为了逃避XSS,我建议在输出数据时进行转义,因为正确的转义取决于输出文档。
如果
@ResponseBody客户端直接使用所产生的JSON响应,并且没有机会让XSS转义内容,那么可以自定义JacksonMessageConverter以对字符串执行XSS转义。
可以像这样自定义JacksonMessageConverter:
1)首先,我们创建ObjectMapper工厂,该工厂将创建我们的自定义对象映射器:
public class HtmlEscapingObjectMapperFactory implements FactoryBean<ObjectMapper> { private final ObjectMapper objectMapper; public HtmlEscapingObjectMapperFactory() { objectMapper = new ObjectMapper(); objectMapper.getJsonFactory().setCharacterEscapes(new HTMLCharacterEscapes()); } @Override public ObjectMapper getObject() throws Exception { return objectMapper; } @Override public Class<?> getObjectType() { return ObjectMapper.class; } @Override public boolean isSingleton() { return true; } public static class HTMLCharacterEscapes extends CharacterEscapes { private final int[] asciiEscapes; public HTMLCharacterEscapes() { // start with set of characters known to require escaping (double-quote, backslash etc) asciiEscapes = CharacterEscapes.standardAsciiEscapesForJSON(); // and force escaping of a few others: asciiEscapes['<'] = CharacterEscapes.ESCAPE_CUSTOM; asciiEscapes['>'] = CharacterEscapes.ESCAPE_CUSTOM; asciiEscapes['&'] = CharacterEscapes.ESCAPE_CUSTOM; asciiEscapes['"'] = CharacterEscapes.ESCAPE_CUSTOM; asciiEscapes['''] = CharacterEscapes.ESCAPE_CUSTOM; } @Override public int[] getEscapeCodesForAscii() { return asciiEscapes; } // and this for others; we don't need anything special here @Override public SerializableString getEscapeSequence(int ch) { return new SerializedString(StringEscapeUtils.escapeHtml4(Character.toString((char) ch))); } }}
(HtmlCharacterEscapes的灵感来自于这个问题:Spring MVC和Jackson
Mapper的HTML转义)
2)然后,我们注册使用自定义对象映射器的消息转换器(例如xml config中的示例):
<bean id="htmlEscapingObjectMapper" /><mvc:annotation-driven> <mvc:message-converters> <bean p:objectMapper-ref="htmlEscapingObjectMapper" /> </mvc:message-converters></mvc:annotation-driven>
现在,由创建的所有JSON消息
@ResponseBody都应具有HTMLCharacterEscapes中指定的转义字符串。
该问题的替代解决方案:
- 对象反序列化后,XSS可以在控制器主体中逃脱所需的 *** 作
- 也许XSS在输出内容之前先在客户端的javascript中转义
除了进行输出转义之外,还可以进行一些输入验证(使用标准的Spring验证方法)来阻止一些您不想输入到系统/数据库中的内容,这可能是有用的。
编辑:JavaConfig
我还没有尝试过,但是在Java配置中它应该像这样工作(您不需要上面的Factory Bean,因为在这种情况下您可以在config中设置所有内容):
@Overridepublic void configureMessageConverters(List<HttpMessageConverter<?>> converters) { super.configureMessageConverters(converters); converters.add(buildHtmlEscapingJsonConverter());}private MappingJacksonHttpMessageConverter buildHtmlEscapingJsonConverter() { MappingJacksonHttpMessageConverter htmlEscapingConverter = new MappingJacksonHttpMessageConverter(); ObjectMapper objectMapper = new ObjectMapper(); objectMapper.getJsonFactory().setCharacterEscapes(new HTMLCharacterEscapes()); htmlEscapingConverter.setObjectMapper(objectMapper); return htmlEscapingConverter; }
请注意,现在通常配置的所有其他非json默认消息转换器(例如XML转换器等)都将丢失,并且如果需要它们,则需要手动添加它们(您可以看到默认情况下处于活动状态)在第2.2节中:http : //www.baeldung.com/spring-httpmessageconverter-
rest)
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