jvmMain.okhttp3.internal.-HostnamesJvm.kt Maven / Gradle / Ivy
/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package okhttp3.internal
import java.net.IDN
import java.net.InetAddress
import java.util.Locale
/**
* If this is an IP address, this returns the IP address in canonical form.
*
* Otherwise this performs IDN ToASCII encoding and canonicalize the result to lowercase. For
* example this converts `☃.net` to `xn--n3h.net`, and `WwW.GoOgLe.cOm` to `www.google.com`.
* `null` will be returned if the host cannot be ToASCII encoded or if the result contains
* unsupported ASCII characters.
*/
fun String.toCanonicalHost(): String? {
val host: String = this
// If the input contains a :, it’s an IPv6 address.
if (":" in host) {
// If the input is encased in square braces "[...]", drop 'em.
val inetAddressByteArray = (if (host.startsWith("[") && host.endsWith("]")) {
decodeIpv6(host, 1, host.length - 1)
} else {
decodeIpv6(host, 0, host.length)
}) ?: return null
val inetAddress = InetAddress.getByAddress(inetAddressByteArray)
val address = inetAddress.address
if (address.size == 16) return inet6AddressToAscii(address)
if (address.size == 4) return inetAddress.hostAddress // An IPv4-mapped IPv6 address.
throw AssertionError("Invalid IPv6 address: '$host'")
}
try {
val result = IDN.toASCII(host).lowercase(Locale.US)
if (result.isEmpty()) return null
return if (result.containsInvalidHostnameAsciiCodes()) {
// The IDN ToASCII result contains illegal characters.
null
} else if (result.containsInvalidLabelLengths()) {
// The IDN ToASCII result contains invalid labels.
null
} else {
result
}
} catch (_: IllegalArgumentException) {
return null
}
}