ETSI TS 103 523-2 V1.1.1 (2021-02)

CYBER; Middlebox Security Protocol; Part 2: Transport layer MSP, profile for fine grained access control

DTS/CYBER-0027-2

General Information

• Status: Not Published
• Technical Committee: CYBER - Cyber Security
• Current Stage: 12 - Completion
• Due Date: 17-Feb-2021
• Completion Date: 09-Feb-2021

Standards Content (Sample)

ETSI TS 103 523-2 V1.1.1 (2021-02)






TECHNICAL SPECIFICATION
CYBER;
Middlebox Security Protocol;
Part 2: Transport layer MSP, profile for fine
grained access control

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2 ETSI TS 103 523-2 V1.1.1 (2021-02)



Reference
DTS/CYBER-0027-2
Keywords
cyber security
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3 ETSI TS 103 523-2 V1.1.1 (2021-02)
Contents
Intellectual Property Rights . 7
Foreword . 7
Modal verbs terminology . 7
Executive summary . 7
Introduction . 8
1 Scope . 9
2 References . 9
2.1 Normative references . 9
2.2 Informative references . 10
3 Definition of terms, symbols and abbreviations . 11
3.1 Terms . 11
3.2 Symbols . 12
3.3 Abbreviations . 12
4 TLMSP specification . 13
4.1 Introduction . 13
4.2 The Record protocol . 14
4.2.1 Overview . 14
4.2.1.1 General . 14
4.2.1.2 Records, containers and contexts . 14
4.2.1.3 Record and container construction and processing overview . 15
4.2.2 Message unit and record processing: cryptographic state and synchronization . 17
4.2.2.1 General . 17
4.2.2.2 MAC overview . 17
4.2.2.2.1 General . 17
4.2.2.2.2 MAC author determination . 18
4.2.2.3 Sequence numbers . 19
4.2.2.3.1 General . 19
4.2.2.3.2 Outgoing message units and records . 21
4.2.2.3.3 Incoming message units and records . 22
4.2.3 Processing of specific message unit types . 22
4.2.3.1 Container message units . 22
4.2.3.1.1 Container usage . 22
4.2.3.1.2 Modifications . 23
4.2.3.1.3 Insertions generally . 23
4.2.3.1.4 Deletion indication containers . 24
4.2.3.1.5 Audit containers. 25
4.2.3.1.6 Alert containers . 26
4.2.3.2 Record message units . 26
4.2.3.2.1 Handshake message units . 26
4.2.3.2.2 ChangeCipherSpec message units . 26
4.2.3.3 Middlebox processing summary . 26
4.2.3.4 MAC usage summary . 27
4.2.4 Container format . 29
4.2.5 Plaintext record format . 29
4.2.6 Compressed record format . 30
4.2.7 Applying message unit and record protection . 30
4.2.7.1 General . 30
4.2.7.2 MAC generation . 31
4.2.7.2.1 General . 31
4.2.7.2.2 Reader, deleter and writer MACs . 31
4.2.7.2.3 Hop-by-hop MAC . 33
4.2.7.3 Cipher suite specifics . 34
ETSI

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4 ETSI TS 103 523-2 V1.1.1 (2021-02)
4.2.7.3.1 General . 34
4.2.7.3.2 Null or stream cipher . 34
4.2.7.3.3 Generic block cipher . 35
4.2.7.3.4 AEAD ciphers . 35
4.3 The Handshake protocol . 35
4.3.1 Overview . 35
4.3.1.1 General . 35
4.3.1.2 Piggy-backing of handshake messages . 38
4.3.2 Middlebox configuration, discovery . 39
4.3.2.1 General . 39
4.3.2.2 Static pre-configuration . 40
4.3.2.3 Dynamic discovery. 40
4.3.2.3.1 General . 40
4.3.2.3.2 Non-transparent middleboxes . 41
4.3.2.3.3 Transparent middleboxes . 42
4.3.2.4 Combined discovery. 43
4.3.2.4.1 Example use case . 43
4.3.2.4.2 Practical considerations . 44
4.3.2.5 Middlebox leave and suspend . 44
4.3.3 Session resumption and renegotiation . 44
4.3.3.1 Resumption . 44
4.3.3.2 Renegotiation . 45
4.3.4 Handshake message types . 45
4.3.5 TLMSP Handshake extensions . 46
4.3.6 Middlebox related messages . 50
4.3.6.1 MboxHello . 50
4.3.6.2 MboxCertificate . 51
4.3.6.3 MboxCertificateRequest . 51
4.3.6.4 Certificate2Mbox . 51
4.3.6.5 MboxKeyExchange . 52
4.3.6.6 MboxHelloDone . 52
4.3.6.7 CertificateVerify2Mbox . 52
4.3.6.8 MboxHelloRequest . 53
4.3.6.9 ServerUnsupport . 53
4.3.6.10 MboxFinished . 53
4.3.7 TLMSPKeyMaterial and TLMSPKeyConf . 54
4.3.7.1 KeyMaterialContribution . 54
4.3.7.2 TLMSPKeyMaterial . 55
4.3.7.3 TLMSPKeyConf . 56
4.3.8 MboxLeaveNotify and MboxLeaveAck . 57
4.3.8.1 Message format . 57
4.3.8.2 Message processing . 57
4.3.8.2.1 General . 57
4.3.8.2.2 Detailed operation . 58
4.3.9 Message hashes . 59
4.3.9.1 ClientHello and ServerHello value substitutions . 59
4.3.9.2 Finished hash. 59
4.3.9.3 MboxFinished hash . 60
4.3.9.4 ClientHello hash (following dynamic discovery). 62
4.3.9.5 TLMSPServerKeyExchange hash . 62
4.3.10 Key generation . 62
4.3.10.1 TLMSPServerKeyExchange . 62
4.3.10.2 General . 63
4.3.10.3 Premaster secret and master secret generation . 63
4.3.10.4 Pairwise encryption and integrity key generation . 64
4.3.10.5 Context specific keys . 65
4.3.10.6 Key extraction . 67
4.4 The Alert protocol . 68
4.4.1 General . 68
4.4.2 Alert message types . 68
4.5 The ChangeCipherSpec protocol . 69
ETSI

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5 ETSI TS 103 523-2 V1.1.1 (2021-02)
Annex A (normative): Defined cipher suites . 70
A.1 General . 70
A.2 Key Exchange . 70
A.3 AES_{128,256}_GCM_SHA{256,384} . 70
A.3.1 General . 70
A.3.2 Additional MAC computations . 71
A.4 AES_{128,256}_CBC_SHA{256,384} . 71
A.5 AES_{128,256}_CTR_SHA{256,384} . 71
A.6 Additional cipher suites . 71
A.7 Summary of security parameters . 72
A.8 Cipher suite identifiers . 72
A.9 Future extensions . 73
Annex B (normative): Alternative cipher suites . 74
B.1 General . 74
B.2 Defined alternative cipher suites . 74
B.2.1 Anon . 74
B.2.2 Preshared keys . 74
B.2.2.1 General . 74
B.2.2.2 Technical Details . 74
B.2.2.2.1 ClientHello and ServerHello . 74
B.2.2.2.2 MboxKeyExchange . 75
B.2.2.2.3 TLMSPKeyMaterial . 75
B.2.3 GBA . 75
B.2.3.1 General . 75
B.2.3.2 Technical details . 75
B.2.3.2.1 General . 75
B.2.3.2.2 ClientHello . 76
B.2.3.2.3 MboxKeyExchange . 76
B.2.3.2.4 TLMSPKeyMaterial . 76
Annex C (normative): TLMSP alternative modes . 77
C.1 Fallback to TLS 1.2 . 77
C.2 Fallback to TLMSP-proxying . 78
C.2.1 General . 78
C.2.2 Fallback procedure . 78
C.2.3 Message and processing details . 81
C.2.3.1 TLMSP proxying and delegate extension and message specifications . 81
C.2.3.2 Delegate message specification . 81
C.2.3.3 Processing . 81
C.3 Middlebox security policy enforcement . 82
C.3.1 General . 82
C.3.2 Message formats . 83
Annex D (informative): Contexts and application layer interaction . 84
D.1 Application layer interaction model . 84
D.2 Example context usage . 84
Annex E (informative): Security considerations . 86
E.1 Trust model . 86
E.2 Cryptographic primitives . 87
ETSI

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6 ETSI TS 103 523-2 V1.1.1 (2021-02)
E.2.1 General . 87
E.2.2 Handshake verification . 88
E.3 Protection against mcTLS attacks . 89
E.4 Inter-session assurance . 90
E.5 Use of the default context zero . 90
E.6 Removal of middlebox insertions . 90
E.7 Removal of support for renegotiation . 91
Annex F (informative): TLMSP design rationale . 92
F.1 General . 92
F.2 Containers . 92
F.3 Sequence numbers and re-ordering/deletion attacks . 92
F.4 MAC for synchronization purposes . 93
F.5 Removal of support for renegotiation . 93
Annex G (
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