iaik.security.ssl

Class NamedGroup

java.lang.Object

iaik.security.ssl.NamedGroup

All Implemented Interfaces:

java.lang.Cloneable

Direct Known Subclasses:

SupportedEllipticCurves.NamedCurve, SupportedGroups.KemGroup, SupportedGroups.NamedFFDHEGroup

public class NamedGroup
extends java.lang.Object
implements java.lang.Cloneable

This class implements the NamedGroup element of the SupportedGroups (supported_groups) TLS extension as specified by RFC 7919, RFC 8446.

The SupportedGroups (supported_groups) extension replaces the SupportedEllipticCurves (elliptic_curves) extension to extend it about support for finite field based Diffie-Hellman (DH) key exchange. Although the [@link SupportedEllipticCurves SupportedEllipticCurves} class can still be used for backwards compatibility to former iSaSiLk versions it is recommended to use this SupportedGroups implementation instead of it.

A SupportedGroups extension might be sent by the client within an extended ClientHello message to tell the server which groups are supported by the client when using an ECDHE or DHE based cipher suite. The server uses the information sent by the client to select an ECC/DHE cipher suite in accordance with the ECDHE/FFDHE groups supported by the client. The server itself generally does not send a SupportedGroups extension.
TLS defines the SupportedGroups extension as list of named groups (see RFC 7919):

 enum {

      Elliptic Curve Groups (ECDHE) 
      secp256r1(0x0017), secp384r1(0x0018), secp521r1(0x0019),
      x25519(0x001D), x448(0x001E),

      // Finite Field Groups (DHE) 
      ffdhe2048(0x0100), ffdhe3072(0x0101), ffdhe4096(0x0102),
      ffdhe6144(0x0103), ffdhe8192(0x0104),

      // Reserved Code Points 
      ffdhe_private_use(0x01FC..0x01FF),
      ecdhe_private_use(0xFE00..0xFEFF),
      (0xFFFF)
 } NamedGroup;

 struct {
     NamedGroup named_group_list<2..2^16-1>;
 } NamedGroupList;
 

The client shall send the list of supported groups in its preference order.

In addition to the elliptic groups listed above, iSaSiLk supports the following Brainpool groups from RFC 7027:

      enum {
           brainpoolP256r1(26),
           brainpoolP384r1(27),
           brainpoolP512r1(28)
      } NamedGroup;
 

iSaSiLk also supports the following hybrid groups combining a classical (ECC) and a PQ (ML-KEM) key exchange algorithm to protect key establishment in transition to post quantum cryptography (see Post-quantum hybrid ECDHE-MLKEM Key Agreement for TLSv1.3 and Hybrid key exchange in TLS 1.3:

      enum {
           SecP256r1MLKEM768(0x11EB),
           X25519MLKEM768(0x11EC)
      } NamedGroup;
 

See Also:

SupportedGroups

Constructor Summary

Constructors

Constructor and Description
NamedGroup(java.lang.String name, int id) Creates a group with the given name, oid string and id.

Method Summary

Modifier and Type	Method and Description
java.lang.Object	clone() Gets a clone of this NamedGroup object.
boolean	equals(java.lang.Object obj) Checks if this NamedGroup is equal to the given object.
int	getID() Gets the TLS id of this group.
java.lang.String	getName() Gets the name of the group.
int	hashCode() Gets a hash code of this NamedGroup object.
java.lang.String	toString() Gets a String representation of this NamedGroup.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

NamedGroup

public NamedGroup(java.lang.String name,
                  int id)

Creates a group with the given name, oid string and id.

Parameters:

name - the name of the group

id - the TLS id of the group

Throws:

java.lang.IllegalArgumentException - if the given TLS id is out-of-range (not between 1 and 2¹⁶-1); or name is null

Method Detail

getName

public java.lang.String getName()

Gets the name of the group.

Returns:

the name of the group (or "UNKNOWN" if the name is not known)

getID

public int getID()

Gets the TLS id of this group.

Returns:

the TLS id of this group

hashCode

public int hashCode()

Gets a hash code of this NamedGroup object.

Overrides:

hashCode in class java.lang.Object

Returns:

a hash code of this NamedGroup object.

equals

public boolean equals(java.lang.Object obj)

Checks if this NamedGroup is equal to the given object.

Overrides:

equals in class java.lang.Object

Returns:

true if this NamedGroup is equal to the given object (same group id), false if it is not equal to it

clone

public java.lang.Object clone()

Gets a clone of this NamedGroup object.

Overrides:

clone in class java.lang.Object

Returns:

a clone of this NamedGroup object

toString

public java.lang.String toString()

Gets a String representation of this NamedGroup.

Overrides:

toString in class java.lang.Object