Encode control characters in URIUtil.encodePath

[boughtonp]

Jetty version(s)
9.4.43 and 10.0.1

Description
Runing Jetty with DefaultServlet, http://localhost/%0A returns a 404 - as expected.

However, when using BalancerServlet, the same request URL causes a 500 error. Same goes for anything from %01 to %1F (i.e. encoded control characters).

By simplifying to a minimal example, it turns out the issue does not occur without the rewrite module enabled.
More specifically, it still doesn't occur if only a RewriteHandler has been added, but adding a VirtualHostRuleContainer triggers it, whether or not there are rules within that container.

Based on the exception, something is decoding the request URL before it is being passed to a URI.create() call, but given that http://localhost/%20 does NOT trigger the error, it's also being partially re-encoded (otherwise URI.create would complain about the space character, which it doesn't).

So, looking at the code, the bug will most likely be in URIUtil.encodePath - perhaps the (c < 0) should be a (c < 20) or (c < 32 ) ? (either way, looks to me like that function could be cleaned up).

There may also be a secondary issue - is RuleContainer.apply being called when it doesn't need to be?
(if the container is either empty, or the virtualhosts don't match the current request, it should be a no-op?)

How to reproduce?
Bash script demonstrating the issue:

JETTY_HOME=/path/to/jetty-home-9.4.43.v20210629
JETTY_BASE=test-badurl

mkdir -p "$JETTY_BASE"/{webapps,modules,etc}
sed 's!etc/jetty-proxy.xml!#&!' "$JETTY_HOME/modules/proxy.mod" > "$JETTY_BASE/modules/rproxy.mod"

echo '<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN" "http://www.eclipse.org/jetty/configure.dtd">
<Configure class="org.eclipse.jetty.servlet.ServletContextHandler">
 <Call name="addServlet">
  <Arg>org.eclipse.jetty.proxy.BalancerServlet</Arg>
  <Arg>/*</Arg>
  <Call name="setInitParameter">
   <Arg>balancerMember.localhost_8123.proxyTo</Arg>
   <Arg>http://localhost:8123/</Arg>
  </Call>
 </Call>
</Configure>' > "$JETTY_BASE/webapps/ROOT.xml"

echo '<?xml version="1.0"?>
<!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN" "http://www.eclipse.org/jetty/configure_9_0.dtd">
<Configure id="Server" class="org.eclipse.jetty.server.Server">
 <Call name="insertHandler">
  <Arg>
   <New class="org.eclipse.jetty.rewrite.handler.RewriteHandler">
    <Set name="originalPathAttribute">requestedPath</Set>
    <Set name="rewriteRequestURI">true</Set>
    <Set name="rules">
     <Array type="org.eclipse.jetty.rewrite.handler.Rule">
      <Item>
       <New class="org.eclipse.jetty.rewrite.handler.VirtualHostRuleContainer">
       </New>
      </Item>
     </Array>
    </Set>
   </New>
  </Arg>
 </Call>
</Configure>' > "$JETTY_BASE/etc/jetty-rewrite.xml"

cd "$JETTY_BASE"
java -jar $JETTY_HOME/start.jar --add-to-start=http,deploy,rproxy,rewrite

java -jar $JETTY_HOME/start.jar &

curl -isS 'http://localhost:8080/%0A'

Related exception:

2021-09-19 21:31:30.505:WARN:oejs.HttpChannel:qtp5592464-19: /|
java.lang.IllegalArgumentException: Illegal character in path at index 24: http://localhost:8123///|
        at java.net.URI.create(Unknown Source)
        at org.eclipse.jetty.proxy.BalancerServlet.rewriteTarget(BalancerServlet.java:142)
        at org.eclipse.jetty.proxy.ProxyServlet.service(ProxyServlet.java:61)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
        at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:799)
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:550)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1434)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:501)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1349)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:191)
        at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:146)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
        at org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:322)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
        at org.eclipse.jetty.server.Server.handle(Server.java:516)
        at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:388)
        at org.eclipse.jetty.server.HttpChannel$$Lambda$87/1776338520.dispatch(Unknown Source)
        at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:633)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:380)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277)
        at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
        at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
        at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034)
        at java.lang.Thread.run(Unknown Source)
Caused by:
java.net.URISyntaxException: Illegal character in path at index 24: http://localhost:8123///|
        at java.net.URI$Parser.fail(Unknown Source)
        at java.net.URI$Parser.checkChars(Unknown Source)
        at java.net.URI$Parser.parseHierarchical(Unknown Source)
        at java.net.URI$Parser.parse(Unknown Source)
        at java.net.URI.<init>(Unknown Source)
        at java.net.URI.create(Unknown Source)
        at org.eclipse.jetty.proxy.BalancerServlet.rewriteTarget(BalancerServlet.java:142)
        at org.eclipse.jetty.proxy.ProxyServlet.service(ProxyServlet.java:61)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
        at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:799)
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:550)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1434)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:501)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1349)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:191)
        at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:146)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
        at org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:322)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
        at org.eclipse.jetty.server.Server.handle(Server.java:516)
        at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:388)
        at org.eclipse.jetty.server.HttpChannel$$Lambda$87/1776338520.dispatch(Unknown Source)
        at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:633)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:380)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277)
        at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
        at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
        at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034)
        at java.lang.Thread.run(Unknown Source)

/end

[joakime]

This is merged for 9.4.x
What about 10.0.x?

[gregw]

Doh! created branch but forgot to push....