ETSI TS 133 179 V13.10.0 (2020-01)

ETSI TS 133 179 V13.10.0 (2020-01)






TECHNICAL SPECIFICATION
LTE;
Security of Mission Critical Push To Talk (MCPTT) over LTE
(3GPP TS 33.179 version 13.10.0 Release 13)

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3GPP TS 33.179 version 13.10.0 Release 13 1 ETSI TS 133 179 V13.10.0 (2020-01)



Reference
RTS/TSGS-0333179vda0
Keywords
LTE,SECURITY
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3GPP TS 33.179 version 13.10.0 Release 13 2 ETSI TS 133 179 V13.10.0 (2020-01)
Intellectual Property Rights
Essential patents
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ETSI

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3GPP TS 33.179 version 13.10.0 Release 13 3 ETSI TS 133 179 V13.10.0 (2020-01)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 7
1 Scope . 8
2 References . 8
3 Definitions and abbreviations . 10
3.1 Definitions . 10
3.2 Abbreviations . 10
4 Overview of MCPTT security . 10
4.1 General . 10
4.2 Signalling plane security architecture. 11
4.3 Application plane security architecture . 11
4.3.1 General . 11
4.3.2 User authentication and authorisation . 12
4.3.3 Identity keying of users and services . 12
4.3.4 Protection of application plane signalling . 13
4.3.5 Media security . 14
4.3.5.1 General . 14
4.3.5.2 Media security for group communications. . 14
4.3.5.3 Media security for private calls . 15
5 Authentication and authorization . 16
5.1 General . 16
5.2 LTE access authentication and security mechanism. 17
5.3 Authentication for SIP core access . 17
5.4 Authentication for HTTP-1 . 17
5.5 User authentication . 17
5.5.1 Identity management functional model . 17
5.5.2 User authentication framework . 19
5.5.3 OpenID Connect (OIDC) . 19
5.5.3.1 General . 19
5.5.3.2 User authentication example using Username/Password . 21
5.6 MCPTT user authorization . 21
5.6.1 General . 21
5.6.2 MCPTT user service authorization with MCPTT Server. 23
5.6.2.0 General . 23
5.6.2.1 Using SIP REGISTER . 23
5.6.2.2 Using SIP PUBLISH . 24
6 Signalling plane protection . 25
6.1 SIP-1 interface security . 25
6.2 HTTP-1 interface security . 25
7 End-to-end communication security . 25
7.1 Overview . 25
7.2 Key provisioning and management . 26
7.2.1 General . 26
7.2.2 Functional model for key management . 26
7.2.2.0 General . 26
7.2.2.1 Reference point CSC-8 (between key management server and the key management client within
the MCPTT UE) . 27
7.2.2.2 Reference point CSC-9 (between the key management server and the key management client
within the MCPTT Server) . 27
ETSI

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3GPP TS 33.179 version 13.10.0 Release 13 4 ETSI TS 133 179 V13.10.0 (2020-01)
7.2.2.3 Reference point CSC-10 (between the key management server and the key management client
within a group management server) . 27
7.2.3 Security procedures for key management . 27
7.2.4 Provisioned key material to support end-to-end communication security . 29
7.3 Group call key distribution . 29
7.3.1 General . 29
7.3.2 Security procedures for GMK provisioning . 31
7.3.3 Key Identification and purpose tags. 32
7.3.4 Group creation procedure . 32
7.3.5 Dynamic group keying . 33
7.3.5.1 General . 33
7.3.5.2 Group regrouping procedures (within a single MCPTT system) . 33
7.3.5.3 Group regrouping procedures (involving multiple MCPTT systems) . 33
7.3.6 Derivation of SRTP/SRTCP master keys . 34
7.3.7 Group member GMK management . 35
7.4 Private call key distribution . 35
7.4.1 General . 35
7.4.2 Security procedures (on-network) . 37
7.4.3 Security procedures (off-network) . 38
7.4.4 Derivation of SRTP/SRTCP master keys . 39
7.4.5 Void . 40
7.5 Protection of media stream (SRTP) . 40
7.5.1 General . 40
7.5.2 Security procedures for media stream protection. 41
7.6 Protection of offline floor and media control signalling (SRTCP) . 42
7.6.1 General . 42
7.6.2 Security procedures for offline floor and media control protection . 43
7.7 Protection of MBMS subchannel control messages (SRTCP) . 44
7.7.1 General . 44
7.7.2 Key distribution . 44
7.7.3 Derivation of SRTCP master keys . 45
8 Inter/Intra domain interface security . 46
8.1 General . 46
9 Protection of floor control and sensitive application signalling . 46
9.1 Key agreement for protection of floor control and sensitive application data (Client to Server) . 46
9.1.1 Identity-based key management for Client Server Key (CSK) . 46
9.1.2 Creation of the CSK . 47
9.1.3 Secure distribution of the CSK . 47
9.1.3.0 General . 47
9.1.3.1 MIKEY-SAKKE I_MESSAGE . 47
9.1.3.2 Distribution of CSK during MCPTT Service Authorization and group subscription . 48
9.1.3.3 Obtaining CSK from the I_MESSAGE. 48
9.1.3.4 Procedure . 48
9.2 Key agreement for protection of floor control and sensitive application data between servers . 49
9.3 Protection of XML content . 50
9.3.1 General . 50
9.3.2 Protected content . 50
9.3.3 Key agreement . 51
9.3.4 Confidentiality protection using XML encryption (xmlenc) . 51
9.3.4.1 General . 51
9.3.4.2 XML content encryption . 51
9.3.4.3 XML URI attribute encryption . 52
9.3.5 Integrity protection using XML signature (xmlsig) . 53
9.4 Key agreement for online floor control (SRTCP) . 54
9.4.1 General . 54
9.4.2 Key agreement between MCPTT client and MCPTT Server . 54
9.4.3 Key agreement between MCPTT Servers . 54
9.4.4 Key agreement for multicast from MCPTT Server . 54
9.4.5 Derivation of SRTCP key material . 54
Annex A (normative): Security requirements . 56
ETSI

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3GPP TS 33.179 version 13.10.0 Release 13 5 ETSI TS 133 179 V13.10.0 (2020-01)
A.0 Introduction . 56
A.1 Configuration & service access . 56
A.2 Group key management. 56
A.3 On-network operation. 56
A.4 Ambient listening . 57
A.5 Data communication between MCPTT network entities . 57
A.6 Key stream re-use . 57
A.7 Late entry to group communication . 58
A.8 Private call confidentiality . 58
A.9 Off-network operation . 58
A.10 Privacy of MCPTT identities . 58
A.11 User authentication and authorization requirements . 59
Annex B (normative): OpenID connect profile for MCPTT . 60
B.0 General . 60
B.1 MCPTT tokens . 60
B.1.1 ID token . 60
B.1.1.0 General . 60
B.1.1.1 Standard claims . 60
B.1.1.2 MCPTT claims . 60
B.1.2 Access token . 61
B.1.2.0 Introduction. 61
B.1.2.1 Standard claims . 61
B.1.2.2 MCPTT claims . 61
B.2 MCPTT client registration. 61
B.3 Obtaining tokens . 61
B.3.0 General . 61
B.3.1 Native MCPTT client . 62
B.3.1.0 General . 62
B.3.1.1 Authentication Request . 62
B.3.1.2 Authentication response . 63
B.3.1.3 Token request . 64
B.3.1.4 Token Response . 64
B.4 Refreshing an access token . 65
B.4.0 General . 65
B.4.1 Access token request . 65
B.4.2 Access token response . 66
B.5 Using the token to access MCPTT resource servers . 66
B.6 Token validation . 67
B.6.1 ID token validation . 67
B.6.2 Access token validation . 67
B.7 IdMS interface security . 67
Annex C (informative): OpenID connect detailed flow . 68
C.1 Detailed flow for MCPTT user authentication and registration using OpenID Connect . 68
Annex D (Normative): KMS provisioning messages to support MCPTT . 70
D.1 General aspects . 70
ETSI

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3GPP TS 33.179 version 13.10.0 Release 13 6 ETSI TS 133 179 V13.10.0 (2020-01)
D.2 KMS requests . 70
D.3 KMS responses . 71
D.3.0 General . 71
D.3.1 KMS certificates .
...