Payment transaction fixed.

QRBee.Core/Data/ClientCardData.cs

@@ -4,8 +4,8 @@
     {
         public string TransactionId      { get; set; }
         public string CardNumber         { get; set; }
-        public string ExpirationDateMMYY { get; set; }
+        public string ExpirationDateYYYYMM { get; set; }
-        public string ValidFrom          { get; set; }
+        public string ValidFromYYYYMM      { get; set; }
         public string CardHolderName     { get; set; }
         public string CVC                { get; set; }
         public int? IssueNo              { get; set; }
@@ -15,7 +15,7 @@
         /// WARNING: this should always be encrypted and never transmitted in clear text form.
         /// </summary>
         /// <returns>Converted string</returns>
-        public string AsString() => $"{TransactionId}|{CardNumber}|{ExpirationDateMMYY}|{ValidFrom}|{CardHolderName}|{CVC}|{IssueNo ?? 0}";
+        public string AsString() => $"{TransactionId}|{CardNumber}|{ExpirationDateYYYYMM}|{ValidFromYYYYMM}|{CardHolderName}|{CVC}|{IssueNo ?? 0}";
 
         public static ClientCardData FromString(string input)
         {
@@ -29,8 +29,8 @@
             {
                 TransactionId      = s[0],
                 CardNumber         = s[1],
-                ExpirationDateMMYY = s[2],
+                ExpirationDateYYYYMM = s[2],
-                ValidFrom = s[3],
+                ValidFromYYYYMM      = s[3],
                 CardHolderName     = s[4],
                 CVC                = s[5]
             };

QRBee.Core/Data/ClientToMerchantResponse.cs

@@ -3,22 +3,17 @@
     public record ClientToMerchantResponse
     {
         public MerchantToClientRequest MerchantRequest { get; set; }
-
         public string ClientId                         { get; set; }
-
         public DateTime TimeStampUTC                   { get; set; }
-
         public string ClientSignature                  { get; set; }
-
         public string EncryptedClientCardData          { get; set; }
 
         /// <summary>
         /// Convert ClientToMerchantResponse to string to be used as QR Code source (along with client signature)
         /// </summary>
         /// <returns> Converted string</returns>
-        public string AsQRCodeString() => $"{ClientId}|{TimeStampUTC:O}|{ClientSignature}";
+        public string AsQRCodeString()     => $"{ClientId}|{TimeStampUTC:yyyy-MM-dd:HH.mm.ss.ffff}|{ClientSignature}|{EncryptedClientCardData}";
-
+        public string AsDataForSignature() => $"{ClientId}|{TimeStampUTC:yyyy-MM-dd:HH.mm.ss.ffff}|{MerchantRequest.AsQRCodeString()}";
-        public string AsDataForSignature() => $"{ClientId}|{TimeStampUTC:O}|{MerchantRequest.AsQRCodeString()}";
 
         /// <summary>
         /// Convert from string
@@ -26,19 +21,26 @@
         /// <param name="input">A string representation of ClientToMerchantResponse</param>
         /// <returns>Converted string</returns>
         /// <exception cref="ApplicationException">Thrown if the input string is incorrect</exception>
-        public static ClientToMerchantResponse FromString(string input)
+        public static ClientToMerchantResponse FromString(string input, MerchantToClientRequest merchantRequest)
         {
+            if (merchantRequest == null)
+                throw new ArgumentNullException(nameof(merchantRequest));
+            if ( string.IsNullOrWhiteSpace(merchantRequest.MerchantSignature) )
+                throw new ApplicationException("Request is not signed by a merchant");
+
             var s = input.Split('|');
-            if (s.Length < 3)
+            if (s.Length < 4)
             {
-                throw new ApplicationException($"Expected 3 or more elements but got {s.Length}");
+                throw new ApplicationException($"Expected 4 elements but got {s.Length}");
             }
 
             var res = new ClientToMerchantResponse()
             {
                 ClientId                = s[0],
-                TimeStampUTC    = DateTime.ParseExact(s[1], "O", null),
+                TimeStampUTC            = DateTime.ParseExact(s[1], "yyyy-MM-dd:HH.mm.ss.ffff", null),
-                ClientSignature = s[2]
+                ClientSignature         = s[2],
+                EncryptedClientCardData = s[3],
+                MerchantRequest         = merchantRequest
             };
 
             return res;

QRBee.Core/Data/MerchantToClientRequest.cs

@@ -5,15 +5,10 @@ namespace QRBee.Core.Data
     public record MerchantToClientRequest
     {
         public string MerchantId            { get; set; }
-
         public string MerchantTransactionId { get; set; }
-
         public string Name                  { get; set; }
-
         public decimal Amount               { get; set; }
-
         public DateTime TimeStampUTC        { get; set; }
-
         public string MerchantSignature     { get; set; }
 
         /// <summary>
@@ -21,8 +16,7 @@ namespace QRBee.Core.Data
         /// </summary>
         /// <returns>String conversion</returns>
         public string AsQRCodeString()     => $"{AsDataForSignature()}|{MerchantSignature}";
-
+        public string AsDataForSignature() => $"{MerchantId}|{MerchantTransactionId}|{Name}|{Amount.ToString("0.00", CultureInfo.InvariantCulture)}|{TimeStampUTC:yyyy-MM-dd:HH.mm.ss.ffff}";
-        public string AsDataForSignature() => $"{MerchantId}|{MerchantTransactionId}|{Name}|{Amount.ToString("0.00", CultureInfo.InvariantCulture)}|{TimeStampUTC:O}";
 
         /// <summary>
         /// Convert from string
@@ -44,7 +38,7 @@ namespace QRBee.Core.Data
                 MerchantTransactionId = s[1],
                 Name                  = s[2],
                 Amount                = Convert.ToDecimal(s[3], CultureInfo.InvariantCulture),
-                TimeStampUTC = DateTime.ParseExact(s[4],"O",null),
+                TimeStampUTC          = DateTime.ParseExact(s[4], "yyyy-MM-dd:HH.mm.ss.ffff", null),
                 MerchantSignature     = s[5]
             };
 

QRBee.Core/Data/PaymentResponse.cs

@@ -18,6 +18,6 @@
         /// Convert PaymentResponse to string to be encrypted and transmitted back to merchant
         /// </summary>
         /// <returns>Converted string</returns>
-        public string AsDataForSignature() => $"{ServerTransactionId}|{PaymentRequest.AsString()}|{ServerTimeStampUTC:O}|{Success}|{RejectReason}";
+        public string AsDataForSignature() => $"{ServerTransactionId}|{PaymentRequest.AsString()}|{ServerTimeStampUTC:yyyy-MM-dd:HH.mm.ss.ffff}|{Success}|{RejectReason}";
     }
 }

QRBee/QRBee/ViewModels/ClientPageViewModel.cs

@@ -149,8 +149,11 @@ namespace QRBee.ViewModels
         {
 
             var answer   = await Application.Current.MainPage.DisplayAlert("Confirmation", "Would you like to accept the offer?", "Yes", "No");
-            if (!answer) return;
+            if (!answer)
+                return;
+
             var settings = _localSettings.LoadSettings();
+
             var response = new ClientToMerchantResponse
             {
                 ClientId                = settings.ClientId,
@@ -158,6 +161,7 @@ namespace QRBee.ViewModels
                 MerchantRequest         = _merchantToClientRequest,
                 EncryptedClientCardData = EncryptCardData(settings, _merchantToClientRequest.MerchantTransactionId)
             };
+
             var clientSignature       = _securityService.Sign(Encoding.UTF8.GetBytes(response.AsDataForSignature()));
             response.ClientSignature  = Convert.ToBase64String(clientSignature);
 
@@ -173,8 +177,8 @@ namespace QRBee.ViewModels
            {
                TransactionId        = transactionId,
                CardNumber           = settings.CardNumber,
-               ExpirationDateMMYY = settings.ExpirationDate,
+               ExpirationDateYYYYMM = string.IsNullOrWhiteSpace(settings.ExpirationDate) ? null : DateTime.Parse(settings.ExpirationDate).ToString("yyyy-MM"),
-               ValidFrom          = settings.ValidFrom,
+               ValidFromYYYYMM      = string.IsNullOrWhiteSpace(settings.ValidFrom)      ? null : DateTime.Parse(settings.ValidFrom).ToString("yyyy-MM"),
                CardHolderName       = settings.CardHolderName,
                CVC                  = settings.CVC,
                IssueNo              = settings.IssueNo

QRBee/QRBee/ViewModels/MerchantPageViewModel.cs

@@ -38,15 +38,16 @@ namespace QRBee.ViewModels
             try
             {
                 var result          = await _scanner.ScanQR();
-                if (result == null) 
+                if (string.IsNullOrWhiteSpace(result)) 
                     return;
 
-                var client = new HttpClient(GetInsecureHandler());
+                var clientResponse  = ClientToMerchantResponse.FromString(result, _lastRequest);
 
-                var service = new Core.Client.Client(_settings.QRBeeApiUrl, client);
+                if (string.IsNullOrWhiteSpace(clientResponse.ClientSignature))
-                var clientResponse = ClientToMerchantResponse.FromString(result);
+                    throw new ApplicationException("Request is not signed by a client");
+                if (string.IsNullOrWhiteSpace(clientResponse.EncryptedClientCardData))
+                    throw new ApplicationException("Request does not contain client's card data");
 
-                clientResponse.MerchantRequest = _lastRequest;
                 var paymentRequest  = new PaymentRequest
                 {
                     ClientResponse  = clientResponse
@@ -55,7 +56,19 @@ namespace QRBee.ViewModels
                 //QrCode = null;
                 IsVisible = false;
 
-                var response = await service.PayAsync(paymentRequest);
+                // ------------------------------------- SEND PAYMENT REQUEST ------------------------------------------
+                // 
+                //                             ____   _ __   ____  __ _____ _   _ _____ 
+                //                            |  _ \ / \\ \ / /  \/  | ____| \ | |_   _|
+                //                            | |_) / _ \\ V /| |\/| |  _| |  \| | | |  
+                //                            |  __/ ___ \| | | |  | | |___| |\  | | |  
+                //                            |_| /_/   \_\_| |_|  |_|_____|_| \_| |_|  
+                //                                           
+                //
+                var apiService = new Core.Client.Client(_settings.QRBeeApiUrl, new HttpClient(GetInsecureHandler()));
+                var response   = await apiService.PayAsync(paymentRequest);
+                //
+                // -----------------------------------------------------------------------------------------------------
 
                 if (response.Success)
                 {

QRBeeApi/Services/Database/IStorage.cs

@@ -31,6 +31,12 @@
         /// <param name="info">Information to be inserted</param>
         Task PutTransactionInfo(TransactionInfo info);
 
+        /// <summary>
+        /// Try to find if the Transaction already exists in the database
+        /// </summary>
+        /// <param name="id">parameter by which to find TransactionInfo</param>
+        /// <returns>null if transaction doesn't exist or TransactionInfo</returns>
+        Task<TransactionInfo?> TryGetTransactionInfoByTransactionId(string id);
         /// <summary>
         /// Retrieve transaction information from database
         /// </summary>

QRBeeApi/Services/Database/Storage.cs

@@ -71,7 +71,7 @@ namespace QRBee.Api.Services.Database
         {
             var collection = _database.GetCollection<TransactionInfo>("Transactions");
 
-            var transaction = await TryGetTransactionInfo(info.Id);
+            var transaction = await TryGetTransactionInfoByTransactionId(info.Id);
 
             if (transaction == null)
             {
@@ -83,12 +83,7 @@ namespace QRBee.Api.Services.Database
             _logger.LogInformation($"Found transaction with ClientId: {info.Id}");
         }
 
-        /// <summary>
+        public async Task<TransactionInfo?> TryGetTransactionInfoByTransactionId(string id)
-        /// Try to find if the Transaction already exists in the database
-        /// </summary>
-        /// <param name="id">parameter by which to find TransactionInfo</param>
-        /// <returns>null if transaction doesn't exist or TransactionInfo</returns>
-        private async Task<TransactionInfo?> TryGetTransactionInfo(string id)
         {
             var collection = _database.GetCollection<TransactionInfo>("Transactions");
             using var cursor = await collection.FindAsync($"{{ _id: \"{id}\" }}");
@@ -102,7 +97,7 @@ namespace QRBee.Api.Services.Database
 
         public async Task<TransactionInfo> GetTransactionInfoByTransactionId(string id)
         {
-            var transaction = await TryGetTransactionInfo(id);
+            var transaction = await TryGetTransactionInfoByTransactionId(id);
             return transaction ?? throw new ApplicationException($"Transaction with Id: {id} not found.");
         }
 

QRBeeApi/Services/QRBeeAPIService.cs

@@ -18,17 +18,19 @@ namespace QRBee.Api.Services
         private readonly ISecurityService   _securityService;
         private readonly IPrivateKeyHandler _privateKeyHandler;
         private readonly IPaymentGateway    _paymentGateway;
+        private readonly ILogger<QRBeeAPIService> _logger;
         private static readonly object      _lock = new ();
 
         private const int MaxNameLength = 512;
         private const int MaxEmailLength = 512;
 
-        public QRBeeAPIService(IStorage storage, ISecurityService securityService, IPrivateKeyHandler privateKeyHandler, IPaymentGateway paymentGateway)
+        public QRBeeAPIService(IStorage storage, ISecurityService securityService, IPrivateKeyHandler privateKeyHandler, IPaymentGateway paymentGateway, ILogger<QRBeeAPIService> logger)
         {
             _storage           = storage;
             _securityService   = securityService;
             _privateKeyHandler = privateKeyHandler;
             _paymentGateway    = paymentGateway;
+            _logger            = logger;
             Init(_privateKeyHandler);
         }
 
@@ -126,10 +128,23 @@ namespace QRBee.Api.Services
 
         public async Task<PaymentResponse> Pay(PaymentRequest value)
         {
+
+            // --------------------------------- RECEIVE PAYMENT REQUEST --------------------------------------
+            // 
+            //                             ____   _ __   ____  __ _____ _   _ _____ 
+            //                            |  _ \ / \\ \ / /  \/  | ____| \ | |_   _|
+            //                            | |_) / _ \\ V /| |\/| |  _| |  \| | | |  
+            //                            |  __/ ___ \| | | |  | | |___| |\  | | |  
+            //                            |_| /_/   \_\_| |_|  |_|_____|_| \_| |_|  
+            //                                           
+            //
+
             try
             {
                 //1. Check payment request parameters for validity
                 ValidateTransaction(value);
+                var tid = value.ClientResponse.MerchantRequest.MerchantTransactionId;
+                _logger.LogInformation($"Transaction=\"{tid}\" Pre-validated");
 
                 //2. Check client signature
                 var t2 = CheckSignature(
@@ -144,22 +159,25 @@ namespace QRBee.Api.Services
                     value.ClientResponse.MerchantRequest.MerchantId);
 
                 //4. Check if transaction was already processed
-                var t4 = CheckTransaction(value.ClientResponse.MerchantRequest.MerchantTransactionId);
+                var t4 = CheckTransaction(tid);
 
                 //Parallel task execution
                 await Task.WhenAll(t2, t3, t4);
+                _logger.LogInformation($"Transaction=\"{tid}\" Fully validated");
 
                 //5. Decrypt client card data
                 var clientCardData = DecryptClientData(value.ClientResponse.EncryptedClientCardData);
 
                 //6. Check client card data for validity
-                await CheckClientCardData(clientCardData);
+                await CheckClientCardData(clientCardData, value.ClientResponse.MerchantRequest.MerchantTransactionId);
+                _logger.LogInformation($"Transaction=\"{tid}\" Client card data validated");
 
                 //7. Register preliminary transaction record with expiry of one minute
                 var info = Convert(value);
                 info.Status = TransactionInfo.TransactionStatus.Pending;
 
                 await _storage.PutTransactionInfo(info);
+                _logger.LogInformation($"Transaction=\"{tid}\" initialized");
 
                 //8. Send client card data to a payment gateway
                 var res = await _paymentGateway.Payment(info, clientCardData);
@@ -175,6 +193,7 @@ namespace QRBee.Api.Services
                     info.RejectReason = res.ErrorMessage;
                 }
                 await _storage.UpdateTransaction(info);
+                _logger.LogInformation($"Transaction=\"{tid}\" complete Status=\"{info.Status}\"");
 
                 //10. Make response for merchant
                 var response = MakePaymentResponse(value, info.TransactionId ?? "", info.Status==TransactionInfo.TransactionStatus.Succeeded, info.RejectReason);
@@ -202,6 +221,7 @@ namespace QRBee.Api.Services
 
             var signature            = _securityService.Sign(Encoding.UTF8.GetBytes(response.AsDataForSignature()));
             response.ServerSignature = System.Convert.ToBase64String(signature);
+
             return response;
         }
 
@@ -246,8 +266,8 @@ namespace QRBee.Api.Services
 
         private async Task CheckTransaction(string transactionId)
         {
-            var info = await _storage.GetTransactionInfoByTransactionId(transactionId);
+            var info = await _storage.TryGetTransactionInfoByTransactionId(transactionId);
-            switch (info.Status)
+            switch (info?.Status)
             {
                 case TransactionInfo.TransactionStatus.Succeeded:
                     throw new ApplicationException($"Transaction with Id: {transactionId} was already made.");
@@ -265,14 +285,20 @@ namespace QRBee.Api.Services
             var info  = System.Convert.FromBase64String(encryptedClientCardData);
             var bytes = _securityService.Decrypt(info);
             var s     = Encoding.UTF8.GetString(bytes);
+
             return ClientCardData.FromString(s);
         }
 
-        private async Task CheckClientCardData(ClientCardData data)
+        private async Task CheckClientCardData(ClientCardData data, string merchantTransactionId)
         {
+            if ( data.TransactionId != merchantTransactionId)
+                throw new ApplicationException($"Transaction IDs don't match");
+
+            //_logger.LogInformation(data.AsString());
+
             var transactionId  = data.TransactionId;
-            var expirationDate = DateTime.Parse(data.ExpirationDateMMYY);
+            var expirationDate = string.IsNullOrWhiteSpace(data.ExpirationDateYYYYMM) ? default : DateTime.ParseExact(data.ExpirationDateYYYYMM, "yyyy-MM", null);
-            var validFrom = DateTime.Parse(data.ValidFrom);
+            var validFrom      = string.IsNullOrWhiteSpace(data.ValidFromYYYYMM)      ? default : DateTime.ParseExact(data.ValidFromYYYYMM,      "yyyy-MM", null);
             var holderName     = data.CardHolderName;
 
             await CheckTransaction(transactionId);

QRBeeApi/appsettings.json

@@ -12,8 +12,8 @@
 
   "Logging": {
     "LogLevel": {
-      "Default": "Trace"
+      "Default": "Trace",
-      //"Microsoft.AspNetCore": "Debug"
+      "Microsoft.AspNetCore": "Information"
     }
   },
   "AllowedHosts": "*"