Target netstandard2.0 and compatibility fixes

MAES.Fiskal.Example/Program.cs

@@ -16,14 +16,15 @@
 	Oib = "18945722090", // Identification number of company
 	OibOper = "18945722090", // Odentitfication numer of person operating POS
 	OznSlijed = OznakaSlijednostiType.N,
-    Pdv = [ // Taxes list
-        new ()
-        {
-            Stopa = "25.00", // Tax percentage (must be format 0.00)
-            Osnovica = "10.00", // Tax base (must be format 0.00)
-            Iznos = "2.50" // Tax amount (must be format 0.00)
-        }
-    ],
+	Pdv = new PorezType[]
+	{ // Taxes list
+		new PorezType
+		{
+			Stopa = "25.00", // Tax percentage (must be format 0.00)
+			Osnovica = "10.00", // Tax base (must be format 0.00)
+			Iznos = "2.50" // Tax amount (must be format 0.00)
+		}
+	},
     USustPdv = true, // Does company falls under tax obligation laws
     NacinPlac = NacinPlacanjaType.G // Type of payment (G - Cash, K - Cards, etc...)
 };

MAES.Fiskal.Tests/FiskalTests.cs

@@ -44,7 +44,7 @@ public class FiskalTests
         Oib = "18945722090",
         OibOper = "18945722090",
         OznSlijed = OznakaSlijednostiType.N,
-        Pdv = [ new() { Stopa = "25.00", Osnovica = "80.00", Iznos = "20.00" } ],
+        Pdv = new PorezType[] { new PorezType { Stopa = "25.00", Osnovica = "80.00", Iznos = "20.00" } },
         USustPdv = true,
         NacinPlac = NacinPlacanjaType.G
     };

MAES.Fiskal/MAES.Fiskal.csproj

@@ -1,16 +1,16 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
-    <!-- <TargetFramework>netstandard2.0</TargetFramework> -->
+    <TargetFramework>netstandard2.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
+    <LangVersion>10.0</LangVersion>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
 
     <!-- NuGet Metadata -->
     <PackageId>MAES.Fiskal</PackageId>
-    <Version>1.2.0</Version>
+    <Version>1.3.0</Version>
     <Authors>Roko Tomović</Authors>
     <Company>MAES</Company>
     <Description>This is a wrapper for invoice fiscalization in Republic of Croatia using C# and .NET 8+</Description>
@@ -22,9 +22,10 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="System.ServiceModel.Duplex" Version="6.0.0" />
-    <PackageReference Include="System.ServiceModel.Http" Version="6.0.0" />
-    <PackageReference Include="System.ServiceModel.Primitives" Version="6.0.0" />
+    <PackageReference Include="System.ServiceModel.Duplex" Version="4.8.1" />
+    <PackageReference Include="System.ServiceModel.Http" Version="4.8.1" />
+    <PackageReference Include="System.ServiceModel.Primitives" Version="4.8.1" />
+    <PackageReference Include="Microsoft.CSharp" Version="4.7.0" />
     <None Include="../README.md" Pack="true" PackagePath="\"/>
     <None Include="../LICENSE.md" Pack="true" PackagePath="" />
   </ItemGroup>

MAES.Fiskal/ReferenceTypeExtensions.cs

@@ -6,6 +6,7 @@
 using System.Text;
 using System.Xml;
 using System.Xml.Serialization;
+using System.Numerics;
 
 namespace MAES.Fiskal;
 
@@ -40,8 +41,8 @@ public static class ReferenceTypeExtensions
     /// <exception cref="ArgumentNullException"></exception>
     public static async Task<RacunOdgovor> SendAsync(this RacunType invoice, X509Certificate2 certificate, string url)
     {
-        ArgumentNullException.ThrowIfNull(invoice);
-        ArgumentNullException.ThrowIfNull(certificate);
+        if (invoice is null) throw new ArgumentNullException(nameof(invoice));
+        if (certificate is null) throw new ArgumentNullException(nameof(certificate));
 
         if (string.IsNullOrEmpty(invoice.ZastKod)) invoice.ZastKod = invoice.ZKI(certificate);
 
@@ -70,8 +71,8 @@ public static async Task<RacunOdgovor> SendAsync(this RacunType invoice, X509Cer
     /// <exception cref="ArgumentNullException"></exception>
     public async static Task<napojnicaResponse> SendAsync(this RacunNapojnicaType invoiceTip, X509Certificate2 certificate, string url)
     {
-        ArgumentNullException.ThrowIfNull(invoiceTip);
-        ArgumentNullException.ThrowIfNull(certificate);
+        if (invoiceTip is null) throw new ArgumentNullException(nameof(invoiceTip));
+        if (certificate is null) throw new ArgumentNullException(nameof(certificate));
 
         if (string.IsNullOrEmpty(invoiceTip.ZastKod)) invoiceTip.ZastKod = invoiceTip.ZKI(certificate);
 
@@ -130,11 +131,12 @@ public static RacunNapojnicaType ToRacunNapojnicaType(this RacunType invoice, Na
     /// <returns>ZKI string (Maybe GUID idk...)</returns>
     public static string ZKI(this RacunType invoice, X509Certificate2 certificate)
     {
-        ArgumentNullException.ThrowIfNull(certificate);
+        if (certificate is null) throw new ArgumentNullException(nameof(certificate));
 
         var b = Encoding.ASCII.GetBytes(invoice.Oib + invoice.DatVrijeme + invoice.BrRac.BrOznRac + invoice.BrRac.OznPosPr + invoice.BrRac.OznNapUr + invoice.IznosUkupno);
         var signData = (certificate.GetRSAPrivateKey()?.SignData(b, HashAlgorithmName.SHA1, RSASignaturePadding.Pkcs1)) ?? throw new Exception("Invalid cerrtificate. No RSA Private key.");
-        return new string([.. MD5.HashData(signData).SelectMany(x => x.ToString("x2"))]);
+        var hash = MD5.Create().ComputeHash(signData);
+        return string.Concat(hash.Select(x => x.ToString("x2")));
     }
 
     /// <summary>
@@ -145,11 +147,12 @@ public static string ZKI(this RacunType invoice, X509Certificate2 certificate)
     /// <returns>ZKI string (Maybe GUID idk...)</returns>
     public static string ZKI(this RacunNapojnicaType invoiceTip, X509Certificate2 certificate)
     {
-        ArgumentNullException.ThrowIfNull(certificate);
+        if (certificate is null) throw new ArgumentNullException(nameof(certificate));
 
         var b = Encoding.ASCII.GetBytes(invoiceTip.Oib + invoiceTip.DatVrijeme + invoiceTip.BrRac.BrOznRac + invoiceTip.BrRac.OznPosPr + invoiceTip.BrRac.OznNapUr + invoiceTip.IznosUkupno);
         var signData = (certificate.GetRSAPrivateKey()?.SignData(b, HashAlgorithmName.SHA1, RSASignaturePadding.Pkcs1)) ?? throw new Exception("Invalid cerrtificate. No RSA Private key.");
-        return new string([.. MD5.HashData(signData).SelectMany(x => x.ToString("x2"))]);
+        var hash2 = MD5.Create().ComputeHash(signData);
+        return string.Concat(hash2.Select(x => x.ToString("x2")));
     }
 
     static void sign(dynamic request, X509Certificate2 certificate)
@@ -191,58 +194,66 @@ static void sign(dynamic request, X509Certificate2 certificate)
 
         var s = xml.Signature;
 
-        if (keyInfoData.IssuerSerials[0] is not X509IssuerSerial serial) throw new Exception("There is no issuer serial in supplied certificate");
+        // Use certificate values directly (avoids depending on internal X509IssuerSerial type)
+        var certIssuerName = certificate.Issuer;
+        // Convert hex serial to decimal string for XML schema compatibility
+        string HexToDecimalString(string hex)
+        {
+            if (string.IsNullOrEmpty(hex)) return string.Empty;
+            var bytes = Enumerable.Range(0, hex.Length)
+                .Where(i => i % 2 == 0)
+                .Select(i => Convert.ToByte(hex.Substring(i, 2), 16))
+                .ToArray();
+            var little = bytes.Reverse().ToArray();
+            var bigInt = new BigInteger(little.Concat(new byte[] { 0 }).ToArray());
+            return bigInt.ToString();
+        }
+
+        var certSerialNumber = HexToDecimalString(certificate.GetSerialNumberString());
 
-        var certSerial = serial;
         request.Signature = new SignatureType
         {
             SignedInfo = new SignedInfoType
             {
                 CanonicalizationMethod = new CanonicalizationMethodType { Algorithm = s.SignedInfo.CanonicalizationMethod },
                 SignatureMethod = new SignatureMethodType { Algorithm = s.SignedInfo.SignatureMethod },
-                Reference =
-                    (from x in s.SignedInfo.References.OfType<Reference>()
-                     select new ReferenceType
-                     {
-                         URI = x.Uri,
-                         Transforms =
-                             (from t in transforms
-                              select new TransformType { Algorithm = t.Algorithm }).ToArray(),
-                         DigestMethod = new DigestMethodType { Algorithm = x.DigestMethod },
-                         DigestValue = x.DigestValue
-                     }).ToArray()
+                Reference = (from x in s.SignedInfo.References.OfType<Reference>()
+                             select new ReferenceType
+                             {
+                                 URI = x.Uri,
+                                 Transforms = (from t in transforms
+                                               select new TransformType { Algorithm = t.Algorithm }).ToArray(),
+                                 DigestMethod = new DigestMethodType { Algorithm = x.DigestMethod },
+                                 DigestValue = x.DigestValue
+                             }).ToArray()
             },
             SignatureValue = new SignatureValueType { Value = s.SignatureValue },
             KeyInfo = new KeyInfoType
             {
-                ItemsElementName = [ItemsChoiceType2.X509Data],
-                Items =
-                [
+                ItemsElementName = new ItemsChoiceType2[] { ItemsChoiceType2.X509Data },
+                Items = new object[]
+                {
                     new X509DataType
                     {
-                        ItemsElementName =
-                        [
-                            ItemsChoiceType.X509IssuerSerial,
-                            ItemsChoiceType.X509Certificate
-                        ],
-                        Items =
-                        [
+                        ItemsElementName = new ItemsChoiceType[] { ItemsChoiceType.X509IssuerSerial, ItemsChoiceType.X509Certificate },
+                        Items = new object[]
+                        {
                             new X509IssuerSerialType
                             {
-                                X509IssuerName = certSerial.IssuerName,
-                                X509SerialNumber = certSerial.SerialNumber
+                                X509IssuerName = certIssuerName,
+                                X509SerialNumber = certSerialNumber
                             },
                             certificate.RawData
-                        ]
+                        }
                     }
-                ]
+                }
             }
         };
     }
 
     static void throwOnResponseErrors(dynamic response)
     {
-        if (response.Greske is not GreskaType[] greske || greske.Length != 0) return;
+        if (response.Greske is not GreskaType[] greske || greske.Length == 0) return;
         throw new Exception($"Greška u fiskalizaciji: {string.Join("\n", greske.Select(x => $"{x.SifraGreske}: {x.PorukaGreske}"))}");
     }
 }