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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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package sun.security.ssl;

import java.security.SecureRandom;
import java.util.Arrays;
import javax.net.ssl.SSLProtocolException;

Encapsulates an SSL session ID.  SSL Session IDs are not reused by
servers during the lifetime of any sessions it created.  Sessions may
be used by many connections, either concurrently (for example, two
connections to a web server at the same time) or sequentially (over as
long a time period as is allowed by a given server).
Author:
Satish Dharmaraj, David Brownell/**
 * Encapsulates an SSL session ID.  SSL Session IDs are not reused by
 * servers during the lifetime of any sessions it created.  Sessions may
 * be used by many connections, either concurrently (for example, two
 * connections to a web server at the same time) or sequentially (over as
 * long a time period as is allowed by a given server).
 *
 * @author Satish Dharmaraj
 * @author David Brownell
 */
final
class SessionId
{
    static int MAX_LENGTH = 32;
    private byte sessionId [];          // max 32 bytes

    
Constructs a new session ID ... perhaps for a rejoinable session /** Constructs a new session ID ... perhaps for a rejoinable session */
    SessionId (boolean isRejoinable, SecureRandom generator)
    {
        if (isRejoinable)
            // this will be unique, it's a timestamp plus much randomness
            sessionId = new RandomCookie (generator).random_bytes;
        else
            sessionId = new byte [0];
    }

    
Constructs a session ID from a byte array (max size 32 bytes) /** Constructs a session ID from a byte array (max size 32 bytes) */
    SessionId (byte sessionId [])
        { this.sessionId = sessionId; }

    
Returns the length of the ID, in bytes /** Returns the length of the ID, in bytes */
    int length ()
        { return sessionId.length; }

    
Returns the bytes in the ID.  May be an empty array.  /** Returns the bytes in the ID.  May be an empty array.  */
    byte [] getId ()
    {
        return sessionId.clone ();
    }

    
Returns the ID as a string /** Returns the ID as a string */
    public String toString ()
    {
        int             len = sessionId.length;
        StringBuffer    s = new StringBuffer (10 + 2 * len);

        s.append ("{");
        for (int i = 0; i < len; i++) {
            s.append (0x0ff & sessionId [i]);
            if (i != (len - 1))
                s.append (", ");
        }
        s.append ("}");
        return s.toString ();
    }


    
Returns a value which is the same for session IDs which are equal /** Returns a value which is the same for session IDs which are equal */
    public int hashCode ()
    {
        return Arrays.hashCode(sessionId);
    }

    
Returns true if the parameter is the same session ID /** Returns true if the parameter is the same session ID */
    public boolean equals (Object obj)
    {
        if (!(obj instanceof SessionId))
            return false;

        SessionId s = (SessionId) obj;
        byte b [] = s.getId ();

        if (b.length != sessionId.length)
            return false;
        for (int i = 0; i < sessionId.length; i++) {
            if (b [i] != sessionId [i])
                return false;
        }
        return true;
    }

    
Checks the length of the session ID to make sure it sits within
the range called out in the specification
/**
     * Checks the length of the session ID to make sure it sits within
     * the range called out in the specification
     */
    void checkLength(ProtocolVersion pv) throws SSLProtocolException {
        // As of today all versions of TLS have a 32-byte maximum length.
        // In the future we can do more here to support protocol versions
        // that may have longer max lengths.
        if (sessionId.length > MAX_LENGTH) {
            throw new SSLProtocolException("Invalid session ID length (" +
                    sessionId.length + " bytes)");
        }
    }

}