使用客户端提供的amazonInfo将文件上传到AWS S3

如何解决使用客户端提供的amazonInfo将文件上传到AWS S3

我们正在与Salesforce客户端集成，该客户端向我们提供了amazonInfo对象，该对象用于将文件上传到s3，如下所示：

"amazonInfo": {
        "UploadId": "a0T1b000000aR41EAF","PolicySigned": "0KtfeVcVYTVWQs3Uj+GjxkB/f8A=","PolicyEncoded": "xyzgICAgImV4cGlyYXRpb24iOiAiMjAyMC0wOC0xNFQxMTo0MjozMS4zODdaIiwKICAgICJjb25kaXWpb25zIjoKICAgIFsKICAgICAgICB7UCJidWNrZXQiOiAiQ2hhcnRzd2FwIiB9LAogICAgICAgIHsgImFjbCI6ICJwcml2YXRlIiB9LAogICAgICAgIHsgImNvbnRlbnQtdHlwZSI6IlNpZ25lZCBBdXRob3JpemF0aW9uIEZvcm0ifSwKICAgICAgICB7ICJ4LWFtei1zZXJ2ZXItc2lkZS1lbmNyeXB0aW9uIjogIkFFUzI1NiJ9LAogICAgICAgIHsgImtleSI6ICJjeC1hMFQxYjAwMDAwMHZSNDFFQUUtMzQ5NjgxLk9DLnRlc3QucGRmIiB9CiAgICBtHs0=","Policy": "{\n    \"expiration\": \"2020-08-14T11:52:31.387Z\",\n    \"conditions\":\n    [\n        { \"bucket\": \"clientBucket\" },\n        { \"acl\": \"private\" },\n        { \"content-type\":\"Signed Form\"},\n        { \"x-amz-server-side-encryption\": \"AES256\"},\n        { \"key\": \"cx-a0T1b000000aR41EAF-349681.OC.test.pdf\" }\n    ]\n}","Key": "AKIAJFOYVDQQZEXAMPLE","FileNameLocal": "349681.OC.test.pdf","FileNameAWS": "cx-a0T1b000000aR41EAF-349681.OC.test.pdf","ErrorMessage": null,"EndPoint": "https://s3.amazonaws.com/clientBucket","ContentType": "Signed Form","Acl": "private"
    }

我尝试通过browser based upload使用此对象，但是我无法映射所有字段，并且它需要使用secretKey进行签名的签名。

我还尝试过使用High Level / Low Level上传，但是它始终需要一个secretKey。

我可以使用此对象在没有密钥的情况下上传文件吗？

我还想知道这里的UploadId和PolicySigned的用途/目的是什么？

解决方法

此信息可用于具有HTTP的MultipartFormDataContent的基于浏览器的上传中，如下所示：

            using (var content = new MultipartFormDataContent(Guid.NewGuid().ToString()))
            {
                content.Add(new StringContent(awsInfo.Acl),"acl");
                content.Add(new StringContent(awsInfo.Key),"AWSAccessKeyId");
                content.Add(new StringContent(awsInfo.ContentType),"content-type");
                content.Add(new StringContent(awsInfo.FileNameAWS),"key");
                content.Add(new StringContent(awsInfo.PolicyEncoded),"policy");
                content.Add(new StringContent(awsInfo.PolicySigned),"signature");
                content.Add(new StringContent("AES256"),"x-amz-server-side-encryption");
                using (FileStream fs = new FileStream(filePath,FileMode.Open,FileAccess.Read))
                {
                    byte[] fileContents = new byte[fs.Length];
                    content.Add(new StreamContent(new MemoryStream(fileContents)),"file",awsInfo.FileNameLocal);
                }

                return await _client.PostAsync(awsInfo.EndPoint,content);
            }

注意： awsInfo是所提供的“ amazonInfo”的反序列化对象，而_client是常规的System.Net.Http.HttpClient实例。