saml2aws

README

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:

• Setup an account alias, either using the default or given a name
• 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 credentials to an aws profile named "saml"

Requirements

• Identity Provider
  • ADFS (2.x or 3.x)
  • PingFederate + PingId
  • Okta + (Duo, SMS, TOTP)
  • KeyCloak + (TOTP)
  • Google Apps SAML see How to Set Up Federated Single Sign-On to AWS Using Google Apps
• 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 defaults to session tokens being issued with a duration of up to 3600 seconds (1 hour), this can now be configured as per Enable Federated API Access to your AWS Resources for up to 12 hours Using IAM Roles and --session-duration flag.
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

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

Dependency 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

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).
      --version                Show application version.
      --verbose                Enable verbose logging
  -i, --provider=PROVIDER      This flag it is obsolete see https://github.com/Versent/saml2aws#adding-idp-accounts.
  -a, --idp-account="default"  The name of the configured IDP account
      --idp-provider=IDP-PROVIDER
                               The configured IDP provider
      --mfa=MFA                The name of the mfa
  -s, --skip-verify            Skip verification of server certificate.
      --url=URL                The URL of the SAML IDP server used to login.
      --username=USERNAME      The username used to login.
      --password=PASSWORD      The password used to login.
      --mfa-token=MFA-TOKEN    The current MFA token (supported in Keycloak, ADFS).
      --role=ROLE              The ARN of the role to assume.
      --aws-urn=AWS-URN        The URN used by SAML when you login.
      --skip-prompt            Skip prompting for parameters during login.
      --session-duration=SESSION-DURATION
                               The duration of your AWS Session.

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

  configure
    Configure a new IDP account.

  login [<flags>]
    Login to a SAML 2.0 IDP and convert the SAML assertion to an STS token.

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

  list-roles
    List available role ARNs.

Configuring IDP Accounts

This is the new way of adding IDP provider accounts, it enables you to have named accounts with whatever settings you like and supports having one default account which is used if you omit the account flag. This replaces the --provider flag and old configuration file in 1.x.

To add a default IdP account to saml2aws just run the following command and follow the prompts.

$ saml2aws configure
? Please choose a provider: Ping
? AWS Profile myaccount

? URL https://example.com
? Username me@example.com

? Password
No password supplied

account {
  URL: https://example.com
  Username: me@example.com
  Provider: Ping
  MFA: Auto
  SkipVerify: false
  AmazonWebservicesURN: urn:amazon:webservices
  SessionDuration: 3600
  Profile: myaccount
}

Configuration saved for IDP account: default

Then to login using this account.

saml2aws login

You can also add named accounts, below is an example where I am setting up an account under the wolfeidau alias, again just follow the prompts.

saml2aws configure -a wolfeidau

You can also configure the account alias without prompts.

saml2aws configure -a wolfeidau --idp-provider KeyCloak --username mark@wolfe.id.au \
  --url https://keycloak.wolfe.id.au/auth/realms/master/protocol/saml/clients/amazon-aws --skip-prompt

Then your ready to use saml2aws.

Example

Log into a service (without MFA).

$ saml2aws login
Using IDP Account default to access Ping https://id.example.com
To use saved password just hit enter.
Username [mark.wolfe@example.com]:
Password: ************

Authenticating as mark.wolfe@example.com ...
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/wolfeidau@example.com

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).

Log into a service (with MFA).

$ saml2aws login
Using IDP Account default to access Ping https://id.example.com
To use saved password just hit enter.
Username [mark.wolfe@example.com]:
Password: ************

Authenticating as mark.wolfe@example.com ...
Enter passcode: 123456

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/wolfeidau@example.com

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 --region us-east-1).

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.

make deps

Install the binary to $GOPATH/bin.

make install

Then to test the software just run.

make test

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
• AWS_PROFILE
• AWS_DEFAULT_PROFILE

Note: That profile environment variables enable you to use exec with a script or command which requires an explicit profile.

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

Releasing

Install github-release.

go get github.com/buildkite/github-release

To release run.

make release

Debugging Issues with IDPs

There are two levels of debugging, first emits debug information and the URL / Method / Status line of requests.

saml2aws login --verbose

The second emits the content of requests and responses, this includes authentication related information so don't copy and paste it into chat or tickets!

DUMP_CONTENT=true saml2aws login --verbose

License

This code is Copyright (c) 2018 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.

Documentation

Index

• Variables
• func AssignPrincipals(awsRoles []*AWSRole, awsAccounts []*AWSAccount)
• func ExtractAwsRoles(data []byte) ([]string, error)
• func ExtractSessionDuration(data []byte) (int64, error)
• func PromptForConfigurationDetails(idpAccount *cfg.IDPAccount) error
• func PromptForLoginDetails(loginDetails *creds.LoginDetails) error
• type AWSAccount
  • func ExtractAWSAccounts(data []byte) ([]*AWSAccount, error)
  • func ParseAWSAccounts(samlAssertion string) ([]*AWSAccount, error)
• type AWSRole
  • func LocateRole(awsRoles []*AWSRole, roleName string) (*AWSRole, error)
  • func ParseAWSRoles(roles []string) ([]*AWSRole, error)
  • func PromptForAWSRoleSelection(accounts []*AWSAccount) (*AWSRole, error)
• type ErrMissingElement
  • func (e ErrMissingElement) Error() string
• type ProviderList
  • func (mfbp ProviderList) Mfas(provider string) []string
  • func (mfbp ProviderList) Names() []string
• type SAMLClient
  • func NewSAMLClient(idpAccount *cfg.IDPAccount) (SAMLClient, error)

Variables

var (
	ErrMissingAssertion = ErrMissingElement{Tag: assertionTag}
)

ErrMissingAssertion indicates that an appropriate assertion element could not be found in the SAML Response

var MFAsByProvider = ProviderList{
	"ADFS":       []string{"Auto", "VIP"},
	"ADFS2":      []string{"Auto", "RSA"},
	"Ping":       []string{"Auto"},
	"PingOne":    []string{"Auto"},
	"JumpCloud":  []string{"Auto"},
	"Okta":       []string{"Auto"},
	"KeyCloak":   []string{"Auto"},
	"GoogleApps": []string{"Auto"},
}

MFAsByProvider a list of providers with their respective supported MFAs

Functions

func AssignPrincipals

func AssignPrincipals(awsRoles []*AWSRole, awsAccounts []*AWSAccount)

AssignPrincipals assign principal from roles

func ExtractAwsRoles

func ExtractAwsRoles(data []byte) ([]string, error)

ExtractAwsRoles given an assertion document extract the aws roles

func ExtractSessionDuration

func ExtractSessionDuration(data []byte) (int64, error)

ExtractSessionDuration this will attempt to extract a session duration from the assertion see https://aws.amazon.com/SAML/Attributes/SessionDuration

func PromptForConfigurationDetails

func PromptForConfigurationDetails(idpAccount *cfg.IDPAccount) error

PromptForConfigurationDetails prompt the user to present their hostname, username and mfa

func PromptForLoginDetails

func PromptForLoginDetails(loginDetails *creds.LoginDetails) error

PromptForLoginDetails prompt the user to present their username, password

Types

type AWSAccount

type AWSAccount struct {
	Name  string
	Roles []*AWSRole
}

AWSAccount holds the AWS account name and roles

func ExtractAWSAccounts

func ExtractAWSAccounts(data []byte) ([]*AWSAccount, error)

ExtractAWSAccounts extract the accounts from the AWS html page

func ParseAWSAccounts

func ParseAWSAccounts(samlAssertion string) ([]*AWSAccount, error)

ParseAWSAccounts extract the aws accounts from the saml assertion

type AWSRole

type AWSRole struct {
	RoleARN      string
	PrincipalARN string
	Name         string
}

AWSRole aws role attributes

func LocateRole

func LocateRole(awsRoles []*AWSRole, roleName string) (*AWSRole, error)

LocateRole locate role by name

func ParseAWSRoles

func ParseAWSRoles(roles []string) ([]*AWSRole, error)

ParseAWSRoles parses and splits the roles while also validating the contents

func PromptForAWSRoleSelection

func PromptForAWSRoleSelection(accounts []*AWSAccount) (*AWSRole, error)

PromptForAWSRoleSelection present a list of roles to the user for selection

type ErrMissingElement

type ErrMissingElement struct {
	Tag, Attribute string
}

ErrMissingElement is the error type that indicates an element and/or attribute is missing. It provides a structured error that can be more appropriately acted upon.

func (ErrMissingElement) Error

func (e ErrMissingElement) Error() string

type ProviderList

type ProviderList map[string][]string

ProviderList list of providers with their MFAs

func (ProviderList) Mfas

func (mfbp ProviderList) Mfas(provider string) []string

Mfas retrieve a sorted list of mfas from the provider list

func (ProviderList) Names

func (mfbp ProviderList) Names() []string

Names get a list of provider names

type SAMLClient

type SAMLClient interface {
	Authenticate(loginDetails *creds.LoginDetails) (string, error)
}

SAMLClient client interface

func NewSAMLClient

func NewSAMLClient(idpAccount *cfg.IDPAccount) (SAMLClient, error)

NewSAMLClient create a new SAML client