JarCasting
Dead Simple SAML 2.0 Client
This library implements a very simple SAML 2.0 client that allows retrieving an authenticated identity from a compliant identity provider, using the HTTP POST binding.
It is based on the OpenSAML library, and only provides the necessary glue code to make it work in a basic scenario. This is by no means a complete implementation supporting all the nitty gritty SAML details, but it does perform the basic task of generating requests and validating responses. It's useful if you need to authenticate with SAML but don't want to bring in an uber large framework such as Spring Security.
In order to work, the library must be provided with the xml metadata information that can be obtained from the identity provider. It is also possible to initialize it by directly providing the required values.
As of now, I've tested the library with ADFS and Okta as identity providers.
Maven
Add this dependency to your pom.xml to reference the library:
<dependency>
<groupId>com.coveo</groupId>
<artifactId>saml-client</artifactId>
<version>3.0.2</version>
</dependency>
Usage
SAML authentication process overview
An SAML authentication exchange involves sending an SAML request to the Identity Provider (ADFS, Okta, etc...) and then receiving a signed SAML response. Both the request and the response will be transferred through POST HTTP requests made from the browser (other means of exchanging the data exist, but aren't supported by this library).
This library provide an easy way to generate the SAML request and then supports decoding and validating the answer returned from the Identity Provider. It also provide an helper method to generate the necessary HTML and JavaScript code to properly POST the SAML request.
Creating an instance of SamlClient
SamlClient client = SamlClient.fromMetadata("MyRelyingPartyIdentifier", "http://some/url/that/processes/assertions", "<your.IDP.metadata.xml>");
Generating a SAML request
String encodedRequest = client.getSamlRequest();
String idpUrl = client.getIdentityProviderUrl();
// redirect to the identity provider, passing the encoded request with the SAMLRequest form parameter.
Processing an SAML response
String encodedResponse = servletRequest.getParameter("SAMLResponse");
SamlResponse response = client.decodeAndValidateSamlResponse(encodedResponse);
String authenticatedUser = response.getNameID();
Generating a SAML logout request (SP initiated SLO)
String encodedRequest = getLogoutRequest(nameID);
// redirect to the identity provider, passing the encoded request with the SAMLRequest form parameter.
Generating a SAML logout response (IDP initiated SLO)
//Allow to inform the IDP the state of the service provider logout
String encodedRequest = getSamlLogoutResponse(statusCode, statusMessage);
// redirect to the identity provider, passing the encoded request with the SAMLRequest form parameter.
Using the helpers for servlet requests and responses
// To initiate the authentication exchange
client.redirectToIdentityProvider(servletResponse, null);
...
// To process the POST containing the SAML response
SamlResponse response = client.processPostFromIdentityProvider(servletRequest);
...
// To process the POST containing the SAML Logout Request
processLogoutRequestPostFromIdentityProvider(servletRequest,nameID)
...
//To process the POST containing the SAML Logout Response
processPostLogoutResponseFromIdentityProvider(servletRequest)
Identity Provider Configuration
ADFS
To configure ADFS to work with this library, you should go to the MMC snap-in for ADFS and add a Relying Party Trust with the following properties:
- In the Identifiers tab, add a Relying Party Identifier that will match the one you'll provide when initializing
SamlClient. - In the Endpoints tab, add the url that will process SAML responses to the list, using
POSTfor the Binding value.
Then, to obtain the metadata provider XML, load this url in your browser: https://myserver.domain.com/FederationMetadata/2007-06/FederationMetadata.xml
Okta
To configure Okta to work with this library, create an SAML 2.0 application with the following settings:
- The Single sign on URL should be the URL that processes SAML responses (e.g. assertions).
- The Audience URI should be a value that matches the one you'll specify when initializing
SamlClient.
Encryption
To generate the public / private keys :
openssl req -new -x509 -days 365 -nodes -sha256 -out saml-public-key.crt -keyout saml-private-key.pem
openssl pkcs8 -topk8 -inform PEM -outform PEM -nocrypt -in saml-private-key.pem -out saml-private-key.key
openssl pkcs8 -topk8 -nocrypt -inform PEM -in saml-private-key.key -outform DER -out saml-private-key.pk8
To add the keys :
// To add the keys (is needed only if you have encrypted assertion or if you want to sign documents)
client.setSPKeys(publicKeyPath,privateKeyPath);
