AWS IAM策略：如何更改AWSLambdaFullAccess策略以仅允许访问一个S3存储桶？

Question

我正在与我的IT团队一起限制我的用户帐户（在root帐户下），以使其无法访问我不想访问的S3存储桶。 启用AWSLambdaFullAccess策略时，它将启用对许多AWS功能（包括所有S3）的完全访问权限。 这是AWSLambdaFullAccess策略：

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "cloudwatch:*",
        "cognito-identity:ListIdentityPools",
        "cognito-sync:GetCognitoEvents",
        "cognito-sync:SetCognitoEvents",
        "dynamodb:*",
        "events:*",
        "iam:ListAttachedRolePolicies",
        "iam:ListRolePolicies",
        "iam:ListRoles",
        "iam:PassRole",
        "kinesis:DescribeStream",
        "kinesis:ListStreams",
        "kinesis:PutRecord",
        "lambda:*",
        "logs:*",
        "s3:*",
        "sns:ListSubscriptions",
        "sns:ListSubscriptionsByTopic",
        "sns:ListTopics",
        "sns:Subscribe",
        "sns:Unsubscribe"
      ],
      "Resource": "*"
    }
  ]
}

大部分都很好。 如何将其作为一项新策略进行更改，以使我只能访问“ arn：aws：s3 ::: lambda-scripts”存储桶？

Answer 1

我能想到的最直接的编辑将涉及从您所拥有的语句中删除“ s3：*”操作，并添加第二条语句，以仅授予S3访问该存储桶的权限。

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "cloudwatch:*",
        "cognito-identity:ListIdentityPools",
        "cognito-sync:GetCognitoEvents",
        "cognito-sync:SetCognitoEvents",
        "dynamodb:*",
        "events:*",
        "iam:ListAttachedRolePolicies",
        "iam:ListRolePolicies",
        "iam:ListRoles",
        "iam:PassRole",
        "kinesis:DescribeStream",
        "kinesis:ListStreams",
        "kinesis:PutRecord",
        "lambda:*",
        "logs:*",
        "sns:ListSubscriptions",
        "sns:ListSubscriptionsByTopic",
        "sns:ListTopics",
        "sns:Subscribe",
        "sns:Unsubscribe"
      ],
      "Resource": "*"
    },
    {
        "Sid": "S3LambdaScripts",
        "Effect": "Allow",
        "Action": [
            "s3:*"
        ],
        "Resource": [
            "arn:aws:s3:::lambda-scripts*"
        ]
    }
  ]
}

更好的答案是，您实际上不应该使用预定义的AWSLambdaFullAccess权限。 相反，可以使用针对您真正需要的服务和资源的多个语句来构建自己的语句。 例如，您是否真的在使用Dynamo，Kinesis，Cognito等？ 是的，这很乏味。 但是，如果将较小的增量保存为IAM中的用户定义策略，则可以更轻松地从自定义和预定义内容中组合合理的策略。

Answer 2

将S3权限拆分为单独的语句，然后修改这些语句的资源设置。 像这样：

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "cloudwatch:*",
        "cognito-identity:ListIdentityPools",
        "cognito-sync:GetCognitoEvents",
        "cognito-sync:SetCognitoEvents",
        "dynamodb:*",
        "events:*",
        "iam:ListAttachedRolePolicies",
        "iam:ListRolePolicies",
        "iam:ListRoles",
        "iam:PassRole",
        "kinesis:DescribeStream",
        "kinesis:ListStreams",
        "kinesis:PutRecord",
        "lambda:*",
        "logs:*",
        "sns:ListSubscriptions",
        "sns:ListSubscriptionsByTopic",
        "sns:ListTopics",
        "sns:Subscribe",
        "sns:Unsubscribe"
      ],
      "Resource": "*"
    },
    {
       "Effect":"Allow",
       "Action":[
          "s3:ListBucket",
          "s3:GetBucketLocation"
       ],
       "Resource":"arn:aws:s3:::lambda-scripts"
      },
    {
     "Effect": "Allow",
     "Action": [        
       "s3:PutObject",
       "s3:GetObject",
       "s3:DeleteObject"
     ],
     "Resource": "arn:aws:s3:::lambda-scripts/*"
    }
  ]
}