AWS Code Sample
Catalog demonstrates how to use Amazon STS AssumeRole with MultiFactor Authentication (MFA) to access resources on an external account.

# Copyright 2010-2019, Inc. or its affiliates. All Rights Reserved. # This file is licensed under the Apache License, Version 2.0 (the "License"). # You may not use this file except in compliance with the License. A copy of # the License is located at # # # # This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR # CONDITIONS OF ANY KIND, either express or implied. See the License for the # specific language governing permissions and limitations under the License. import boto3 # Prompt for an MFA time-based one-time password (TOTP) mfa_TOTP = input('Enter the MFA code: ') # Create an STS client sts_client = boto3.client('sts') # Assume a role defined on an external account. The role specifies the # permissions that are allowed on the account. # Replace EXTERNAL_ACCOUNT_NUMBER with the account number of the external account. # Replace ROLE_NAME with the name of the role defined on the external account. # Replace MFA_DEVICE with the virtual MFA device ID. Alternatively, set the # SerialNumber string to the serial number of the MFA hardware device, such as # SerialNumber='GAHT12345678'. # Optional, but recommended: Specify a unique ExternalId= string assigned by the external account. response = sts_client.assume_role(RoleArn='arn:aws:iam::EXTERNAL_ACCOUNT_NUMBER:role/ROLE_NAME', RoleSessionName='AssumeRoleSession1', SerialNumber='arn:aws:iam::MFA_DEVICE:mfa/user', TokenCode=mfa_TOTP) # Reference the temporary credentials section of the response tempCredentials = response['Credentials'] # Use the temporary credentials to create an S3 client that can access the # external account. s3_client = boto3.client('s3', aws_access_key_id=tempCredentials['AccessKeyId'], aws_secret_access_key=tempCredentials['SecretAccessKey'], aws_session_token=tempCredentials['SessionToken']) # Replace BUCKET_NAME with a bucket that exists on the external account bucket_name = 'BUCKET_NAME' # List the objects in the external account's bucket. The assumed role's # permissions must allow this type of S3 access. try: response = s3_client.list_objects_v2(Bucket=bucket_name) except Exception as e: print(f'ERROR: Could not find bucket {bucket_name}') else: print(f'Objects in {bucket_name}') for obj in response['Contents']: print(f' {obj["Key"]}')

Sample Details

Service: iam

Last tested: 2019-01-22

Author: stephswo (AWS)

Type: full-example

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