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Authentication Failure

 

Authentication Failure is mostly related to wrong AUTN value in Authentication Request message. There are three main parameters including AUTN value and these main parameter would cause three different failure cause as follows.

 

Parameter

Failure Code

MAC Code

#20:MAC failure (Example)

Separation Bit (First bit of AMF)

#26:Non-EPS authentication unacceptable (Example)

SQN

#21:Synch failure (Example)

 

 

Example : Invalid MAC Code

 

Following example is for Invalid MAC Code and this test is based on the following test USIM. This test USIM uses 3GPP Test Algorithm specifed in 34.108

 

Correct Parameters :

    SQN=000000000000

    AMF=8000

    K=  00112233445566778899AABBCCDDEEFF

    --------------------------------------------

    RAND=31323131353836343132313135383634

    IK=  1302716D5043B9AB9B8AF9E5D8CB3123

    CK=  231302716D5043B9AB9B8AF9E5D8CB31

    AUTN=02716D5043B9800031231302716DD043

 

Invalid Parameters used for Test :

    SQN=FFFFFFFFFFFF

    AMF=8000

    K=  00112233445566778899AABBCCDDEEFF

    --------------------------------------------

    RAND=31323131353836343132313135383634

    IK=  1302716D5043B9AB9B8AF9E5D8CB3123

    CK=  231302716D5043B9AB9B8AF9E5D8CB31

    AUTN=FD8E92AFBC458000CEDCECFD8E92D043

 

Step

Direction

Message

1

UE <- NW

Authentication Request

2

UE -> NW

Authentication Failure

 

1) Authentication Request

 

DL-DCCH-Message

    message: c1 (0)

        c1: dlInformationTransfer (1)

            dlInformationTransfer

                rrc-TransactionIdentifier: 0

                criticalExtensions: c1 (0)

                    c1: dlInformationTransfer-r8 (0)

                        dlInformationTransfer-r8

                            dedicatedInfoType: dedicatedInfoNAS (0)

                                dedicatedInfoNAS: 0752033132313135383634313231313538363410fd8e92af...

                                    Non-Access-Stratum (NAS)PDU

                                        0000 .... = Security header type: Plain NAS message, not security protected (0)

                                        .... 0111 = Protocol discriminator: EPS mobility management messages (0x07)

                                        NAS EPS Mobility Management Message Type: Authentication request (0x52)

                                        0000 .... = Spare half octet: 0

                                        .... 0... = Type of security context flag (TSC): Native security context

                                                    (for KSIasme)

                                        .... .011 = NAS key set identifier:  (3) ASME

                                        Authentication Parameter RAND - EPS challenge

                                            RAND value: 31323131353836343132313135383634

                                        Authentication Parameter AUTN (UMTS and EPS authentication challenge)

                                                                 - EPS challenge

                                            Length: 16

                                            AUTN value: fd8e92afbc458000cedcecfd8e92d043

                                                SQN xor AK: fd8e92afbc45

                                                AMF: 8000

                                                MAC: cedcecfd8e92d043

 

2) Authentication Failure

 

UL-DCCH-Message

    message: c1 (0)

        c1: ulInformationTransfer (9)

            ulInformationTransfer

                criticalExtensions: c1 (0)

                    c1: ulInformationTransfer-r8 (0)

                        ulInformationTransfer-r8

                            dedicatedInfoType: dedicatedInfoNAS (0)

                                dedicatedInfoNAS: 1792f6a1a905075c14

                                    Non-Access-Stratum (NAS)PDU

                                        0001 .... = Security header type: Integrity protected (1)

                                        .... 0111 = Protocol discriminator: EPS mobility management messages (0x07)

                                        Message authentication code: 0x92f6a1a9

                                        Sequence number: 5

                                        0000 .... = Security header type: Plain NAS message, not security protected (0)

                                        .... 0111 = Protocol discriminator: EPS mobility management messages (0x07)

                                        NAS EPS Mobility Management Message Type: Authentication failure (0x5c)

                                        EMM cause

                                            Cause: MAC failure (20)

 

 

Example : Invalid Separation Bit

 

Following example is for Invalid MAC Code and this test is based on the following test USIM. This test USIM uses 3GPP Test Algorithm specifed in 34.108

 

Correct Parameters :

    SQN=000000000000

    AMF=8000

    K=  00112233445566778899AABBCCDDEEFF

    --------------------------------------------

    RAND=31323131353836343132313135383634

    IK=  1302716D5043B9AB9B8AF9E5D8CB3123

    CK=  231302716D5043B9AB9B8AF9E5D8CB31

    AUTN=02716D5043B9800031231302716DD043

 

Invalid Parameters used for Test :

    SQN=000000000000

    AMF=0000

    K=  00112233445566778899AABBCCDDEEFF

    --------------------------------------------

    RAND=31323131353836343132313135383634

    IK=1302716D5043B9AB9B8AF9E5D8CB3123

    CK=231302716D5043B9AB9B8AF9E5D8CB31

    AUTN=02716D5043B9000031231302716D5043

 

Step

Direction

Message

1

UE <- NW

Authentication Request

2

UE -> NW

Authentication Failure

 

1) Authentication Request

 

DL-DCCH-Message

    message: c1 (0)

        c1: dlInformationTransfer (1)

            dlInformationTransfer

                rrc-TransactionIdentifier: 0

                criticalExtensions: c1 (0)

                    c1: dlInformationTransfer-r8 (0)

                        dlInformationTransfer-r8

                            dedicatedInfoType: dedicatedInfoNAS (0)

                                dedicatedInfoNAS: 075200313231313538363431323131353836341002716d50...

                                    Non-Access-Stratum (NAS)PDU

                                        0000 .... = Security header type: Plain NAS message, not security protected (0)

                                        .... 0111 = Protocol discriminator: EPS mobility management messages (0x07)

                                        NAS EPS Mobility Management Message Type: Authentication request (0x52)

                                        0000 .... = Spare half octet: 0

                                        .... 0... = Type of security context flag (TSC): Native security context (

                                                     for KSIasme)

                                        .... .000 = NAS key set identifier:  (0) ASME

                                        Authentication Parameter RAND - EPS challenge

                                            RAND value: 31323131353836343132313135383634

                                        Authentication Parameter AUTN (UMTS and EPS authentication challenge)

                                                     - EPS challenge

                                            Length: 16

                                            AUTN value: 02716d5043b9000031231302716d5043

                                                SQN xor AK: 02716d5043b9

                                                AMF: 0000

                                                MAC: 31231302716d5043

 

2) Authentication Failure

 

UL-DCCH-Message

    message: c1 (0)

        c1: ulInformationTransfer (9)

            ulInformationTransfer

                criticalExtensions: c1 (0)

                    c1: ulInformationTransfer-r8 (0)

                        ulInformationTransfer-r8

                            dedicatedInfoType: dedicatedInfoNAS (0)

                                dedicatedInfoNAS: 075c1a

                                    Non-Access-Stratum (NAS)PDU

                                        0000 .... = Security header type: Plain NAS message, not security protected (0)

                                        .... 0111 = Protocol discriminator: EPS mobility management messages (0x07)

                                        NAS EPS Mobility Management Message Type: Authentication failure (0x5c)

                                        EMM cause

                                            Cause: Non-EPS authentication unacceptable (26)