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记一次升级Tomcat

总述

    JDK都要出12了，而我们项目使用的jdk却仍然还停留在JDK1.6。为了追寻技术的发展的脚步，我这边准备将项目升级到JDK1.8。而作为一个web项目，我们的容器使用的是Tomcat。看了下Tomcat版本与JDK版本之间的兼容关系http://tomcat.apache.org/whichversion.html以及网上所传的各种JDK1.8和Tomcat7不兼容的问题， 我决定将Tomcat升级到8。我这里本地验证采用的tomcat版本是8.5.38https://tomcat.apache.org/download-80.cgi。

问题一：请求js文件报404错误

    其实这个问题严格来讲不是升级到Tomcat8出现的问题，而是升级到Tomcat9出现的问题。正好我开始尝试的是Tomcat9，无法解决这个问题才降到Tomcat8。所以这里一并记录下来。

    这个问题在从Tomcat6升级到Tomcat7之后也会存在，原因如下，在项目代码中对js的请求路径中包含了{、}等特殊符号：

<script type="text/javascript" src="${ctx}/js/common/include_css.js?{'ctx':'${ctx}','easyui':'easyui'}"></script>

    前台会发现加载js的时候报了404的错误，后台报错信息如下：

Invalid character found in the request target.The valid characters are defined in RFC 7230 and RFC3986

    出现这个问题的原因是因为Tomcat升级之后对安全进行了升级，其中就有对请求中的特殊字符进行校验，具体校验规则参照下面的代码：

(InternalInputBuffer、InternalAprInputBuffer、InternalNioInputBuffer)

/**
 * Read the request line. This function is meant to be used during the
 * HTTP request header parsing. Do NOT attempt to read the request body
 * using it.
 *
 * @throws IOException If an exception occurs during the underlying socket
 * read operations, or if the given buffer is not big enough to accommodate
 * the whole line.
 */
@Override
public boolean parseRequestLine(boolean useAvailableDataOnly)

    throws IOException {

    int start = 0;

    //
    // Skipping blank lines
    //

    byte chr = 0;
    do {

        // Read new bytes if needed
        if (pos >= lastValid) {
            if (!fill())
                throw new EOFException(sm.getString("iib.eof.error"));
        }
        // Set the start time once we start reading data (even if it is
        // just skipping blank lines)
        if (request.getStartTime() < 0) {
            request.setStartTime(System.currentTimeMillis());
        }
        chr = buf[pos++];
    } while ((chr == Constants.CR) || (chr == Constants.LF));

    pos--;

    // Mark the current buffer position
    start = pos;

    //
    // Reading the method name
    // Method name is a token
    //

    boolean space = false;

    while (!space) {

        // Read new bytes if needed
        if (pos >= lastValid) {
            if (!fill())
                throw new EOFException(sm.getString("iib.eof.error"));
        }

        // Spec says method name is a token followed by a single SP but
        // also be tolerant of multiple SP and/or HT.
        if (buf[pos] == Constants.SP || buf[pos] == Constants.HT) {
            space = true;
            request.method().setBytes(buf, start, pos - start);
        } else if (!HttpParser.isToken(buf[pos])) {
            throw new IllegalArgumentException(sm.getString("iib.invalidmethod"));
        }

        pos++;

    }

    // Spec says single SP but also be tolerant of multiple SP and/or HT
    while (space) {
        // Read new bytes if needed
        if (pos >= lastValid) {
            if (!fill())
                throw new EOFException(sm.getString("iib.eof.error"));
        }
        if (buf[pos] == Constants.SP || buf[pos] == Constants.HT) {
            pos++;
        } else {
            space = false;
        }
    }

    // Mark the current buffer position
    start = pos;
    int end = 0;
    int questionPos = -1;

    //
    // Reading the URI
    //

    boolean eol = false;

    while (!space) {

        // Read new bytes if needed
        if (pos >= lastValid) {
            if (!fill())
                throw new EOFException(sm.getString("iib.eof.error"));
        }

        // Spec says single SP but it also says be tolerant of HT
        if (buf[pos] == Constants.SP || buf[pos] == Constants.HT) {
            space = true;
            end = pos;
        } else if ((buf[pos] == Constants.CR)
                   || (buf[pos] == Constants.LF)) {
            // HTTP/0.9 style request
            eol = true;
            space = true;
            end = pos;
        } else if ((buf[pos] == Constants.QUESTION) && (questionPos == -1)) {
            questionPos = pos;
        } else if (HttpParser.isNotRequestTarget(buf[pos])) {
            throw new IllegalArgumentException(sm.getString("iib.invalidRequestTarget"));
        }

        pos++;

    }

    request.unparsedURI().setBytes(buf, start, end - start);
    if (questionPos >= 0) {
        request.queryString().setBytes(buf, questionPos + 1,
                                       end - questionPos - 1);
        request.requestURI().setBytes(buf, start, questionPos - start);
    } else {
        request.requestURI().setBytes(buf, start, end - start);
    }

    // Spec says single SP but also says be tolerant of multiple SP and/or HT
    while (space) {
        // Read new bytes if needed
        if (pos >= lastValid) {
            if (!fill())
                throw new EOFException(sm.getString("iib.eof.error"));
        }
        if (buf[pos] == Constants.SP || buf[pos] == Constants.HT) {
            pos++;
        } else {
            space = false;
        }
    }

    // Mark the current buffer position
    start = pos;
    end = 0;

    //
    // Reading the protocol
    // Protocol is always "HTTP/" DIGIT "." DIGIT
    //
    while (!eol) {

        // Read new bytes if needed
        if (pos >= lastValid) {
            if (!fill())
                throw new EOFException(sm.getString("iib.eof.error"));
        }

        if (buf[pos] == Constants.CR) {
            end = pos;
        } else if (buf[pos] == Constants.LF) {
            if (end == 0)
                end = pos;
            eol = true;
        } else if (!HttpParser.isHttpProtocol(buf[pos])) {
            // 关键点在这一句，如果校验不通过，则会报参数异常
            throw new IllegalArgumentException(sm.getString("iib.invalidHttpProtocol"));
        }

        pos++;

    }

    if ((end - start) > 0) {
        request.protocol().setBytes(buf, start, end - start);
    } else {
        request.protocol().setString("");
    }

    return true;

}

我们进一步跟进HttpParser中的方法：

public static boolean isNotRequestTarget(int c) {
    // Fast for valid request target characters, slower for some incorrect
    // ones
    try {
        // 关键在于这个数组
        return IS_NOT_REQUEST_TARGET[c];
    } catch (ArrayIndexOutOfBoundsException ex) {
        return true;
    }
}


// Combination of multiple rules from RFC7230 and RFC 3986. Must be
// ASCII, no controls plus a few additional characters excluded
if (IS_CONTROL[i] || i > 127 ||
        i == ' ' || i == '\"' || i == '#' || i == '<' || i == '>' || i == '\\' ||
        i == '^' || i == '`'  || i == '{' || i == '|' || i == '}') {
    // 可以看到只有在REQUEST_TARGET_ALLOW数组中的值才不会设置成true，所以我们需要追踪REQUEST_TARGET_ALLOW数组的赋值
    if (!REQUEST_TARGET_ALLOW[i]) {
        IS_NOT_REQUEST_TARGET[i] = true;
    }
}

String prop = System.getProperty("tomcat.util.http.parser.HttpParser.requestTargetAllow");
if (prop != null) {
    for (int i = 0; i < prop.length(); i++) {
        char c = prop.charAt(i);
        // 可以看到在配置文件中配置了tomcat.util.http.parser.HttpParser.requestTargetAllow并且包含{、}、|的时候，REQUEST_TARGET_ALLOW数组中的值才会为true
        if (c == '{' || c == '}' || c == '|') {
            REQUEST_TARGET_ALLOW[c] = true;
        } else {
            log.warn(sm.getString("httpparser.invalidRequestTargetCharacter",
                    Character.valueOf(c)));
        }
    }
}

    解决办法: 其实通过源码分析不难得到解决办法

当然需要注意的是，这个后门在Tomcat8.5以后就无法使用的，Tomcat9之后的解决办法暂时未找到，可能只有对URL进行编码了。

问题二：Cookie设置报错

     这个问题就是在升级到Tomcat8.5以上的时候会出现的，具体原因是Tomcat8.5采用的Cookie处理类是：

Rfc6265CookieProcessor,而在之前使用的处理类是LegacyCookieProcessor。该处理类对domai进行了校验：

private void validateDomain(String domain) {
    int i = 0;
    int prev = -1;
    int cur = -1;
    char[] chars = domain.toCharArray();
    while (i < chars.length) {
        prev = cur;
        cur = chars[i];
        if (!domainValid.get(cur)) {
            throw new IllegalArgumentException(sm.getString(
                    "rfc6265CookieProcessor.invalidDomain", domain));
        }
        // labels must start with a letter or number
        if ((prev == '.' || prev == -1) && (cur == '.' || cur == '-')) {
            throw new IllegalArgumentException(sm.getString(
                    "rfc6265CookieProcessor.invalidDomain", domain));
        }
        // labels must end with a letter or number
        if (prev == '-' && cur == '.') {
            throw new IllegalArgumentException(sm.getString(
                    "rfc6265CookieProcessor.invalidDomain", domain));
        }
        i++;
    }
    // domain must end with a label
    if (cur == '.' || cur == '-') {
        throw new IllegalArgumentException(sm.getString(
                "rfc6265CookieProcessor.invalidDomain", domain));
    }
}

新的Cookie规范对domain有以下要求

原来的代码设置domain时如下：

cookie.setDomain(".aaa.com");

这就导致设置domain的时候不符合新的规范，直接报错如下：

java.lang.IllegalArgumentException: An invalid domain [.aaa.com] was specified for this cookie
        at org.apache.tomcat.util.http.Rfc6265CookieProcessor.validateDomain(Rfc6265CookieProcessor.java:181)
        at org.apache.tomcat.util.http.Rfc6265CookieProcessor.generateHeader(Rfc6265CookieProcessor.java:123)
        at org.apache.catalina.connector.Response.generateCookieString(Response.java:989)
        at org.apache.catalina.connector.Response.addCookie(Response.java:937)
        at org.apache.catalina.connector.ResponseFacade.addCookie(ResponseFacade.java:386)

    解决办法(以下3中任意一种皆可)

  1. 修改原来代码为：

    cookie.setDomain("aaa.com");

  2. 如果是Spring-boot环境，直接替换默认的Cookie处理类：

    @Configuration
@ConditionalOnExpression("${tomcat.useLegacyCookieProcessor:false}")
public class LegacyCookieProcessorConfiguration {
    @Bean
    EmbeddedServletContainerCustomizer embeddedServletContainerCustomizerLegacyCookieProcessor() {
        return new EmbeddedServletContainerCustomizer() {
            @Override
            public void customize(ConfigurableEmbeddedServletContainer factory) {
                if (factory instanceof TomcatEmbeddedServletContainerFactory) {
                    TomcatEmbeddedServletContainerFactory tomcatFactory =
                            (TomcatEmbeddedServletContainerFactory) factory;
                    tomcatFactory.addContextCustomizers(new TomcatContextCustomizer() {
                        @Override
                        public void customize(Context context) {
                            context.setCookieProcessor(new LegacyCookieProcessor());
                        }
                    });
                }
            }
        };
    }
}

  3. 在Tomcat的context.xml中增加如下配置，指定Cookie的处理类：

    <CookieProcessor className="org.apache.tomcat.util.http.LegacyCookieProcessor" />

参考链接

02-28 20:02
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