我需要从 C# 应用程序调用托管在 AWS 上并使用 SIGV4 保护的 API。
我已经从 AWS 下载了 C# 的 SIGV4 示例，但显然没有关于如何调用 API 的示例。所以我修改了示例代码以获取一个 S3 对象来调用“execute-api”服务。
这是我的代码：
public class GetExecuteApiSample
{
static readonly string AWSAccessKey = ConfigurationManager.AppSettings["AWSAccessKey"];
static readonly string AWSSecretKey = ConfigurationManager.AppSettings["AWSSecretKey"];
public static void Run()
{
var endpointUri = string.Format("https://XXXXXX.execute-api.eu-west-1.amazonaws.com");
var uri = new Uri(endpointUri + "/api/v1/list-my-results");
// for a simple GET, we have no body so supply the precomputed 'empty' hash
var headers = new Dictionary<string, string>
{
{AWS4SignerBase.X_Amz_Content_SHA256, AWS4SignerBase.EMPTY_BODY_SHA256},
{"content-type", "text/plain"}
};
var signer = new AWS4SignerForAuthorizationHeader
{
EndpointUri = uri,
HttpMethod = "GET",
Service = "execute-api",
Region = "eu-west-1"
};
var authorization = signer.ComputeSignature(headers,
"", // no query parameters
AWS4SignerBase.EMPTY_BODY_SHA256,
AWSAccessKey,
AWSSecretKey);
// place the computed signature into a formatted 'Authorization' header
headers.Add("Authorization", authorization);
HttpHelpers.InvokeHttpRequest(uri, "GET", headers, null);
}
}
但是当我发送请求时出现以下错误：
"Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host."
您可以在下面找到 的代码HttpHelpers，这是 AWS 示例中的代码。
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
namespace AWSSignatureV4_S3_Sample.Util
{
/// <summary>
/// Various Http helper routines
/// </summary>
public static class HttpHelpers
{
/// <summary>
/// Makes a http request to the specified endpoint
/// </summary>
/// <param name="endpointUri"></param>
/// <param name="httpMethod"></param>
/// <param name="headers"></param>
/// <param name="requestBody"></param>
public static void InvokeHttpRequest(Uri endpointUri,
string httpMethod,
IDictionary<string, string> headers,
string requestBody)
{
try
{
var request = ConstructWebRequest(endpointUri, httpMethod, headers);
if (!string.IsNullOrEmpty(requestBody))
{
var buffer = new byte[8192]; // arbitrary buffer size
var requestStream = request.GetRequestStream();
using (var inputStream = new MemoryStream(Encoding.UTF8.GetBytes(requestBody)))
{
var bytesRead = 0;
while ((bytesRead = inputStream.Read(buffer, 0, buffer.Length)) > 0)
{
requestStream.Write(buffer, 0, bytesRead);
}
}
}
CheckResponse(request);
}
catch (WebException ex)
{
using (var response = ex.Response as HttpWebResponse)
{
if (response != null)
{
var errorMsg = ReadResponseBody(response);
Console.WriteLine("\n-- HTTP call failed with exception '{0}', status code '{1}'", errorMsg, response.StatusCode);
}
}
}
}
/// <summary>
/// Construct a HttpWebRequest onto the specified endpoint and populate
/// the headers.
/// </summary>
/// <param name="endpointUri">The endpoint to call</param>
/// <param name="httpMethod">GET, PUT etc</param>
/// <param name="headers">The set of headers to apply to the request</param>
/// <returns>Initialized HttpWebRequest instance</returns>
public static HttpWebRequest ConstructWebRequest(Uri endpointUri,
string httpMethod,
IDictionary<string, string> headers)
{
var request = (HttpWebRequest)WebRequest.Create(endpointUri);
request.Method = httpMethod;
foreach (var header in headers.Keys)
{
// not all headers can be set via the dictionary
if (header.Equals("host", StringComparison.OrdinalIgnoreCase))
request.Host = headers[header];
else if (header.Equals("content-length", StringComparison.OrdinalIgnoreCase))
request.ContentLength = long.Parse(headers[header]);
else if (header.Equals("content-type", StringComparison.OrdinalIgnoreCase))
request.ContentType = headers[header];
else
request.Headers.Add(header, headers[header]);
}
return request;
}
public static void CheckResponse(HttpWebRequest request)
{
// Get the response and read any body into a string, then display.
using (var response = (HttpWebResponse)request.GetResponse())
{
if (response.StatusCode == HttpStatusCode.OK)
{
Console.WriteLine("\n-- HTTP call succeeded");
var responseBody = ReadResponseBody(response);
if (!string.IsNullOrEmpty(responseBody))
{
Console.WriteLine("\n-- Response body:");
Console.WriteLine(responseBody);
}
}
else
Console.WriteLine("\n-- HTTP call failed, status code: {0}", response.StatusCode);
}
}
/// <summary>
/// Reads the response data from the service call, if any
/// </summary>
/// <param name="response">
/// The response instance obtained from the previous request
/// </param>
/// <returns>The body content of the response</returns>
public static string ReadResponseBody(HttpWebResponse response)
{
if (response == null)
throw new ArgumentNullException("response", "Value cannot be null");
// Then, open up a reader to the response and read the contents to a string
// and return that to the caller.
string responseBody = string.Empty;
using (var responseStream = response.GetResponseStream())
{
if (responseStream != null)
{
using (var reader = new StreamReader(responseStream))
{
responseBody = reader.ReadToEnd();
}
}
}
return responseBody;
}
/// <summary>
/// Helper routine to url encode canonicalized header names and values for safe
/// inclusion in the presigned url.
/// </summary>
/// <param name="data">The string to encode</param>
/// <param name="isPath">Whether the string is a URL path or not</param>
/// <returns>The encoded string</returns>
public static string UrlEncode(string data, bool isPath = false)
{
// The Set of accepted and valid Url characters per RFC3986. Characters outside of this set will be encoded.
const string validUrlCharacters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.~";
var encoded = new StringBuilder(data.Length * 2);
string unreservedChars = String.Concat(validUrlCharacters, (isPath ? "/:" : ""));
foreach (char symbol in System.Text.Encoding.UTF8.GetBytes(data))
{
if (unreservedChars.IndexOf(symbol) != -1)
encoded.Append(symbol);
else
encoded.Append("%").Append(String.Format("{0:X2}", (int)symbol));
}
return encoded.ToString();
}
}
}