[HTTPCLIENT-1795] Http Client does not support RFC-compliant quoted IPv6 Link-Local host literals

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.5.2
• Fix Version/s: 5.3-alpha1
• Component/s: HttpClient (async)
• Labels: stuck volunteers-wanted
• Assignee: Unassigned
• Reporter: Andreas Wundsam
• Created: 08/Dec/16 18:16
• Updated: 26/Apr/23 07:21
• Resolved: 26/Apr/23 07:21

Description

RFC 6874 states that, when constructing a URL with an LLv6 literal, the % sign that prefixes the ZoneID must be quoted as %25. E.g., the LLv6 address
fe80::221:b7ff:fe8a:57d5%en4 should be specified as scheme://[fe80::221:b7ff:fe8a:57d5%25en4]/... in a URL.

httpclient does not seem to support quoted host literals:

Example:

        Request.Get("http://[fe80::221:b7ff:fe8a:57d5%25en4]/")
                .connectTimeout(1000)
                .socketTimeout(1000)
                .execute().returnContent().asString();

results in

java.net.UnknownHostException: no such interface 25en4

	at java.net.Inet6Address.initstr(Inet6Address.java:487)
	at java.net.Inet6Address.<init>(Inet6Address.java:408)
	at java.net.InetAddress.getAllByName(InetAddress.java:1181)
	at java.net.InetAddress.getAllByName(InetAddress.java:1126)
	at org.apache.http.impl.conn.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:45)
	at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:111)
	at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:353)
	at org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:380)
	at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:236)
	at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
	at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
	at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
	at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
	at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
	at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:55)
	at org.apache.http.client.fluent.Request.internalExecute(Request.java:173)
	at org.apache.http.client.fluent.Request.execute(Request.java:177)
	at Test.name(Test.java:12)
[...]

It appears that httpclient directly passes the host literal [fe80::221:b7ff:fe8a:57d5%25en4] to the Java standard method InetAddress.getAllByName(host), which does not support the URL quoting that RFC 6874 prescribes.