Amazon S3: Allows Amazon Cognito users to access objects in their bucket

This example shows how you might create an identity-based policy that allows Amazon Cognito users to access objects in a specific S3 bucket. This policy allows access only to objects with a name that includes cognito, the name of the application, and the federated user's ID, represented by the ${cognito-identity.amazonaws.com:sub} variable. This policy grants the permissions necessary to complete this action programmatically from the AWS API or AWS CLI. To use this policy, replace the italicized placeholder text in the example policy with your own information. Then, follow the directions in create a policy or edit a policy.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "ListYourObjects",
      "Effect": "Allow",
      "Action": "s3:ListBucket",
      "Resource": [
        "arn:aws:s3:::bucket-name"
      ],
      "Condition": {
        "StringLike": {
          "s3:prefix": [
            "cognito/application-name/${cognito-identity.amazonaws.com:sub}/*"
          ]
        }
      }
    },
    {
      "Sid": "ReadWriteDeleteYourObjects",
      "Effect": "Allow",
      "Action": [
        "s3:DeleteObject",
        "s3:GetObject",
        "s3:PutObject"
      ],
      "Resource": [
        "arn:aws:s3:::bucket-name/cognito/application-name/${cognito-identity.amazonaws.com:sub}/*"
      ]
    }
  ]
}

Amazon Cognito provides authentication, authorization, and user management for your web and mobile apps. Your users can sign in directly with a user name and password, or through a third party such as Facebook, Amazon, or Google.

The two main components of Amazon Cognito are user pools and identity pools. User pools are user directories that provide sign-up and sign-in options for your app users. Identity pools enable you to grant your users access to other AWS services. You can use identity pools and user pools separately or together.

For more information about Amazon Cognito, see Amazon Cognito User Guide.