Configuring AWS credentials using Amazon Cognito for DynamoDB

To configure credentials to integrate with Amazon Cognito

1. Create an Amazon Cognito identity pool that allows unauthenticated identities.

   aws cognito-identity create-identity-pool \
       --identity-pool-name DynamoPool \
       --allow-unauthenticated-identities \
       --output json
   {
       "IdentityPoolId": "us-west-2:12345678-1ab2-123a-1234-a12345ab12",
       "AllowUnauthenticatedIdentities": true,
       "IdentityPoolName": "DynamoPool"
   } 

2. Copy the following policy into a file named myCognitoPolicy.json. Replace the identity pool ID (us-west-2:12345678-1ab2-123a-1234-a12345ab12) with your own IdentityPoolId obtained in the previous step.

   {
     "Version": "2012-10-17",
     "Statement": [
       {
         "Effect": "Allow",
         "Principal": {
           "Federated": "cognito-identity.amazonaws.com"
         },
         "Action": "sts:AssumeRoleWithWebIdentity",
         "Condition": {
           "StringEquals": {
             "cognito-identity.amazonaws.com:aud": "us-west-2:12345678-1ab2-123a-1234-a12345ab12"
           },
           "ForAnyValue:StringLike": {
             "cognito-identity.amazonaws.com:amr": "unauthenticated"
           }
         }
       }
     ]
   }

3. Create an IAM role that assumes the previous policy. In this way, Amazon Cognito becomes a trusted entity that can assume the Cognito_DynamoPoolUnauth role.

   aws iam create-role --role-name Cognito_DynamoPoolUnauth \
   --assume-role-policy-document file://PathToFile/myCognitoPolicy.json --output json 

4. Grant the Cognito_DynamoPoolUnauth role full access to DynamoDB by attaching a managed policy (AmazonDynamoDBFullAccess).

   aws iam attach-role-policy --policy-arn arn:aws:iam::aws:policy/AmazonDynamoDBFullAccess \
   --role-name Cognito_DynamoPoolUnauth 

   Note

   Alternatively, you can grant fine-grained access to DynamoDB. For more information, see Using IAM policy conditions for fine-grained access control.

5. Obtain and copy the IAM role Amazon Resource Name (ARN).

   aws iam get-role --role-name Cognito_DynamoPoolUnauth --output json 

6. Add the Cognito_DynamoPoolUnauth role to the DynamoPool identity pool. The format to specify is KeyName=string, where KeyName is unauthenticated and the string is the role ARN obtained in the previous step.

   aws cognito-identity set-identity-pool-roles \
   --identity-pool-id "us-west-2:12345678-1ab2-123a-1234-a12345ab12" \
   --roles unauthenticated=arn:aws:iam::123456789012:role/Cognito_DynamoPoolUnauth --output json

7. Specify the Amazon Cognito credentials in your files. Modify the IdentityPoolId and RoleArn accordingly.

   AWS.config.credentials = new AWS.CognitoIdentityCredentials({
   IdentityPoolId: "us-west-2:12345678-1ab2-123a-1234-a12345ab12",
   RoleArn: "arn:aws:iam::123456789012:role/Cognito_DynamoPoolUnauth"
   });