Key update method, network device, system, and storage medium

A key update method, applied to a Bluetooth mesh network comprising at least two mesh nodes, wherein a configuration node is a mesh node in the Bluetooth mesh network, wherein the configuration node configures a network key of the Bluetooth mesh network, wherein a first mesh node is any mesh node of the at least two mesh nodes other than the configuration node, wherein the first mesh node is a mesh node outside a key update blacklist and that fails to send a first notification in a key refresh procedure, and the method comprises:

• sending, by the first mesh node, a fourth message to a second mesh node based on the first mesh node switching from a sleep state to an awake state,
• wherein the second mesh node has established a friend relationship with the first mesh node,
• wherein the second mesh node is configured to temporarily store a message for the first mesh node when the first mesh node is in the sleep state, and
• wherein the fourth message requests obtaining the message temporarily stored by the second mesh node for the first mesh node;
• broadcasting, by the first mesh node, a fifth message for requesting to establish a friend relationship,
• wherein broadcasting the fifth message is based on a quantity of times of sending the fourth message reaching a preset first threshold and a feedback message from the second mesh node is never received;
• sending, by the first mesh node, a second message to the configuration node,
• wherein sending the second message is based on a quantity of times of sending the fifth message reaching a preset second threshold and a feedback message from another mesh node is never received, and
• wherein the second message is used to request to synchronize the network key;
• receiving, by the first mesh node, a first message from the configuration node,
• wherein the first message carries a first ciphertext obtained by encrypting a second network key of the Bluetooth mesh network by using a device key of the first mesh node, and
• wherein a first network key locally maintained by the first mesh node is inconsistent with the second network key;
• decrypting, by the first mesh node, the first ciphertext by using a device key of the second network key to obtain the second network key;
• and
• updating, by the first mesh node, the first network key to the second network key.

A device comprising at least one processor and a memory, wherein the memory stores computer-executable instructions, and wherein the at least one processor executes the computer-executable instructions to cause the device to perform at least the following operation:

• determining a first mesh node from at least two mesh nodes in a Bluetooth mesh network comprising the at least two mesh nodes,
• wherein the device is a mesh node in the Bluetooth mesh network,
• wherein the device configures a network key of the Bluetooth mesh network,
• wherein a first network key locally maintained by the first mesh node is inconsistent with a second network key of the Bluetooth mesh network, and
• wherein determining the first mesh node includes either
• receiving a second message used to request to synchronize the network key and determining a mesh node indicated by a requester identifier carried in the second message as the first mesh node based on the mesh node indicated by the requester identifier not being a deleted node, or
• determining each long power supply node in an update failure list as the first mesh node, wherein the update failure list is records all mesh nodes that fail to update a key and are not deleted nodes in the Bluetooth mesh network, and the long power supply node is a mesh node other than a low power node in the Bluetooth mesh network;
• encrypting the second network key by using a device key of the first mesh node to obtain a first ciphertext;
• and
• sending a first message so that the first mesh node obtains the second network key, wherein the first message carries the first ciphertext.