Package io.github.mahmoudimus.quic.crypto

Class RetryIntegrity

java.lang.Object

io.github.mahmoudimus.quic.crypto.RetryIntegrity

public final class RetryIntegrity
extends Object

The Retry Integrity Tag (RFC 9001 section 5.8, RFC 9369 section 3.3.3): AES-128-GCM with a fixed per-version key and nonce over the Retry pseudo-packet, which is the original Destination Connection ID (with its length byte) followed by the Retry packet without its tag.

All methods are static and thread-safe; each call makes its own Cipher.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	TAG_LENGTH	The tag length in bytes.

Method Summary

Modifier and Type	Method	Description
static byte[]	tag(QuicVersion version, ConnectionId originalDestinationId, byte[] packet, int offset, int length)	Computes the tag of a Retry packet held in an array.
static byte[]	tag(QuicVersion version, ConnectionId originalDestinationId, ByteBuffer retryWithoutTag)	Computes the tag of a Retry packet.
static boolean	verify(QuicVersion version, ConnectionId originalDestinationId, ByteBuffer retryPacket)	Checks the tag at the end of a received Retry packet, in constant time.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

TAG_LENGTH

public static final int TAG_LENGTH

The tag length in bytes.

See Also:

• Constant Field Values

Method Details

tag

public static byte[] tag(QuicVersion version,
 ConnectionId originalDestinationId,
 ByteBuffer retryWithoutTag)

Computes the tag of a Retry packet.

Parameters:

version - the version of the Retry packet

originalDestinationId - the Destination Connection ID of the client's Initial

retryWithoutTag - the Retry packet up to its tag, between position and limit; the buffer is not changed

Returns:

the 16-byte tag

tag

public static byte[] tag(QuicVersion version,
 ConnectionId originalDestinationId,
 byte[] packet,
 int offset,
 int length)

Computes the tag of a Retry packet held in an array.

Parameters:

version - the version of the Retry packet

originalDestinationId - the Destination Connection ID of the client's Initial

packet - the array

offset - the first byte of the Retry packet

length - the length of the Retry packet without its tag

Returns:

the 16-byte tag

verify

public static boolean verify(QuicVersion version,
 ConnectionId originalDestinationId,
 ByteBuffer retryPacket)

Checks the tag at the end of a received Retry packet, in constant time.

Parameters:

version - the version of the Retry packet

originalDestinationId - the Destination Connection ID the client sent in its Initial

retryPacket - the whole Retry packet, tag included, between position and limit; the buffer is not changed

Returns:

true if the tag is valid