/*
* Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package javax.net.ssl;
import java.util.Arrays;
/**
* Instances of this class represent a server name in a Server Name
* Indication (SNI) extension.
* <P>
* The SNI extension is a feature that extends the SSL/TLS/DTLS protocols to
* indicate what server name the client is attempting to connect to during
* handshaking. See section 3, "Server Name Indication", of <A
* HREF="http://www.ietf.org/rfc/rfc6066.txt">TLS Extensions (RFC 6066)</A>.
* <P>
* {@code SNIServerName} objects are immutable. Subclasses should not provide
* methods that can change the state of an instance once it has been created.
*
* @see SSLParameters#getServerNames()
* @see SSLParameters#setServerNames(List)
*
* @since 1.8
*/
public abstract class SNIServerName {
// the type of the server name
private final int type;
// the encoded value of the server name
private final byte[] encoded;
// the hex digitals
private static final char[] HEXES = "0123456789ABCDEF".toCharArray();
/**
* Creates an {@code SNIServerName} using the specified name type and
* encoded value.
* <P>
* Note that the {@code encoded} byte array is cloned to protect against
* subsequent modification.
*
* @param type
* the type of the server name
* @param encoded
* the encoded value of the server name
*
* @throws IllegalArgumentException if {@code type} is not in the range
* of 0 to 255, inclusive.
* @throws NullPointerException if {@code encoded} is null
*/
protected SNIServerName(int type, byte[] encoded) {
if (type < 0) {
throw new IllegalArgumentException(
"Server name type cannot be less than zero");
} else if (type > 255) {
throw new IllegalArgumentException(
"Server name type cannot be greater than 255");
}
this.type = type;
if (encoded == null) {
throw new NullPointerException(
"Server name encoded value cannot be null");
}
this.encoded = encoded.clone();
}
/**
* Returns the name type of this server name.
*
* @return the name type of this server name
*/
public final int getType() {
return type;
}
/**
* Returns a copy of the encoded server name value of this server name.
*
* @return a copy of the encoded server name value of this server name
*/
public final byte[] getEncoded() {
return encoded.clone();
}
/**
* Indicates whether some other object is "equal to" this server name.
*
* @return true if, and only if, {@code other} is of the same class
* of this object, and has the same name type and
* encoded value as this server name.
*/
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (this.getClass() != other.getClass()) {
return false;
}
SNIServerName that = (SNIServerName)other;
return (this.type == that.type) &&
Arrays.equals(this.encoded, that.encoded);
}
/**
* Returns a hash code value for this server name.
* <P>
* The hash code value is generated using the name type and encoded
* value of this server name.
*
* @return a hash code value for this server name.
*/
@Override
public int hashCode() {
int result = 17; // 17/31: prime number to decrease collisions
result = 31 * result + type;
result = 31 * result + Arrays.hashCode(encoded);
return result;
}
/**
* Returns a string representation of this server name, including the server
* name type and the encoded server name value in this
* {@code SNIServerName} object.
* <P>
* The exact details of the representation are unspecified and subject
* to change, but the following may be regarded as typical:
* <pre>
* "type={@literal <name type>}, value={@literal <name value>}"
* </pre>
* <P>
* In this class, the format of "{@literal <name type>}" is
* "[LITERAL] (INTEGER)", where the optional "LITERAL" is the literal
* name, and INTEGER is the integer value of the name type. The format
* of "{@literal <name value>}" is "XX:...:XX", where "XX" is the
* hexadecimal digit representation of a byte value. For example, a
* returned value of an pseudo server name may look like:
* <pre>
* "type=(31), value=77:77:77:2E:65:78:61:6D:70:6C:65:2E:63:6E"
* </pre>
* or
* <pre>
* "type=host_name (0), value=77:77:77:2E:65:78:61:6D:70:6C:65:2E:63:6E"
* </pre>
*
* <P>
* Please NOTE that the exact details of the representation are unspecified
* and subject to change, and subclasses may override the method with
* their own formats.
*
* @return a string representation of this server name
*/
@Override
public String toString() {
if (type == StandardConstants.SNI_HOST_NAME) {
return "type=host_name (0), value=" + toHexString(encoded);
} else {
return "type=(" + type + "), value=" + toHexString(encoded);
}
}
// convert byte array to hex string
private static String toHexString(byte[] bytes) {
if (bytes.length == 0) {
return "(empty)";
}
StringBuilder sb = new StringBuilder(bytes.length * 3 - 1);
boolean isInitial = true;
for (byte b : bytes) {
if (isInitial) {
isInitial = false;
} else {
sb.append(':');
}
int k = b & 0xFF;
sb.append(HEXES[k >>> 4]);
sb.append(HEXES[k & 0xF]);
}
return sb.toString();
}
}