5 Services offered by the 5G PKMF

29.5593GPP5G ProSe Key Management Services5G SystemRelease 17Stage 3TS

5.1 Introduction

The table 5.1-1 shows the PKMF Services and PKMF Service Operations:

Table 5.1-1: List of 5G PKMF Services

Service Name	Service Operations	Operation Semantics	Example Consumer(s)
Npkmf_PKMFKeyRequest	ProseKey	Request/Response	PKMF

Table 5.1-2 summarizes the corresponding APIs defined for this specification.

Table 5.1-2: API Descriptions

Service Name	Clause	Description	OpenAPI Specification File	apiName	Annex
Npkmf_PKMFKeyRequest	6.1	PKMF Key Request Service	TS29559_Npkmf_PKMFKeyRequest.yaml	npkmf-keyrequest	A.2

5.2 Npkmf_PKMFKeyRequest Service

5.2.1 Service Description

This service enables an NF (i.e. another PKMF in another PLMN) to request information related to 5G ProSe keying. The following are the key functionalities of this NF service.

– Provide 5G ProSe related keying material

5.2.2 Service Operations

5.2.2.1 Introduction

5.2.2.2 ProseKey

5.2.2.2.1 General

The ProseKey service operation is invoked by a NF Service Consumer, i.e. another PKMF in another PLMN, towards the PKMF to retrieve the keying material related to 5G ProSe.

The ProseKey service operation is used during the following procedure:

– PC5 security establishment for 5G ProSe UE-to-Network relay communication over User Plane (see 3GPP TS 33.503 [4], clause 6.3.3.2.2)

The NF Service Consumer (i.e. another PKMF in another PLMN) shall retrieve the 5G ProSe related keying material by invoking the "request " custom method on the resource URI of "Prose Keys Collection" resource, see clause 6.1.3.2.4. See also Figure 5.2.2.2.1-1.

Figure 5.2.2.2.1-1 ProseKey service operation

1. The NF Service Consumer shall send a HTTP POST request to invoke "request" custom method. The payload of the request shall be an object of "ProseKeyReqData" data type. The payload shall include the Relay Service Code, the KNRP freshness parameter 1, and either the SUCI of the 5G ProSe Remote UE or the UP-PRUK ID.

2a. On success, the PKMF shall respond with the status code "200 OK". The payload of the response shall be an object of "ProseKeyRspData" data type. They payload shall include the KNRP, the KNRP freshness parameter 2 and optionally the GPI.

2b. On failure or redirection, one of the HTTP status codes listed in table 6.1.3.2.4.2.2-2 shall be returned. For a 4xx/5xx response, the message body shall contain a ProblemDetails structure with the "cause" attribute set to one of the application errors listed in table 6.1.3.2.4.2.2-2.

3. [conditional] If synchronization failed when UE processes the authentication challenge in the GPI and a subsequent Key Request is send for resynchronization, the NF Service Consumer shall send a HTTP POST request to invoke "request" custom method. The payload of the request shall be an object of "ProseKeyReqData" data type. The payload shall include the Relay Service Code, the KNRP freshness parameter 1, the information for resynchronization (RAND and AUTS).

4a. On success, the PKMF shall respond with the status code "200 OK". The payload of the response shall be an object of "ProseKeyRspData" data type. They payload shall include the KNRP, the KNRP freshness parameter 2 and the GPI.

4b. On failure or redirection, one of the HTTP status codes listed in table 6.1.3.2.4.2.2-2 shall be returned. For a 4xx/5xx response, the message body shall contain a ProblemDetails structure with the "cause" attribute set to one of the application errors listed in table 6.1.3.2.4.2.2-2.