net.i2p.data.i2np

Class BuildResponseRecord

java.lang.Object

net.i2p.data.i2np.BuildResponseRecord

public class BuildResponseRecord
extends Object

Class that creates an encrypted tunnel build message record. The reply record is the same size as the request record (528 bytes). When decrypted:

 Bytes 0-31 contain the hash of bytes 32-527
 Bytes 32-526 contain random data.
 Byte 527 contains the reply.

Method Summary

Modifier and Type	Method and Description
static EncryptedBuildRecord	create(I2PAppContext ctx, int status, SessionKey replyKey, byte[] replyIV, long responseMessageId) Creates a new AES-encrypted response record.
static EncryptedBuildRecord	create(I2PAppContext ctx, int status, SessionKey replyKey, byte[] replyAD, Properties options) Creates a new ChaCha/Poly-encrypted response record (long format).
static ShortEncryptedBuildRecord	createShort(I2PAppContext ctx, int status, SessionKey replyKey, byte[] replyAD, Properties options, int slot) Creates a new ChaCha/Poly-encrypted response record (short format).
static boolean	decrypt(EncryptedBuildRecord rec, SessionKey key, byte[] ad) Decrypts a standard ChaCha/Poly-encrypted record.
static boolean	decrypt(EncryptedBuildRecord rec, SessionKey key, byte[] ad, int nonce) Decrypts a short ChaCha/Poly-encrypted record.

Methods inherited from class java.lang.Object

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

Method Detail

create

public static EncryptedBuildRecord create(I2PAppContext ctx,
                                          int status,
                                          SessionKey replyKey,
                                          byte[] replyIV,
                                          long responseMessageId)

Creates a new AES-encrypted response record. Create a new encrypted response. AES only for ElGamal routers.

Parameters:

ctx - the application context

status - the response 0-255

replyKey - the session key for reply encryption

replyIV - 16 bytes IV

responseMessageId - unused except for debugging

Returns:

a 528-byte response record

create

public static EncryptedBuildRecord create(I2PAppContext ctx,
                                          int status,
                                          SessionKey replyKey,
                                          byte[] replyAD,
                                          Properties options)

Creates a new ChaCha/Poly-encrypted response record (long format). Create a new encrypted response (long record). ChaCha/Poly only for ECIES routers.

Parameters:

ctx - the application context

status - the response 0-255

replyKey - the session key for reply encryption

replyAD - 32 bytes associated data

options - 511 bytes max when serialized

Returns:

a 528-byte response record

Throws:

IllegalArgumentException - if options too big or on encryption failure

createShort

public static ShortEncryptedBuildRecord createShort(I2PAppContext ctx,
                                                    int status,
                                                    SessionKey replyKey,
                                                    byte[] replyAD,
                                                    Properties options,
                                                    int slot)

Creates a new ChaCha/Poly-encrypted response record (short format). Create a new encrypted response (short record). ChaCha/Poly only for ECIES routers.

Parameters:

ctx - the application context

status - the response 0-255

replyKey - the session key for reply encryption

replyAD - 32 bytes associated data

options - 116 bytes max when serialized

slot - the slot number, 0-7

Returns:

a 218-byte response record

Throws:

IllegalArgumentException - if options too big or on encryption failure

decrypt

public static boolean decrypt(EncryptedBuildRecord rec,
                              SessionKey key,
                              byte[] ad)

Decrypts a standard ChaCha/Poly-encrypted record. ChaCha/Poly only for ECIES routers. Handles standard (528) byte records only. Decrypts in place. Status will be rec.getData()[511]. Properties will be at rec.getData()[0].

Parameters:

rec - 528 bytes, data will be decrypted in place

key - the session key for decryption

ad - non-null associated data (32 bytes)

Returns:

true on success, false on decryption failure

Throws:

IllegalArgumentException - if record length is incorrect

decrypt

public static boolean decrypt(EncryptedBuildRecord rec,
                              SessionKey key,
                              byte[] ad,
                              int nonce)

Decrypts a short ChaCha/Poly-encrypted record. ChaCha/Poly only for ECIES routers. Handles short (218) byte records only. Decrypts in place. Status will be rec.getData()[201]. Properties will be at rec.getData()[0].

Parameters:

rec - 218 bytes, data will be decrypted in place

key - the session key for decryption

ad - non-null associated data (32 bytes)

nonce - the slot number, 0-7

Returns:

true on success, false on decryption failure

Throws:

IllegalArgumentException - if record length or nonce is invalid