Save credentials

src/WinSW.Core/Native/ConsoleEx.cs

@@ -75,6 +75,7 @@ namespace WinSW.Native
                     }
                     else if (key == '\r')
                     {
+                        Write(consoleOutput, Environment.NewLine);
                         break;
                     }
                     else if (key == '\b')

src/WinSW.Core/Native/CredentialApis.cs

@@ -7,7 +7,15 @@ namespace WinSW.Native
 {
     internal static class CredentialApis
     {
+        internal const uint CRED_PERSIST_LOCAL_MACHINE = 2;
+
+        internal const uint CRED_TYPE_GENERIC = 1;
+
         internal const uint CREDUIWIN_GENERIC = 0x00000001;
+        internal const uint CREDUIWIN_CHECKBOX = 0x00000002;
+
+        [DllImport(Libraries.Advapi32, SetLastError = false)]
+        internal static extern unsafe void CredFree(CREDENTIALW* buffer);
 
         [DllImport(Libraries.CredUI, SetLastError = true, CharSet = CharSet.Unicode, EntryPoint = "CredPackAuthenticationBufferW")]
         internal static extern bool CredPackAuthenticationBuffer(
@@ -17,6 +25,9 @@ namespace WinSW.Native
             IntPtr packedCredentials,
             ref int packedCredentialsSize);
 
+        [DllImport(Libraries.Advapi32, SetLastError = true, CharSet = CharSet.Unicode)]
+        internal static extern unsafe bool CredReadW(string targetName, uint type, uint flags, out CREDENTIALW* credential);
+
         [DllImport(Libraries.CredUI, SetLastError = false, CharSet = CharSet.Unicode, EntryPoint = "CredUIPromptForWindowsCredentialsW")]
         internal static extern int CredUIPromptForWindowsCredentials(
             in CREDUI_INFO uiInfo,
@@ -41,6 +52,26 @@ namespace WinSW.Native
             string? password,
             ref int maxPassword);
 
+        [DllImport(Libraries.Advapi32, SetLastError = true)]
+        internal static extern bool CredWriteW(in CREDENTIALW credential, uint flags);
+
+        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
+        internal unsafe struct CREDENTIALW
+        {
+            internal uint Flags;
+            internal uint Type;
+            internal char* TargetName;
+            internal char* Comment;
+            internal FileTime LastWritten;
+            internal int CredentialBlobSize;
+            internal IntPtr CredentialBlob;
+            internal uint Persist;
+            internal uint AttributeCount;
+            internal uint Attributes;
+            internal char* TargetAlias;
+            internal char* UserName;
+        }
+
         [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
         internal struct CREDUI_INFO
         {

src/WinSW.Core/Native/Credentials.cs

@@ -7,6 +7,52 @@ namespace WinSW.Native
 {
     internal static class Credentials
     {
+        internal static unsafe bool Load(string targetName, out string? userName, out string? password)
+        {
+            if (!CredReadW(targetName, CRED_TYPE_GENERIC, 0, out var credential))
+            {
+                userName = null;
+                password = null;
+                return false;
+            }
+
+            try
+            {
+                userName = Marshal.PtrToStringUni((IntPtr)credential->UserName);
+                password = Marshal.PtrToStringUni(credential->CredentialBlob, credential->CredentialBlobSize);
+                return true;
+            }
+            finally
+            {
+                CredFree(credential);
+            }
+        }
+
+        internal static unsafe void Save(string targetName, string? userName, string? password)
+        {
+#pragma warning disable SA1519 // Braces should not be omitted from multi-line child statement
+            fixed (char* targetNamePtr = targetName)
+            fixed (char* userNamePtr = userName)
+            fixed (char* passwordPtr = password)
+            {
+                var credential = new CREDENTIALW
+                {
+                    Type = CRED_TYPE_GENERIC,
+                    TargetName = targetNamePtr,
+                    CredentialBlobSize = password?.Length * sizeof(char) ?? 0,
+                    CredentialBlob = (IntPtr)passwordPtr,
+                    Persist = CRED_PERSIST_LOCAL_MACHINE,
+                    UserName = userNamePtr,
+                };
+
+                if (!CredWriteW(credential, 0))
+                {
+                    Throw.Command.Win32Exception("Failed to save credential.");
+                }
+            }
+#pragma warning restore SA1519 // Braces should not be omitted from multi-line child statement
+        }
+
         internal static void PromptForCredentialsConsole(ref string? userName, ref string? password)
         {
             using var consoleOutput = ConsoleEx.OpenConsoleOutput();
@@ -24,7 +70,7 @@ namespace WinSW.Native
             }
         }
 
-        internal static void PromptForCredentialsDialog(ref string? userName, ref string? password, string caption, string message)
+        internal static void PromptForCredentialsDialog(ref string? userName, ref string? password, string caption, string message, ref bool save)
         {
             userName ??= string.Empty;
             password ??= string.Empty;
@@ -52,12 +98,11 @@ namespace WinSW.Native
 
                 var info = new CREDUI_INFO
                 {
-                    Size = Marshal.SizeOf(typeof(CREDUI_INFO)),
+                    Size = Marshal.SizeOf<CREDUI_INFO>(),
                     CaptionText = caption,
                     MessageText = message,
                 };
                 uint authPackage = 0;
-                bool save = false;
                 int error = CredUIPromptForWindowsCredentials(
                     info,
                     0,
@@ -67,10 +112,15 @@ namespace WinSW.Native
                     out var outBuffer,
                     out uint outBufferSize,
                     ref save,
-                    CREDUIWIN_GENERIC);
+                    CREDUIWIN_GENERIC | CREDUIWIN_CHECKBOX);
 
                 if (error != Errors.ERROR_SUCCESS)
                 {
+                    if (error == Errors.ERROR_CANCELLED)
+                    {
+                        Throw.Command.Win32Exception(error);
+                    }
+
                     throw new Win32Exception(error);
                 }
 

src/WinSW.Core/Native/FileTime.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace WinSW.Native
+{
+    internal struct FileTime
+    {
+        internal int LowDateTime;
+        internal int HighDateTime;
+
+        public DateTime ToDateTime() => DateTime.FromFileTime(((long)this.HighDateTime << 32) + this.LowDateTime);
+    }
+}

src/WinSW.Core/Native/RegistryApis.cs

@@ -18,14 +18,6 @@ namespace WinSW.Native
             int* maxValueNameLength,
             int* maxValueLength,
             int* securityDescriptorLength,
-            out FILETIME lastWriteTime);
-
-        internal struct FILETIME
-        {
-            internal int LowDateTime;
-            internal int HighDateTime;
-
-            public long ToTicks() => ((long)this.HighDateTime << 32) + this.LowDateTime;
-        }
+            out FileTime lastWriteTime);
     }
 }

src/WinSW.Core/Util/RegistryKeyExtensions.cs

@@ -16,7 +16,7 @@ namespace WinSW.Util
                 Throw.Command.Win32Exception(error, "Failed to query registry key.");
             }
 
-            return DateTime.FromFileTime(lastWriteTime.ToTicks());
+            return lastWriteTime.ToDateTime();
         }
     }
 }

src/WinSW/Program.cs

@@ -434,6 +434,7 @@ namespace WinSW
                     Throw.Command.Win32Exception(Errors.ERROR_SERVICE_EXISTS, "Failed to install the service.");
                 }
 
+                bool saveCredential = false;
                 if (config.HasServiceAccount())
                 {
                     username = config.ServiceAccountUserName ?? username;
@@ -444,11 +445,16 @@ namespace WinSW
                         switch (config.ServiceAccountPrompt)
                         {
                             case "dialog":
+                                if (!Credentials.Load($"WinSW:{config.Name}", out username, out password))
+                                {
                                     Credentials.PromptForCredentialsDialog(
                                         ref username,
                                         ref password,
                                         "Windows Service Wrapper",
-                                    "Enter the service account credentials");
+                                        "Enter the service account credentials",
+                                        ref saveCredential);
+                                }
+
                                 break;
 
                             case "console":
@@ -472,6 +478,11 @@ namespace WinSW
                     username,
                     password);
 
+                if (saveCredential)
+                {
+                    Credentials.Save($"WinSW:{config.Name}", username, password);
+                }
+
                 string description = config.Description;
                 if (description.Length != 0)
                 {