org.springframework.security.web.authentication.rememberme.TokenBasedRememberMeServices Maven / Gradle / Ivy
/*
* Copyright 2004, 2005, 2006 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
*
* https://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.rememberme;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Date;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.crypto.codec.Hex;
import org.springframework.security.crypto.codec.Utf8;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
/**
* Identifies previously remembered users by a Base-64 encoded cookie.
*
*
* This implementation does not rely on an external database, so is attractive for simple
* applications. The cookie will be valid for a specific period from the date of the last
* {@link #loginSuccess(HttpServletRequest, HttpServletResponse, Authentication)}. As per
* the interface contract, this method will only be called when the principal completes a
* successful interactive authentication. As such the time period commences from the last
* authentication attempt where they furnished credentials - not the time period they last
* logged in via remember-me. The implementation will only send a remember-me token if the
* parameter defined by {@link #setParameter(String)} is present.
*
* An {@link org.springframework.security.core.userdetails.UserDetailsService} is required
* by this implementation, so that it can construct a valid Authentication
* from the returned {@link org.springframework.security.core.userdetails.UserDetails}.
* This is also necessary so that the user's password is available and can be checked as
* part of the encoded cookie.
*
* The cookie encoded by this implementation adopts the following form:
*
*
* username + ":" + expiryTime + ":"
* + Md5Hex(username + ":" + expiryTime + ":" + password + ":" + key)
*
*
*
* As such, if the user changes their password, any remember-me token will be invalidated.
* Equally, the system administrator may invalidate every remember-me token on issue by
* changing the key. This provides some reasonable approaches to recovering from a
* remember-me token being left on a public machine (e.g. kiosk system, Internet cafe
* etc). Most importantly, at no time is the user's password ever sent to the user agent,
* providing an important security safeguard. Unfortunately the username is necessary in
* this implementation (as we do not want to rely on a database for remember-me services).
* High security applications should be aware of this occasionally undesired disclosure of
* a valid username.
*
* This is a basic remember-me implementation which is suitable for many applications.
* However, we recommend a database-based implementation if you require a more secure
* remember-me approach (see {@link PersistentTokenBasedRememberMeServices}).
*
* By default the tokens will be valid for 14 days from the last successful authentication
* attempt. This can be changed using {@link #setTokenValiditySeconds(int)}. If this value
* is less than zero, the expiryTime will remain at 14 days, but the negative
* value will be used for the maxAge property of the cookie, meaning that it will
* not be stored when the browser is closed.
*
* @author Ben Alex
*/
public class TokenBasedRememberMeServices extends AbstractRememberMeServices {
public TokenBasedRememberMeServices(String key, UserDetailsService userDetailsService) {
super(key, userDetailsService);
}
@Override
protected UserDetails processAutoLoginCookie(String[] cookieTokens, HttpServletRequest request,
HttpServletResponse response) {
if (cookieTokens.length != 3) {
throw new InvalidCookieException(
"Cookie token did not contain 3" + " tokens, but contained '" + Arrays.asList(cookieTokens) + "'");
}
long tokenExpiryTime = getTokenExpiryTime(cookieTokens);
if (isTokenExpired(tokenExpiryTime)) {
throw new InvalidCookieException("Cookie token[1] has expired (expired on '" + new Date(tokenExpiryTime)
+ "'; current time is '" + new Date() + "')");
}
// Check the user exists. Defer lookup until after expiry time checked, to
// possibly avoid expensive database call.
UserDetails userDetails = getUserDetailsService().loadUserByUsername(cookieTokens[0]);
Assert.notNull(userDetails, () -> "UserDetailsService " + getUserDetailsService()
+ " returned null for username " + cookieTokens[0] + ". " + "This is an interface contract violation");
// Check signature of token matches remaining details. Must do this after user
// lookup, as we need the DAO-derived password. If efficiency was a major issue,
// just add in a UserCache implementation, but recall that this method is usually
// only called once per HttpSession - if the token is valid, it will cause
// SecurityContextHolder population, whilst if invalid, will cause the cookie to
// be cancelled.
String expectedTokenSignature = makeTokenSignature(tokenExpiryTime, userDetails.getUsername(),
userDetails.getPassword());
if (!equals(expectedTokenSignature, cookieTokens[2])) {
throw new InvalidCookieException("Cookie token[2] contained signature '" + cookieTokens[2]
+ "' but expected '" + expectedTokenSignature + "'");
}
return userDetails;
}
private long getTokenExpiryTime(String[] cookieTokens) {
try {
return new Long(cookieTokens[1]);
}
catch (NumberFormatException nfe) {
throw new InvalidCookieException(
"Cookie token[1] did not contain a valid number (contained '" + cookieTokens[1] + "')");
}
}
/**
* Calculates the digital signature to be put in the cookie. Default value is MD5
* ("username:tokenExpiryTime:password:key")
*/
protected String makeTokenSignature(long tokenExpiryTime, String username, String password) {
String data = username + ":" + tokenExpiryTime + ":" + password + ":" + getKey();
try {
MessageDigest digest = MessageDigest.getInstance("MD5");
return new String(Hex.encode(digest.digest(data.getBytes())));
}
catch (NoSuchAlgorithmException ex) {
throw new IllegalStateException("No MD5 algorithm available!");
}
}
protected boolean isTokenExpired(long tokenExpiryTime) {
return tokenExpiryTime < System.currentTimeMillis();
}
@Override
public void onLoginSuccess(HttpServletRequest request, HttpServletResponse response,
Authentication successfulAuthentication) {
String username = retrieveUserName(successfulAuthentication);
String password = retrievePassword(successfulAuthentication);
// If unable to find a username and password, just abort as
// TokenBasedRememberMeServices is
// unable to construct a valid token in this case.
if (!StringUtils.hasLength(username)) {
this.logger.debug("Unable to retrieve username");
return;
}
if (!StringUtils.hasLength(password)) {
UserDetails user = getUserDetailsService().loadUserByUsername(username);
password = user.getPassword();
if (!StringUtils.hasLength(password)) {
this.logger.debug("Unable to obtain password for user: " + username);
return;
}
}
int tokenLifetime = calculateLoginLifetime(request, successfulAuthentication);
long expiryTime = System.currentTimeMillis();
// SEC-949
expiryTime += 1000L * ((tokenLifetime < 0) ? TWO_WEEKS_S : tokenLifetime);
String signatureValue = makeTokenSignature(expiryTime, username, password);
setCookie(new String[] { username, Long.toString(expiryTime), signatureValue }, tokenLifetime, request,
response);
if (this.logger.isDebugEnabled()) {
this.logger.debug(
"Added remember-me cookie for user '" + username + "', expiry: '" + new Date(expiryTime) + "'");
}
}
/**
* Calculates the validity period in seconds for a newly generated remember-me login.
* After this period (from the current time) the remember-me login will be considered
* expired. This method allows customization based on request parameters supplied with
* the login or information in the Authentication object. The default value
* is just the token validity period property, tokenValiditySeconds.
*
* The returned value will be used to work out the expiry time of the token and will
* also be used to set the maxAge property of the cookie.
*
* See SEC-485.
* @param request the request passed to onLoginSuccess
* @param authentication the successful authentication object.
* @return the lifetime in seconds.
*/
protected int calculateLoginLifetime(HttpServletRequest request, Authentication authentication) {
return getTokenValiditySeconds();
}
protected String retrieveUserName(Authentication authentication) {
if (isInstanceOfUserDetails(authentication)) {
return ((UserDetails) authentication.getPrincipal()).getUsername();
}
return authentication.getPrincipal().toString();
}
protected String retrievePassword(Authentication authentication) {
if (isInstanceOfUserDetails(authentication)) {
return ((UserDetails) authentication.getPrincipal()).getPassword();
}
if (authentication.getCredentials() != null) {
return authentication.getCredentials().toString();
}
return null;
}
private boolean isInstanceOfUserDetails(Authentication authentication) {
return authentication.getPrincipal() instanceof UserDetails;
}
/**
* Constant time comparison to prevent against timing attacks.
*/
private static boolean equals(String expected, String actual) {
byte[] expectedBytes = bytesUtf8(expected);
byte[] actualBytes = bytesUtf8(actual);
return MessageDigest.isEqual(expectedBytes, actualBytes);
}
private static byte[] bytesUtf8(String s) {
return (s != null) ? Utf8.encode(s) : null;
}
}