sap-bt

README

SAP-BT

0 Naming

SAML Authentication Proxy - with Bearer Token header support.

Inspired by:

• https://github.com/itzg/saml-auth-proxy
• https://github.com/bitsensor/saml-proxy

then taking it to another level (cleaner, simpler, with bearer token authn).

1 What it is

The service itself runs as an independent "proxy" applicaiton. When accessed, it does SAML authentication; if successful, it loads the "BACKEND_URL".

Can be used to use SAML authentication to protect web resources, for example, kubernetes dashboard.

2 How to Use

2.1 Configuration

Configuration is passed as environment variables.

2.1.1 Mandatory Config ENV Vars

ROOT_URL

External URL of this proxy itself.

BACKEND_URL

URL of the backend to go to after SAML auth.

IDP_METADATA_URL

URL of the identity provider's metadata XML. Only URL supported, not local file (I don't like if/else).

SP_KEY_PATH

The path to the X509 private key PEM file for this service provider.

Defaults to saml-auth-proxy.key at the current directory.

SP_CERT_PATH

The path to the X509 public certificate PEM file for this service provider.

Defaults to saml-auth-proxy.cert.

2.1.2 Optional Config ENV Vars

AUTHORIZE_ATTRIBUTE

Enables authorization and specifies the attribute to check for authorized values.

Example:

export AUTHORIZE_ATTRIBUTE=Groups

If not set, it will return authenticated.

AUTHORIZE_VALUES

Used with AUTHORIZE_ATTRIBUTE, values that must exist in AUTHORIZE_ATTRIBUTE in order to be considered as authorized.

A list, value being comma separated strings, Example:

export AUTHORIZE_VALUES=group1,group2,group3

AUTHORIZE_VALUE_BEARER_TOKEN_MAPPING

Used with AUTHORIZE_VALUES, a map, key being one of the AUTHORIZE_VALUES, value is the Bearer token to set. Example:

export AUTHORIZE_VALUE_BEARER_TOKEN_MAPPING=group1:asdf,group2:jkl,group3:xyz

ATTRIBUTE_HEADER_MAPPINGS

Comma separated list of attribute=header pairs mapping SAML response attributes to forwarded request header.

BIND

host:port for this proxy server to listen on.

Defaults to :8080.

HTTP_PROXY

If you are using proxy. The snake-case values, such as SAML_PROXY_BACKEND_URL, are the equivalent environment variables that can be set instead of passing configuration via the command-line.

The command-line argument usage renders with only a single leading dash, but GNU-style double-dashes can be used also, such as --sp-key-path.

2.2 Build

Go 1.14 required.

Go module enabled, so doesn't have to pull ths repo into go path.

Just run:

go build

2.3 Deploy in k8s

There is a healthcheck endpoint at /_health can be used for k8s liveness/readiness probe.

It returns HTTP 200.

2.4 Docker Image

https://hub.docker.com/repository/docker/ironcore864/sap-bt