spring mvc url匹配禁用后缀访问
在spring mvc中默认 访问url 加任意后缀名都能访问
比如:你想访问 /login ,但是通过 /login.do /login.action /login.json 都能访问
通常来说可能没有影响,但对于权限控制,这就严重了。
权限控制通常有两种思路:
1)弱权限控制
允许所有url通过,仅对个别重要的url做权限控制。此种方式比较简单,不需要对所有url资源进行配置,只配置重要的资源。
2)强权限控制
默认禁止所有url请求通过,仅开放授权的资源。此种方式对所有的url资源进行控制。在系统种需要整理所有的请求,或者某一目录下所有的url资源。这种方式安全控制比较严格,操作麻烦,但相对安全。
如果用第二种方式,则上面spring mvc的访问策略对安全没有影响。
但如果用第一种安全策略,则会有很大的安全风险。
例如:我们控制了/login 的访问,但是我们默认除/login的资源不受权限控制约束,那么攻击者就可以用 /login.do /login.xxx 来访问我们的资源。
在spring 3.1之后,url找对应方法的处理步骤,第一步,直接调用RequestMappingHandlerMapping查找到相应的处理方法,第二步,调用RequestMappingHandlerAdapter进行处理
我们在RequestMappingHandlerMapping中可以看到
/** * Whether to use suffix pattern match for registered file extensions only * when matching patterns to requests. * <p>If enabled, a controller method mapped to "/users" also matches to * "/users.json" assuming ".json" is a file extension registered with the * provided {@link #setContentNegotiationManager(ContentNegotiationManager) * contentNegotiationManager}. This can be useful for allowing only specific * URL extensions to be used as well as in cases where a "." in the URL path * can lead to ambiguous interpretation of path variable content, (e.g. given * "/users/{user}" and incoming URLs such as "/users/john.j.joe" and * "/users/john.j.joe.json"). * <p>If enabled, this flag also enables * {@link #setUseSuffixPatternMatch(boolean) useSuffixPatternMatch}. The * default value is {@code false}. */ public void setUseRegisteredSuffixPatternMatch(boolean useRegisteredSuffixPatternMatch) { this.useRegisteredSuffixPatternMatch = useRegisteredSuffixPatternMatch; this.useSuffixPatternMatch = (useRegisteredSuffixPatternMatch || this.useSuffixPatternMatch); }
那么如何来配置呢?
<mvc:annotation-driven> <mvc:path-matching suffix-pattern="false" /> </mvc:annotation-driven>
在匹配模式时是否使用后缀模式匹配,默认值为true。这样你想访问 /login ,通过 /login.* 就不能访问了。
spring mvc 之 请求url 带后缀的情况
RequestMappingInfoHandlerMapping 在处理http请求的时候, 如果 请求url 有后缀,如果找不到精确匹配的那个@RequestMapping方法。
那么,就把后缀去掉,然后.* 去匹配,这样,一般都可以匹配。 比如有一个@RequestMapping("/rest"), 那么精确匹配的情况下, 只会匹配/rest请求。
但如果我前端发来一个 /rest.abcdef 这样的请求, 又没有配置 @RequestMapping("/rest.abcdef") 这样映射的情况下, 那么@RequestMapping("/rest") 就会生效。
原理呢?处理链是这样的:
at org.springframework.web.servlet.mvc.condition.PatternsRequestCondition.getMatchingPattern(PatternsRequestCondition.java:254) at org.springframework.web.servlet.mvc.condition.PatternsRequestCondition.getMatchingPatterns(PatternsRequestCondition.java:230) at org.springframework.web.servlet.mvc.condition.PatternsRequestCondition.getMatchingCondition(PatternsRequestCondition.java:210) at org.springframework.web.servlet.mvc.method.RequestMappingInfo.getMatchingCondition(RequestMappingInfo.java:214) at org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping.getMatchingMapping(RequestMappingInfoHandlerMapping.java:79) at org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping.getMatchingMapping(RequestMappingInfoHandlerMapping.java:56) at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.addMatchingMappings(AbstractHandlerMethodMapping.java:358) at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.lookupHandlerMethod(AbstractHandlerMethodMapping.java:328) at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.getHandlerInternal(AbstractHandlerMethodMapping.java:299) at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.getHandlerInternal(AbstractHandlerMethodMapping.java:57) at org.springframework.web.servlet.handler.AbstractHandlerMapping.getHandler(AbstractHandlerMapping.java:299) at org.springframework.web.servlet.DispatcherServlet.getHandler(DispatcherServlet.java:1104) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:916)
关键是PatternsRequestCondition, 具体来说是这个方法:
AbstractHandlerMethodMapping 的getHandlerInternal: protected HandlerMethod getHandlerInternal(HttpServletRequest request) throws Exception { String lookupPath = this.getUrlPathHelper().getLookupPathForRequest(request); if (this.logger.isDebugEnabled()) { this.logger.debug("Looking up handler method for path " + lookupPath); } HandlerMethod handlerMethod = this.lookupHandlerMethod(lookupPath, request);// 这里是关键,它去寻找,找到了就找到了,找不到就不会再去寻找了 if (this.logger.isDebugEnabled()) { if (handlerMethod != null) { this.logger.debug("Returning handler method [" + handlerMethod + "]"); } else { this.logger.debug("Did not find handler method for [" + lookupPath + "]"); } } return handlerMethod != null ? handlerMethod.createWithResolvedBean() : null; } protected HandlerMethod lookupHandlerMethod(String lookupPath, HttpServletRequest request) throws Exception { List<AbstractHandlerMethodMapping<T>.Match> matches = new ArrayList(); List<T> directPathMatches = (List)this.urlMap.get(lookupPath); // directPathMatches, 直接匹配, 也可以说是 精确匹配 if (directPathMatches != null) { this.addMatchingMappings(directPathMatches, matches, request);// 如果能够精确匹配, 就会进来这里 } if (matches.isEmpty()) { this.addMatchingMappings(this.handlerMethods.keySet(), matches, request);// 如果无法精确匹配, 就会进来这里 } if (!matches.isEmpty()) { Comparator<AbstractHandlerMethodMapping<T>.Match> comparator = new AbstractHandlerMethodMapping.MatchComparator(this.getMappingComparator(request)); Collections.sort(matches, comparator); if (this.logger.isTraceEnabled()) { this.logger.trace("Found " + matches.size() + " matching mapping(s) for [" + lookupPath + "] : " + matches); } AbstractHandlerMethodMapping<T>.Match bestMatch = (AbstractHandlerMethodMapping.Match)matches.get(0); if (matches.size() > 1) { AbstractHandlerMethodMapping<T>.Match secondBestMatch = (AbstractHandlerMethodMapping.Match)matches.get(1); if (comparator.compare(bestMatch, secondBestMatch) == 0) { Method m1 = bestMatch.handlerMethod.getMethod(); Method m2 = secondBestMatch.handlerMethod.getMethod(); throw new IllegalStateException("Ambiguous handler methods mapped for HTTP path '" + request.getRequestURL() + "': {" + m1 + ", " + m2 + "}"); } } this.handleMatch(bestMatch.mapping, lookupPath, request); return bestMatch.handlerMethod; } else { return this.handleNoMatch(this.handlerMethods.keySet(), lookupPath, request); } } public List<String> getMatchingPatterns(String lookupPath) { List<String> matches = new ArrayList(); Iterator var3 = this.patterns.iterator(); while(var3.hasNext()) { String pattern = (String)var3.next(); // pattern 是 @RequestMapping 提供的映射 String match = this.getMatchingPattern(pattern, lookupPath); // lookupPath + .* 后能够匹配pattern, 那么就不为空 if (match != null) { matches.add(match);// 对于有后缀的情况, .* 后 } } Collections.sort(matches, this.pathMatcher.getPatternComparator(lookupPath)); return matches; } 最关键是这里 getMatchingPatterns : private String getMatchingPattern(String pattern, String lookupPath) { if (pattern.equals(lookupPath)) { return pattern; } else { if (this.useSuffixPatternMatch) { if (!this.fileExtensions.isEmpty() && lookupPath.indexOf(46) != -1) { Iterator var5 = this.fileExtensions.iterator(); while(var5.hasNext()) { String extension = (String)var5.next(); if (this.pathMatcher.match(pattern + extension, lookupPath)) { return pattern + extension; } } } else { boolean hasSuffix = pattern.indexOf(46) != -1; if (!hasSuffix && this.pathMatcher.match(pattern + ".*", lookupPath)) { return pattern + ".*"; // 关键是这里 } } } if (this.pathMatcher.match(pattern, lookupPath)) { return pattern; } else { return this.useTrailingSlashMatch && !pattern.endsWith("/") && this.pathMatcher.match(pattern + "/", lookupPath) ? pattern + "/" : null; } } }
而对于AbstractUrlHandlerMapping ,匹配不上就是匹配不上, 不会进行 +.* 后在匹配。
关键方法是这个:
protected Object lookupHandler(String urlPath, HttpServletRequest request) throws Exception { Object handler = this.handlerMap.get(urlPath); if (handler != null) { if (handler instanceof String) { String handlerName = (String)handler; handler = this.getApplicationContext().getBean(handlerName); } this.validateHandler(handler, request); return this.buildPathExposingHandler(handler, urlPath, urlPath, (Map)null); } else { List<String> matchingPatterns = new ArrayList(); Iterator var5 = this.handlerMap.keySet().iterator(); while(var5.hasNext()) { String registeredPattern = (String)var5.next(); if (this.getPathMatcher().match(registeredPattern, urlPath)) { matchingPatterns.add(registeredPattern); } } String bestPatternMatch = null; Comparator<String> patternComparator = this.getPathMatcher().getPatternComparator(urlPath); if (!matchingPatterns.isEmpty()) { Collections.sort(matchingPatterns, patternComparator); if (this.logger.isDebugEnabled()) { this.logger.debug("Matching patterns for request [" + urlPath + "] are " + matchingPatterns); } bestPatternMatch = (String)matchingPatterns.get(0); } if (bestPatternMatch != null) { handler = this.handlerMap.get(bestPatternMatch); String pathWithinMapping; if (handler instanceof String) { pathWithinMapping = (String)handler; handler = this.getApplicationContext().getBean(pathWithinMapping); } this.validateHandler(handler, request); pathWithinMapping = this.getPathMatcher().extractPathWithinPattern(bestPatternMatch, urlPath); Map<String, String> uriTemplateVariables = new LinkedHashMap(); Iterator var9 = matchingPatterns.iterator(); while(var9.hasNext()) { String matchingPattern = (String)var9.next(); if (patternComparator.compare(bestPatternMatch, matchingPattern) == 0) { Map<String, String> vars = this.getPathMatcher().extractUriTemplateVariables(matchingPattern, urlPath); Map<String, String> decodedVars = this.getUrlPathHelper().decodePathVariables(request, vars); uriTemplateVariables.putAll(decodedVars); } } if (this.logger.isDebugEnabled()) { this.logger.debug("URI Template variables for request [" + urlPath + "] are " + uriTemplateVariables); } return this.buildPathExposingHandler(handler, bestPatternMatch, pathWithinMapping, uriTemplateVariables); } else { return null; } } }
当然, 或许我们可以设置自定义的PathMatcher ,从而到达目的。 默认的 是AntPathMatcher 。
以上为个人经验,希望能给大家一个参考,也希望大家多多支持自由互联。