Spring Security Web 5.1.2ソース解析-BaicAuthentication Filter
概要
処理
このフィルタは、
頭の解析が失敗したら、このフィルタは異常
認証に失敗した場合、
ソースコード解析 Spring Security Web 5.1.2ソース解析-安全関連Filterリスト
処理
HTTPは、要求されたBASIC authorizationのヘッダに、認証結果をSecurityContextHolderに書き込む.HTTPの要求にAuthorizationという名前のヘッダが含まれており、その値フォーマットがBasic xxxである場合、FilterはBASIC authorizationの頭部であると考えられ、xxxの部分はbase64の符号化された{username}:{password}文字列であるべきである.例えば、ユーザ名／パスワードがそれぞれadmin/secretである場合、対応するヘッダはBasic YWRtaW46c2VjcmV0である.このフィルタは、
HTTP BASIC authorizationのヘッダからそれぞれのユーザ名とパスワードを解析し、AuthenticationManagerを呼び出して認証し、成功すれば、認証された結果をSecurityContextHolderのSecurityContextの属性authenticationに書き込む.また、Remember Meなどの他の処理も行われる.頭の解析が失敗したら、このフィルタは異常
BadCredentialsExceptionを投げます.認証に失敗した場合、
SecurityContextHolderのSecurityContextが消去される.そして、filter chainの実行を続行しない.ソースコード解析
package org.springframework.security.web.authentication.www;
import java.io.IOException;
import java.util.Base64;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.security.authentication.AnonymousAuthenticationToken;
import org.springframework.security.authentication.AuthenticationDetailsSource;
import org.springframework.security.authentication.AuthenticationManager;
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.context.SecurityContextHolder;
import org.springframework.security.web.AuthenticationEntryPoint;
import org.springframework.security.web.authentication.NullRememberMeServices;
import org.springframework.security.web.authentication.RememberMeServices;
import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
import org.springframework.util.Assert;
import org.springframework.web.filter.OncePerRequestFilter;
public class BasicAuthenticationFilter extends OncePerRequestFilter {
// ~ Instance fields
// ================================================================================================
// Authentication details
private AuthenticationDetailsSource<HttpServletRequest, ?> authenticationDetailsSource =
new WebAuthenticationDetailsSource();
private AuthenticationEntryPoint authenticationEntryPoint;
private AuthenticationManager authenticationManager;
private RememberMeServices rememberMeServices = new NullRememberMeServices();
private boolean ignoreFailure = false;
private String credentialsCharset = "UTF-8";
/**
* Creates an instance which will authenticate against the supplied
* AuthenticationManager and which will ignore failed authentication attempts,
* allowing the request to proceed down the filter chain.
*
* @param authenticationManager the bean to submit authentication requests to
*/
public BasicAuthenticationFilter(AuthenticationManager authenticationManager) {
Assert.notNull(authenticationManager, "authenticationManager cannot be null");
this.authenticationManager = authenticationManager;
this.ignoreFailure = true;
}
/**
* Creates an instance which will authenticate against the supplied
* AuthenticationManager and use the supplied AuthenticationEntryPoint
* to handle authentication failures.
*
* @param authenticationManager the bean to submit authentication requests to
* @param authenticationEntryPoint will be invoked when authentication fails.
* Typically an instance of BasicAuthenticationEntryPoint.
*/
public BasicAuthenticationFilter(AuthenticationManager authenticationManager,
AuthenticationEntryPoint authenticationEntryPoint) {
Assert.notNull(authenticationManager, "authenticationManager cannot be null");
Assert.notNull(authenticationEntryPoint,
"authenticationEntryPoint cannot be null");
this.authenticationManager = authenticationManager;
this.authenticationEntryPoint = authenticationEntryPoint;
}
// ~ Methods
// ========================================================================================================
@Override
public void afterPropertiesSet() {
Assert.notNull(this.authenticationManager,
"An AuthenticationManager is required");
if (!isIgnoreFailure()) {
Assert.notNull(this.authenticationEntryPoint,
"An AuthenticationEntryPoint is required");
}
}
@Override
protected void doFilterInternal(HttpServletRequest request,
HttpServletResponse response, FilterChain chain)
throws IOException, ServletException {
final boolean debug = this.logger.isDebugEnabled();
// Authorization
String header = request.getHeader("Authorization");
if (header == null || !header.toLowerCase().startsWith("basic ")) {
// Authorization basic ，
// ， ， filter chain
chain.doFilter(request, response);
return;
}
// http basic authentication ， ，
// Authorization ( ) : "basic xxxxxx"
try {
// Authorization
String[] tokens = extractAndDecodeHeader(header, request);
assert tokens.length == 2;
// tokens[0] ， tokens[1]
String username = tokens[0];
if (debug) {
this.logger
.debug("Basic Authentication Authorization header found for user '"
+ username + "'");
}
// username
if (authenticationIsRequired(username)) {
// ， / UsernamePasswordAuthenticationToken,
//
UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(
username, tokens[1]);
authRequest.setDetails(
this.authenticationDetailsSource.buildDetails(request));
//
Authentication authResult = this.authenticationManager
.authenticate(authRequest);
if (debug) {
this.logger.debug("Authentication success: " + authResult);
}
// ， Authentication authRequest SecurityContextHolder
// SecurityContext 。
SecurityContextHolder.getContext().setAuthentication(authResult);
// RememberMe
this.rememberMeServices.loginSuccess(request, response, authResult);
// : ，
onSuccessfulAuthentication(request, response, authResult);
}
}
catch (AuthenticationException failed) {
// ， SecurityContextHolder
SecurityContextHolder.clearContext();
if (debug) {
this.logger.debug("Authentication request for failed: " + failed);
}
// RememberMe
this.rememberMeServices.loginFail(request, response);
// : ，
onUnsuccessfulAuthentication(request, response, failed);
if (this.ignoreFailure) {
chain.doFilter(request, response);
}
else {
this.authenticationEntryPoint.commence(request, response, failed);
}
return;
}
// http basic authentication ， ， filter chain
chain.doFilter(request, response);
}
/**
* Decodes the header into a username and password.
* http basic authentication
*
* @throws BadCredentialsException if the Basic header is not present or is not valid
* Base64
*/
private String[] extractAndDecodeHeader(String header, HttpServletRequest request)
throws IOException {
// 6 , UTF-8
// : "Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==",
// "QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
byte[] base64Token = header.substring(6).getBytes("UTF-8");
// Base64 base64Token
byte[] decoded;
try {
decoded = Base64.getDecoder().decode(base64Token);
}
catch (IllegalArgumentException e) {
throw new BadCredentialsException(
"Failed to decode basic authentication token");
}
// credentialsCharset "{ }:{ }"
// credentialsCharset UTF-8
String token = new String(decoded, getCredentialsCharset(request));
// ,
int delim = token.indexOf(":");
if (delim == -1) {
throw new BadCredentialsException("Invalid basic authentication token");
}
return new String[] { token.substring(0, delim), token.substring(delim + 1) };
}
private boolean authenticationIsRequired(String username) {
// Only reauthenticate if username doesn't match SecurityContextHolder and user
// isn't authenticated
// (see SEC-53)
Authentication existingAuth = SecurityContextHolder.getContext()
.getAuthentication();
// SecurityContextHolder SecurityContext Authentication,
// null ，
if (existingAuth == null || !existingAuth.isAuthenticated()) {
return true;
}
// Limit username comparison to providers which use usernames (ie
// UsernamePasswordAuthenticationToken)
// (see SEC-348)
// SecurityContextHolder SecurityContext Authentication
// ， username ，
if (existingAuth instanceof UsernamePasswordAuthenticationToken
&& !existingAuth.getName().equals(username)) {
return true;
}
// Handle unusual condition where an AnonymousAuthenticationToken is already
// present
// This shouldn't happen very often, as BasicProcessingFitler is meant to be
// earlier in the filter
// chain than AnonymousAuthenticationFilter. Nevertheless, presence of both an
// AnonymousAuthenticationToken
// together with a BASIC authentication request header should indicate
// reauthentication using the
// BASIC protocol is desirable. This behaviour is also consistent with that
// provided by form and digest,
// both of which force re-authentication if the respective header is detected (and
// in doing so replace
// any existing AnonymousAuthenticationToken). See SEC-610.
// SecurityContextHolder SecurityContext Authentication ，
//
if (existingAuth instanceof AnonymousAuthenticationToken) {
return true;
}
// SecurityContextHolder SecurityContext Authentication ,
// username ，
return false;
}
protected void onSuccessfulAuthentication(HttpServletRequest request,
HttpServletResponse response, Authentication authResult) throws IOException {
}
protected void onUnsuccessfulAuthentication(HttpServletRequest request,
HttpServletResponse response, AuthenticationException failed)
throws IOException {
}
protected AuthenticationEntryPoint getAuthenticationEntryPoint() {
return this.authenticationEntryPoint;
}
protected AuthenticationManager getAuthenticationManager() {
return this.authenticationManager;
}
protected boolean isIgnoreFailure() {
return this.ignoreFailure;
}
public void setAuthenticationDetailsSource(
AuthenticationDetailsSource<HttpServletRequest, ?> authenticationDetailsSource) {
Assert.notNull(authenticationDetailsSource,
"AuthenticationDetailsSource required");
this.authenticationDetailsSource = authenticationDetailsSource;
}
public void setRememberMeServices(RememberMeServices rememberMeServices) {
Assert.notNull(rememberMeServices, "rememberMeServices cannot be null");
this.rememberMeServices = rememberMeServices;
}
public void setCredentialsCharset(String credentialsCharset) {
Assert.hasText(credentialsCharset, "credentialsCharset cannot be null or empty");
this.credentialsCharset = credentialsCharset;
}
protected String getCredentialsCharset(HttpServletRequest httpRequest) {
return this.credentialsCharset;
}
}