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Class: AWS::STS

Inherits:
Object
  • Object
show all
Includes:
Core::ServiceInterface
Defined in:
lib/aws/sts.rb,
lib/aws/sts/policy.rb,
lib/aws/sts/errors.rb,
lib/aws/sts/client.rb,
lib/aws/sts/session.rb,
lib/aws/sts/federated_session.rb

Overview

This class is a starting point for working with the AWS Security Token Service. The AWS Security Token Service is a web service that enables you to request temporary, limited-privilege credentials for users that you authenticate (federated users), or IAM users.

Examples:

Getting temporary credentials and using them to make an EC2 request


sts = AWS::STS.new(:access_key_id => "LONG_TERM_KEY",
                   :secret_access_key => "LONG_TERM_SECRET")
session = sts.new_session(:duration => 60*60)
ec2 = AWS::EC2.new(session.credentials)
ec2.instances.to_a

Getting temporary credentials with restricted permissions


policy = AWS::STS::Policy.new
policy.allow(:actions => ["s3:*", "ec2:*"],
             :resources => :any)
session = sts.new_federated_session("TemporaryUser", :policy => policy)
ec2 = AWS::EC2.new(session.credentials)
ec2.instances.to_a

Defined Under Namespace

Modules: Errors Classes: Client, FederatedSession, Policy, Session

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Core::ServiceInterface

included, #initialize, #inspect

Instance Attribute Details

#client ⇒ Client (readonly)

Returns the low-level STS client object

Returns:

  • (Client) —

    the low-level STS client object



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# File 'lib/aws/sts.rb', line 44

class STS

  autoload :Client, 'aws/sts/client'
  autoload :Errors, 'aws/sts/errors'
  autoload :FederatedSession, 'aws/sts/federated_session'
  autoload :Policy, 'aws/sts/policy'
  autoload :Session, 'aws/sts/session'

  include Core::ServiceInterface

  endpoint_prefix 'sts', :global => true

  # (see Client#assume_role)
  def assume_role options = {}
    client.assume_role(options).data
  end

  # Returns a set of temporary credentials for an AWS account or IAM
  # User. The credentials consist of an Access Key ID, a Secret
  # Access Key, and a security token. These credentials are valid
  # for the specified duration only. The session duration for IAM
  # users can be between one and 36 hours, with a default of 12
  # hours. The session duration for AWS account owners is restricted
  # to one hour.
  #
  # @param [Hash] opts Options for getting temporary credentials.
  #
  # @option opts [Integer] :duration The duration, in seconds, that
  #   the session should last. Acceptable durations for IAM user
  #   sessions range from 3600s (one hour) to 129600s (36 hours),
  #   with 43200s (12 hours) as the default. Sessions for AWS
  #   account owners are restricted to a maximum of 3600s (one
  #   hour).
  #
  # @option opts [String] :serial_number The identification number of the
  #   Multi-Factor Authentication (MFA) device for the user.
  #
  # @option opts [String] :token_code The value provided by the MFA device.
  #   If the user has an access policy requiring an MFA code, provide the
  #   value here to get permission to resources as specified in the access
  #   policy.
  #
  # @return [Session]
  def new_session(opts = {})
    get_session(:get_session_token, opts) do |resp, session_opts|
      Session.new(session_opts)
    end
  end

  # Returns a set of temporary credentials for a federated user with
  # the user name and policy specified in the request. The
  # credentials consist of an Access Key ID, a Secret Access Key,
  # and a security token. The credentials are valid for the
  # specified duration, between one and 36 hours.
  #
  # The federated user who holds these credentials has only those
  # permissions allowed by intersection of the specified policy and
  # any resource or user policies that apply to the caller of the
  # GetFederationToken API. For more information about how token
  # permissions work, see
  # {http://docs.aws.amazon.com/IAM/latest/UserGuide/TokenPermissions.html
  # Controlling Token Permissions} in Using AWS Identity and Access
  # Management.
  #
  # @param [String] name The name of the federated user associated
  #   with the session.  Must be between 2 and 32 characters in
  #   length.
  #
  # @param [Hash] opts Options for getting temporary credentials.
  #
  # @option opts [Integer] :duration The duration, in seconds, that
  #   the session should last. Acceptable durations for federation
  #   sessions range from 3600s (one hour) to 129600s (36 hours),
  #   with one hour as the default.
  #
  # @option opts [String, AWS::STS::Policy] :policy A policy
  #   specifying the permissions to associate with the session. The
  #   caller can delegate their own permissions by specifying a
  #   policy for the session, and both policies will be checked when
  #   a service call is made. In other words, permissions of the
  #   session credentials are the intersection of the policy
  #   specified in the API and the policies associated with the user
  #   who issued the session.
  #
  # @return [FederatedSession]
  #
  def new_federated_session(name, opts = {})
    opts = opts.merge(:name => name)
    case
    when opts[:policy].kind_of?(String) || !opts[:policy]
      # leave it alone
    when opts[:policy].respond_to?(:to_json)
      opts[:policy] = opts[:policy].to_json
    end
    get_session(:get_federation_token, opts) do |resp, session_opts|
      session_opts.merge!(
        :user_id => resp[:federated_user][:federated_user_id],
        :user_arn => resp[:federated_user][:arn],
        :packed_policy_size => resp[:packed_policy_size]
      )
      FederatedSession.new(session_opts)
    end
  end

  protected

  def get_session(method, opts = {})
    opts[:duration_seconds] = opts.delete(:duration) if
      opts[:duration]
    resp = client.send(method, opts)
    credentials = resp[:credentials].dup
    session_opts = {
      :credentials => credentials,
      :expires_at => credentials.delete(:expiration),
    }
    yield(resp, session_opts)
  end

end

Instance Method Details

#assume_role(options = {}) ⇒ Core::Response

Calls the AssumeRole API operation.

Parameters:

  • options (Hash) (defaults to: {}) —
    • :role_arn - required - (String)
    • :role_session_name - required - (String)
    • :policy - (String)
    • :duration_seconds - (Integer)
    • :external_id - (String)
    • :serial_number - (String)
    • :token_code - (String)

Returns:

  • (Core::Response) —

    The #data method of the response object returns a hash with the following structure:

    • :credentials - (Hash)
      • :access_key_id - (String)
      • :secret_access_key - (String)
      • :session_token - (String)
      • :expiration - (Time)
    • :assumed_role_user - (Hash)
      • :assumed_role_id - (String)
      • :arn - (String)
    • :packed_policy_size - (Integer)


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# File 'lib/aws/sts.rb', line 57

def assume_role options = {}
  client.assume_role(options).data
end

#new_federated_session(name, opts = {}) ⇒ FederatedSession

Returns a set of temporary credentials for a federated user with the user name and policy specified in the request. The credentials consist of an Access Key ID, a Secret Access Key, and a security token. The credentials are valid for the specified duration, between one and 36 hours.

The federated user who holds these credentials has only those permissions allowed by intersection of the specified policy and any resource or user policies that apply to the caller of the GetFederationToken API. For more information about how token permissions work, see Controlling Token Permissions in Using AWS Identity and Access Management.

Parameters:

  • name (String) —

    The name of the federated user associated with the session. Must be between 2 and 32 characters in length.

  • opts (Hash) (defaults to: {}) —

    Options for getting temporary credentials.

Options Hash (opts):

  • :duration (Integer) —

    The duration, in seconds, that the session should last. Acceptable durations for federation sessions range from 3600s (one hour) to 129600s (36 hours), with one hour as the default.

  • :policy (String, AWS::STS::Policy) —

    A policy specifying the permissions to associate with the session. The caller can delegate their own permissions by specifying a policy for the session, and both policies will be checked when a service call is made. In other words, permissions of the session credentials are the intersection of the policy specified in the API and the policies associated with the user who issued the session.

Returns:



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# File 'lib/aws/sts.rb', line 130

def new_federated_session(name, opts = {})
  opts = opts.merge(:name => name)
  case
  when opts[:policy].kind_of?(String) || !opts[:policy]
    # leave it alone
  when opts[:policy].respond_to?(:to_json)
    opts[:policy] = opts[:policy].to_json
  end
  get_session(:get_federation_token, opts) do |resp, session_opts|
    session_opts.merge!(
      :user_id => resp[:federated_user][:federated_user_id],
      :user_arn => resp[:federated_user][:arn],
      :packed_policy_size => resp[:packed_policy_size]
    )
    FederatedSession.new(session_opts)
  end
end

#new_session(opts = {}) ⇒ Session

Returns a set of temporary credentials for an AWS account or IAM User. The credentials consist of an Access Key ID, a Secret Access Key, and a security token. These credentials are valid for the specified duration only. The session duration for IAM users can be between one and 36 hours, with a default of 12 hours. The session duration for AWS account owners is restricted to one hour.

Parameters:

  • opts (Hash) (defaults to: {}) —

    Options for getting temporary credentials.

Options Hash (opts):

  • :duration (Integer) —

    The duration, in seconds, that the session should last. Acceptable durations for IAM user sessions range from 3600s (one hour) to 129600s (36 hours), with 43200s (12 hours) as the default. Sessions for AWS account owners are restricted to a maximum of 3600s (one hour).

  • :serial_number (String) —

    The identification number of the Multi-Factor Authentication (MFA) device for the user.

  • :token_code (String) —

    The value provided by the MFA device. If the user has an access policy requiring an MFA code, provide the value here to get permission to resources as specified in the access policy.

Returns:



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# File 'lib/aws/sts.rb', line 87

def new_session(opts = {})
  get_session(:get_session_token, opts) do |resp, session_opts|
    Session.new(session_opts)
  end
end