorMessage = "The signature is required")]
+        [JsonProperty(PropertyName = "signature")]
+        public string Signature { get; set; }
+    }
 }

src/Stratis.Bitcoin.Features.PoA/Voting/JoinFederationRequestService.cs

@@ -20,6 +20,8 @@ namespace Stratis.Features.PoA.Voting
 {
     public interface IJoinFederationRequestService
     {
+        JoinFederationRequest BuildJoinFederationRequest(string collateralAddress);
+        Task<PubKey> BroadcastSignedJoinRequestAsync(JoinFederationRequest request, string walletName, string walletPassword, string walletAccount, CancellationToken cancellationToken);
         Task<PubKey> JoinFederationAsync(JoinFederationRequestModel request, CancellationToken cancellationToken);
     }
 
@@ -47,29 +49,7 @@ public JoinFederationRequestService(ICounterChainSettings counterChainSettings,
         public async Task<PubKey> JoinFederationAsync(JoinFederationRequestModel request, CancellationToken cancellationToken)
         {
             // Get the address pub key hash.
-            BitcoinAddress address = BitcoinAddress.Create(request.CollateralAddress, this.counterChainSettings.CounterChainNetwork);
-            KeyId addressKey = PayToPubkeyHashTemplate.Instance.ExtractScriptPubKeyParameters(address.ScriptPubKey);
-
-            // Get mining key.
-            var keyTool = new KeyTool(this.nodeSettings.DataFolder);
-            Key minerKey = keyTool.LoadPrivateKey();
-            if (minerKey == null)
-                throw new Exception($"The private key file ({KeyTool.KeyFileDefaultName}) has not been configured or is not present.");
-
-            var expectedCollateralAmount = CollateralFederationMember.GetCollateralAmountForPubKey(this.network, minerKey.PubKey);
-
-            var collateralAmount = new Money(expectedCollateralAmount, MoneyUnit.BTC);
-
-            var joinRequest = new JoinFederationRequest(minerKey.PubKey, collateralAmount, addressKey);
-
-            // Populate the RemovalEventId.
-            var collateralFederationMember = new CollateralFederationMember(minerKey.PubKey, false, joinRequest.CollateralAmount, request.CollateralAddress);
-
-            byte[] federationMemberBytes = (this.network.Consensus.ConsensusFactory as CollateralPoAConsensusFactory).SerializeFederationMember(collateralFederationMember);
-            Poll poll = this.votingManager.GetApprovedPolls().FirstOrDefault(x => x.IsExecuted &&
-                  x.VotingData.Key == VoteKey.KickFederationMember && x.VotingData.Data.SequenceEqual(federationMemberBytes));
-
-            joinRequest.RemovalEventId = (poll == null) ? Guid.Empty : new Guid(poll.PollExecutedBlockData.Hash.ToBytes().TakeLast(16).ToArray());
+            JoinFederationRequest joinRequest = BuildJoinFederationRequest(request.CollateralAddress);
 
             // Get the signature by calling the counter-chain "signmessage" API.
             var signMessageRequest = new SignMessageRequest()
@@ -92,16 +72,76 @@ public async Task<PubKey> JoinFederationAsync(JoinFederationRequestModel request
                 throw new Exception($"The call to sign the join federation request failed: '{err.Message}'.");
             }
 
+            if (!VerifyCollateralSignature(joinRequest))
+            {
+                throw new Exception($"The signature from the collateral address {joinRequest.CollateralMainchainAddress} is invalid");
+            }
+
+            return await BroadcastSignedJoinRequestAsync(joinRequest, request.WalletName, request.WalletPassword, request.WalletAccount, cancellationToken);
+        }
+
+        public async Task<PubKey> BroadcastSignedJoinRequestAsync(JoinFederationRequest request, string walletName, string walletPassword, string walletAccount, CancellationToken cancellationToken)
+        {
+            if(!VerifyCollateralSignature(request))
+            {
+                throw new Exception($"The signature from the collateral address {request.CollateralMainchainAddress} is invalid");
+            }
+
             IWalletTransactionHandler walletTransactionHandler = this.fullNode.NodeService<IWalletTransactionHandler>();
             var encoder = new JoinFederationRequestEncoder();
-            JoinFederationRequestResult result = JoinFederationRequestBuilder.BuildTransaction(walletTransactionHandler, this.network, joinRequest, encoder, request.WalletName, request.WalletAccount, request.WalletPassword);
+            JoinFederationRequestResult result = JoinFederationRequestBuilder.BuildTransaction(walletTransactionHandler, this.network, request, encoder, walletName, walletAccount, walletPassword);
             if (result.Transaction == null)
                 throw new Exception(result.Errors);
 
             IWalletService walletService = this.fullNode.NodeService<IWalletService>();
             await walletService.SendTransaction(new SendTransactionRequest(result.Transaction.ToHex()), cancellationToken);
 
-            return minerKey.PubKey;
+            return GetMinerKey().PubKey;
+        }
+
+        public JoinFederationRequest BuildJoinFederationRequest(string collateralAddress)
+        {
+            Key minerKey = GetMinerKey();
+
+            var expectedCollateralAmount = CollateralFederationMember.GetCollateralAmountForPubKey(this.network, minerKey.PubKey);
+
+            var collateralAmount = new Money(expectedCollateralAmount, MoneyUnit.BTC);
+
+            BitcoinAddress address = BitcoinAddress.Create(collateralAddress, this.counterChainSettings.CounterChainNetwork);
+            KeyId addressKey = PayToPubkeyHashTemplate.Instance.ExtractScriptPubKeyParameters(address.ScriptPubKey);
+
+            var joinRequest = new JoinFederationRequest(minerKey.PubKey, collateralAmount, addressKey);
+
+            // Populate the RemovalEventId.
+            var collateralFederationMember = new CollateralFederationMember(minerKey.PubKey, false, joinRequest.CollateralAmount, collateralAddress);
+
+            byte[] federationMemberBytes = (this.network.Consensus.ConsensusFactory as CollateralPoAConsensusFactory).SerializeFederationMember(collateralFederationMember);
+            Poll poll = this.votingManager.GetApprovedPolls().FirstOrDefault(x => x.IsExecuted &&
+                  x.VotingData.Key == VoteKey.KickFederationMember && x.VotingData.Data.SequenceEqual(federationMemberBytes));
+
+            joinRequest.RemovalEventId = (poll == null) ? Guid.Empty : new Guid(poll.PollExecutedBlockData.Hash.ToBytes().TakeLast(16).ToArray());
+            return joinRequest;
+        }
+
+        private Key GetMinerKey()
+        {
+            // Get mining key.
+            var keyTool = new KeyTool(this.nodeSettings.DataFolder);
+            Key minerKey = keyTool.LoadPrivateKey();
+            if (minerKey == null)
+                throw new Exception($"The private key file ({KeyTool.KeyFileDefaultName}) has not been configured or is not present.");
+            return minerKey;
+        }
+
+        /// <summary>
+        /// Returns true if the join request message is signed by the given collateral address.
+        /// </summary>
+        /// <param name="request"></param>
+        /// <returns></returns>
+        public bool VerifyCollateralSignature(JoinFederationRequest request)
+        {
+            BitcoinPubKeyAddress bitcoinPubKeyAddress = new BitcoinPubKeyAddress(request.CollateralMainchainAddress, this.counterChainSettings.CounterChainNetwork);
+            return bitcoinPubKeyAddress.VerifyMessage(request.SignatureMessage, request.Signature);
         }
     }
 }

src/Stratis.Features.Collateral/CollateralController.cs

@@ -16,6 +16,8 @@ namespace Stratis.Features.Collateral
     public static class CollateralRouteEndPoint
     {
         public const string JoinFederation = "joinfederation";
+        public const string JoinFederationSigned = "joinfederationsigned";
+        public const string GetJoinMessageForSigning = "getjoinmessageforsigning";
     }
 
     /// <summary>Controller providing operations on collateral federation members.</summary>
@@ -82,5 +84,97 @@ public async Task<IActionResult> JoinFederationAsync([FromBody] JoinFederationRe
                 return ErrorHelpers.BuildErrorResponse(HttpStatusCode.BadRequest, e.Message, e.ToString());
             }
         }
+
+        /// <summary>
+        /// Called by a miner wanting to join the federation.
+        /// </summary>
+        /// <param name="request">See <see cref="JoinFederationRequestModel"></see>.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>An instance of <see cref="JoinFederationResponseModel"/>.</returns>
+        /// <response code="200">Returns a valid response.</response>
+        /// <response code="400">Unexpected exception occurred</response>
+        [Route(CollateralRouteEndPoint.GetJoinMessageForSigning)]
+        [HttpPost]
+        [ProducesResponseType((int)HttpStatusCode.OK)]
+        [ProducesResponseType((int)HttpStatusCode.BadRequest)]
+        [ProducesResponseType((int)HttpStatusCode.InternalServerError)]
+        public async Task<IActionResult> GetJoinMessageForSigning([FromBody] GetJoinMessageModel request, CancellationToken cancellationToken = default)
+        {
+            Guard.NotNull(request, nameof(request));
+
+            // Checks that the request is valid.
+            if (!this.ModelState.IsValid)
+            {
+                this.logger.Trace("(-)[MODEL_STATE_INVALID]");
+                return ModelStateErrors.BuildErrorResponse(this.ModelState);
+            }
+
+            if (!(this.network.Consensus.Options as PoAConsensusOptions).AutoKickIdleMembers)
+                return ErrorHelpers.BuildErrorResponse(HttpStatusCode.BadRequest, "Error", "This feature is currently disabled.");
+
+            try
+            {
+                var joinFederationRequest = this.joinFederationRequestService.BuildJoinFederationRequest(request.CollateralAddress);
+
+                return this.Json(joinFederationRequest.SignatureMessage);
+            }
+            catch (Exception e)
+            {
+                this.logger.Error("Exception occurred: {0}", e.ToString());
+                this.logger.Trace("(-)[ERROR]");
+                return ErrorHelpers.BuildErrorResponse(HttpStatusCode.BadRequest, e.Message, e.ToString());
+            }
+        }
+
+        /// <summary>
+        /// Called by a miner wanting to join the federation.
+        /// </summary>
+        /// <param name="request">See <see cref="JoinFederationRequestModel"></see>.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>An instance of <see cref="JoinFederationResponseModel"/>.</returns>
+        /// <response code="200">Returns a valid response.</response>
+        /// <response code="400">Unexpected exception occurred</response>
+        [Route(CollateralRouteEndPoint.JoinFederationSigned)]
+        [HttpPost]
+        [ProducesResponseType((int)HttpStatusCode.OK)]
+        [ProducesResponseType((int)HttpStatusCode.BadRequest)]
+        [ProducesResponseType((int)HttpStatusCode.InternalServerError)]
+        public async Task<IActionResult> JoinFederationSigned([FromBody] JoinFederationRequestWithSignature request, CancellationToken cancellationToken = default)
+        {
+            Guard.NotNull(request, nameof(request));
+
+            // Checks that the request is valid.
+            if (!this.ModelState.IsValid)
+            {
+                this.logger.Trace("(-)[MODEL_STATE_INVALID]");
+                return ModelStateErrors.BuildErrorResponse(this.ModelState);
+            }
+
+            if (!(this.network.Consensus.Options as PoAConsensusOptions).AutoKickIdleMembers)
+                return ErrorHelpers.BuildErrorResponse(HttpStatusCode.BadRequest, "Error", "This feature is currently disabled.");
+
+            try
+            {
+                var joinFederationRequest = this.joinFederationRequestService.BuildJoinFederationRequest(request.CollateralAddress);
+
+                joinFederationRequest.AddSignature(request.Signature);
+
+                PubKey minerPubKey = await this.joinFederationRequestService.BroadcastSignedJoinRequestAsync(joinFederationRequest, request.WalletName, request.WalletPassword, request.WalletAccount, cancellationToken);
+
+                var model = new JoinFederationResponseModel
+                {
+                    MinerPublicKey = minerPubKey.ToHex()
+                };
+
+                this.logger.Trace("(-):'{0}'", model);
+                return this.Json(model);
+            }
+            catch (Exception e)
+            {
+                this.logger.Error("Exception occurred: {0}", e.ToString());
+                this.logger.Trace("(-)[ERROR]");
+                return ErrorHelpers.BuildErrorResponse(HttpStatusCode.BadRequest, e.Message, e.ToString());
+            }
+        }
     }
 }