为什么我的访问在 s3 上被拒绝（使用适用于 Node.js 的 aws-sdk）？

我试图从我的 s3 存储桶中读取现有文件，但我不断收到“访问被拒绝”的消息，并且没有任何解释或说明如何处理它。Here https://github.com/vigour-io/imaginate/blob/s3/lib/cloud.js是我正在使用的代码：

'use strict'

var AWS = require('aws-sdk')
const options = {
  apiVersion: '2006-03-01',
  params: {
    Bucket: process.env['IMAGINATOR_BUCKET']
  },
  accessKeyId: process.env['IMAGINATOR_AWS_ACCESS_KEY_ID'],
  secretAccessKey: process.env['IMAGINATOR_AWS_SECRET_ACCESS_KEY'],
  signatureVersion: 'v4'
}
console.log('options', options)
var s3 = new AWS.S3(options)

module.exports = exports = {
  get (name, cb) {
    const params = {
      Key: name + '.json'
    }
    console.log('get params', params)
    return s3.getObject(params, cb)
  },
  set (name, body, cb) {
    const params = {
      Key: name + '.json',
      Body: body
    }
    console.log('set params', params)
    return s3.putObject(params, cb)
  }
}

这就是我使用时得到的输出get方法并记录回调中提供的错误（敏感信息已被删除）：

options { apiVersion: '2006-03-01',
  params: { Bucket: CENSORED_BUT_CORRECT },
  accessKeyId: CENSORED_BUT_CORRECT,
  secretAccessKey: CENSORED_BUT_CORRECT,
  signatureVersion: 'v4' }
get params { Key: 'whitelist.json' }
err { [AccessDenied: Access Denied]
  message: 'Access Denied',
  code: 'AccessDenied',
  region: null,
  time: Wed Sep 21 2016 11:17:50 GMT-0400 (EDT),
  requestId: CENSORED,
  extendedRequestId: CENSORED,
  cfId: undefined,
  statusCode: 403,
  retryable: false,
  retryDelay: 20.084538962692022 }
/Users/shawn/git/vigour-io/imaginate/node_modules/aws-sdk/lib/request.js:31
            throw err;
            ^

AccessDenied: Access Denied
    at Request.extractError (/Users/shawn/git/vigour-io/imaginate/node_modules/aws-sdk/lib/services/s3.js:538:35)
    at Request.callListeners (/Users/shawn/git/vigour-io/imaginate/node_modules/aws-sdk/lib/sequential_executor.js:105:20)
    at Request.emit (/Users/shawn/git/vigour-io/imaginate/node_modules/aws-sdk/lib/sequential_executor.js:77:10)
    at Request.emit (/Users/shawn/git/vigour-io/imaginate/node_modules/aws-sdk/lib/request.js:668:14)
    at Request.transition (/Users/shawn/git/vigour-io/imaginate/node_modules/aws-sdk/lib/request.js:22:10)
    at AcceptorStateMachine.runTo (/Users/shawn/git/vigour-io/imaginate/node_modules/aws-sdk/lib/state_machine.js:14:12)
    at /Users/shawn/git/vigour-io/imaginate/node_modules/aws-sdk/lib/state_machine.js:26:10
    at Request.<anonymous> (/Users/shawn/git/vigour-io/imaginate/node_modules/aws-sdk/lib/request.js:38:9)
    at Request.<anonymous> (/Users/shawn/git/vigour-io/imaginate/node_modules/aws-sdk/lib/request.js:670:12)
    at Request.callListeners (/Users/shawn/git/vigour-io/imaginate/node_modules/aws-sdk/lib/sequential_executor.js:115:18)

现在我不知道该怎么做，因为我认为我根据文档正确地做事，但它不起作用，并且错误消息没有说明为什么我的访问被拒绝...知道下一步应该做什么是为了让这个工作吗？

问题是我的新 IAM 用户没有附加策略。我给它分配了AmazonS3FullAccess政策，现在它起作用了。

正如评论中指出的，限制性更强的政策会安全得多