The GSS-API accommodates the concept of caller-provided channel * binding information. Channel bindings are used to strengthen the * quality with which peer entity authentication is provided during * context establishment. They enable the GSS-API callers to bind the * establishment of the security context to relevant characteristics * like addresses or to application specific data.
* *The caller initiating the security context must determine the * appropriate channel binding values to set in the {@link GSSContext} * object. The acceptor must provide an identical binding in order to * validate that received tokens possess correct channel-related * characteristics.
* *Use of channel bindings is optional in GSS-API. Since channel-binding * information may be transmitted in context establishment tokens, * applications should therefore not use confidential data as * channel-binding components.
*/ public class ChannelBinding { // Fields. // ------------------------------------------------------------------------- private final byte[] appData; private final InetAddress initAddr; private final InetAddress acceptAddr; // Constructor. // ------------------------------------------------------------------------- /** * Create a ChannelBinding object with user supplied address information * and data.null values can be used for any fields which the
* application does not want to specify.
*
* @param initAddr The address of the context initiator. null
* value can be supplied to indicate that the application
* does not want to set this value.
* @param acceptAddr The address of the context acceptor. null
* value can be supplied to indicate that the application
* does not want to set this value.
* @param appData Application supplied data to be used as part of the
* channel bindings. null value can be
* supplied to indicate that the application does not
* want to set this value.
*/
public ChannelBinding(InetAddress initAddr, InetAddress acceptAddr,
byte[] appData)
{
this.appData = (appData != null) ? (byte[]) appData.clone() : null;
this.initAddr = initAddr;
this.acceptAddr = acceptAddr;
}
/**
* Creates a ChannelBinding object without any addressing information.
*
* @param appData Application supplied data to be used as part of the
* channel bindings.
*/
public ChannelBinding(byte[] appData)
{
this(null, null, appData);
}
// Instance methods.
// -------------------------------------------------------------------------
/**
* Returns the initiator's address for this channel binding.
* null is returned if the address has not been set.
*
* @return The initiator's address, or null.
*/
public InetAddress getInitiatorAddress()
{
return initAddr;
}
/**
* Returns the acceptor's address for this channel binding.
* null is returned if the address has not been set.
*
* @return The acceptor's address, or null.
*/
public InetAddress getAcceptorAddress()
{
return acceptAddr;
}
/**
* Returns application data being used as part of the ChannelBinding.
* null is returned if no application data has been
* specified for the channel binding.
*
* @return The application data, or null.
*/
public byte[] getApplicationData()
{
if (appData != null)
return (byte[]) appData.clone();
return null;
}
/**
* Returns true if two channel bindings match.
*
* @param obj Another channel binding to compare with.
* @return True if this channel binding equals the other.
*/
public boolean equals(Object obj)
{
if (!(obj instanceof ChannelBinding))
return false;
ChannelBinding cb = (ChannelBinding) obj;
boolean b1 = Arrays.equals(appData, cb.appData);
boolean b2 = (initAddr == null && cb.initAddr == null)
|| (cb.initAddr != null && initAddr.equals(cb.initAddr));
boolean b3 = (acceptAddr == null && cb.acceptAddr == null)
|| (cb.acceptAddr != null && acceptAddr.equals(cb.acceptAddr));
return b1 && b2 && b3;
}
/**
* Returns the hash code for this channel binding.
*
* @return The hash code.
*/
public int hashCode()
{
int code = 0;
if (appData != null)
for (int i = 0; i < appData.length; i++)
code ^= appData[i] << ((8 * i) & 31);
if (initAddr != null)
code ^= initAddr.hashCode();
if (acceptAddr != null)
code ^= acceptAddr.hashCode();
return code;
}
}