Merge pull request #498 from codebude/feature/392-fix-and-improve-payment-payload-generator-validation

Feature/392 fix and improve payment payload generator validation

Author: codebude

QRCoder/PayloadGenerator.cs

@@ -2512,6 +2512,13 @@ public override string ToString()
 
             public byte[] ToBytes()
             {
+                //Setup byte encoder
+                //Encode return string as byte[] with correct CharacterSet
+#if !NET35_OR_GREATER
+                Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
+#endif
+                var cp = this.characterSet.ToString().Replace("_", "-");
+
                 //Calculate the seperator
                 separator = DetermineSeparator();
 
@@ -2523,21 +2530,19 @@ public byte[] ToBytes()
                     $"{separator}BIC={mFields.BIC}" +
                     $"{separator}CorrespAcc={mFields.CorrespAcc}";
 
+                //Check length of mandatory field block (-8 => Removing service data block bytes from ret length)
+                int bytesMandatoryLen = Encoding.Convert(Encoding.UTF8, Encoding.GetEncoding(cp), Encoding.UTF8.GetBytes(ret)).Length - 8;
+                if (bytesMandatoryLen > 300)
+                    throw new RussiaPaymentOrderException($"Data too long. Mandatory data must not exceed 300 bytes, but actually is {bytesMandatoryLen} bytes long. Remove additional data fields or shorten strings/values.");
+
+
                 //Add optional fields, if filled
                 var optionalFieldsList = GetOptionalFieldsAsList();
                 if (optionalFieldsList.Count > 0)
                     ret += $"|{string.Join("|", optionalFieldsList.ToArray())}";
                 ret += separator;
 
-                //Encode return string as byte[] with correct CharacterSet
-#if !NET35_OR_GREATER
-                Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
-#endif
-                var cp = this.characterSet.ToString().Replace("_", "-");
-                byte[] bytesOut = Encoding.Convert(Encoding.UTF8, Encoding.GetEncoding(cp), Encoding.UTF8.GetBytes(ret));
-                if (bytesOut.Length > 300)
-                    throw new RussiaPaymentOrderException($"Data too long. Payload must not exceed 300 bytes, but actually is {bytesOut.Length} bytes long. Remove additional data fields or shorten strings/values.");
-                return bytesOut;
+                return Encoding.Convert(Encoding.UTF8, Encoding.GetEncoding(cp), Encoding.UTF8.GetBytes(ret));
             }
 
 

QRCoderTests/PayloadGeneratorTests.cs

@@ -3280,24 +3280,44 @@ public void russiapayment_generator_should_throw_no_separator_exception()
         [Fact]
         [Category("PayloadGenerator/RussiaPaymentOrder")]
         public void russiapayment_generator_should_throw_data_too_long_exception()
+        {
+            var account = "40702810138250123017";
+            var bic = "044525225";
+            var bankName = "A very very very very very long bank name";
+            // We use € symbol for the test case, because it needs 2-bytes. Otherwise we couldn't generate more than 300 bytes
+            // of mandatory data to trigger the test case and stay at the same time within the 160 chars field validation limit
+            var name = "A very €€€€ €€€€ €€€€ €€€€ very very very very very very very very very very very very very very very very very very very very very very very very ver long name";
+            var correspAcc = "30101810400000000225";
+            var generator = new PayloadGenerator.RussiaPaymentOrder(name, account, bankName, bic, correspAcc);
+
+            var exception = Record.Exception(() => generator.ToString());
+            Assert.NotNull(exception);
+            Assert.IsType<PayloadGenerator.RussiaPaymentOrder.RussiaPaymentOrderException>(exception);
+            exception.Message.ShouldStartWith("Data too long");
+        }
+
+        [Fact]
+        [Category("PayloadGenerator/RussiaPaymentOrder")]
+        public void russiapayment_generator_should_throw_no_data_too_long_exception()
         {
             var account = "40702810138250123017";
             var bic = "044525225";
             var bankName = "ОАО | \"БАНК\"";
-            var name = "A very very very very very very very very very very very very very very very very very very very very very very very very very very very very very long name";
+            var name = "A name";
             var correspAcc = "30101810400000000225";
             var optionalFields = new PayloadGenerator.RussiaPaymentOrder.OptionalFields()
             {
                 FirstName = "Another long long long long long long long long long long long long long long firstname",
                 LastName = "Another long long long long long long long long long long long long long long lastname",
+                Category = "A pretty long long long long long long long long long long long long long category",
                 Sum = "125000"
             };
             var generator = new PayloadGenerator.RussiaPaymentOrder(name, account, bankName, bic, correspAcc, optionalFields);
 
+            // Should throw no exception as the 300 byte limit applies only to the mandatory fields
+            // See https://github.com/codebude/QRCoder/issues/392
             var exception = Record.Exception(() => generator.ToString());
-            Assert.NotNull(exception);
-            Assert.IsType<PayloadGenerator.RussiaPaymentOrder.RussiaPaymentOrderException>(exception);
-            exception.Message.ShouldStartWith("Data too long");
+            Assert.Null(exception);
         }
 
         [Fact]