io.github.intisy.gradle.github.impl.download

Class RedirectPolicyInterceptor

java.lang.Object

io.github.intisy.gradle.github.impl.download.RedirectPolicyInterceptor

All Implemented Interfaces:

okhttp3.Interceptor

public final class RedirectPolicyInterceptor
extends java.lang.Object
implements okhttp3.Interceptor

Follows a redirect with a policy OkHttp's own on/off followRedirects cannot express: a same-host redirect keeps the caller's headers (same origin, nothing leaks); a cross-host redirect is still followed, but the caller's headers are stripped first, which is exactly what makes a presigned-URL redirect from a private Nexus/Artifactory/S3-backed host work, since the new URL carries its own authorization; an https-to-http redirect is never followed at all, so a header can never be forwarded to the target in cleartext by way of a downgrade.

Implementation Note:

Requires the OkHttpClient this is installed on to have followRedirects(false) set, so OkHttp's own redirect-following interceptor never intercepts a 3xx before this one gets to decide; this class does its own following by re-invoking Interceptor.Chain#proceed, the documented pattern for custom redirect handling.

Nested Class Summary

Nested classes/interfaces inherited from interface okhttp3.Interceptor

okhttp3.Interceptor.Chain, okhttp3.Interceptor.Companion

Field Summary

Fields inherited from interface okhttp3.Interceptor

Companion

Constructor Summary

Constructors

Constructor and Description
RedirectPolicyInterceptor()

Method Summary

Modifier and Type	Method and Description
okhttp3.Response	intercept(okhttp3.Interceptor.Chain chain)
static boolean	isCrossHost(okhttp3.HttpUrl from, okhttp3.HttpUrl to)
static boolean	isHttpsToHttpDowngrade(okhttp3.HttpUrl from, okhttp3.HttpUrl to)
static boolean	isRedirect(okhttp3.Response response)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RedirectPolicyInterceptor

public RedirectPolicyInterceptor()

Method Detail

intercept

public okhttp3.Response intercept(okhttp3.Interceptor.Chain chain)
                           throws java.io.IOException

Specified by:

intercept in interface okhttp3.Interceptor

Throws:

java.io.IOException

isRedirect

public static boolean isRedirect(okhttp3.Response response)

Parameters:

response - the response to inspect.

Returns:

true if response is a redirect status carrying a Location header.

isHttpsToHttpDowngrade

public static boolean isHttpsToHttpDowngrade(okhttp3.HttpUrl from,
                                             okhttp3.HttpUrl to)

Parameters:

from - the URL being redirected from.

to - the URL being redirected to.

Returns:

true if following the redirect from from to to would downgrade https to http.

isCrossHost

public static boolean isCrossHost(okhttp3.HttpUrl from,
                                  okhttp3.HttpUrl to)

Parameters:

from - the URL being redirected from.

to - the URL being redirected to.

Returns:

true if to has a different host (case-insensitively) or a different port than from. A different port on the same hostname is still a different origin: the caller's headers must not survive a redirect to another port any more than to another host.