我测试了code，它的作品！你只需要一个额外的\ n与变化HTTP到HTTPS，就大功告成了。

 字符串stringToConvert =GET \ N
                          +\ N
                          +\ N
                          +\ N
                          +X-AMZ-日期：+的timeStamp +\ N
                          +/+ bucketName +/+文件名;
 

亚马逊的REST API不具备良好的文档，缺少的例子让大家去的SDK代替。

I'm trying to get some code working to fetch a file from S3 using the REST API via C#. I've seen other people doing similar things but for some reason I keep getting a 403 error. I've tried to do the same thing with the AWS SDK for .Net and it works so I assume it's the way I'm creating the authorization header.

Is anyone able to shed any light on this please?

string awsAccessId = "***";
string awsSecretKey = "***";
string bucketName = "thebucket";

string httpDate = DateTime.Now.ToString("ddd, dd MMM yyyy HH:mm:ss +0000\n");
                string canonicalString = "GET\n"
                                        + "\n"
                                        + "\n"
                                        + "x-amz-date:" + httpDate + "\n"
                                        + "/" + bucketName + "/readme.txt";

                // now encode the canonical string
                Encoding ae = new UTF8Encoding();
                // create a hashing object
                HMACSHA1 signature = new HMACSHA1();
                // secretId is the hash key
                signature.Key = ae.GetBytes(awsSecretKey);
                byte[] bytes = ae.GetBytes(canonicalString);
                byte[] moreBytes = signature.ComputeHash(bytes);
                // convert the hash byte array into a base64 encoding
                string encodedCanonical = Convert.ToBase64String(moreBytes);

                // Send the request
                HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create("http://" + bucketName +".s3.amazonaws.com/readme.txt");
                request.Headers.Add("x-amz-date", httpDate);
                request.Headers.Add("Authorization", "AWS " + awsAccessId + ":" + encodedCanonical);
                request.Method = "GET";

                // Get the response
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                Console.WriteLine(response.StatusCode);
                Console.Read();

I tested your code, it works! you just need an extra \n plus change http to https and you're done.

 string stringToConvert = "GET\n"
                          + "\n"
                          + "\n"
                          + "\n"
                          + "x-amz-date:" + timeStamp + "\n"  
                          + "/" + bucketName + "/" + FileName;

Amazon Rest API don't have a good documentation, the lack of examples makes everyone go to the SDK instead.