图形验证码+短信验证码实战

前言：

　　上一篇分分享了基于阿里云实现的短信验证码文章，考虑到为了防止登录时，非人工操作，频繁获取验证码，趁热打铁，现在添加了图片验证码服务功能。借鉴网上传统的做法，把实现这两个验证的功能做成有个独立的服务，通过Http分别请求获取校验图片验证码和短信验证码。

一、需求描述：

• 图形验证码为，短信验证码为6位纯数字
• 同一系统图片验证码缓存中只存在一个，没有有效期，每次刷新更新旧图形验证码
• 短信验证码有效期2分钟
• 每个手机号60秒内只能发送一次短信验证码，在服务器端执行校验
• 同一个手机号在同一时间内可以有多个有效的短信验证码，根据不同系统类型区分
• 每个短信验证码至多可被使用3次,无论和请求中的验证码是否匹配，随后立即作废，以防止暴力攻击
• 发送短信验证码之前，先验证图形验证码是否正确

二、图片验证码实现：

生成随机验证码字符串：

 /// 

        /// 获取随机验证码
        /// 
        /// 
        public static string GenerateCaptchaCode()
        {
            Random rand = new Random();
            int maxRand = Letters.Length - 1;

            StringBuilder sb = new StringBuilder();

            for (int i = 0; i < 4; i++)
            {
                int index = rand.Next(maxRand);
                sb.Append(Letters[index]);
            }

            return sb.ToString();
        }

随机验证码生成验证码图片：

 /// 

        /// 生成随机验证码图片
        /// 
        /// 
        /// 
        /// 
        /// 
        public static CaptchaResult GenerateCaptcha(int width, int height, string captchaCode)
        {
            using (Bitmap baseMap = new Bitmap(width, height))
            using (Graphics graph = Graphics.FromImage(baseMap))
            {
                Random rand = new Random();

                graph.Clear(GetRandomLightColor());

                DrawCaptchaCode();
                DrawDisorderLine();
                AdjustRippleEffect();

                MemoryStream ms = new MemoryStream();

                baseMap.Save(ms, ImageFormat.Png);

                return new CaptchaResult { CaptchaCode = captchaCode, CaptchaByteData = ms.ToArray(), Timestamp = DateTime.Now };

                int GetFontSize(int imageWidth, int captchCodeCount)
                {
                    var averageSize = imageWidth / captchCodeCount;

                    return Convert.ToInt32(averageSize);
                }

                Color GetRandomDeepColor()
                {
                    int redlow = 160, greenLow = 100, blueLow = 160;
                    return Color.FromArgb(rand.Next(redlow), rand.Next(greenLow), rand.Next(blueLow));
                }

                Color GetRandomLightColor()
                {
                    int low = 180, high = 255;

                    int nRend = rand.Next(high) % (high - low) + low;
                    int nGreen = rand.Next(high) % (high - low) + low;
                    int nBlue = rand.Next(high) % (high - low) + low;

                    return Color.FromArgb(nRend, nGreen, nBlue);
                }

                void DrawCaptchaCode()
                {
                    SolidBrush fontBrush = new SolidBrush(Color.Black);
                    int fontSize = GetFontSize(width, captchaCode.Length);
                    Font font = new Font(FontFamily.GenericSerif, fontSize, FontStyle.Bold, GraphicsUnit.Pixel);
                    for (int i = 0; i < captchaCode.Length; i++)
                    {
                        fontBrush.Color = GetRandomDeepColor();

                        int shiftPx = fontSize / 6;

                        //float x = i * fontSize + rand.Next(-shiftPx, shiftPx) + rand.Next(-shiftPx, shiftPx);
                        float x = i * fontSize + rand.Next(-shiftPx, shiftPx) / 2;
                        //int maxY = height - fontSize;
                        int maxY = height - fontSize * 2;
                        if (maxY < 0)
                        {
                            maxY = 0;
                        }
                        float y = rand.Next(0, maxY);

                        graph.DrawString(captchaCode[i].ToString(), font, fontBrush, x, y);
                    }
                }

                void DrawDisorderLine()
                {
                    Pen linePen = new Pen(new SolidBrush(Color.Black), 2);
                    //for (int i = 0; i < rand.Next(3, 5); i++)
                    for (int i = 0; i < 2; i++)
                    {
                        linePen.Color = GetRandomDeepColor();

                        Point startPoint = new Point(rand.Next(0, width), rand.Next(0, height));
                        Point endPoint = new Point(rand.Next(0, width), rand.Next(0, height));
                        graph.DrawLine(linePen, startPoint, endPoint);

                        //Point bezierPoint1 = new Point(rand.Next(0, width), rand.Next(0, height));
                        //Point bezierPoint2 = new Point(rand.Next(0, width), rand.Next(0, height));

                        //graph.DrawBezier(linePen, startPoint, bezierPoint1, bezierPoint2, endPoint);
                    }
                }

                void AdjustRippleEffect()
                {
                    short nWave = 6;
                    int nWidth = baseMap.Width;
                    int nHeight = baseMap.Height;

                    Point[,] pt = new Point[nWidth, nHeight];

                    for (int x = 0; x < nWidth; ++x)
                    {
                        for (int y = 0; y < nHeight; ++y)
                        {
                            var xo = nWave * Math.Sin(2.0 * 3.1415 * y / 128.0);
                            var yo = nWave * Math.Cos(2.0 * 3.1415 * x / 128.0);

                            var newX = x + xo;
                            var newY = y + yo;

                            if (newX > 0 && newX < nWidth)
                            {
                                pt[x, y].X = (int)newX;
                            }
                            else
                            {
                                pt[x, y].X = 0;
                            }


                            if (newY > 0 && newY < nHeight)
                            {
                                pt[x, y].Y = (int)newY;
                            }
                            else
                            {
                                pt[x, y].Y = 0;
                            }
                        }
                    }

                    Bitmap bSrc = (Bitmap)baseMap.Clone();

                    BitmapData bitmapData = baseMap.LockBits(new Rectangle(0, 0, baseMap.Width, baseMap.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
                    BitmapData bmSrc = bSrc.LockBits(new Rectangle(0, 0, bSrc.Width, bSrc.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);

                    int scanline = bitmapData.Stride;

                    IntPtr scan0 = bitmapData.Scan0;
                    IntPtr srcScan0 = bmSrc.Scan0;

                    unsafe
                    {
                        byte* p = (byte*)(void*)scan0;
                        byte* pSrc = (byte*)(void*)srcScan0;

                        int nOffset = bitmapData.Stride - baseMap.Width * 3;

                        for (int y = 0; y < nHeight; ++y)
                        {
                            for (int x = 0; x < nWidth; ++x)
                            {
                                var xOffset = pt[x, y].X;
                                var yOffset = pt[x, y].Y;

                                if (yOffset >= 0 && yOffset < nHeight && xOffset >= 0 && xOffset < nWidth)
                                {
                                    if (pSrc != null)
                                    {
                                        p[0] = pSrc[yOffset * scanline + xOffset * 3];
                                        p[1] = pSrc[yOffset * scanline + xOffset * 3 + 1];
                                        p[2] = pSrc[yOffset * scanline + xOffset * 3 + 2];
                                    }
                                }

                                p += 3;
                            }
                            p += nOffset;
                        }
                    }

                    baseMap.UnlockBits(bitmapData);
                    bSrc.UnlockBits(bmSrc);
                    bSrc.Dispose();
                }
            }
        }

三、短信验证码实现：

见上篇：

传送门：基于Aliyun短信验证码实现

四、图片验证码获取与校验:

获取：

代码：

  /// 

        /// 获取图片验证码
        /// 
        /// 图形验证码请求信息
        [HttpGet("img")]
        public IActionResult GetImageCaptcha([FromQuery]ImgCaptchaDto imgCaptchaDto)
        {
            var result = _captchaService.GetImageCaptcha(imgCaptchaDto);
            var stream = new MemoryStream(result.CaptchaByteData);

            return new FileStreamResult(stream, "image/png");
        }

Http调用：详细调用参数和方式见下方接口在线文档。

校验：

代码：

 /// 

        /// 验证图片验证码
        /// 
        /// 图形验证码信息
        /// 
        [HttpPost("img")]
        public IActionResult ValidateImageCaptcha(ImgCaptchaDto imgCaptchaDto)
        {
            bool isCaptchaValid = _captchaService.ValidateImageCaptcha(imgCaptchaDto);
            if (isCaptchaValid)
            {
                HttpResponseDto httpResponseDto = new HttpResponseDto()
                {
                    IsSuccess = true,
                    Code = StatusCodes.Status200OK,
                    Message = "图形验证码验证成功"
                };
                var responJson = JsonConvert.SerializeObject(httpResponseDto);
                return Ok(responJson);
            }
            else
            {
                HttpResponseDto httpResponseDto = new HttpResponseDto()
                {
                    IsSuccess = false,
                    Code = StatusCodes.Status403Forbidden,
                    Message = "验证失败，请输入正确手机号及获取到的验证码"
                };
                var responJson = JsonConvert.SerializeObject(httpResponseDto);
                return StatusCode(StatusCodes.Status403Forbidden, responJson);
            }
        }

Http调用：详细调用参数和方式见下方接口在线文档。

五、短信验证码获取与校验：

获取：

代码：

/// 

        /// 获取短信验证码
        /// 
        /// 短信验证码请求信息
        /// 
        [HttpGet("msg")]
        public IActionResult GetMsgCaptcha([FromQuery]MsgCaptchaDto msgCaptchaDto)
        {
            var msgSendResult = _captchaService.GetMsgCaptcha(msgCaptchaDto);
            if (msgSendResult.Item1)
            {
                return Ok(msgSendResult.Item2);
            }
            else
            {
                return StatusCode(StatusCodes.Status403Forbidden, msgSendResult.Item2);
            }
        }

Http调用：详细调用参数和方式见下方接口在线文档。

校验:

代码：

/// 

        /// 验证短信验证码
        /// 
        /// 短信验证码信息
        /// 
        [HttpPost("msg")]
        public IActionResult ValidateMsgCaptcha(MsgCaptchaDto msgCaptchaDto)
        {
            var validateResult = _captchaService.ValidateMsgCaptcha(msgCaptchaDto);
            if (validateResult.Item1)
            {
                HttpResponseDto httpResponseDto = new HttpResponseDto()
                {
                    IsSuccess = true,
                    Code = StatusCodes.Status200OK,
                    Message = validateResult.Item2
                };
                var responJson = JsonConvert.SerializeObject(httpResponseDto);
                return Ok(responJson);
            }
            else
            {
                HttpResponseDto httpResponseDto = new HttpResponseDto()
                {
                    IsSuccess = false,
                    Code = StatusCodes.Status403Forbidden,
                    Message = validateResult.Item2
                };
                var responJson = JsonConvert.SerializeObject(httpResponseDto);
                return StatusCode(StatusCodes.Status403Forbidden, responJson);
            }
        }

Http调用：详细调用参数和方式见下方接口在线文档。

源码链接地址：

Gitee完整实例地址：

https://gitee.com/mingliang_it/Captcha

接口在线文档：

链接地址：

https://console-docs.apipost.cn/preview/82c61b0950bae0c8/924487d25ec3df36