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feat: CUID & fix: reorder bug

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This commit is contained in:
Jaro Kaulmann
2026-03-02 16:34:18 +01:00
parent 9b261dbf78
commit f0d51bc85e
5 changed files with 275 additions and 152 deletions
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8
CarManagerV3/Classes/Car.cs
View File

@@ -1,4 +1,5 @@
using System;
using CarManagerV3.Util;
namespace CarManagerV3
{
@@ -115,12 +116,15 @@ namespace CarManagerV3
int numericId = 0;
if ((string.IsNullOrWhiteSpace(id) || int.TryParse(id, out numericId)) && id != "0")
{
id = Guid.NewGuid().ToString();
id = CUID.NewCUID().ToString();
if (numericId > 0)
{
order = numericId + order;
}
}
if(id.Length > 8)
{
id = CUID.NewCUID().ToString();
}
// Sets the properties using the setters to ensure validation is applied.
this.id = id;

245
CarManagerV3/Forms/MainForm.Designer.cs generated
View File

@@ -29,171 +29,170 @@
private void InitializeComponent()
{
System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(MainForm));
this.tableLayoutPanel1 = new System.Windows.Forms.TableLayoutPanel();
this.flpCars = new System.Windows.Forms.FlowLayoutPanel();
this.tableLayoutPanel2 = new System.Windows.Forms.TableLayoutPanel();
this.tbxSearch = new System.Windows.Forms.TextBox();
this.btnNewCar = new System.Windows.Forms.Button();
this.menuStrip1 = new System.Windows.Forms.MenuStrip();
this.fileToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
this.openToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
this.saveToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
this.saveAsToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
this.importToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
this.recentFilesToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
this.revealInFileExplorerToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
this.tableLayoutPanel1.SuspendLayout();
this.tableLayoutPanel2.SuspendLayout();
this.menuStrip1.SuspendLayout();
this.SuspendLayout();
tableLayoutPanel1 = new System.Windows.Forms.TableLayoutPanel();
flpCars = new System.Windows.Forms.FlowLayoutPanel();
tableLayoutPanel2 = new System.Windows.Forms.TableLayoutPanel();
tbxSearch = new System.Windows.Forms.TextBox();
btnNewCar = new System.Windows.Forms.Button();
menuStrip1 = new System.Windows.Forms.MenuStrip();
fileToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
openToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
saveToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
saveAsToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
importToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
recentFilesToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
revealInFileExplorerToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
tableLayoutPanel1.SuspendLayout();
tableLayoutPanel2.SuspendLayout();
menuStrip1.SuspendLayout();
SuspendLayout();
//
// tableLayoutPanel1
//
this.tableLayoutPanel1.ColumnCount = 1;
this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 100F));
this.tableLayoutPanel1.Controls.Add(this.flpCars, 0, 2);
this.tableLayoutPanel1.Controls.Add(this.tableLayoutPanel2, 0, 1);
this.tableLayoutPanel1.Controls.Add(this.menuStrip1, 0, 0);
this.tableLayoutPanel1.Dock = System.Windows.Forms.DockStyle.Fill;
this.tableLayoutPanel1.Location = new System.Drawing.Point(0, 0);
this.tableLayoutPanel1.Name = "tableLayoutPanel1";
this.tableLayoutPanel1.RowCount = 3;
this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle());
this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Absolute, 40F));
this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle());
this.tableLayoutPanel1.Size = new System.Drawing.Size(802, 458);
this.tableLayoutPanel1.TabIndex = 0;
this.tableLayoutPanel1.Paint += new System.Windows.Forms.PaintEventHandler(this.tableLayoutPanel1_Paint);
tableLayoutPanel1.ColumnCount = 1;
tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 100F));
tableLayoutPanel1.Controls.Add(flpCars, 0, 2);
tableLayoutPanel1.Controls.Add(tableLayoutPanel2, 0, 1);
tableLayoutPanel1.Controls.Add(menuStrip1, 0, 0);
tableLayoutPanel1.Dock = System.Windows.Forms.DockStyle.Fill;
tableLayoutPanel1.Location = new System.Drawing.Point(0, 0);
tableLayoutPanel1.Margin = new System.Windows.Forms.Padding(3, 4, 3, 4);
tableLayoutPanel1.Name = "tableLayoutPanel1";
tableLayoutPanel1.RowCount = 3;
tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle());
tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Absolute, 50F));
tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle());
tableLayoutPanel1.Size = new System.Drawing.Size(802, 572);
tableLayoutPanel1.TabIndex = 0;
tableLayoutPanel1.Paint += tableLayoutPanel1_Paint;
//
// flpCars
//
this.flpCars.AutoScroll = true;
this.flpCars.AutoScrollMargin = new System.Drawing.Size(0, 200);
this.flpCars.Dock = System.Windows.Forms.DockStyle.Fill;
this.flpCars.Location = new System.Drawing.Point(3, 67);
this.flpCars.Name = "flpCars";
this.flpCars.Size = new System.Drawing.Size(796, 412);
this.flpCars.TabIndex = 1;
flpCars.AutoScroll = true;
flpCars.AutoScrollMargin = new System.Drawing.Size(0, 200);
flpCars.Dock = System.Windows.Forms.DockStyle.Fill;
flpCars.Location = new System.Drawing.Point(3, 82);
flpCars.Margin = new System.Windows.Forms.Padding(3, 4, 3, 4);
flpCars.Name = "flpCars";
flpCars.Size = new System.Drawing.Size(796, 515);
flpCars.TabIndex = 1;
//
// tableLayoutPanel2
//
this.tableLayoutPanel2.ColumnCount = 2;
this.tableLayoutPanel2.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 50F));
this.tableLayoutPanel2.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 50F));
this.tableLayoutPanel2.Controls.Add(this.tbxSearch, 0, 0);
this.tableLayoutPanel2.Controls.Add(this.btnNewCar, 1, 0);
this.tableLayoutPanel2.Dock = System.Windows.Forms.DockStyle.Fill;
this.tableLayoutPanel2.Location = new System.Drawing.Point(3, 27);
this.tableLayoutPanel2.Name = "tableLayoutPanel2";
this.tableLayoutPanel2.RowCount = 1;
this.tableLayoutPanel2.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 100F));
this.tableLayoutPanel2.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Absolute, 34F));
this.tableLayoutPanel2.Size = new System.Drawing.Size(796, 34);
this.tableLayoutPanel2.TabIndex = 2;
tableLayoutPanel2.ColumnCount = 2;
tableLayoutPanel2.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 50F));
tableLayoutPanel2.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 50F));
tableLayoutPanel2.Controls.Add(tbxSearch, 0, 0);
tableLayoutPanel2.Controls.Add(btnNewCar, 1, 0);
tableLayoutPanel2.Dock = System.Windows.Forms.DockStyle.Fill;
tableLayoutPanel2.Location = new System.Drawing.Point(3, 32);
tableLayoutPanel2.Margin = new System.Windows.Forms.Padding(3, 4, 3, 4);
tableLayoutPanel2.Name = "tableLayoutPanel2";
tableLayoutPanel2.RowCount = 1;
tableLayoutPanel2.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 100F));
tableLayoutPanel2.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Absolute, 42F));
tableLayoutPanel2.Size = new System.Drawing.Size(796, 42);
tableLayoutPanel2.TabIndex = 2;
//
// tbxSearch
//
this.tbxSearch.Dock = System.Windows.Forms.DockStyle.Fill;
this.tbxSearch.Location = new System.Drawing.Point(3, 3);
this.tbxSearch.Name = "tbxSearch";
this.tbxSearch.Size = new System.Drawing.Size(392, 22);
this.tbxSearch.TabIndex = 3;
this.tbxSearch.TextChanged += new System.EventHandler(this.tbxSearch_TextChanged);
tbxSearch.Dock = System.Windows.Forms.DockStyle.Fill;
tbxSearch.Location = new System.Drawing.Point(3, 4);
tbxSearch.Margin = new System.Windows.Forms.Padding(3, 4, 3, 4);
tbxSearch.Name = "tbxSearch";
tbxSearch.Size = new System.Drawing.Size(392, 27);
tbxSearch.TabIndex = 3;
tbxSearch.TextChanged += tbxSearch_TextChanged;
//
// btnNewCar
//
this.btnNewCar.Location = new System.Drawing.Point(401, 3);
this.btnNewCar.Name = "btnNewCar";
this.btnNewCar.Size = new System.Drawing.Size(75, 23);
this.btnNewCar.TabIndex = 4;
this.btnNewCar.Text = "Add Car";
this.btnNewCar.UseVisualStyleBackColor = true;
this.btnNewCar.Click += new System.EventHandler(this.btnNewCar_Click);
btnNewCar.Location = new System.Drawing.Point(401, 4);
btnNewCar.Margin = new System.Windows.Forms.Padding(3, 4, 3, 4);
btnNewCar.Name = "btnNewCar";
btnNewCar.Size = new System.Drawing.Size(75, 29);
btnNewCar.TabIndex = 4;
btnNewCar.Text = "Add Car";
btnNewCar.UseVisualStyleBackColor = true;
btnNewCar.Click += btnNewCar_Click;
//
// menuStrip1
//
this.menuStrip1.ImageScalingSize = new System.Drawing.Size(20, 20);
this.menuStrip1.Items.AddRange(new System.Windows.Forms.ToolStripItem[] {
this.fileToolStripMenuItem});
this.menuStrip1.Location = new System.Drawing.Point(0, 0);
this.menuStrip1.Name = "menuStrip1";
this.menuStrip1.Size = new System.Drawing.Size(802, 24);
this.menuStrip1.TabIndex = 3;
this.menuStrip1.Text = "menuStrip1";
menuStrip1.ImageScalingSize = new System.Drawing.Size(20, 20);
menuStrip1.Items.AddRange(new System.Windows.Forms.ToolStripItem[] { fileToolStripMenuItem });
menuStrip1.Location = new System.Drawing.Point(0, 0);
menuStrip1.Name = "menuStrip1";
menuStrip1.Size = new System.Drawing.Size(802, 28);
menuStrip1.TabIndex = 3;
menuStrip1.Text = "menuStrip1";
//
// fileToolStripMenuItem
//
this.fileToolStripMenuItem.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] {
this.openToolStripMenuItem,
this.saveToolStripMenuItem,
this.saveAsToolStripMenuItem,
this.importToolStripMenuItem,
this.recentFilesToolStripMenuItem,
this.revealInFileExplorerToolStripMenuItem});
this.fileToolStripMenuItem.Name = "fileToolStripMenuItem";
this.fileToolStripMenuItem.Size = new System.Drawing.Size(37, 20);
this.fileToolStripMenuItem.Text = "File";
fileToolStripMenuItem.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] { openToolStripMenuItem, saveToolStripMenuItem, saveAsToolStripMenuItem, importToolStripMenuItem, recentFilesToolStripMenuItem, revealInFileExplorerToolStripMenuItem });
fileToolStripMenuItem.Name = "fileToolStripMenuItem";
fileToolStripMenuItem.Size = new System.Drawing.Size(46, 24);
fileToolStripMenuItem.Text = "File";
//
// openToolStripMenuItem
//
this.openToolStripMenuItem.Name = "openToolStripMenuItem";
this.openToolStripMenuItem.Size = new System.Drawing.Size(187, 22);
this.openToolStripMenuItem.Text = "Open";
this.openToolStripMenuItem.Click += new System.EventHandler(this.openToolStripMenuItem_Click);
openToolStripMenuItem.Name = "openToolStripMenuItem";
openToolStripMenuItem.Size = new System.Drawing.Size(238, 26);
openToolStripMenuItem.Text = "Open";
openToolStripMenuItem.Click += openToolStripMenuItem_Click;
//
// saveToolStripMenuItem
//
this.saveToolStripMenuItem.Name = "saveToolStripMenuItem";
this.saveToolStripMenuItem.Size = new System.Drawing.Size(187, 22);
this.saveToolStripMenuItem.Text = "Save";
this.saveToolStripMenuItem.Click += new System.EventHandler(this.saveToolStripMenuItem_Click);
saveToolStripMenuItem.Name = "saveToolStripMenuItem";
saveToolStripMenuItem.Size = new System.Drawing.Size(238, 26);
saveToolStripMenuItem.Text = "Save";
saveToolStripMenuItem.Click += saveToolStripMenuItem_Click;
//
// saveAsToolStripMenuItem
//
this.saveAsToolStripMenuItem.Name = "saveAsToolStripMenuItem";
this.saveAsToolStripMenuItem.Size = new System.Drawing.Size(187, 22);
this.saveAsToolStripMenuItem.Text = "Save as";
this.saveAsToolStripMenuItem.Click += new System.EventHandler(this.saveAsToolStripMenuItem_Click);
saveAsToolStripMenuItem.Name = "saveAsToolStripMenuItem";
saveAsToolStripMenuItem.Size = new System.Drawing.Size(238, 26);
saveAsToolStripMenuItem.Text = "Save as";
saveAsToolStripMenuItem.Click += saveAsToolStripMenuItem_Click;
//
// importToolStripMenuItem
//
this.importToolStripMenuItem.Name = "importToolStripMenuItem";
this.importToolStripMenuItem.Size = new System.Drawing.Size(187, 22);
this.importToolStripMenuItem.Text = "Import";
this.importToolStripMenuItem.Click += new System.EventHandler(this.importToolStripMenuItem_Click);
importToolStripMenuItem.Name = "importToolStripMenuItem";
importToolStripMenuItem.Size = new System.Drawing.Size(238, 26);
importToolStripMenuItem.Text = "Import";
importToolStripMenuItem.Click += importToolStripMenuItem_Click;
//
// recentFilesToolStripMenuItem
//
this.recentFilesToolStripMenuItem.Name = "recentFilesToolStripMenuItem";
this.recentFilesToolStripMenuItem.Size = new System.Drawing.Size(187, 22);
this.recentFilesToolStripMenuItem.Text = "Recent Files";
this.recentFilesToolStripMenuItem.Click += new System.EventHandler(this.recentFilesToolStripMenuItem_Click);
recentFilesToolStripMenuItem.Name = "recentFilesToolStripMenuItem";
recentFilesToolStripMenuItem.Size = new System.Drawing.Size(238, 26);
recentFilesToolStripMenuItem.Text = "Recent Files";
recentFilesToolStripMenuItem.Click += recentFilesToolStripMenuItem_Click;
//
// revealInFileExplorerToolStripMenuItem
//
this.revealInFileExplorerToolStripMenuItem.Name = "revealInFileExplorerToolStripMenuItem";
this.revealInFileExplorerToolStripMenuItem.Size = new System.Drawing.Size(187, 22);
this.revealInFileExplorerToolStripMenuItem.Text = "Reveal in File Explorer";
this.revealInFileExplorerToolStripMenuItem.Click += new System.EventHandler(this.revealInFileExplorerToolStripMenuItem_Click);
revealInFileExplorerToolStripMenuItem.Name = "revealInFileExplorerToolStripMenuItem";
revealInFileExplorerToolStripMenuItem.Size = new System.Drawing.Size(238, 26);
revealInFileExplorerToolStripMenuItem.Text = "Reveal in File Explorer";
revealInFileExplorerToolStripMenuItem.Click += revealInFileExplorerToolStripMenuItem_Click;
//
// MainForm
//
this.AutoScaleDimensions = new System.Drawing.SizeF(8F, 16F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(802, 458);
this.Controls.Add(this.tableLayoutPanel1);
this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon")));
this.MainMenuStrip = this.menuStrip1;
this.MinimumSize = new System.Drawing.Size(818, 497);
this.Name = "MainForm";
this.Text = "Carmanager 3";
this.tableLayoutPanel1.ResumeLayout(false);
this.tableLayoutPanel1.PerformLayout();
this.tableLayoutPanel2.ResumeLayout(false);
this.tableLayoutPanel2.PerformLayout();
this.menuStrip1.ResumeLayout(false);
this.menuStrip1.PerformLayout();
this.ResumeLayout(false);
AutoScaleDimensions = new System.Drawing.SizeF(8F, 20F);
AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
ClientSize = new System.Drawing.Size(802, 572);
Controls.Add(tableLayoutPanel1);
Icon = (System.Drawing.Icon)resources.GetObject("$this.Icon");
MainMenuStrip = menuStrip1;
Margin = new System.Windows.Forms.Padding(3, 4, 3, 4);
MinimumSize = new System.Drawing.Size(818, 609);
Name = "MainForm";
Text = "Carmanager 3";
tableLayoutPanel1.ResumeLayout(false);
tableLayoutPanel1.PerformLayout();
tableLayoutPanel2.ResumeLayout(false);
tableLayoutPanel2.PerformLayout();
menuStrip1.ResumeLayout(false);
menuStrip1.PerformLayout();
ResumeLayout(false);
}

2
CarManagerV3/Forms/MainForm.cs
View File

@@ -139,6 +139,7 @@ namespace CarManagerV3
int temp = car.Order;
car.Order = other.Order;
other.Order = temp;
cars = StateManager.normalizeOrders(cars);
SafeManager.SaveCars(filepath, cars);
refreshCars(cars);
}
@@ -155,6 +156,7 @@ namespace CarManagerV3
int temp = car.Order;
car.Order = other.Order;
other.Order = temp;
cars = StateManager.normalizeOrders(cars);
SafeManager.SaveCars(filepath, cars);
refreshCars(cars);
}

54
CarManagerV3/Forms/MainForm.resx
View File

@@ -1,17 +1,17 @@
<?xml version="1.0" encoding="utf-8"?>
<root>
<!--
Microsoft ResX Schema
<!--
Microsoft ResX Schema
Version 2.0
The primary goals of this format is to allow a simple XML format
that is mostly human readable. The generation and parsing of the
various data types are done through the TypeConverter classes
The primary goals of this format is to allow a simple XML format
that is mostly human readable. The generation and parsing of the
various data types are done through the TypeConverter classes
associated with the data types.
Example:
... ado.net/XML headers & schema ...
<resheader name="resmimetype">text/microsoft-resx</resheader>
<resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
<value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
<comment>This is a comment</comment>
</data>
There are any number of "resheader" rows that contain simple
There are any number of "resheader" rows that contain simple
name/value pairs.
Each data row contains a name, and value. The row also contains a
type or mimetype. Type corresponds to a .NET class that support
text/value conversion through the TypeConverter architecture.
Classes that don't support this are serialized and stored with the
Each data row contains a name, and value. The row also contains a
type or mimetype. Type corresponds to a .NET class that support
text/value conversion through the TypeConverter architecture.
Classes that don't support this are serialized and stored with the
mimetype set.
The mimetype is used for serialized objects, and tells the
ResXResourceReader how to depersist the object. This is currently not
The mimetype is used for serialized objects, and tells the
ResXResourceReader how to depersist the object. This is currently not
extensible. For a given mimetype the value must be set accordingly:
Note - application/x-microsoft.net.object.binary.base64 is the format
that the ResXResourceWriter will generate, however the reader can
Note - application/x-microsoft.net.object.binary.base64 is the format
that the ResXResourceWriter will generate, however the reader can
read any of the formats listed below.
mimetype: application/x-microsoft.net.object.binary.base64
value : The object must be serialized with
value : The object must be serialized with
: System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
: and then encoded with base64 encoding.
mimetype: application/x-microsoft.net.object.soap.base64
value : The object must be serialized with
value : The object must be serialized with
: System.Runtime.Serialization.Formatters.Soap.SoapFormatter
: and then encoded with base64 encoding.
mimetype: application/x-microsoft.net.object.bytearray.base64
value : The object must be serialized into a byte array
value : The object must be serialized into a byte array
: using a System.ComponentModel.TypeConverter
: and then encoded with base64 encoding.
-->

118
CarManagerV3/Util/CUID.cs Normal file
View File

@@ -0,0 +1,118 @@
using System;
using System.Buffers.Binary;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
namespace CarManagerV3.Util
{
internal class CUID
{
public const int DefaultLength = 6;
private static int _counter = RandomNumberGenerator.GetInt32(int.MaxValue);
/// <summary>
/// Generate a random CUID (Collision-resistant Unique Identifier) of a specified length.
/// The CUID is designed to be unique across different machines and time, making it suitable for use as an identifier for cars in the application.
/// The length must be between 4 and 32 characters to ensure a good balance between uniqueness and readability.
/// The generated CUID consists of a combination of alphanumeric characters to ensure uniqueness and readability.
/// </summary>
/// <param name="length">The desired length of the generated CUID</param>
/// <param name="prefixWithC">Whether to prefix the CUID with 'c' for better readability and to avoid starting with a digit.</param>"
/// <returns></returns>
public static string NewCUID(int length = DefaultLength, bool prefixWithC = true)
{
// CUIDv2 specs allow between 4 and 32 chars.
if(length < 4 || length > 32) throw new ArgumentOutOfRangeException("length");
// We will produce enough encoded chars to satisfy 'length' after prefixing and truncation.
// Base64 encodes 3 bytes -> 4 chars. So bytesNeeded ≈ ceil(charsNeeded * 3/4).
int charsNeeded = prefixWithC ? (length - 1) : length;
int bytesNeeded = (int)Math.Ceiling(charsNeeded * 3.0 / 4.0);
Span<byte> material = stackalloc byte[32];
FillMaterial(material);
byte[] outputBytes = ExpandWithSha256(material, bytesNeeded);
string encoded = Base64UrlEncode(outputBytes);
if (encoded.Length < charsNeeded)
{
// Extremely unlikely unless length is huge; ensure we have enough by expanding more.
// (Kept as a guard; for typical lengths like 24-64, you're fine.)
outputBytes = ExpandWithSha256(material, bytesNeeded + 32);
encoded = Base64UrlEncode(outputBytes);
}
string body = encoded.Substring(0, charsNeeded);
return prefixWithC ? ("c" + body) : body;
}
private static void FillMaterial(Span<byte> dst32)
{
// Compose a payload with:
// - 16 bytes random
// - 8 bytes timestamp (UTC ticks)
// - 4 bytes counter
// - 4 bytes process/thread noise
Span<byte> payload = stackalloc byte[16 + 8 + 4 + 4];
RandomNumberGenerator.Fill(payload.Slice(0, 16));
long ticks = DateTime.UtcNow.Ticks;
BinaryPrimitives.WriteInt64LittleEndian(payload.Slice(16, 8), ticks);
int c = Interlocked.Increment(ref _counter);
BinaryPrimitives.WriteInt32LittleEndian(payload.Slice(24, 4), c);
// Some extra variability (not relied on for security)
int noise = Environment.ProcessId ^ Thread.CurrentThread.ManagedThreadId ^ (int)Stopwatch.GetTimestamp();
BinaryPrimitives.WriteInt32LittleEndian(payload.Slice(28, 4), noise);
// Hash to produce 32 bytes of uniformly distributed output
SHA256.HashData(payload, dst32);
}
private static byte[] ExpandWithSha256(ReadOnlySpan<byte> seed32, int bytesNeeded)
{
if (bytesNeeded <= 0) return Array.Empty<byte>();
// If <= 32 bytes, we can just take from seed32 by hashing once more for separation.
// We'll use SHA256(seed || blockIndex) to generate blocks.
int blocks = (int)Math.Ceiling(bytesNeeded / 32.0);
byte[] result = new byte[blocks * 32];
Span<byte> input = stackalloc byte[32 + 4];
seed32.CopyTo(input.Slice(0, 32));
for (int i = 0; i < blocks; i++)
{
BinaryPrimitives.WriteInt32LittleEndian(input.Slice(32, 4), i);
Span<byte> block = result.AsSpan(i * 32, 32);
SHA256.HashData(input, block);
}
if (result.Length == bytesNeeded) return result;
byte[] trimmed = new byte[bytesNeeded];
Buffer.BlockCopy(result, 0, trimmed, 0, bytesNeeded);
return trimmed;
}
private static string Base64UrlEncode(byte[] bytes)
{
// Standard base64url without padding per RFC 4648 §5
string b64 = Convert.ToBase64String(bytes);
return b64.Replace('+', '-').Replace('/', '_').TrimEnd('=');
}
}
}