package org.apache.rahas.impl;
import java.security.PublicKey;
import java.security.cert.X509Certificate;
import javax.xml.namespace.QName;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.impl.dom.jaxp.DocumentBuilderFactoryImpl;
import org.apache.axiom.soap.SOAPEnvelope;
import org.apache.axis2.context.MessageContext;
import org.apache.axis2.description.Parameter;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.rahas.RahasConstants;
import org.apache.rahas.RahasData;
import org.apache.rahas.Token;
import org.apache.rahas.TokenStorage;
import org.apache.rahas.TokenValidator;
import org.apache.rahas.TrustException;
import org.apache.rahas.TrustUtil;
import org.apache.ws.security.components.crypto.Crypto;
import org.apache.ws.security.components.crypto.CryptoFactory;
import org.opensaml.SAMLAssertion;
import org.opensaml.SAMLException;
import org.w3c.dom.Element;
/**
* Implementation of a SAML Token Validator for the Security Token Service.
*/
public class SAMLTokenValidator implements TokenValidator {
Log log = LogFactory.getLog(SAMLTokenValidator.class);
private String configFile;
private OMElement configElement;
private String configParamName;
/**
* Returns a SOAPEnvelope with the result of the validation.
*
* @param data
* the RahasData object, containing information about the
* request.
*/
public SOAPEnvelope validate(RahasData data) throws TrustException {
// retrieve the message context
MessageContext inMsgCtx = data.getInMessageContext();
// retrieve the list of tokens from the message context
TokenStorage tkStorage = TrustUtil.getTokenStore(inMsgCtx);
try {
// Set the DOM impl to DOOM
DocumentBuilderFactoryImpl.setDOOMRequired(true);
// Create envelope
SOAPEnvelope env = TrustUtil.createSOAPEnvelope(inMsgCtx
.getEnvelope().getNamespace().getNamespaceURI());
// Create RSTR element, with respective version
OMElement rstrElem;
int wstVersion = data.getVersion();
if (RahasConstants.VERSION_05_02 == wstVersion) {
rstrElem = TrustUtil.createRequestSecurityTokenResponseElement(
wstVersion, env.getBody());
} else {
OMElement rstrcElem = TrustUtil
.createRequestSecurityTokenResponseCollectionElement(
wstVersion, env.getBody());
rstrElem = TrustUtil.createRequestSecurityTokenResponseElement(
wstVersion, rstrcElem);
}
// Create TokenType element, set to RSTR/Status
TrustUtil.createTokenTypeElement(wstVersion, rstrElem).setText(
TrustUtil.getWSTNamespace(wstVersion)
+ RahasConstants.TOK_TYPE_STATUS);
// Create Status element
OMElement statusElement = createMessageElement(wstVersion,
rstrElem, RahasConstants.LocalNames.STATUS);
// Obtain the token
Token tk = tkStorage.getToken(data.getTokenId());
// create the crypto object
PublicKey issuerPBKey = getIssuerPublicKey(inMsgCtx);
boolean valid = isValid(tk, issuerPBKey);
String validityCode;
if (valid) {
validityCode = RahasConstants.STATUS_CODE_VALID;
} else {
validityCode = RahasConstants.STATUS_CODE_INVALID;
}
// Create Code element (inside Status) and set it to the
// correspondent value
createMessageElement(wstVersion, statusElement,
RahasConstants.LocalNames.CODE).setText(
TrustUtil.getWSTNamespace(wstVersion) + validityCode);
return env;
} finally {
DocumentBuilderFactoryImpl.setDOOMRequired(false);
}
}
/**
* Checks whether the token is valid or not, by verifying the issuer's own
* signature. If it has been signed by the token issuer, then it is a valid
* token.
*
* @param token
* the token to validate.
* @return true if the token has been signed by the issuer.
*/
private boolean isValid(Token token, PublicKey issuerPBKey) {
// extract SAMLAssertion object from token
OMElement assertionOMElement = token.getToken();
SAMLAssertion samlAssertion = null;
try {
samlAssertion = new SAMLAssertion((Element) assertionOMElement);
log.info("Verifying token validity...");
// check if the token has been signed by the issuer.
samlAssertion.verify(issuerPBKey);
} catch (SAMLException e) {
log.error("Could not verify signature", e);
return false;
}
// if there was no exception, then the token is valid
return true;
}
//here we basically reuse the SAMLTokenIssuer config
// to create the crypto object, so we can load the issuer's certificates
private PublicKey getIssuerPublicKey(MessageContext inMsgCtx) {
PublicKey issuerPBKey = null;
SAMLTokenIssuerConfig config = null;
try {
if (configElement != null) {
config = new SAMLTokenIssuerConfig(
configElement
.getFirstChildWithName(SAMLTokenIssuerConfig.SAML_ISSUER_CONFIG));
}
// Look for the file
if ((config == null) && (configFile != null)) {
config = new SAMLTokenIssuerConfig(configFile);
}
// Look for the param
if ((config == null) && (configParamName != null)) {
Parameter param = inMsgCtx.getParameter(configParamName);
if ((param != null) && (param.getParameterElement() != null)) {
config = new SAMLTokenIssuerConfig(param
.getParameterElement().getFirstChildWithName(
SAMLTokenIssuerConfig.SAML_ISSUER_CONFIG));
} else {
throw new TrustException("expectedParameterMissing",
new String[] { configParamName });
}
}
if (config == null) {
throw new TrustException("configurationIsNull");
}
Crypto crypto;
if (config.cryptoElement != null) { // crypto props
// defined as
// elements
crypto = CryptoFactory.getInstance(TrustUtil
.toProperties(config.cryptoElement), inMsgCtx
.getAxisService().getClassLoader());
} else { // crypto props defined in a properties file
crypto = CryptoFactory.getInstance(config.cryptoPropertiesFile,
inMsgCtx.getAxisService().getClassLoader());
}
X509Certificate[] issuerCerts = crypto
.getCertificates(config.issuerKeyAlias);
issuerPBKey = issuerCerts[0].getPublicKey();
} catch (Exception e) {
log.error("Could not retrieve issuer public key", e);
}
return issuerPBKey;
}
/**
* Returns the <wst:Status> element.
*
* @param version
* WS-Trust version.
* @param parent
* the parent OMElement.
*/
private static OMElement createMessageElement(int version,
OMElement parent, String elementName) throws TrustException {
return createOMElement(parent, TrustUtil.getWSTNamespace(version),
elementName, RahasConstants.WST_PREFIX);
}
private static OMElement createOMElement(OMElement parent, String ns,
String ln, String prefix) {
return parent.getOMFactory().createOMElement(new QName(ns, ln, prefix),
parent);
}
// ========================================================================
/**
* Set the configuration file of this TokenValidator. <p/> This is the text
* value of the <configuration-file> element of the
* token-dispatcher-configuration
*
* @param configFile
*/
public void setConfigurationFile(String configFile) {
this.configFile = configFile;
}
/**
* Set the name of the configuration parameter. <p/> If this is used then
* there must be a <code>org.apache.axis2.description.Parameter</code>
* object available in the via the messageContext when the
* <code>TokenValidator</code> is called.
*
* @param configParamName
* @see org.apache.axis2.description.Parameter
*/
public void setConfigurationParamName(String configParamName) {
this.configParamName = configParamName;
}
public void setConfigurationElement(OMElement configElement) {
this.configElement = configElement;
}
}