Added creatig receiving addresses for an account

Breeze/src/Breeze.Api.Tests/Postman requests/Wallet.postman_collection.json

@@ -2,7 +2,7 @@
 	"variables": [],
 	"info": {
 		"name": "Wallet",
-		"_postman_id": "25ac0bc5-23f5-e00d-932f-a8fde7787e7a",
+		"_postman_id": "5eec0912-fcf0-50f5-05a2-0835fa13c670",
 		"description": "Requests relating to operations on the wallet",
 		"schema": "https://schema.getpostman.com/json/collection/v2.0.0/collection.json"
 	},
@@ -206,6 +206,66 @@
 				"description": "Gets all the wallets files stored in the default folder"
 			},
 			"response": []
+		},
+		{
+			"name": "New account for non-existant wallet fails",
+			"request": {
+				"url": "http://localhost:5000/api/v1/wallet/account",
+				"method": "POST",
+				"header": [
+					{
+						"key": "Content-Type",
+						"value": "application/json",
+						"description": ""
+					}
+				],
+				"body": {
+					"mode": "raw",
+					"raw": "{\n\t\"walletName\": \"myFirstWallet\",\n\t\"accountName\": \"account one\"\n}"
+				},
+				"description": ""
+			},
+			"response": []
+		},
+		{
+			"name": "Create new account for wallet",
+			"request": {
+				"url": "http://localhost:5000/api/v1/wallet/account",
+				"method": "POST",
+				"header": [
+					{
+						"key": "Content-Type",
+						"value": "application/json",
+						"description": ""
+					}
+				],
+				"body": {
+					"mode": "raw",
+					"raw": "{\n\t\"walletName\": \"myFirstWallet\",\n\t\"accountName\": \"account one\",\n\t\"password\": \"123456\"\n}"
+				},
+				"description": ""
+			},
+			"response": []
+		},
+		{
+			"name": "Create new address for wallet",
+			"request": {
+				"url": "http://localhost:5000/api/v1/wallet/address",
+				"method": "POST",
+				"header": [
+					{
+						"key": "Content-Type",
+						"value": "application/json",
+						"description": ""
+					}
+				],
+				"body": {
+					"mode": "raw",
+					"raw": "{\n\t\"walletName\": \"myFirstWallet\",\n\t\"accountName\": \"account one\"\n}"
+				},
+				"description": ""
+			},
+			"response": []
 		}
 	]
 }
\ No newline at end of file

Breeze/src/Breeze.Wallet/Controllers/WalletController.cs

@@ -328,7 +328,33 @@ namespace Breeze.Wallet.Controllers
 
             try
             {
-                var result = this.walletManager.CreateNewAccount(request.WalletName, request.AccountName);
+                var result = this.walletManager.CreateNewAccount(request.WalletName, request.AccountName, request.Password);
+                return this.Json(result);
+            }
+            catch (Exception e)
+            {
+                return ErrorHelpers.BuildErrorResponse(HttpStatusCode.BadRequest, e.Message, e.ToString());
+            }
+        }
+
+        /// <summary>
+        /// Creates a new address for a wallet.
+        /// </summary>
+        /// <returns>An address in Base58 format.</returns>
+        [Route("address")]
+        [HttpPost]
+        public IActionResult CreateNewAddress([FromBody]CreateAddressModel request)
+        {
+            // checks the request is valid
+            if (!this.ModelState.IsValid)
+            {
+                var errors = this.ModelState.Values.SelectMany(e => e.Errors.Select(m => m.ErrorMessage));
+                return ErrorHelpers.BuildErrorResponse(HttpStatusCode.BadRequest, "Formatting error", string.Join(Environment.NewLine, errors));
+            }
+
+            try
+            {
+                var result = this.walletManager.CreateNewAddress(request.WalletName, request.AccountName);
                 return this.Json(result);
             }
             catch (Exception e)

Breeze/src/Breeze.Wallet/IWalletManager.cs

@@ -55,12 +55,21 @@ namespace Breeze.Wallet
         /// </summary>
         /// <param name="walletName">The name of the wallet in which this account will be created.</param>
         /// <param name="accountName">The name by which this account will be identified.</param>
+        /// <param name="password">The password used to decrypt the private key.</param>
         /// <remarks>
         /// According to BIP44, an account at index (i) can only be created when the account
         /// at index (i - 1) contains transactions.
         /// </remarks>
         /// <returns>The name of the new account.</returns>
-        string CreateNewAccount(string walletName, string accountName);
+        string CreateNewAccount(string walletName, string accountName, string password);
+
+        /// <summary>
+        /// Creates the new address.
+        /// </summary>
+        /// <param name="walletName">The name of the wallet in which this address will be created.</param>
+        /// <param name="accountName">The name of the account in which this address will be created.</param>        
+        /// <returns>The new address, in Base58 format.</returns>
+        string CreateNewAddress(string walletName, string accountName);
         
         WalletGeneralInfoModel GetGeneralInfo(string walletName);
 

Breeze/src/Breeze.Wallet/Models/CreateAccountModel.cs

@@ -18,5 +18,13 @@ namespace Breeze.Wallet.Models
         /// </summary>
         [Required]
         public string AccountName { get; set; }
+
+        /// <summary>
+        /// The password for this wallet.
+        /// </summary>
+        [Required]
+        public string Password { get; set; }
+
+
     }
 }

Breeze/src/Breeze.Wallet/Models/CreateAddressModel.cs

+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.Text;
+
+namespace Breeze.Wallet.Models
+{
+    public class CreateAddressModel
+    {
+        /// <summary>
+        /// The name of the wallet in which to create the address.
+        /// </summary>
+        [Required]
+        public string WalletName { get; set; }
+
+        /// <summary>
+        /// The name of the account in which to create the address.
+        /// </summary>
+        [Required]
+        public string AccountName { get; set; }
+    }
+}

Breeze/src/Breeze.Wallet/Wallet.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using Breeze.Wallet.JsonConverters;
 using NBitcoin;
+using NBitcoin.JsonConverters;
 using Newtonsoft.Json;
 
 namespace Breeze.Wallet
@@ -93,6 +94,12 @@ namespace Breeze.Wallet
         [JsonProperty(PropertyName = "name")]
         public string Name { get; set; }
 
+        /// <summary>
+        /// An extended pub key used to generate addresses.
+        /// </summary>
+        [JsonProperty(PropertyName = "extPubKey")]
+        public string ExtendedPubKey { get; set; }
+
         /// <summary>
         /// Gets or sets the creation time.
         /// </summary>
@@ -118,6 +125,12 @@ namespace Breeze.Wallet
     /// </summary>
     public class HdAddress
     {
+        /// <summary>
+        /// The index of the address.
+        /// </summary>
+        [JsonProperty(PropertyName = "index")]
+        public int Index { get; set; }
+
         /// <summary>
         /// Gets or sets the creation time.
         /// </summary>
@@ -129,13 +142,14 @@ namespace Breeze.Wallet
         /// The script pub key for this address.
         /// </summary>
         [JsonProperty(PropertyName = "scriptPubKey")]
+        [JsonConverter(typeof(ScriptJsonConverter))]
         public Script ScriptPubKey { get; set; }
 
         /// <summary>
         /// The Base58 representation of this address.
         /// </summary>
         [JsonProperty(PropertyName = "address")]        
-        public BitcoinAddress Address { get; set; }
+        public string Address { get; set; }
 
         /// <summary>
         /// A path to the address as defined in BIP44.

Breeze/src/Breeze.Wallet/WalletManager.cs

@@ -6,6 +6,7 @@ using Breeze.Wallet.Helpers;
 using Breeze.Wallet.Models;
 using NBitcoin;
 using Newtonsoft.Json;
+using Stratis.Bitcoin.Utilities;
 
 namespace Breeze.Wallet
 {
@@ -77,7 +78,7 @@ namespace Breeze.Wallet
         }
         
         /// <inheritdoc />
-        public string CreateNewAccount(string walletName, string accountName)
+        public string CreateNewAccount(string walletName, string accountName, string password)
         {
             Wallet wallet = this.Wallets.SingleOrDefault(w => w.Name == walletName);
             if (wallet == null)
@@ -85,7 +86,7 @@ namespace Breeze.Wallet
                 throw new Exception($"No wallet with name {walletName} could be found.");    
             }
 
-            var lastAccountIndex = 0;
+            int newAccountIndex = 0;
 
             // validate account creation
             if (wallet.Accounts.Any())
@@ -97,17 +98,27 @@ namespace Breeze.Wallet
                 }
 
                 // check account at index i - 1 contains transactions.
-                lastAccountIndex = wallet.Accounts.Max(a => a.Index);
+                int lastAccountIndex = wallet.Accounts.Max(a => a.Index);
                 HdAccount previousAccount = wallet.Accounts.Single(a => a.Index == lastAccountIndex);
                 if (!previousAccount.ExternalAddresses.Any(addresses => addresses.Transactions.Any()) && !previousAccount.InternalAddresses.Any(addresses => addresses.Transactions.Any()))
                 {
                     throw new Exception($"Cannot create new account '{accountName}' in '{walletName}' if the previous account '{previousAccount.Name}' has not been used.");
                 }
+
+                newAccountIndex = lastAccountIndex + 1;
             }
 
+            // get the extended pub key used to generate addresses for this account
+            var privateKey = Key.Parse(wallet.EncryptedSeed, password, wallet.Network);
+            var seedExtKey = new ExtKey(privateKey, wallet.ChainCode);
+            KeyPath keyPath = new KeyPath($"m/44'/{(int)wallet.CoinType}'/{newAccountIndex}'");
+            var accountExtKey = seedExtKey.Derive(keyPath);
+            ExtPubKey accountExtPubKey = accountExtKey.Neuter();
+
             wallet.Accounts = wallet.Accounts.Concat(new[] {new HdAccount
             {
-                Index = lastAccountIndex + 1,
+                Index = newAccountIndex,
+                ExtendedPubKey = accountExtPubKey.ToString(wallet.Network),
                 ExternalAddresses = new List<HdAddress>(),
                 InternalAddresses = new List<HdAddress>(),
                 Name = accountName,
@@ -119,6 +130,56 @@ namespace Breeze.Wallet
             return accountName;
         }
 
+        /// <inheritdoc />
+        public string CreateNewAddress(string walletName, string accountName)
+        {
+            Wallet wallet = this.Wallets.SingleOrDefault(w => w.Name == walletName);
+            if (wallet == null)
+            {
+                throw new Exception($"No wallet with name {walletName} could be found.");
+            }
+
+            HdAccount account = wallet.Accounts.SingleOrDefault(a => a.Name == accountName);
+            if (account == null)
+            {
+                throw new Exception($"No account with name {accountName} could be found.");
+            }
+
+            int newAddressIndex = 0;
+
+            // validate address creation
+            if (account.ExternalAddresses.Any())
+            {
+                // check last created address contains transactions.
+                int lastAddressIndex = account.ExternalAddresses.Max(a => a.Index);
+                var lastAddress = account.ExternalAddresses.SingleOrDefault(a => a.Index == lastAddressIndex);
+                if (lastAddress != null && !lastAddress.Transactions.Any())
+                {
+                    throw new Exception($"Cannot create new address in account '{accountName}' if the previous address '{lastAddress.Address}' has not been used.");
+                }
+
+                newAddressIndex = lastAddressIndex + 1;
+            }
+            
+            // generate new receiving address
+            BitcoinPubKeyAddress address = this.GenerateAddress(account.ExtendedPubKey, newAddressIndex, false, wallet.Network);
+
+            // add address details
+            account.ExternalAddresses = account.ExternalAddresses.Concat(new[] {new HdAddress
+            {
+                Index = newAddressIndex,
+                HdPath = CreateBip44Path(wallet.CoinType, account.Index, newAddressIndex, false),
+                ScriptPubKey = address.ScriptPubKey,
+                Address = address.ToString(),
+                Transactions = new List<TransactionData>(),
+                CreationTime = DateTimeOffset.Now
+            }});
+
+            this.SaveToFile(wallet);
+
+            return address.ToString();
+        }
+
         public WalletGeneralInfoModel GetGeneralInfo(string name)
         {
             throw new System.NotImplementedException();
@@ -215,5 +276,30 @@ namespace Breeze.Wallet
                 this.Wallets.Add(wallet);
             }
         }
+
+        private BitcoinPubKeyAddress GenerateAddress(string accountExtPubKey, int index, bool isChange, Network network)
+        {
+            int change = isChange ? 1 : 0;
+            KeyPath keyPath = new KeyPath($"{change}/{index}");
+            ExtPubKey extPubKey = ExtPubKey.Parse(accountExtPubKey).Derive(keyPath);
+            return extPubKey.PubKey.GetAddress(network);
+        }
+
+        /// <summary>
+        /// Creates the bip44 path.
+        /// </summary>
+        /// <param name="coinType">Type of the coin.</param>
+        /// <param name="accountIndex">Index of the account.</param>
+        /// <param name="addressIndex">Index of the address.</param>
+        /// <param name="isChange">if set to <c>true</c> [is change].</param>
+        /// <returns></returns>
+        public static string CreateBip44Path(CoinType coinType, int accountIndex, int addressIndex, bool isChange = false)
+        {
+            //// populate the items according to the BIP44 path 
+            //// [m/purpose'/coin_type'/account'/change/address_index]
+
+            int change = isChange ? 1 : 0;
+            return $"m/44'/{(int)coinType}'/{accountIndex}'/{change}/{addressIndex}";
+        }
     }
 }