/*
* Copyright 2016 Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.keycloak.protocol.saml;
import java.security.Key;
import org.keycloak.common.VerificationException;
import org.keycloak.common.util.PemUtils;
import org.keycloak.models.ClientModel;
import org.keycloak.saml.SignatureAlgorithm;
import org.keycloak.saml.common.constants.GeneralConstants;
import org.keycloak.saml.common.exceptions.ProcessingException;
import org.keycloak.saml.processing.api.saml.v2.sig.SAML2Signature;
import org.keycloak.saml.processing.web.util.RedirectBindingUtil;
import org.w3c.dom.Document;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.UriBuilder;
import javax.ws.rs.core.UriInfo;
import java.security.PublicKey;
import java.security.Signature;
import java.security.cert.Certificate;
import org.keycloak.dom.saml.v2.SAML2Object;
import org.keycloak.dom.saml.v2.protocol.ExtensionsType;
import org.keycloak.dom.saml.v2.protocol.RequestAbstractType;
import org.keycloak.dom.saml.v2.protocol.StatusResponseType;
import org.keycloak.rotation.HardcodedKeyLocator;
import org.keycloak.rotation.KeyLocator;
import org.keycloak.saml.processing.core.saml.v2.common.SAMLDocumentHolder;
import org.keycloak.saml.processing.core.util.KeycloakKeySamlExtensionGenerator;
import org.w3c.dom.Element;
/**
* @author <a href="mailto:bill@burkecentral.com">Bill Burke</a>
* @version $Revision: 1 $
*/
public class SamlProtocolUtils {
/**
* Verifies a signature of the given SAML document using settings for the given client.
* Throws an exception if the client signature is expected to be present as per the client
* settings and it is invalid, otherwise returns back to the caller.
*
* @param client
* @param document
* @throws VerificationException
*/
public static void verifyDocumentSignature(ClientModel client, Document document) throws VerificationException {
SamlClient samlClient = new SamlClient(client);
if (!samlClient.requiresClientSignature()) {
return;
}
PublicKey publicKey = getSignatureValidationKey(client);
verifyDocumentSignature(document, new HardcodedKeyLocator(publicKey));
}
/**
* Verifies a signature of the given SAML document using keys obtained from the given key locator.
* Throws an exception if the client signature is invalid, otherwise returns back to the caller.
*
* @param document
* @param keyLocator
* @throws VerificationException
*/
public static void verifyDocumentSignature(Document document, KeyLocator keyLocator) throws VerificationException {
SAML2Signature saml2Signature = new SAML2Signature();
try {
if (!saml2Signature.validate(document, keyLocator)) {
throw new VerificationException("Invalid signature on document");
}
} catch (ProcessingException e) {
throw new VerificationException("Error validating signature", e);
}
}
/**
* Returns public part of SAML signing key from the client settings.
* @param client
* @return Public key for signature validation.
* @throws VerificationException
*/
public static PublicKey getSignatureValidationKey(ClientModel client) throws VerificationException {
return getPublicKey(new SamlClient(client).getClientSigningCertificate());
}
/**
* Returns public part of SAML encryption key from the client settings.
* @param client
* @return Public key for encryption.
* @throws VerificationException
*/
public static PublicKey getEncryptionKey(ClientModel client) throws VerificationException {
return getPublicKey(client, SamlConfigAttributes.SAML_ENCRYPTION_CERTIFICATE_ATTRIBUTE);
}
public static PublicKey getPublicKey(ClientModel client, String attribute) throws VerificationException {
String certPem = client.getAttribute(attribute);
return getPublicKey(certPem);
}
private static PublicKey getPublicKey(String certPem) throws VerificationException {
if (certPem == null) throw new VerificationException("Client does not have a public key.");
Certificate cert = null;
try {
cert = PemUtils.decodeCertificate(certPem);
} catch (Exception e) {
throw new VerificationException("Could not decode cert", e);
}
return cert.getPublicKey();
}
public static void verifyRedirectSignature(SAMLDocumentHolder documentHolder, KeyLocator locator, UriInfo uriInformation, String paramKey) throws VerificationException {
MultivaluedMap<String, String> encodedParams = uriInformation.getQueryParameters(false);
String request = encodedParams.getFirst(paramKey);
String algorithm = encodedParams.getFirst(GeneralConstants.SAML_SIG_ALG_REQUEST_KEY);
String signature = encodedParams.getFirst(GeneralConstants.SAML_SIGNATURE_REQUEST_KEY);
String decodedAlgorithm = uriInformation.getQueryParameters(true).getFirst(GeneralConstants.SAML_SIG_ALG_REQUEST_KEY);
if (request == null) throw new VerificationException("SAM was null");
if (algorithm == null) throw new VerificationException("SigAlg was null");
if (signature == null) throw new VerificationException("Signature was null");
String keyId = getMessageSigningKeyId(documentHolder.getSamlObject());
// Shibboleth doesn't sign the document for redirect binding.
// todo maybe a flag?
UriBuilder builder = UriBuilder.fromPath("/")
.queryParam(paramKey, request);
if (encodedParams.containsKey(GeneralConstants.RELAY_STATE)) {
builder.queryParam(GeneralConstants.RELAY_STATE, encodedParams.getFirst(GeneralConstants.RELAY_STATE));
}
builder.queryParam(GeneralConstants.SAML_SIG_ALG_REQUEST_KEY, algorithm);
String rawQuery = builder.build().getRawQuery();
try {
byte[] decodedSignature = RedirectBindingUtil.urlBase64Decode(signature);
SignatureAlgorithm signatureAlgorithm = SignatureAlgorithm.getFromXmlMethod(decodedAlgorithm);
Signature validator = signatureAlgorithm.createSignature(); // todo plugin signature alg
Key key = locator.getKey(keyId);
if (key instanceof PublicKey) {
validator.initVerify((PublicKey) key);
validator.update(rawQuery.getBytes("UTF-8"));
} else {
throw new VerificationException("Invalid key locator for signature verification");
}
if (!validator.verify(decodedSignature)) {
throw new VerificationException("Invalid query param signature");
}
} catch (Exception e) {
throw new VerificationException(e);
}
}
private static String getMessageSigningKeyId(SAML2Object doc) {
final ExtensionsType extensions;
if (doc instanceof RequestAbstractType) {
extensions = ((RequestAbstractType) doc).getExtensions();
} else if (doc instanceof StatusResponseType) {
extensions = ((StatusResponseType) doc).getExtensions();
} else {
return null;
}
if (extensions == null) {
return null;
}
for (Object ext : extensions.getAny()) {
if (! (ext instanceof Element)) {
continue;
}
String res = KeycloakKeySamlExtensionGenerator.getMessageSigningKeyIdFromElement((Element) ext);
if (res != null) {
return res;
}
}
return null;
}
}