Gimme AWS Creds

gimme-aws-creds is a CLI that utilizes an Okta IdP via SAML to acquire temporary AWS credentials via AWS STS.

Okta is a SAML identity provider (IdP), that can be easily set-up to do SSO to your AWS console. Okta does offer an OSS java CLI tool to obtain temporary AWS credentials, but I found it needs more information than the average Okta user would have and doesn't scale well if have more than one Okta App.

With gimme-aws-creds all you need to know is your username, password, Okta url and MFA token, if MFA is enabled. gimme-aws-creds gives you the option to select which Okta AWS application and role you want credentials for. Alternatively, you can pre-configure the app and role name by passing -c or editing the config file. This is all covered in the usage section.

Disclaimer

Okta is a registered trademark of Okta, Inc. and this tool has no affiliation with or sponsorship by Okta, Inc.

Prerequisites

Okta SAML integration to AWS using the AWS App

Python 3.7+

Optional

Gimme-creds-lambda can be used as a proxy to the Okta APIs needed by gimme-aws-creds. This removes the requirement of an Okta API key. Gimme-aws-creds authenticates to gimme-creds-lambda using OpenID Connect and the lambda handles all interactions with the Okta APIs. Alternately, you can set the OKTA_API_KEY environment variable and the gimme_creds_server configuration value to 'internal' to call the Okta APIs directly from gimme-aws-creds.

Installation

This is a Python 3 project.

Install/Upgrade from PyPi:

pip3 install --upgrade gimme-aws-creds

Install/Upgrade the latest gimme-aws-creds package direct from GitHub:

pip3 install --upgrade git+git://github.com/Nike-Inc/gimme-aws-creds.git

Install the gimme-aws-creds package if you have already cloned the source:

python -m pip install .

Use homebrew

brew install gimme-aws-creds

Use with nix flakes

# flake.nix
# Use by running `nix develop`
{
  description = "Shell example";

  inputs.flake-utils.url = "github:numtide/flake-utils";
  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
  inputs.gimme-aws-creds.url = "github:Nike-Inc/gimme-aws-creds";

  outputs = {
    self,
    nixpkgs,
    flake-utils,
    gimme-aws-creds,
    ...
  } @ inputs:
    flake-utils.lib.eachDefaultSystem
    (
      system: let
        pkgs = nixpkgs.legacyPackages.${system};
      in {
        devShells.default = pkgs.mkShell {
          packages = [pkgs.bash gimme-aws-creds.defaultPackage.${system}];
        };
      }
    );
}

Use with original nix

# shell.nix
# Use by running `nix-shell`
{pkgs ? import <nixpkgs> {}, ...}:
with pkgs; let
  gimme-src = fetchgit {
    name = "gimme-aws-creds";
    url = "https://github.com/Nike-Inc/gimme-aws-creds";
    branchName = "master";
    sha256 = "<replace>"; #nix-prefetch-url --unpack https://github.com/Nike-Inc/gimme-aws-creds/archive/master.tar.gz
  };

  gimme-aws-creds = import gimme-src;
in
  mkShell rec {
    name = "gimme-aws-creds";

    buildInputs = [
      bash
      (gimme-aws-creds.default)
    ];
  }

Build the docker image locally:

docker build -t gimme-aws-creds .

To make it easier you can also create an alias for the gimme-aws-creds command with docker:

# make sure you have the "~/.okta_aws_login_config" locally first!
touch ~/.okta_aws_login_config && \
alias gimme-aws-creds="docker run -it --rm \
  -v ~/.aws/credentials:/root/.aws/credentials \
  -v ~/.okta_aws_login_config:/root/.okta_aws_login_config \
  gimme-aws-creds"

With this config, you will be able to run further commands seamlessly!

Command Auto Completion

If you are using Bash or Zsh, you can add autocompletion for the gimme-aws-creds commandline options and profile names. To add the autocomplete config, add the following to the end of your .bashrc or .zshrc:

.bashrc

INSTALL_DIR=$(dirname $(which gimme-aws-creds))
source ${INSTALL_DIR}/gimme-aws-creds-autocomplete.sh"

.zshrc

INSTALL_DIR=$(dirname $(which gimme-aws-creds))
autoload bashcompinit
bashcompinit
source ${INSTALL_DIR}/gimme-aws-creds-autocomplete.sh

Using gimme-aws-creds with Okta Identity Engine

There are two options for using gimme-aws-creds with an OIE domain:

Device Authorization Flow
Forcing the use of the Okta Classic login flow

Okta Identity Engine and Device Authorization Flow

This is the recommended method for authentication with OIE. It matches the flow used by Okta's AWS client. When using gimme-aws-creds with the Device Authorization flow, you will authenticate using your browser. Storing credentials in keychain or passing MFA codes through the command-line is NOT POSSIBLE.

To use gimme-aws-creds with an Okta Identity Engine (OIE) domain, you must create a new OIDC Native Application and connect it to your AWS integration app(s).

The OIDC Native Application requires Grant Types Authorization Code, Device Authorization , and Token Exchange. These settings are in the Okta Admin UI at Applications > [the OIDC app] > General Settings > Grant type.

The pairing with the AWS Federation Application is achieved in the Fed app's Sign On Settings. These settings are in the Okta Admin UI at Applications > [the AWS Fed app] > Sign On. Make sure to set the Allowed Web SSO Client value to the Client ID of the OIDC Native Application. Repeat that setting for each AWS application you want to access with gimme-aws-creds.

Finally, set the Client ID in gimme-aws-creds (gimme-aws-creds --action-configure or update the client_id parameter in your config file)

Make sure to use the same authentication policy for both the AWS Federation Application and the OIDC application ( or at least use equivalent policy rules for both). If not, you'll receive a 400 Bad Request response when requesting the Web SSO token.

Forcing the use of the Okta Classic login flow

The login flow used in Okta Classic currently still works with Okta Identity Engine domains, BUT there are a couple caveats:

The Okta classic flow passes the stateToken parameter when requesting "step-up" authentication. This capability was removed in OIE, so if the authentication policy on your AWS app(s) requires MFA but the Global Session Policy does not (or if a higher level of MFA factor is required to access AWS), you cannot authenticate using the classic login flow.
MFA using Okta Verify is only supported on mobile devices. Okta Verify on macOS/Windows is not supported.
Passwordless authentication and endpoint security checks are not supported.

Configuration

To set-up the configuration run:

gimme-aws-creds --action-configure

You can also set up different Okta configuration profiles, this is useful if you have multiple Okta accounts or environments you need credentials for. You can use the configuration wizard or run:

gimme-aws-creds --action-configure --profile profileName

A configuration wizard will prompt you to enter the necessary configuration parameters for the tool to run, the only one that is required is the okta_org_url. The configuration file is written to ~/.okta_aws_login_config, but you can change the location with the environment variable OKTA_CONFIG.

conf_profile - This sets the Okta configuration profile name, the default is DEFAULT.
okta_org_url - This is your Okta organization url, which is typically something like https://companyname.okta.com.
okta_auth_server - Okta API Authorization Server used for OpenID Connect authentication for gimme-creds-lambda
client_id - OAuth client ID for user authentication in Okta Identity Engine and gimme-creds-lambda in Okta "classic"
gimme_creds_server
- URL for gimme-creds-lambda
- 'internal' for direct interaction with the Okta APIs (OKTA_API_KEY environment variable required)
- 'appurl' to set an aws application link url. This setting removes the need of an OKTA API key.
write_aws_creds - True or False - If True, the AWS credentials will be written to ~/.aws/credentials otherwise it will be written to stdout.
cred_profile - If writing to the AWS cred file, this sets the name of the AWS credential profile.
- The reserved word role will use the name component of the role arn as the profile name. i.e. arn:aws:iam::123456789012:role/okta-1234-role becomes section [okta-1234-role] in the aws credentials file
- The reserved word acc will use the account number (or alias if resolve_aws_alias is set to y) as the profile name. i.e. arn:aws:iam::123456789012:role/okta-1234-role becomes section [arn:aws:iam::123456789012] or if resolve_aws_alias [okta-1234-role] in the aws credentials file.
- The reserved word acc-role will use the name component of the role arn prepended with account number (or alias if resolve_aws_alias is set to y) to avoid collisions, i.e. arn:aws:iam::123456789012:role/okta-1234-role becomes section [123456789012-okta-1234-role], or if resolve_aws_alias [okta-1234-role] in the aws credentials file
- If set to default then the temp creds will be stored in the default profile
- Note: if there are multiple roles, and default is selected it will be overwritten multiple times and last role wins. The same happens when role is selected and you have many accounts with the same role names. Consider using acc-role if this happens.
aws_appname - This is optional. The Okta AWS App name, which has the role you want to assume.
aws_rolename - This is optional. The ARN of the role you want temporary AWS credentials for. The reserved word 'all' can be used to get and store credentials for every role the user is permissioned for.
aws_default_duration = This is optional. Lifetime for temporary credentials, in seconds. Defaults to 1 hour (3600)
app_url - If using 'appurl' setting for gimme_creds_server, this sets the url to the aws application configured in Okta. It is typically something like https://something.okta[preview].com/home/amazon_aws/app_instance_id/something
okta_username - use this username to authenticate
enable_keychain - enable the use of the system keychain to store the user's password
preferred_mfa_type - automatically select a particular device when prompted for MFA:
- push - Okta Verify App push or DUO push (depends on okta supplied provider type)
- token:software:totp - OTP using the Okta Verify App
- token:hardware - OTP using hardware like Yubikey
- call - OTP via Voice call
- sms - OTP via SMS message
- email - OTP via email
- web - DUO uses localhost webbrowser to support push|call|passcode
- passcode - DUO uses OKTA_MFA_CODE or --mfa-code if set, or prompts user for passcode(OTP).
- claims_provider - DUO Universal Prompt
duo_universal_factor - (optional) Configure which type of factor to use with Duo Universal Prompt. Must be one of (case-sensitive):
- Duo Push (default)
- Passcode
- Phone Call
resolve_aws_alias - y or n. If yes, gimme-aws-creds will try to resolve AWS account ids with respective alias names (default: n). This option can also be set interactively in the command line using -r or --resolve parameter
include_path - (optional) Includes full role path to the role name in AWS credential profile name. (default: n). If y: <acct>-/some/path/administrator. If n: <acct>-administrator
remember_device - y or n. If yes, the MFA device will be remembered by Okta service for a limited time. This option can also be set interactively in the command line using -m or --remember-device
output_format - json , export or windows, determines default credential output format, can be also specified by --output-format FORMAT and -o FORMAT.
open-browser - Open the device authentication link in the default web browser automatically (Okta Identity Engine domains only)
force-classic - Force the use of the Okta Classic login process (Okta Identity Engine domains only)

Configuration File

The config file follows a configfile format. By default, it is located in $HOME/.okta_aws_login_config

Example file:

[myprofile]
client_id = myclient_id

Configurations can inherit from other configurations to share common configuration parameters.

[my-base-profile]
client_id = myclient_id
[myprofile]
inherits = my-base-profile
aws_rolename = my-role

Usage

If you are not using gimme-creds-lambda nor using appurl settings, make sure you set the OKTA_API_KEY environment variable.

After running --action-configure, just run gimme-aws-creds. You will be prompted for the necessary information.

$ ./gimme-aws-creds
Username: user@domain.com
Password for user@domain.com:
Authentication Success! Calling Gimme-Creds Server...
Pick an app:
[ 0 ] AWS Test Account
[ 1 ] AWS Prod Account
Selection: 1
Pick a role:
[ 0 ]: OktaAWSAdminRole
[ 1 ]: OktaAWSReadOnlyRole
Selection: 1
Multi-factor Authentication required.
Pick a factor:
[ 0 ] Okta Verify App: SmartPhone_IPhone: iPhone
[ 1 ] token:software:totp: user@domain.com
Selection: 0
Okta Verify push sent...
export AWS_ACCESS_KEY_ID=AQWERTYUIOP
export AWS_SECRET_ACCESS_KEY=T!#$JFLOJlsoddop1029405-P

You can automate the environment variable creation by running $(gimme-aws-creds) on linux or gimme-aws-creds | iex using Windows Powershell

You can run a specific configuration profile with the --profile parameter:

./gimme-aws-creds --profile profileName

The username and password you are prompted for are the ones you login to Okta with. You can predefine your username by setting the OKTA_USERNAME environment variable or using the -u username parameter.

If you have not configured an Okta App or Role, you will prompted to select one.

If all goes well you will get your temporary AWS access, secret key and token, these will either be written to stdout or ~/.aws/credentials.

You can always run gimme-aws-creds --help for all the available options.

Alternatively, you can overwrite values in the config section with environment variables for instances where say you may want to change the duration of your token. A list of values of to change with environment variables are:

AWS_DEFAULT_DURATION - corresponds to aws_default_duration configuration
AWS_SHARED_CREDENTIALS_FILE - file to write credentials to, points to ~/.aws/credentials by default
GIMME_AWS_CREDS_CLIENT_ID - corresponds to client_id configuration
GIMME_AWS_CREDS_CRED_PROFILE - corresponds to cred_profile configuration
GIMME_AWS_CREDS_OUTPUT_FORMAT - corresponds to output_format configuration and --output-format CLI option
OKTA_AUTH_SERVER - corresponds to okta_auth_server configuration
OKTA_DEVICE_TOKEN - corresponds to device_token configuration, can be used in CI
OKTA_MFA_CODE - corresponds to --mfa-code CLI option
OKTA_PASSWORD - provides password during authentication, can be used in CI
OKTA_USERNAME - corresponds to okta_username configuration and --username CLI option
AWS_STS_REGION - force the use of the STS in a specific region (us-east-1, eu-north-1, etc.)

Example: GIMME_AWS_CREDS_CLIENT_ID='foobar' AWS_DEFAULT_DURATION=12345 gimme-aws-creds

For changing variables outside of this, you'd need to create a separate profile altogether with gimme-aws-creds --action-configure --profile profileName

Viewing Profiles

gimme-aws-creds --action-list-profiles will go to your okta config file and print out all profiles created and their settings.

Viewing roles

gimme-aws-creds --action-list-roles will print all available roles to STDOUT without retrieving their credentials.

Credential expiration time

Writing to the AWS credentials file will include the x_security_token_expires value in RFC3339 format. This allows tools to validate if the credentials are expiring or are expiring soon and warn the user or trigger a refresh.

Generate credentials as json

gimme-aws-creds -o json will print out credentials in JSON format - 1 entry per line

Store credentials from json

gimme-aws-creds --action-store-json-creds will store JSON formatted credentials from stdin to aws credentials file, eg: gimme-aws-creds -o json | gimme-aws-creds --action-store-json-creds. Data can be modified by scripts on the way.

Usage in python code

Configuration and interactions can be configured using gimme_aws_creds.ui, UserInterfaces support all kind of interactions within library including: asking for input, sys.argv and os.environ overrides.

import sys
import gimme_aws_creds.main
import gimme_aws_creds.ui

account_ids = sys.argv[1:] or [
  '123456789012',
  '120123456789',
]

pattern = "|".join(sorted(set(account_ids)))
pattern = '/:({}):/'.format(pattern)
ui = gimme_aws_creds.ui.CLIUserInterface(argv=[sys.argv[0], '--roles', pattern])
creds = gimme_aws_creds.main.GimmeAWSCreds(ui=ui)

# Print out all selected roles:
for role in creds.aws_selected_roles:
    print(role)

# Generate credentials overriding profile name with `okta-<account_id>`
for data in creds.iter_selected_aws_credentials():
    arn = data['role']['arn']
    account_id = None
    for piece in arn.split(':'):
        if len(piece) == 12 and piece.isdigit():
            account_id = piece
            break

    if account_id is None:
        raise ValueError("Didn't find aws_account_id (12 digits) in {}".format(arn))

    data['profile']['name'] = 'okta-{}'.format(account_id)
    creds.write_aws_creds_from_data(data)

MFA security keys support

gimme-aws-creds works both on FIDO1 enabled org and WebAuthN enabled org

Note that FIDO1 will probably be deprecated in the near future as standards moves forward to WebAuthN

WebAuthN support is available for usb security keys (gimme-aws-creds relies on the yubico fido2 lib).

To use your local machine as an authenticator, along with Touch ID or Windows Hello, if available, you must register a new authenticator via gimme-aws-creds, using:

gimme-aws-creds --action-setup-fido-authenticator

Then, you can choose the newly registered authenticator from the factors list.

Running Tests

You can run all the unit tests using pytest. Most of the tests are mocked.

pytest -vv tests

Maintenance

This project is maintained by Eric Pierce

Thanks and Credit

I came across okta_aws_login written by Joe Keegan, when I was searching for a CLI tool that generates AWS tokens via Okta. Unfortunately it hasn't been updated since 2015 and didn't seem to work with the current Okta version. But there was still some great code I was able to reuse under the MIT license for gimme-aws-creds. I have noted in the comments where I used his code, to make sure he receives proper credit.