Service-oriented architecture in a vehicle

1. A computer comprising a processor and a memory storing instructions executable by the processor to:

generate a symmetric key upon starting of a vehicle including a first node of a plurality of nodes on a wired vehicle communications network;

receive a request to publish or subscribe to a first message topic of a plurality of message topics from the first node via the wired vehicle communications network, wherein at least one of the nodes is a publisher of the first message topic that publishes messages about the first message topic over the wired vehicle communications network, at least one of the nodes is a subscriber of the first message topic that receives the messages about the first message topic, and the message topics are categories of data;

authenticate the first node using the request;

authorize the first node by verifying that the node is on a first permission list for the first message topic, the message topics having respective permission lists; and

upon authenticating and authorizing the node, transmit the symmetric key to the node, wherein the symmetric key is usable to encrypt or decrypt messages about the message topic.

2. The computer of claim 1 , wherein the instructions include instructions to receive a sample message from the first node encrypted with the symmetric key, decrypt the sample message, and retransmit the symmetric key to the first node upon determining that the decrypted sample message does not match a stored sample message.

3. The computer of claim 1 , wherein authenticating the first node includes applying public key cryptography to the request.

4. The computer of claim 3 , wherein the public key cryptography is a digital signature for which the request is encrypted with a node private key, and authenticating the first node includes decrypting the request with a node public key paired with the node private key.

5. The computer of claim 4 , wherein the instructions include instructions to encrypt the symmetric key with the node public key before transmitting the symmetric key to the first node.

6. The computer of claim 1 , wherein the instructions include instructions to generate a plurality of symmetric keys including the symmetric key for the respective message topics including the first message topic.

7. The computer of claim 1 , wherein the request is a request to publish the first message topic, and the symmetric key is usable to encrypt messages about the first message topic.

8. The computer of claim 7 , wherein the first node is a publisher node, the symmetric key is a first symmetric key, and the instructions include instructions to:

receive a request to subscribe to the first message topic from a subscriber node on the wired vehicle communications network via the wired vehicle communications network;

authenticate the subscriber node using the request to subscribe;

authorize the subscriber node by verifying that the subscriber node is on the first permission list; and

upon authenticating and authorizing the subscriber node, transmit a second symmetric key paired with the first symmetric key to the subscriber node, wherein the second symmetric key is usable to decrypt messages about the first message topic.

9. The computer of claim 1 , wherein the symmetric key is not usable to encrypt or decrypt messages about the message topics besides the first message topic.

10. The computer of claim 1 , wherein the instructions further include instructions to, in response to the vehicle being turned off, delete the symmetric key.

11. A vehicle system comprising:

a manager module;

a node; and

a wired vehicle communications network connecting the node and the manager module;

wherein the manager module is programmed to:

receive a request to publish or subscribe to a first message topic of a plurality of message topics from a first node of the nodes, wherein at least one of the nodes is a publisher of the first message topic that publishes messages about the first message topic over the wired vehicle communications network, at least one of the nodes is a subscriber of the first message topic that receives the messages about the first message topic, and the message topics are categories of data;

authenticate the first node using the request;

authorize the first node by verifying that the first node is on a first permission list for the first message topic, the message topics having respective permission lists;

upon authenticating and authorizing the first node, transmit a symmetric key to the node;

in response to a vehicle including the manager module and first node being turned off, delete the symmetric key; and

the first node is programmed to encrypt or decrypt messages about the message topic using the symmetric key.

12. The vehicle system of claim 11 , further comprising a hardware security module physically connected to the manager module, wherein the first permission list is stored on the hardware security module.

13. The vehicle system of claim 11 , wherein the first node is storing a node private key, and the first node is programmed to encrypt the request with the node private key and then transmit the request to the manager module.

14. The vehicle system of claim 13 , further comprising a hardware security module physically connected to the manager module, wherein authenticating the first node includes decrypting the request with a node public key paired with the node private key, and the node public key is stored on the hardware security module.

15. The vehicle system of claim 11 , wherein the first node is a publisher node, the request is a request to publish the message topic, and the symmetric key is usable to encrypt message about the message topic.

16. The vehicle system of claim 15 , further comprising a subscriber node connected to the manager module and the publisher node via the wired vehicle communications network.

17. A method comprising:

generating a symmetric key by a manager module upon starting of a vehicle including a first node of a plurality of nodes on a wired vehicle communications network;

transmitting a request to publish or subscribe to a first message topic of a plurality of message topics by the first node to the manager module in the vehicle, wherein at least one of the nodes is a publisher of the first message topic that publishes messages about the first message topic over the wired vehicle communications network, at least one of the nodes is a subscriber of the first message topic that receives the messages about the first message topic, and the message topics are categories of data;

authenticating the first node using the request by the manager module;

authorizing the first node by verifying that the first node is on a first permission list for the first message topic by the manager module, the message topics having respective permission lists;

upon authenticating and authorizing the first node, transmitting the symmetric key to the node by the manager module; and

encrypting or decrypting messages about the message topic using the symmetric key by the first node.

18. The method of claim 17 , further comprising, upon receiving the symmetric key, encrypting a sample message with the symmetric key by the first node, and transmitting the encrypted sample message by the node to the manager module.