awscli-login 0.2b1

Plugin for the AWS CLI that retrieves and rotates credentials using SAML ECP and STS.

The awscli-login plugin allows retrieving temporary Amazon credentials by authenticating against a SAML Identity Provider (IdP). This application is fully supported under Linux, macOS, and the Windows Subsystem for Linux. Currently, Windows PowerShell, Command Prompt, and Git Shell for Windows are supported with limitations (See Windows Issues).

Jump to:

• Installation

• Getting Started

• Advanced Usage

• Advanced Configuration

• Command line arguments

• Known Issues

Installation

The simplest way to install the awscli-login plugin is to use pip:

$ pip install awscli-login

After awscli-login has been installed, run the following command to enable the plugin:

$ aws configure set plugins.login awscli_login

If you receive a bad interpreter error or other error please see the Known Issues section below.

Getting Started

Before using awscli-login to retrieve temporary credentials, optionally configure one or more named profiles for use with the plugin. To configure this plugin, you must know the URL of the ECP Endpoint for your IdP. If you do not have this information, contact your IdP administrator.

Here is an example configuring the default profile for use with the University of Illinois at Urbana-Champaign’s IdP:

$ aws login configure
ECP Endpoint URL [None]: https://shibboleth.illinois.edu/idp/profile/SAML2/SOAP/ECP
Username [None]:
Enable Keyring [False]:
Duo Factor [None]:
Role ARN [None]:

To log in, type the following command:

$ aws login
Username [username]: netid
Password: ********
Factor: passcode
Code: 123456789

The username and password are the values needed to authenticate against the IdP configured for the selected profile. The factor is only required if your IdP requires Duo for authentication. If it does not, leave factor blank. If your IdP does require Duo then factor may be one of auto, push, passcode, sms, or phone. If factor is left blank, auto is the default. The code is a Duo code useful for use with a YubiKey, SMS codes, or other one-time codes.

If you have access to more than one role, you will be prompted to choose one. For example:

$ aws login
Username [username]: netid
Password: ********
Factor:
Please choose the role you would like to assume:
    Account: 978517677611
        [ 0 ]: Admin
    Account: 520135271718
        [ 1 ]: ReadOnlyUser
        [ 2 ]: S3Admin
Selection: 2

To switch roles, first log out, then log in again selecting a different role. Note that if you log in to the same IdP using the same username, you will not be prompted for your password or Duo factor until the IdP session expires:

$ aws logout
$ aws login
Username [netid]:
Please choose the role you would like to assume:
    Account: 520135271718
        [ 0 ]: TestUser
        [ 1 ]: IAMUser
Selection: 0

Advanced Usage

It is possible to be logged in to more than one role at the same time using multiple named profiles. For example, consider the following configuration involving two profiles – one called prod, and the other test:

$ aws --profile prod login configure
ECP Endpoint URL [None]: https://shibboleth.illinois.edu/idp/profile/SAML2/SOAP/ECP
Username [None]: netid
Enable Keyring [False]: True
Duo Factor [None]: auto
Role ARN [None]: arn:aws:iam::999999999999:role/Admin

$ aws --profile test login configure
ECP Endpoint URL [None]: https://shibboleth.illinois.edu/idp/profile/SAML2/SOAP/ECP
Username [None]: netid
Enable Keyring [False]: True
Duo Factor [None]: passcode
Role ARN [None]: arn:aws:iam::111111111111:role/Admin

This example involves several advanced features. First, we are setting the username, factor, and role. This means we will not be prompted for this information when logging in to these two profiles. In addition, we are using a keyring. On the first login using one of the profiles, the user will be prompted for his password. On subsequent logins the user will not be prompted for his password because it has been stored in a secure keyring.

For example, when we initially log in to prod:

$ export AWS_PROFILE=test
$ aws login
Password: ********
Code: 123456789

We are only prompted for the password and code. We’re prompted for the password because this is the initial login, and the code because this profile is configured for use with a passcode device such as a YubiKey. We are now no longer prompted when we log in to test:

$ aws --profile prod login

Even if the IdP session has expired in this case, we will not be prompted for a password because it is stored in the keyring. The user will receive either a phone call or a push to the default Duo device.

Advanced Configuration

The plugin’s configuration file (~/.aws-login/config) is an ini file that supports more configuration options than is exposed via the basic interactive configuration as seen in the Getting Started section. Each section corresponds to an AWS named profile just like the awscli’s credentials file ~/.aws/credentials.

Here is a simple example configuration file:

[default]
ecp_endpoint_url = https://shib.uiuc.edu/idp/profile/SAML2/SOAP/ECP
username = netid
enable_keyring = True
factor = auto

[prod]
username = netid
ecp_endpoint_url = https://shib.uiuc.edu/idp/profile/SAML2/SOAP/ECP

and the corresponding awscli configuration file ~/.aws/config

[plugins]
login = awscli_login

[default]
region = us-east-2
output = json

[profile prod]
region = us-east-2
output = json

All configuration options are documented below in the properties section.

Properties

Each property can be overridden at the command line using a flag. See the online documentation for further details by running aws login help.

ecp_endpoint_url

The ECP endpoint URL of the IdP. This is the only required property:

ecp_endpoint_url = https://shibboleth.illinois.edu/idp/profile/SAML2/SOAP/ECP

username

The username to use on login to the IdP. If the username is not supplied the user will be prompted:

username = netid

password

The password to use on login to the IdP. If the password is not supplied the user will be prompted. It is not recommended to use this property. Instead supply the password interactively or use the keyring for secure storage:

password = secret

The password property and command line flag are ignored if the keyring is enabled. When this happens a warning is issued.

factor

The Duo factor to use on login:

factor = auto

The following values are currently supported:

factor
auto	authenticates with push if available, otherwise fallbacks to phone
push	authenticates with Duo Push
passcode	authenticates the user with a user supplied code from a hardware token, Duo Mobile, or bypass code
sms	sends a batch of SMS passcodes to the user
phone	Authenticates with phone callback

To login using sms, requires two attempts. The first attempt will send SMS passcodes, and return authentication failed. The second attempt will use the passcodes:

$ aws login --factor sms
Authentication failed!
$ aws login --factor passcode
Code: 829437

passcode

A bypass code or Duo passcode generated by Duo Mobile, SMS, or a hardware token can be set using the passcode property:

passcode = 829437

It is not recommended to store a passcode in your configuration file since a passcode can only be used once. A passcode is better passed interactivally or by the --passcode command line flag.

role_arn

The role ARN to select. If the IdP returns a single role it is autoselected:

role_arn = arn:aws:iam::999999999999:role/Admin

enable_keyring

By default the keyring is not used for password storage. The keyring is implemented using the Python module keyring, and supports various secure backends such as the macOS Keychain, Windows Credential Locker, and Linux keyrings. Additional, system configuration may be required to use a keyring on Linux systems (See https://pypi.org/project/keyring for details). Set to True to enable:

enable_keyring = True

The password property and command line flag are ignored when the keyring is enabled.

disable_refresh:

On POSIX systems tokens are refreshed automatically unless this property is set to True:

disable-refresh = True

refresh

How often the refresh process attempts to renew the STS credentials in seconds. When set to 0 the refresh process will refresh once 90% of the time till expiration has transpired (Default 0):

refresh = 1800

duration

Set the time in seconds that the STS token will last. The token lasts for the duration you specify, or until the time specified by the IdP, whichever is shorter. The default is an hour, and the minimum is 15 minutes (See AssumeRoleWithSAML for details):

duration = 3600

http_header_factor

HTTP Header to store the user’s Duo factor:

http_header_factor = X-Shibboleth-Duo-Factor

http_header_passcode

HTTP Header to store the user’s passcode:

http_header_passcode = X-Shibboleth-Duo-Passcode

Command line arguments

The plugin supports two subcommands login and logout.

login

Detailed online documentation can be accessed using the following command:

$ aws login help

All properties, except for enable_keyring, can be overridden with a corresponding command line option. Properties that contain an underscore will have a corresponding option with hyphens, for example the property ecp_endpoint_url becomes --ecp-endpoint-url. For details on these options see the documentation above or refer to the online documentation. Options not avaliable as properties are documented below.

options

--ask-password

Force prompt for password. This can be used to override the enable_keyring property.

--force-refresh

Forces the refresh process to retrieve new credentials for the user selected role. If the refresh process is not running then a normal login will proceed after a warning.

--verbose

Display verbose output. The flag can be repeated up to three times. Each time it is repeated more detailed information is returned.

configure

See Getting Started and online documentation for documentation on this subcommand:

$ aws login configure help

options

--verbose

Display verbose output. The flag can be repeated up to three times. Each time it is repeated more detailed information is returned.

logout

See Getting Started and online documentation for documentation on this subcommand:

$ aws logout help

options

--verbose

Display verbose output. The flag can be repeated up to three times. Each time it is repeated more detailed information is returned.

Known Issues

Unable to authenticate after changing password

After the user changes his IdP password, subsequent logins fail. To remedy the situation, change the data stored in the keyring as follows:

$ keyring set awscli_login username@hostname_of_your_IdP

You may be prompted for your user login password by your operating system, depending on how your key store is configured.

Command line flag --ecp-endpoint-url error parsing parameter

If you encounter the following error it is because the awscli expects urls passed as arguments to return a 200 on an HTTP GET (See aws-cli#4473):

$ aws login --ecp-endpoint-url https://shibboleth.illinois.edu/idp/profile/SAML2/SOAP/ECP
Error parsing parameter '--ecp-endpoint-url': Unable to retrieve https://shibboleth.illinois.edu/idp/profile/SAML2/SOAP/ECP: received non 200 status code of 500

This check can be disabled on a per profile basis using the following command:

$ aws configure set cli_follow_urlparam off

Windows issues

Auto-renewal is not supported under the Windows PowerShell, Command Prompt, or Git Shell for Windows. Auto-renewal is supported under the Windows Subsystem for Linux (WSL).

GitBash bad interpreter errors

If you receive a bad interpreter error from the aws command it may be because you have a space in the path of your Python interpreter:

bash: /c/Users/me/AppData/Roaming/Python/Python38/Scripts/aws: c:\program: bad interpreter: No such file or directory

To fix this issue either reinstall your Python interpreter to a path that does not contain a space and then reinstall the awscli package, or more simply just define an alias in your bashrc file:

alias aws='python $(which aws)'

Windows Subsystem for Linux bad interpreter error

If you receive a bad interpreter error from the aws command on Windows Subsystem for Linux (WSL) it may be because the location where the awscli is installed is not listed in the WSL’s PATH before the location of a Windows install of awscli:

-bash: /mnt/c/Python39/Scripts/aws: c:\python39\python.exe^M: bad interpreter: No such file or directory

To remedy this issue please ensure that the location where the awscli is installed in the WSL comes before the location of the Windows install in the WSL PATH environment variable.