title: How do you increase the token expiration time for a boto3.s3.transfer download?
body: <p>I am using boto3's s3.transfer to download several 4GB+ files from s3. All but one were able to download, but the one that failed gave the following error:</p>
  
  <pre><code>ERROR: An error occurred (ExpiredToken) when calling the GetObject operation: The provided token has expired.
  </code></pre>
  
  <p>I am using it the same way it is document at <a href="http://boto3.readthedocs.org/en/latest/_modules/boto3/s3/transfer.html" rel="noreferrer">http://boto3.readthedocs.org/en/latest/_modules/boto3/s3/transfer.html</a></p>
  
  <pre><code>s3_client = session.client('s3')
  transfer = S3Transfer(s3_client)
  # Download s3://bucket/key to /tmp/myfile
  transfer.download_file('bucket', 'key', '/tmp/myfile')
  </code></pre>
  
  <p>Is there a way to increase the expiration time of the signed url used inside boto3?</p>
  
  <p>In case it is relevant, I am using Cognito to get the credentials, and with them, a session</p>
  
  <pre><code>    client = boto3.client('cognito-identity', AWS_REGION)
  
      # credentials[] contains the IdentityId and Token I get from my server
      # which I get using client.get_open_id_token_for_developer_identity 
      # with TokenDuration=86400
      resp = client.get_credentials_for_identity(IdentityId=credentials['IdentityId'],
                                                 Logins={'cognito-identity.amazonaws.com': credentials['Token']})
  
      # The resp contains the actual temporary AWS secret/access codes and a session token, to be
      # used with the rest of the AWS APIs
      secretKey = resp['Credentials']['SecretKey']
      accessKey = resp['Credentials']['AccessKeyId']
      sessionToken = resp['Credentials']['SessionToken']
  
      session = Session(aws_access_key_id=accessKey,
                        aws_secret_access_key=secretKey,
                        aws_session_token=sessionToken,
                        region_name=AWS_REGION)
  
      s3_client = session.client('s3')
  </code></pre>