Spring cloud gateway uri decoding failing

Question

I wrote a gateway application using Spring cloud Greenwich binaries. I'm seeing issues when special characters are present in URL. The request fails with below exception in Spring gateway when request URI contains special characters.

localhost:8080/myresource/WG_splchar_%26%5E%26%25%5E%26%23%25%24%5E%26%25%26*%25%2B)!%24%23%24%25%26%5E_new

When I hit above url, Spring fails with below exception. I'm not able to figure out why it's an invalid sequence and how things like these can be handled.

 java.lang.IllegalArgumentException: Invalid encoded sequence "%^&#%$^&%&*%+)!$#$%&^_new"
at org.springframework.util.StringUtils.uriDecode(StringUtils.java:741) ~[spring-core-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.http.server.DefaultPathContainer.parsePathSegment(DefaultPathContainer.java:126) ~[spring-web-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.http.server.DefaultPathContainer.createFromUrlPath(DefaultPathContainer.java:111) ~[spring-web-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.http.server.PathContainer.parsePath(PathContainer.java:76) ~[spring-web-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.cloud.gateway.handler.predicate.PathRoutePredicateFactory.lambda$apply$2(PathRoutePredicateFactory.java:79) ~[spring-cloud-gateway-core-2.1.0.RC3.jar:2.1.0.RC3]
at org.springframework.cloud.gateway.support.ServerWebExchangeUtils.lambda$toAsyncPredicate$1(ServerWebExchangeUtils.java:128) ~[spring-cloud-gateway-core-2.1.0.RC3.jar:2.1.0.RC3]
at org.springframework.cloud.gateway.handler.AsyncPredicate.lambda$and$1(AsyncPredicate.java:35) ~[spring-cloud-gateway-core-2.1.0.RC3.jar:2.1.0.RC3]
at org.springframework.cloud.gateway.handler.RoutePredicateHandlerMapping.lambda$null$2(RoutePredicateHandlerMapping.java:112) ~[spring-cloud-gateway-core-2.1.0.RC3.jar:2.1.0.RC3]
at reactor.core.publisher.MonoFilterWhen$MonoFilterWhenMain.onNext(MonoFilterWhen.java:116) [reactor-core-3.2.5.RELEASE.jar:3.2.5.RELEASE]
at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2070) [reactor-core-3.2.5.RELEASE.jar:3.2.5.RELEASE]
at reactor.core.publisher.MonoFilterWhen$MonoFilterWhenMain.onSubscribe(MonoFilterWhen.java:103) [reactor-core-3.2.5.RELEASE.jar:3.2.5.RELEASE]
at reactor.core.publisher.MonoJust.subscribe(MonoJust.java:54) [reactor-core-3.2.5.RELEASE.jar:3.2.5.RELEASE]
at reactor.core.publisher.MonoFilterWhen.subscribe(MonoFilterWhen.java:56) [reactor-core-3.2.5.RELEASE.jar:3.2.5.RELEASE]

Answer 1

I answered the other question already and don't feel like retyping. The spirit of the answer is the exact same.

Write a unit test exercising this method off of the Spring cloud utils. This is what's breaking. You can try passing in more or less of the string you're concerned about to find where the breakage is. Use a binary search to figure out what's broken. Make sure you don't split the string in the middle of an encoded character or else you'll give yourself a false positive. When it says you have an invalid sequence I would expect you have something like %99 where 99 is does not map to any valid character (I'm just making one up)

https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/util/StringUtils.html#uriDecode-java.lang.String-java.nio.charset.Charset-

As an aside

Where is this encoded string coming from? Did someone at your company create their own solution to encode this string to begin with? Are you accepting user data? It's VERY POSSIBLE that whomever is responsible for producing this string encoded it incorrectly by homerolling their own encoder.

ALTERNATIVELY

spring.cloud.gateway.routes[7].predicates[0]=Path=/test/{testId}/test1/test_%26%5E%26%25%5E%26%25%26*%25%2B)!

When I look at this I see a path that is already encoded. For example, you've taken your ampersand & character and replaced it with %26

Have you tried inputting a path that is NOT already encoded?

For example spring.cloud.gateway.routes[7].predicates[0]=Path=/test/{testId}/test1/test_&^&%^ < I only partially decoded it by hand using this chart. https://www.w3schools.com/tags/ref_urlencode.asp