Javascript s3“；签名不'；“t匹配”；客户端后jquery文件上载

我正在生成一个签名，用于在后端的节点中将客户端发布到s3，并通过客户端上的jquery文件上传提交。我的签名生成如下所示：

  app.post('/api/v1/s3', function(req, res){
    var data = utils.getReqJson(req.body);
    var mime_type = mime.lookup(data.filename);
    var expire = moment().utc().add('hour', 1).toJSON("YYYY-MM-DDTHH:mm:ss Z");
    var policy = JSON.stringify({
      "expiration": expire,
      "conditions": [ 
        {"bucket": aws_bucket},
        ["starts-with", "$key", aws_bucket_dir],
        {"acl": "private"},
        {"success_action_status": "201"},
        ["starts-with", "$Content-Type", ''],
        ["content-length-range", 0, max_filesize]
      ]
    });
    var base64policy = new Buffer(policy).toString('base64');
    var signature = crypto.createHmac('sha1', process.env.AWS_SECRET).update(base64policy).digest('base64');
    signature = encodeURIComponent(signature.trim());
    signature = signature.replace('%2B','+');
    var file_key = uuid.v4();
    res.json({ policy: base64policy,
      signature: signature,
      key: aws_bucket_dir + file_key + "_" + data.filename,
      contentType: mime_type,
      aws_access: process.env.AWS_ACCESS_KEY,
      bucket_dir: aws_bucket_dir,
      bucket: aws_bucket
    });
  });

在前端，我有以下代码：

this.$().fileupload({
  dataType: 'json',
  type: 'POST',
  autoUpload: true,
  add: function (e, data) {
    $.ajax({
      url: window.ENV.api_url+'/' + window.ENV.api_namespace + '/s3',
      type: 'POST',
      dataType: 'json',
      data: {
        "filename": data.files[0].name
      },
      async: false,
      success: function(retdata) {
        //do actual upload stuff now.
        data.url = 'https://'+retdata.bucket+'.s3.amazonaws.com/';
        data.formData = {
          key: retdata.key,
          AWSAccessKeyId: retdata.aws_access,
          acl: 'private',
          policy: retdata.policy,
          signature: retdata.signature,
          success_action_status: 201,
          "Content-Type": retdata.contentType 
        };
        data.submit()
          .success(function (result, textStatus, jqXHR) {
            console.log('Success: ' + result);
          })
          .error(function (jqXHR, textStatus, errorThrown) {
            console.log('Error: ' + errorThrown);
            console.log(jqXHR);
            console.log('Status: ' + textStatus);                
          });
        console.log(retdata);
      },
      error: function (xhr, ajaxOptions, thrownError) {
        console.log('AJAX: ' + xhr);
        console.log('AJAX: ' + thrownError);
      }
    });
  },
  progressall: function (e, data) {
    var progress = parseInt(data.loaded / data.total * 100, 10);
    $('#progress .progress-bar').css(
      'width',
      progress + '%'
    );
  }
});

似乎我正在提交正确的表单数据以匹配签名生成，但每次尝试提交时都会出现以下错误：

SignatureDesNotMatch-我们计算的请求签名与您提供的签名不匹配。检查您的密钥和签名方法。

---

我正在努力找出我可能做错了什么，如果有人能帮助我，我将不胜感激。

我为此奋斗了一段时间，并最终通过以下方法使其工作：

  app.post('/api/v1/s3', function(req, res){
    var data = utils.getReqJson(req.body);
    var mime_type = mime.lookup(data.filename);
    var expire = moment().utc().add('hour', 1).toJSON("YYYY-MM-DDTHH:mm:ss Z");
    var policy = JSON.stringify({
      "expiration": expire,
      "conditions": [ 
        {"bucket": aws_bucket},
        ["starts-with", "$key", aws_bucket_dir],
        {"acl": "private"},
        {"success_action_status": "201"},
        ["starts-with", "$Content-Type", ''],
        ["content-length-range", 0, max_filesize]
      ]
    });
    var base64policy = new Buffer(policy).toString('base64');
    var signature = crypto.createHmac('sha1', process.env.AWS_SECRET).update(base64policy).digest('base64');
    signature = encodeURIComponent(signature.trim());
    signature = signature.replace('%2B','+');
    var file_key = uuid.v4();
    res.json({ policy: base64policy,
      signature: signature,
      key: aws_bucket_dir + file_key + "_" + data.filename,
      contentType: mime_type,
      aws_access: process.env.AWS_ACCESS_KEY,
      bucket_dir: aws_bucket_dir,
      bucket: aws_bucket
    });
  });

在s3处理程序中：

var uploadToS3 = function(s3Url, cb){
  var fd = new FormData();
  var file = document.getElementById('file').files[0];
  var key = 'uploads\/' + file.name;

  fd.append('key', 'uploads\/' + file.name);
  fd.append('acl', 'public-read');
  fd.append('Content-Type', 'multipart/form-data');
  fd.append('AWSAccessKeyId', 'XXXX');
  fd.append('policy', s3Url.s3Policy);
  fd.append('signature', s3Url.s3Signature);
  fd.append('file', file);

  var xhr = new XMLHttpRequest();
  xhr.open('POST', 'https://XXXX.s3.amazonaws.com', true);

  /////////////////////////////////////////////////////////
  // Keep track of upload progress so that we can message//
  // it to the user.                                     //
  /////////////////////////////////////////////////////////

  var firstProgressEvent = true;
  xhr.loaded = 0;
  xhr.upload.addEventListener('progress', function(e) {
    if (firstProgressEvent) {
      firstProgressEvent = false;
    }
    xhr.loaded += (e.loaded - xhr.loaded);
    $('progress').val((xhr.loaded / e.total) * 100);
  }, false);

  xhr.onreadystatechange = function(){ 
    if ( xhr.readyState == 4 ) { 
      if ( xhr.status >= 200 && xhr.status < 400 ) { 
        cb(xhr.status);
      } else { 
        cb(xhr.status);
      } 
    } 
  }; 
  xhr.onerror = function () { 
    error(xhr, xhr.status); 
  }; 
  xhr.send(fd);
};

---

成功了，谢谢。我的问题似乎与我发布表单数据的方式有关，但现在一切都在运行。非常感谢，再次感谢。