onetinov/saml2aws

CLI tool which enables you to login and retrieve AWS temporary credentials using a SAML IDP

saml2aws

CLI tool which enables you to login and retrieve AWS temporary credentials using SAML with ADFS or PingFederate Identity Providers.

This is based on python code from How to Implement a General Solution for Federated API/CLI Access Using SAML 2.0.

The process goes something like this:

• Prompt user for credentials
• Log in to Identity Provider using form based authentication
• Build a SAML assertion containing AWS roles
• Exchange the role and SAML assertion with AWS STS service to get a temporary set of credentials
• Save these creds to an aws profile named "saml"

Requirements

• Identity Provider
  • ADFS (2.x or 3.x)
  • PingFederate + PingId
  • Okta + Duo
  • KeyCloak
• AWS SAML Provider configured

Caveats

Aside from Okta, most of the providers in this project are using screen scraping to log users into SAML, this isn't ideal and hopefully vendors make this easier in the future. In addition to this there are some things you need to know:

1. AWS only permits session tokens being issued with a duration of up to 3600 seconds (1 hour), this is constrained by the STS AssumeRoleWithSAML API call and DurationSeconds field.
2. Every SAML provider is different, the login process, MFA support is pluggable and therefore some work may be needed to integrate with your identity server

Usage

usage: saml2aws [<flags>] <command> [<args> ...]

A command line tool to help with SAML access to the AWS token service.

Flags:
      --help            Show context-sensitive help (also try --help-long and --help-man).
  -p, --profile="saml"  The AWS profile to save the temporary credentials
  -s, --skip-verify     Skip verification of server certificate.
  -i, --provider="ADFS" The type of SAML IDP provider.
      --version         Show application version.

Commands:
  help [<command>...]
    Show help.


  login
    Login to a SAML 2.0 IDP and convert the SAML assertion to an STS token.


  exec [<command>...]
    Exec the supplied command with env vars from STS token.

saml2aws will default to using ADFS 3.x as the Identity Provider. To use another provider, use the --provider flag:

IdP
ADFS 2.x	--provider=ADFS2
PingFederate	--provider=Ping
JumpCloud	--provider=JumpCloud
Okta	--provider=Okta
KeyCloak	--provider=KeyCloak

Install

OSX

If you're on OSX you can install saml2aws using homebrew!

brew tap versent/homebrew-taps
brew install saml2aws

Windows

If you're on Windows you can install saml2aws using chocolatey!

choco install saml2aws
saml2aws --version

Setup

Install the AWS CLI see https://docs.aws.amazon.com/cli/latest/userguide/installing.html, in our case we are using homebrew on OSX.

brew install awscli

Configure an empty default profile with your region of choice.

$ aws configure
AWS Access Key ID [None]:
AWS Secret Access Key [None]:
Default region name [None]: us-west-2
Default output format [None]:

Then your ready to use saml2aws.

Example

Log into a service.

$ saml2aws login
Hostname [id.example.com]:
Username [[email protected]]:
Password: ************

ADFS https://id.example.com
Authenticating to ADFS...
Please choose the role you would like to assume:
[ 0 ]:  arn:aws:iam::123123123123:role/AWS-Admin-CloudOPSBuild
[ 1 ]:  arn:aws:iam::123123123123:role/AWS-Admin-CloudOPSNonProd
Selection: 1
Selected role: arn:aws:iam::123123123123:role/AWS-Admin-CloudOPSNonProd
Requesting AWS credentials using SAML assertion
Saving credentials
Logged in as: arn:aws:sts::123123123123:assumed-role/AWS-Admin-CloudOPSNonProd/[email protected]

Your new access key pair has been stored in the AWS configuration
Note that it will expire at 2016-09-19 15:59:49 +1000 AEST
To use this credential, call the AWS CLI with the --profile option (e.g. aws --profile saml ec2 describe-instances).

Run ansible with an expired token present, exec verifies the token and requests login.

$ saml2aws exec --skip-verify -- ansible-playbook -e "aws_region=ap-southeast-2" playbook.yml
Hostname [id.example.com]:
Username [[email protected]]:
Password: ************

ADFS https://id.example.com
Authenticating to ADFS...
Please choose the role you would like to assume:
[ 0 ]:  arn:aws:iam::123123123123:role/AWS-Admin-CloudOPSBuild
[ 1 ]:  arn:aws:iam::123123123123:role/AWS-Admin-CloudOPSNonProd
Selection: 1
Selected role: arn:aws:iam::123123123123:role/AWS-Admin-CloudOPSNonProd
Requesting AWS credentials using SAML assertion
Saving credentials
Logged in as: arn:aws:sts::123123123123:assumed-role/AWS-Admin-CloudOPSNonProd/[email protected]

Your new access key pair has been stored in the AWS configuration
Note that it will expire at 2016-09-19 15:59:49 +1000 AEST
To use this credential, call the AWS CLI with the --profile option (e.g. aws --profile saml ec2 describe-instances).

PLAY [create cloudformation stack] *************************************************

...

PLAY RECAP *********************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0

Building

To build this software on osx clone to the repo to $GOPATH/src/github.com/versent/saml2aws and ensure you have $GOPATH/bin in your $PATH.

If you don't have glide installed you can install it using homebrew.

brew install glide

Then to build the software just run.

make

Install the binary to $GOPATH/bin.

make install

To release run.

make release

Environment vars

The exec sub command will export the following environment variables.

• AWS_ACCESS_KEY_ID
• AWS_SECRET_ACCESS_KEY
• AWS_SESSION_TOKEN
• AWS_SECURITY_TOKEN
• EC2_SECURITY_TOKEN

Dependencies

This tool would not be possible without some great opensource libraries.

• goquery html querying
• etree xpath selector
• kingpin command line flags
• aws-sdk-go AWS Go SDK
• go-ini INI file parser
• go-ntlmssp NTLM/Negotiate authentication

License

This code is Copyright (c) 2015 Versent and released under the MIT license. All rights not explicitly granted in the MIT license are reserved. See the included LICENSE.md file for more details.