UADP messages may be signed and encrypted. In this case the SecurityHeader and the Signature have to be added to the message. See clause 7.2.2.4.3 for a complete description of the security mechanisms.
This header layout is basically the same as the header layout defined in A.3.4 but with additional security level ‘Signing and encryption’. The NetworkMessage header layout with signing and encryption is shown in Figure A.9.
Figure A.9 – UADP NetworkMessage header layout with integrity and confidentiality
Table A.10 shows the configuration for the NetworkMessage header with signing and encryption. The table contains only the added or modified rows from Table A.7.
Table A.10 – UADP NetworkMessage header layout with integrity and confidentiality
|
Name |
Type |
Restrictions |
|
ExtendedFlags1 |
Byte |
Bit 4: SecurityHeader enabled = 1 |
|
SecurityHeader |
|
|
|
SecurityFlags |
Byte |
Bit 0: NetworkMessage Signed enabled = 1 Bit 1: NetworkMessage Encryption enabled = 1 Bit 2: SecurityFooter enabled = 0 Bit 3: Force key reset enabled = 0 Bit range 4-7: Reserved |
|
SecurityTokenId |
IntegerId |
The ID of the security token that identifies the security key in a SecurityGroup. |
|
NonceLength |
Byte |
The length of the Nonce used to initialize the encryption algorithm. |
|
MessageNonce |
Byte[NonceLength] |
A number used exactly once for a given security key. |