/* Copyright 2004, 2005, 2006 2009 Acegi Technology Pty Limited
*
* 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.springframework.security.web.authentication.www;
import java.io.IOException;
import java.util.Map;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.context.MessageSource;
import org.springframework.context.MessageSourceAware;
import org.springframework.context.support.MessageSourceAccessor;
import org.springframework.security.authentication.AuthenticationDetailsSource;
import org.springframework.security.authentication.AuthenticationServiceException;
import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.core.SpringSecurityMessageSource;
import org.springframework.security.crypto.codec.Base64;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserCache;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.security.core.userdetails.cache.NullUserCache;
import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.springframework.web.filter.GenericFilterBean;
/**
* Processes a HTTP request's Digest authorization headers, putting the result into the
* <code>SecurityContextHolder</code>.
* <p>
* For a detailed background on what this filter is designed to process, refer to
* <a href="http://www.ietf.org/rfc/rfc2617.txt">RFC 2617</a> (which superseded RFC 2069, although this
* filter support clients that implement either RFC 2617 or RFC 2069).
* <p>
* This filter can be used to provide Digest authentication services to both remoting protocol clients (such as
* Hessian and SOAP) as well as standard user agents (such as Internet Explorer and FireFox).
* <p>
* This Digest implementation has been designed to avoid needing to store session state between invocations.
* All session management information is stored in the "nonce" that is sent to the client by the {@link
* DigestAuthenticationEntryPoint}.
* <p>
* If authentication is successful, the resulting {@link org.springframework.security.core.Authentication Authentication}
* object will be placed into the <code>SecurityContextHolder</code>.
* <p>
* If authentication fails, an {@link org.springframework.security.web.AuthenticationEntryPoint AuthenticationEntryPoint}
* implementation is called. This must always be {@link DigestAuthenticationEntryPoint}, which will prompt the user
* to authenticate again via Digest authentication.
* <p>
* Note there are limitations to Digest authentication, although it is a more comprehensive and secure solution
* than Basic authentication. Please see RFC 2617 section 4 for a full discussion on the advantages of Digest
* authentication over Basic authentication, including commentary on the limitations that it still imposes.
*
* @author Ben Alex
* @author Luke Taylor
* @since 1.0.0
*/
public class DigestAuthenticationFilter extends GenericFilterBean implements MessageSourceAware {
//~ Static fields/initializers =====================================================================================
private static final Log logger = LogFactory.getLog(DigestAuthenticationFilter.class);
//~ Instance fields ================================================================================================
private AuthenticationDetailsSource<HttpServletRequest,?> authenticationDetailsSource = new WebAuthenticationDetailsSource();
private DigestAuthenticationEntryPoint authenticationEntryPoint;
protected MessageSourceAccessor messages = SpringSecurityMessageSource.getAccessor();
private UserCache userCache = new NullUserCache();
private UserDetailsService userDetailsService;
private boolean passwordAlreadyEncoded = false;
private boolean createAuthenticatedToken = false;
//~ Methods ========================================================================================================
@Override
public void afterPropertiesSet() {
Assert.notNull(userDetailsService, "A UserDetailsService is required");
Assert.notNull(authenticationEntryPoint, "A DigestAuthenticationEntryPoint is required");
}
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;
String header = request.getHeader("Authorization");
if (header == null || !header.startsWith("Digest ")) {
chain.doFilter(request, response);
return;
}
if (logger.isDebugEnabled()) {
logger.debug("Digest Authorization header received from user agent: " + header);
}
DigestData digestAuth = new DigestData(header);
try {
digestAuth.validateAndDecode(authenticationEntryPoint.getKey(), authenticationEntryPoint.getRealmName());
} catch (BadCredentialsException e) {
fail(request, response, e);
return;
}
// Lookup password for presented username
// NB: DAO-provided password MUST be clear text - not encoded/salted
// (unless this instance's passwordAlreadyEncoded property is 'false')
boolean cacheWasUsed = true;
UserDetails user = userCache.getUserFromCache(digestAuth.getUsername());
String serverDigestMd5;
try {
if (user == null) {
cacheWasUsed = false;
user = userDetailsService.loadUserByUsername(digestAuth.getUsername());
if (user == null) {
throw new AuthenticationServiceException(
"AuthenticationDao returned null, which is an interface contract violation");
}
userCache.putUserInCache(user);
}
serverDigestMd5 = digestAuth.calculateServerDigest(user.getPassword(), request.getMethod());
// If digest is incorrect, try refreshing from backend and recomputing
if (!serverDigestMd5.equals(digestAuth.getResponse()) && cacheWasUsed) {
if (logger.isDebugEnabled()) {
logger.debug(
"Digest comparison failure; trying to refresh user from DAO in case password had changed");
}
user = userDetailsService.loadUserByUsername(digestAuth.getUsername());
userCache.putUserInCache(user);
serverDigestMd5 = digestAuth.calculateServerDigest(user.getPassword(), request.getMethod());
}
} catch (UsernameNotFoundException notFound) {
fail(request, response,
new BadCredentialsException(messages.getMessage("DigestAuthenticationFilter.usernameNotFound",
new Object[]{digestAuth.getUsername()}, "Username {0} not found")));
return;
}
// If digest is still incorrect, definitely reject authentication attempt
if (!serverDigestMd5.equals(digestAuth.getResponse())) {
if (logger.isDebugEnabled()) {
logger.debug("Expected response: '" + serverDigestMd5 + "' but received: '" + digestAuth.getResponse()
+ "'; is AuthenticationDao returning clear text passwords?");
}
fail(request, response,
new BadCredentialsException(messages.getMessage("DigestAuthenticationFilter.incorrectResponse",
"Incorrect response")));
return;
}
// To get this far, the digest must have been valid
// Check the nonce has not expired
// We do this last so we can direct the user agent its nonce is stale
// but the request was otherwise appearing to be valid
if (digestAuth.isNonceExpired()) {
fail(request, response,
new NonceExpiredException(messages.getMessage("DigestAuthenticationFilter.nonceExpired",
"Nonce has expired/timed out")));
return;
}
if (logger.isDebugEnabled()) {
logger.debug("Authentication success for user: '" + digestAuth.getUsername()
+ "' with response: '" + digestAuth.getResponse() + "'");
}
SecurityContextHolder.getContext().setAuthentication(createSuccessfulAuthentication(request, user));
chain.doFilter(request, response);
}
private Authentication createSuccessfulAuthentication(HttpServletRequest request, UserDetails user) {
UsernamePasswordAuthenticationToken authRequest;
if (createAuthenticatedToken) {
authRequest = new UsernamePasswordAuthenticationToken(user, user.getPassword(), user.getAuthorities());
}
else {
authRequest = new UsernamePasswordAuthenticationToken(user, user.getPassword());
}
authRequest.setDetails(authenticationDetailsSource.buildDetails((HttpServletRequest) request));
return authRequest;
}
private void fail(HttpServletRequest request, HttpServletResponse response, AuthenticationException failed)
throws IOException, ServletException {
SecurityContextHolder.getContext().setAuthentication(null);
if (logger.isDebugEnabled()) {
logger.debug(failed);
}
authenticationEntryPoint.commence(request, response, failed);
}
protected final DigestAuthenticationEntryPoint getAuthenticationEntryPoint() {
return authenticationEntryPoint;
}
public UserCache getUserCache() {
return userCache;
}
public UserDetailsService getUserDetailsService() {
return userDetailsService;
}
public void setAuthenticationDetailsSource(AuthenticationDetailsSource<HttpServletRequest,?> authenticationDetailsSource) {
Assert.notNull(authenticationDetailsSource, "AuthenticationDetailsSource required");
this.authenticationDetailsSource = authenticationDetailsSource;
}
public void setAuthenticationEntryPoint(DigestAuthenticationEntryPoint authenticationEntryPoint) {
this.authenticationEntryPoint = authenticationEntryPoint;
}
public void setMessageSource(MessageSource messageSource) {
this.messages = new MessageSourceAccessor(messageSource);
}
public void setPasswordAlreadyEncoded(boolean passwordAlreadyEncoded) {
this.passwordAlreadyEncoded = passwordAlreadyEncoded;
}
public void setUserCache(UserCache userCache) {
this.userCache = userCache;
}
public void setUserDetailsService(UserDetailsService userDetailsService) {
this.userDetailsService = userDetailsService;
}
/**
* If you set this property, the Authentication object, which is
* created after the successful digest authentication will be marked
* as <b>authenticated</b> and filled with the authorities loaded by
* the UserDetailsService. It therefore will not be re-authenticated
* by your AuthenticationProvider. This means, that only the password
* of the user is checked, but not the flags like isEnabled() or
* isAccountNonExpired(). You will save some time by enabling this flag,
* as otherwise your UserDetailsService will be called twice. A more secure
* option would be to introduce a cache around your UserDetailsService, but
* if you don't use these flags, you can also safely enable this option.
*
* @param createAuthenticatedToken default is false
*/
public void setCreateAuthenticatedToken(boolean createAuthenticatedToken) {
this.createAuthenticatedToken = createAuthenticatedToken;
}
private class DigestData {
private final String username;
private final String realm;
private final String nonce;
private final String uri;
private final String response;
private final String qop;
private final String nc;
private final String cnonce;
private final String section212response;
private long nonceExpiryTime;
DigestData(String header) {
section212response = header.substring(7);
String[] headerEntries = DigestAuthUtils.splitIgnoringQuotes(section212response, ',');
Map<String,String> headerMap = DigestAuthUtils.splitEachArrayElementAndCreateMap(headerEntries, "=", "\"");
username = headerMap.get("username");
realm = headerMap.get("realm");
nonce = headerMap.get("nonce");
uri = headerMap.get("uri");
response = headerMap.get("response");
qop = headerMap.get("qop"); // RFC 2617 extension
nc = headerMap.get("nc"); // RFC 2617 extension
cnonce = headerMap.get("cnonce"); // RFC 2617 extension
if (logger.isDebugEnabled()) {
logger.debug("Extracted username: '" + username + "'; realm: '" + realm + "'; nonce: '"
+ nonce + "'; uri: '" + uri + "'; response: '" + response + "'");
}
}
void validateAndDecode(String entryPointKey, String expectedRealm) throws BadCredentialsException {
// Check all required parameters were supplied (ie RFC 2069)
if ((username == null) || (realm == null) || (nonce == null) || (uri == null) || (response == null)) {
throw new BadCredentialsException(messages.getMessage("DigestAuthenticationFilter.missingMandatory",
new Object[]{section212response}, "Missing mandatory digest value; received header {0}"));
}
// Check all required parameters for an "auth" qop were supplied (ie RFC 2617)
if ("auth".equals(qop)) {
if ((nc == null) || (cnonce == null)) {
if (logger.isDebugEnabled()) {
logger.debug("extracted nc: '" + nc + "'; cnonce: '" + cnonce + "'");
}
throw new BadCredentialsException(messages.getMessage("DigestAuthenticationFilter.missingAuth",
new Object[]{section212response}, "Missing mandatory digest value; received header {0}"));
}
}
// Check realm name equals what we expected
if (!expectedRealm.equals(realm)) {
throw new BadCredentialsException(messages.getMessage("DigestAuthenticationFilter.incorrectRealm",
new Object[]{realm, expectedRealm},
"Response realm name '{0}' does not match system realm name of '{1}'"));
}
// Check nonce was Base64 encoded (as sent by DigestAuthenticationEntryPoint)
if (!Base64.isBase64(nonce.getBytes())) {
throw new BadCredentialsException(messages.getMessage("DigestAuthenticationFilter.nonceEncoding",
new Object[]{nonce}, "Nonce is not encoded in Base64; received nonce {0}"));
}
// Decode nonce from Base64
// format of nonce is:
// base64(expirationTime + ":" + md5Hex(expirationTime + ":" + key))
String nonceAsPlainText = new String(Base64.decode(nonce.getBytes()));
String[] nonceTokens = StringUtils.delimitedListToStringArray(nonceAsPlainText, ":");
if (nonceTokens.length != 2) {
throw new BadCredentialsException(messages.getMessage("DigestAuthenticationFilter.nonceNotTwoTokens",
new Object[]{nonceAsPlainText}, "Nonce should have yielded two tokens but was {0}"));
}
// Extract expiry time from nonce
try {
nonceExpiryTime = new Long(nonceTokens[0]).longValue();
} catch (NumberFormatException nfe) {
throw new BadCredentialsException(messages.getMessage("DigestAuthenticationFilter.nonceNotNumeric",
new Object[]{nonceAsPlainText},
"Nonce token should have yielded a numeric first token, but was {0}"));
}
// Check signature of nonce matches this expiry time
String expectedNonceSignature = DigestAuthUtils.md5Hex(nonceExpiryTime + ":" + entryPointKey);
if (!expectedNonceSignature.equals(nonceTokens[1])) {
new BadCredentialsException(messages.getMessage("DigestAuthenticationFilter.nonceCompromised",
new Object[]{nonceAsPlainText}, "Nonce token compromised {0}"));
}
}
String calculateServerDigest(String password, String httpMethod) {
// Compute the expected response-digest (will be in hex form)
// Don't catch IllegalArgumentException (already checked validity)
return DigestAuthUtils.generateDigest(passwordAlreadyEncoded, username, realm, password,
httpMethod, uri, qop, nonce, nc, cnonce);
}
boolean isNonceExpired() {
long now = System.currentTimeMillis();
return nonceExpiryTime < now;
}
String getUsername() {
return username;
}
String getResponse() {
return response;
}
}
}