using Admin.Core.Common.Attributes; using Admin.Core.Common.Cache; using Newtonsoft.Json; using System; using System.Drawing; using System.Drawing.Drawing2D; using System.Drawing.Imaging; using System.IO; using System.Threading.Tasks; namespace Admin.Tools.Captcha { /// /// 滑块拼图验证 /// [SingleInstance] public class SlideJigsawCaptcha : ICaptcha { private readonly ICache _cache; public SlideJigsawCaptcha(ICache cache) { _cache = cache; } /// /// Bitmap转为base64编码的文本 /// /// /// private string ImgToBase64String(Bitmap bmp) { try { MemoryStream ms = new MemoryStream(); bmp.Save(ms, ImageFormat.Png); byte[] arr = new byte[ms.Length]; ms.Position = 0; ms.Read(arr, 0, (int)ms.Length); ms.Close(); return Convert.ToBase64String(arr); } catch { return null; } } /// /// 根据模板生成拼图 /// /// /// /// /// /// private Bitmap CutByTemplate(Bitmap baseImage, Bitmap templateImage, int x, int y) { Bitmap newImage = new Bitmap(templateImage.Width, baseImage.Height, PixelFormat.Format32bppRgb); newImage.MakeTransparent(); int xLength = templateImage.Width; int yLength = templateImage.Height; // 模板图像宽度 for (int i = 0; i < xLength; i++) { // 模板图片高度 for (int j = 0; j < yLength; j++) { // 如果模板图像当前像素点不是透明色 copy源文件信息到目标图片中 int rgb = templateImage.GetPixel(i, j).ToArgb(); if (rgb < 0) { Color oriImageColor = baseImage.GetPixel(x + i, y + j); newImage.SetPixel(i, y + j, oriImageColor); //抠图区域半透明 baseImage.SetPixel(x + i, y + j, Color.FromArgb(120, oriImageColor.R, oriImageColor.G, oriImageColor.B)); } //防止数组越界判断 if (i == (xLength - 1) || j == (yLength - 1)) { continue; } int rightRgb = templateImage.GetPixel(i + 1, j).ToArgb(); int downRgb = templateImage.GetPixel(i, j + 1).ToArgb(); //描边处理,,取带像素和无像素的界点,判断该点是不是临界轮廓点,如果是设置该坐标像素是白色 if ((rgb >= 0 && rightRgb < 0) || (rgb < 0 && rightRgb >= 0) || (rgb >= 0 && downRgb < 0) || (rgb < 0 && downRgb >= 0)) { newImage.SetPixel(i, y + j, Color.White); baseImage.SetPixel(x + i, y + j, Color.White); } } } return newImage; } /// /// 根据模板生成干扰图 /// /// /// /// /// private void InterferenceByTemplate(Bitmap baseImage, Bitmap templateImage, int x, int y) { int xLength = templateImage.Width; int yLength = templateImage.Height; // 模板图像宽度 for (int i = 0; i < xLength; i++) { // 模板图片高度 for (int j = 0; j < yLength; j++) { // 如果模板图像当前像素点不是透明色 copy源文件信息到目标图片中 int rgb = templateImage.GetPixel(i, j).ToArgb(); if (rgb < 0) { Color oriImageColor = baseImage.GetPixel(x + i, y + j); //抠图区域半透明 baseImage.SetPixel(x + i, y + j, Color.FromArgb(120, oriImageColor.R, oriImageColor.G, oriImageColor.B)); } //防止数组越界判断 if (i == (xLength - 1) || j == (yLength - 1)) { continue; } int rightRgb = templateImage.GetPixel(i + 1, j).ToArgb(); int downRgb = templateImage.GetPixel(i, j + 1).ToArgb(); //描边处理,,取带像素和无像素的界点,判断该点是不是临界轮廓点,如果是设置该坐标像素是白色 if ((rgb >= 0 && rightRgb < 0) || (rgb < 0 && rightRgb >= 0) || (rgb >= 0 && downRgb < 0) || (rgb < 0 && downRgb >= 0)) { baseImage.SetPixel(x + i, y + j, Color.White); } } } } /// /// 更改图片尺寸 /// /// /// /// /// private Bitmap ResizeImage(Bitmap bmp, int width, int height) { try { Bitmap b = new Bitmap(width, height); Graphics g = Graphics.FromImage(b); // 图画质量 g.InterpolationMode = InterpolationMode.HighQualityBicubic; g.DrawImage(bmp, new Rectangle(0, 0, width, height), new Rectangle(0, 0, bmp.Width, bmp.Height), GraphicsUnit.Pixel); g.Dispose(); return b; } catch { return null; } } /// /// 随机范围内数字 /// /// /// /// public int GetRandomInt(int startNum, int endNum) { return (endNum > startNum ? new Random().Next(endNum - startNum) : 0) + startNum; } /// /// 随机生成拼图坐标 /// /// /// /// /// /// private PointModel GeneratePoint(int originalWidth, int originalHeight, int templateWidth, int templateHeight) { Random random = new Random(); int widthDifference = originalWidth - templateWidth; int heightDifference = originalHeight - templateHeight; int x; if (widthDifference <= 0) { x = 5; } else { x = random.Next(originalWidth - templateWidth - 100) + 100; } int y; if (heightDifference <= 0) { y = 5; } else { y = random.Next(originalHeight - templateHeight - 5) + 5; } return new PointModel(x, y); } /// /// 随机生成干扰图坐标 /// /// /// /// /// /// /// /// private PointModel GenerateInterferencePoint(int originalWidth, int originalHeight, int templateWidth, int templateHeight, int blockX, int blockY) { int x; if (originalWidth - blockX - 5 > templateWidth * 2) { //在原扣图右边插入干扰图 x = GetRandomInt(blockX + templateWidth + 5, originalWidth - templateWidth); } else { //在原扣图左边插入干扰图 x = GetRandomInt(100, blockX - templateWidth - 5); } int y; if (originalHeight - blockY - 5 > templateHeight * 2) { //在原扣图下边插入干扰图 y = GetRandomInt(blockY + templateHeight + 5, originalHeight - templateHeight); } else { //在原扣图上边插入干扰图 y = GetRandomInt(5, blockY - templateHeight - 5); } return new PointModel(x, y); } /// /// 获得验证数据 /// /// JObject public async Task GetAsync() { //获取网络图片 //var client = new HttpClient(); //var stream = await client.GetStreamAsync("https://picsum.photos/310/155"); //client.Dispose(); //更改图片尺寸 //Bitmap oriImage = new Bitmap(stream); //Bitmap baseImage = ResizeImage(oriImage, 310, 155); //oriImage.Dispose(); //Bitmap baseImage = new Bitmap(stream); var oriImage = Image.FromFile(Directory.GetCurrentDirectory() + $@"\wwwroot\captcha\jigsaw\{new Random().Next(1, 4)}.jpg"); Bitmap baseImage = new Bitmap(oriImage); oriImage.Dispose(); var oriTemplate = Image.FromFile(Directory.GetCurrentDirectory() + $@"\wwwroot\captcha\jigsaw\templates\{new Random().Next(1, 7)}.png"); Bitmap templateImage = new Bitmap(oriTemplate); oriTemplate.Dispose(); int baseWidth = baseImage.Width; int baseHeight = baseImage.Height; int templateWidth = templateImage.Width; int templateHeight = templateImage.Height; //随机生成拼图坐标 PointModel point = GeneratePoint(baseWidth, baseHeight, templateWidth, templateHeight); int x = point.X; int y = point.Y; //生成拼图 string blockImageBase64 = "data:image/png;base64," + ImgToBase64String(CutByTemplate(baseImage, templateImage, x, y)); //生成干扰图 PointModel interferencePoint = GenerateInterferencePoint(baseWidth, baseHeight, templateWidth, templateHeight, x, y); InterferenceByTemplate(baseImage, templateImage, interferencePoint.X, interferencePoint.Y); string baseImageBase64 = "data:image/png;base64," + ImgToBase64String(baseImage); templateImage.Dispose(); baseImage.Dispose(); var token = Guid.NewGuid().ToString(); CaptchaOutput captchaData = new CaptchaOutput { Token = token, Data = new SlideJigsawCaptchaModel() { BlockImage = blockImageBase64, BaseImage = baseImageBase64 } }; var key = string.Format(CacheKey.VerifyCodeKey, token); await _cache.SetAsync(key, point.X); return captchaData; } /// /// 检查验证数据 /// public async Task CheckAsync(SlideJigsawCaptchaInput input) { var key = string.Format(CacheKey.VerifyCodeKey, input.Token); if (await _cache.ExistsAsync(key)) { try { var point = JsonConvert.DeserializeObject(input.Point); var x = await _cache.GetAsync(key); if (Math.Abs(x - point.X) < 5) { return true; } else { return false; } } catch { await _cache.DelAsync(key); return false; } } else { return false; } } } }