AfRApay.FTM: Ignore Yubikeys

AfRApay.FTM/AfRApay.FTM.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="PCSC" Version="6.1.3" />
+    <PackageReference Include="PCSC.Iso7816" Version="6.1.3" />
+    <PackageReference Include="System.CommandLine" Version="2.0.0-beta4.22272.1" />
+  </ItemGroup>
+
+</Project>

AfRApay.FTM/Program.cs

@@ -0,0 +1,182 @@
+using System.CommandLine;
+using PCSC;
+using PCSC.Monitoring;
+using PCSC.Iso7816;
+
+const decimal DefaultAmount = 1.50M;
+
+var rootCommand = new RootCommand("Fancy Test Machine for AfRApay");
+
+var listReadersOption = new Option<bool>("--list-readers", "List card readers and exit");
+rootCommand.Add(listReadersOption);
+
+var webAddrOption = new Option<Uri>("--web-addr", "Base URL for AfRApay.Web");
+webAddrOption.SetDefaultValue(new Uri("http://127.0.0.1:5296"));
+rootCommand.Add(webAddrOption);
+
+rootCommand.SetHandler((listReaders, webAddr) => {
+    using (var context = ContextFactory.Instance.Establish(SCardScope.System)) {
+        // Ignore Yubikeys.
+        var readerNames = context.GetReaders()
+            .Where((readerName) => !readerName.Contains("Yubico"))
+            .ToArray();
+
+        // We need at least one card reader or this won't work!
+        if (readerNames.Length == 0) {
+            Console.Error.WriteLine("Error: no card reader detected");
+            Environment.Exit(1);
+        }
+
+        // If --list-readers is passed, list readers and exit.
+        if (listReaders) {
+            Console.Error.WriteLine("----------- Connected Readers ----------");
+            foreach (var name in readerNames) {
+                Console.WriteLine(name);
+            }
+            Console.Error.WriteLine("----------------------------------------");
+            Environment.Exit(0);
+        }
+
+        using HttpClient httpClient = new();
+        httpClient.BaseAddress = webAddr;
+
+        Console.Error.WriteLine("----------------------------------------");
+        Console.Error.WriteLine("--- AfRApay FTM - Fancy Test Machine ---");
+        Console.Error.WriteLine("----------------------------------------");
+        Console.Error.WriteLine();
+        Console.Error.WriteLine("AfRApay.Web: {0}", httpClient.BaseAddress);
+        Console.Error.WriteLine();
+        Console.Error.WriteLine("Hotkeys (case insensitive):");
+        Console.Error.WriteLine("    [-] Debit (default)");
+        Console.Error.WriteLine("    [+] Credit");
+        Console.Error.WriteLine("    [=] Set amount (default: €1.50)");
+        Console.Error.WriteLine();
+        Console.Error.WriteLine("    [B] Balance query");
+        Console.Error.WriteLine("    [L] Link card (initiate from web UI)");
+        Console.Error.WriteLine("  [Esc] Cancel, reset state and amount");
+        Console.Error.WriteLine();
+        Console.Error.WriteLine("----------------------------------------");
+
+
+        // Listen for events on all connected readers.
+        using (var monitor = MonitorFactory.Instance.Create(SCardScope.System)) {
+            var state = TerminalState.Debit;
+            decimal amount = DefaultAmount;
+
+            monitor.Initialized += (_, args) => Console.WriteLine("[ Reader Initialized: {0} ]", args.ReaderName);
+            monitor.MonitorException += (_, args) => {
+                Console.Error.WriteLine("! ERROR: {0}", args);
+                Environment.Exit(1);
+            };
+            monitor.StatusChanged += (_, args) => Console.WriteLine("~ {0} -> {1}", args.LastState, args.NewState);
+            monitor.CardInserted += (_, args) => {
+                Console.WriteLine("> TAP: {0}", Convert.ToHexString(args.Atr));
+                var reader = new IsoReader(context, args.ReaderName, SCardShareMode.Shared, SCardProtocol.Any);
+                HandleTap(reader, httpClient, state, amount);
+            };
+            monitor.CardRemoved += (_, args) => {
+                Console.WriteLine("< OFF");
+                Console.WriteLine(); // Write a blank line between card taps for readability.
+            };
+
+            Console.WriteLine("[ Starting... ]");
+            monitor.Start(readerNames);
+            while (true) {
+                var key = Console.ReadKey();
+                var dontPrint = false;
+                 switch (key.Key) {
+                    case ConsoleKey.Subtract:
+                    case ConsoleKey.OemMinus:
+                        state = TerminalState.Debit;
+                        break;
+                    case ConsoleKey.Add:
+                    case ConsoleKey.OemPlus:
+                        state = TerminalState.Credit;
+                        break;
+                    case (ConsoleKey)0 when key.KeyChar == '=':
+                        Console.Error.Write("\b => ENTER AMOUNT: ");
+                        amount = Math.Abs(Decimal.Parse(Console.ReadLine() ?? "1.50".Trim()));
+                        break;
+                    case ConsoleKey.L:
+                        state = TerminalState.Link;
+                        break;
+                    case ConsoleKey.B:
+                        state = TerminalState.Balance;
+                        break;
+                    case ConsoleKey.Escape:
+                        state = TerminalState.Debit;
+                        amount = DefaultAmount;
+                        break;
+                    default:
+                        Console.Error.Write("\b");
+                        dontPrint = true;
+                        break;
+                };
+                if (dontPrint) {
+                    // Invalid input, just ignore it.
+                } else if (state == TerminalState.Debit || state == TerminalState.Credit) {
+                    Console.Error.WriteLine("\b => {0}: €{1}", state, amount);
+                } else {
+                    Console.Error.WriteLine("\b => {0}", state);
+                }
+            }
+        }
+    }
+}, listReadersOption, webAddrOption);
+
+return await rootCommand.InvokeAsync(args);
+
+// Queries a card for data when one is tapped.
+static async void HandleTap(IsoReader reader, HttpClient httpClient, TerminalState state, decimal amount) {
+    // Send a PCSC pseudo-APDU to query the ISO 14443 UID.
+    var uidRsp = reader.Transmit(new CommandApdu(IsoCase.Case2Short, SCardProtocol.Any) {
+        CLA = 0xFF,
+        Instruction = InstructionCode.GetData,
+        P1 = 0x00,
+        P2 = 0x00,
+    });
+    if (!IsSucc(uidRsp)) {
+        Console.Error.WriteLine("--> Card Error: SW1={0} SW2={1}", (SW1Code)uidRsp.SW1, uidRsp.SW2);
+        return;
+    }
+    var uid = uidRsp.GetData();
+    Console.WriteLine("  UID: {0}", Convert.ToHexString(uid));
+
+    // Query the backend, which endpoint depending on terminal state.
+    switch (state) {
+        case TerminalState.Debit:
+        case TerminalState.Credit:
+            var finalAmount = Math.Abs(amount) * (state == TerminalState.Debit ? 1 : -1);
+            await CallGet(httpClient, String.Format("/api/card/transaction?card={0}&amount={1}", Convert.ToHexString(uid), finalAmount));
+            break;
+        case TerminalState.Link:
+            await CallGet(httpClient, String.Format("/api/card/link?card={0}", Convert.ToHexString(uid)));
+            break;
+        case TerminalState.Balance:
+            await CallGet(httpClient, String.Format("/api/card/balance?card={0}", Convert.ToHexString(uid)));
+            break;
+        default:
+            Console.Error.WriteLine("UNKNOWN TERMINAL STATE: {0}", state);
+            break;
+    }
+}
+
+// Was the command successful?
+static bool IsSucc(Response rsp) {
+    return rsp.SW1 == (byte)SW1Code.Normal && rsp.SW2 == 0x00;
+}
+
+static async Task<string> CallGet(HttpClient client, string path) {
+    Console.WriteLine("  -> GET {0}", path);
+    var rsp = await client.GetStringAsync(path);
+    Console.WriteLine("  <- {0}", rsp);
+    return rsp;
+}
+
+// Terminal State.
+enum TerminalState {
+    Debit,
+    Credit,
+    Link,
+    Balance,
+};

AfRApay.sln

@@ -1,7 +1,10 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
+# 
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AfRApay.Web", "AfRApay.Web\AfRApay.Web.csproj", "{7187F28E-58C5-44BC-BDBA-17C387EA7AF3}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AfRApay.FTM", "AfRApay.FTM\AfRApay.FTM.csproj", "{019D3978-5C9A-40C6-BFA0-0742E9F561E7}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -12,5 +15,9 @@ Global
 		{7187F28E-58C5-44BC-BDBA-17C387EA7AF3}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{7187F28E-58C5-44BC-BDBA-17C387EA7AF3}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{7187F28E-58C5-44BC-BDBA-17C387EA7AF3}.Release|Any CPU.Build.0 = Release|Any CPU
+		{019D3978-5C9A-40C6-BFA0-0742E9F561E7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{019D3978-5C9A-40C6-BFA0-0742E9F561E7}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{019D3978-5C9A-40C6-BFA0-0742E9F561E7}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{019D3978-5C9A-40C6-BFA0-0742E9F561E7}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal

shell.nix

@@ -3,8 +3,12 @@ pkgs.mkShell {
   name = "afrapay";
   packages = with pkgs; [
     dotnet-sdk_7
+    pcsclite
 
     # ESP32 tooling (for MateCard)
     platformio
   ];
+
+  # AfRApay.FTM tries to dlopen the pcsclite library at runtime.
+  LD_LIBRARY_PATH = [ "${pkgs.pcsclite.out}/lib" ];
 }