简介

本文档提供关于生成对象预签名链接的示例代码。

说明：

• 建议用户使用临时密钥生成预签名，通过临时授权的方式进一步提高预签名上传、下载等请求的安全性。申请临时密钥时，请遵循 最小权限指引原则，防止泄漏目标存储桶或对象之外的资源。
• 如果您一定要使用永久密钥来生成预签名，建议永久密钥的权限范围仅限于上传或下载操作，以规避风险。
• 关于临时密钥的获取，请参见 临时密钥生成及使用指引。

SDK API 参考

SDK 所有接口的具体参数与方法说明，请参考 SDK API。

生成对象预签名链接

示例代码一：生成预签名 URL

try
{
 PreSignatureStruct preSignatureStruct = new PreSignatureStruct();
 // APPID 获取参考 https://console.cloud.tencent.com/developer
 preSignatureStruct.appid = "1250000000";
 // 存储桶所在地域, COS 地域的简称请参照 https://intl.cloud.tencent.com/document/product/436/6224?from_cn_redirect=1
 preSignatureStruct.region = "COS_REGION"; 
 // 存储桶名称，此处填入格式必须为 bucketname-APPID, 其中 APPID 获取参考 https://console.cloud.tencent.com/developer
 preSignatureStruct.bucket = "examplebucket-1250000000";
 preSignatureStruct.key = "exampleobject"; //对象键
 preSignatureStruct.httpMethod = "GET"; //HTTP 请求方法
 preSignatureStruct.isHttps = true; //生成 HTTPS 请求 URL
 preSignatureStruct.signDurationSecond = 600; //请求签名时间为600s
 preSignatureStruct.headers = null;//签名中需要校验的 header
 preSignatureStruct.queryParameters = null; //签名中需要校验的 URL 中请求参数
  string requestSignURL = cosXml.GenerateSignURL(preSignatureStruct); 
  //下载请求预签名 URL (使用永久密钥方式计算的签名 URL)
 string localDir = System.IO.Path.GetTempPath();//本地文件夹
 string localFileName = "my-local-temp-file"; //指定本地保存的文件名
 GetObjectRequest request = new GetObjectRequest(null, null, localDir, localFileName);
 //设置下载请求预签名 URL
 request.RequestURLWithSign = requestSignURL;
 //设置进度回调
 request.SetCosProgressCallback(delegate (long completed, long total)
 {
   Console.WriteLine(String.Format("progress = {0:##.##}%", completed * 100.0 / total));
 });
 //执行请求
 GetObjectResult result = cosXml.GetObject(request);
 //请求成功
 Console.WriteLine(result.GetResultInfo());
}
catch (COSXML.CosException.CosClientException clientEx)
{
 //请求失败
 Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
 //请求失败
 Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}

说明：

更多完整示例，请前往 GitHub 查看。

示例代码二：生成预签名上传链接

try
{
 PreSignatureStruct preSignatureStruct = new PreSignatureStruct();
 // APPID 获取参考 https://console.cloud.tencent.com/developer
 preSignatureStruct.appid = "1250000000";
 // 存储桶所在地域, COS 地域的简称请参照 https://intl.cloud.tencent.com/document/product/436/6224?from_cn_redirect=1
 preSignatureStruct.region = "COS_REGION";
 // 存储桶名称，此处填入格式必须为 bucketname-APPID, 其中 APPID 获取参考 https://console.cloud.tencent.com/developer
 preSignatureStruct.bucket = "examplebucket-1250000000";
 preSignatureStruct.key = "exampleobject"; //对象键
 preSignatureStruct.httpMethod = "PUT"; //HTTP 请求方法
 preSignatureStruct.isHttps = true; //生成 HTTPS 请求 URL
 preSignatureStruct.signDurationSecond = 600; //请求签名时间为 600s
 preSignatureStruct.headers = null;//签名中需要校验的 header
 preSignatureStruct.queryParameters = null; //签名中需要校验的 URL 中请求参数
  //上传预签名 URL (使用永久密钥方式计算的签名 URL)
 string requestSignURL = cosXml.GenerateSignURL(preSignatureStruct);
  string srcPath = @"temp-source-file";//本地文件绝对路径
 PutObjectRequest request = new PutObjectRequest(null, null, srcPath);
 //设置上传请求预签名 URL
 request.RequestURLWithSign = requestSignURL;
 //设置进度回调
 request.SetCosProgressCallback(delegate (long completed, long total)
 {
   Console.WriteLine(String.Format("progress = {0:##.##}%", completed * 100.0 / total));
 });
 //执行请求
 PutObjectResult result = cosXml.PutObject(request);
 //请求成功
 Console.WriteLine(result.GetResultInfo());
}
catch (COSXML.CosException.CosClientException clientEx)
{
 //请求失败
 Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
 //请求失败
 Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}

说明：

更多完整示例，请前往 GitHub 查看。

示例代码三：生成预签名 URL，并在签名中携带 Host

try
{
 PreSignatureStruct preSignatureStruct = new PreSignatureStruct();
 // APPID 获取参考 https://console.cloud.tencent.com/developer
 preSignatureStruct.appid = "1250000000";
 // 存储桶所在地域, COS 地域的简称请参照 https://intl.cloud.tencent.com/document/product/436/6224?from_cn_redirect=1
 preSignatureStruct.region = "COS_REGION"; 
 // 存储桶名称，此处填入格式必须为 bucketname-APPID, 其中 APPID 获取参考 https://console.cloud.tencent.com/developer
 preSignatureStruct.bucket = "examplebucket-1250000000";
 preSignatureStruct.key = "exampleobject"; //对象键
 preSignatureStruct.httpMethod = "GET"; //HTTP 请求方法
 preSignatureStruct.isHttps = true; //生成 HTTPS 请求 URL
 preSignatureStruct.signDurationSecond = 600; //请求签名时间为600s
 preSignatureStruct.signHost = true; // 请求中签入Host，建议开启，能够有效防止越权请求，需要注意，开启后实际请求也需要携带Host请求头
 preSignatureStruct.headers = null;//签名中需要校验的 header
 preSignatureStruct.queryParameters = null; //签名中需要校验的 URL 中请求参数
  string requestSignURL = cosXml.GenerateSignURL(preSignatureStruct); 
 Console.WriteLine("requestUrl is:" + requestSignURL);
  //下载请求预签名 URL (使用永久密钥方式计算的签名 URL)
 string localDir = System.IO.Path.GetTempPath();//本地文件夹
 string localFileName = "my-local-temp-file"; //指定本地保存的文件名
 GetObjectRequest request = new GetObjectRequest(null, null, localDir, localFileName);
 //设置下载请求预签名 URL
 request.RequestURLWithSign = requestSignURL;
 //设置进度回调
 request.SetCosProgressCallback(delegate (long completed, long total)
 {
   Console.WriteLine(String.Format("progress = {0:##.##}%", completed * 100.0 / total));
 });
 //执行请求
 GetObjectResult result = cosXml.GetObject(request);
 //请求成功
 Console.WriteLine(result.GetResultInfo());
}
catch (COSXML.CosException.CosClientException clientEx)
{
 //请求失败
 Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
 //请求失败
 Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}

示例代码四：生成预签名URL，并在签名中携带请求参数

try
{
 PreSignatureStruct preSignatureStruct = new PreSignatureStruct();
 // APPID 获取参考 https://console.cloud.tencent.com/developer
 preSignatureStruct.appid = "1250000000";
 // 存储桶所在地域, COS 地域的简称请参照 https://intl.cloud.tencent.com/document/product/436/6224?from_cn_redirect=1
 preSignatureStruct.region = "COS_REGION"; 
 // 存储桶名称，此处填入格式必须为 bucketname-APPID, 其中 APPID 获取参考 https://console.cloud.tencent.com/developer
 preSignatureStruct.bucket = "examplebucket-1250000000";
 preSignatureStruct.key = "exampleobject"; //对象键
 preSignatureStruct.httpMethod = "GET"; //HTTP 请求方法
 preSignatureStruct.isHttps = true; //生成 HTTPS 请求 URL
 preSignatureStruct.signDurationSecond = 600; //请求签名时间为600s
 preSignatureStruct.signHost = true; // 请求中签入Host，建议开启，能够有效防止越权请求，需要注意，开启后实际请求也需要携带Host请求头
 preSignatureStruct.headers = null; // 签名中需要校验的 header
 string ci_params = "imageMogr2/thumbnail/!50p";
 preSignatureStruct.queryParameters = new Dictionary<string, string>(); // 签名中需要校验的 URL 中请求参数，以请求万象图片处理为例
 preSignatureStruct.queryParameters.Add(ci_params, null);
  string requestSignURL = cosXml.GenerateSignURL(preSignatureStruct); 
 Console.WriteLine("requestUrl is:" + requestSignURL);
  //下载请求预签名 URL (使用永久密钥方式计算的签名 URL)
 string localDir = System.IO.Path.GetTempPath();//本地文件夹
 string localFileName = "my-local-temp-file"; //指定本地保存的文件名
 GetObjectRequest request = new GetObjectRequest(null, null, localDir, localFileName);
 //设置下载请求预签名 URL
 request.RequestURLWithSign = requestSignURL;
 //设置进度回调
 request.SetCosProgressCallback(delegate (long completed, long total)
 {
   Console.WriteLine(String.Format("progress = {0:##.##}%", completed * 100.0 / total));
 });
 //执行请求
 GetObjectResult result = cosXml.GetObject(request);
 //请求成功
 Console.WriteLine(result.GetResultInfo());
}
catch (COSXML.CosException.CosClientException clientEx)
{
 //请求失败
 Console.WriteLine("CosClientException: " + clientEx);
}
catch (COSXML.CosException.CosServerException serverEx)
{
 //请求失败
 Console.WriteLine("CosServerException: " + serverEx.GetInfo());
}