AUSF improvement 2

• About tha fatal lines info -> Link
• Type these commands :

cd NFs/amf
go get github.com/free5gc/util/mongoapi@v1.0.5-0.20230306071612-a52909216bd2
go get github.com/free5gc/amf/internal/sbi/consumer

• I don't know if it is right to go get in the root folder.
  

• Need to go get in the folder which has go.mod
  

• So I just ignore it and keep debugging.

1. 
   ->
2. The logger problem : logger printing functions used in UDR/UDM/AUSF are not in AMF.
   • When you check the logger.go it imports in AMF and UDR, you will find they has very similar structure.
     
     
   • So I think we can just add the logger variable that AMF does not have, but UDR has.
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3. This variable is definded in orignal file, by a const function, so add it.
   
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4. Add variables
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5. Plus M to prevent the repeat error.
   • 

1. This error is that I didnt deal with the parameters in the function calling which I have commented out.
   
   • For checking whther this action will affect the DB modifiction or not, I print out these two variables in original free5gc, so the modification is the SQN number, and we can make sure that the modification is made between these two RestfulAPIGetOne.
     
   • And if you check the content of the notify functions, you can find that they only use these got values for sending http message, not for computing or something, so we can peacefully ignore them.
     
     
   • So this check item is finished.
     
   • And the method is adding two print line so the variables will be used.
     
     
2. Need to difine it using :=, or the compiler can not verify it in return line.
   
   ->
3. 
   • In error place, it use the received err to give to Detail.
     
   • In the called function, the pd is returned as err.
     
   • As you can see, the pd is also created from problemDetails.
     
   • So there is no one item called err.Error() for us to use, I think it is because it is originally call API, not function, there will has some funciton we can call.
   • Here I change it to one of the item in the models.ProblemDetails that can be called, and to represent the Detail(DATA NOT FOUND).
     
   • Change the function name.
     
     ->
4. 
   • The compiler can not find the PermanentKey item, I guess it is because the passing format problem or naming problem.
     
     
   • I print the passing value in three places
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     • 
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   • The results are like below, we can see that the value turn to memory address after API process.
     
   • So based on the error message, we need to transform the map[string]interface format.
     • About the explanation, disadvantage and reason of this format -> Link .
       • The other reason that I don't use this fromat directly as below, is that there are too many palce need to modify, so it's more efficient by creating a structure.
     • First do the definition.
       
       • Compared to the content of map format.
         
     • Then do the transformation of the data received from MongoDB in this function.
       
     • The original calling of authSubs should be done successfully, notice that the return format defining should be changed correctlly, or the compiler will report the same error.
       
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     • Compared to Terry's MongoDB client -> Link .
5. 
   
   • This is also defined as const in original funciton, so add it.
     

1. The AuthSubs declaration is in the same file with calling function, so don't need to add model. to import.
   
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2. Just delete the redundent returned variable, I forgot why I put one more variable here.
   
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1. 
   • I think the problem here is the previous declaration assign err as *model.ProblemDetails, because the called function is from UDR, the return format is not the same as here(hex.DecodeString originally from UDM).
     
   • So I change the parameter name which will be used only for hex function,
     
2. 
   • The problem is the checking action here can not match the structure(Milenage.Op) with nil.
     
   • Here we can reserver the OpValue only, because the error report here is just to know whther the OpValue exists or not.
     
3. The remaining errors are all the same with 1.
   
   • So I just change their names.
     
     
   • Here is another function calling(milenage), so I change to another nameing.
     
   • The 411 line is still hex function.
     
   • Need to change to :=, or there will have this problem
     
     
     
     
   • Or like this.
     
     

• The same so keep changing.
  
  
  
  

1. 
   • It is continued from problem 2-5, and is same as problem 3-3.
   • In func ModifyAuthenticationProcedure, the returned structure include Cause and Detail, but Detail is assigned as "", so we can only use Cause to print out what happened("MODIFY_NOT_ALLOWED").
     
     
2. At line 602.
   
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3. At line 609.
   
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   • I dont know why it doesnt need := here, the error pops up when I add :=.
     
4. 
   • From the model it imports, the type is not string.
     
   • One solution is that transfer the string format to model.AuthMethod.
     
     • But we need to define this model like the github import.
       
   • Another solution is that change the declaration in AuthSub.
     
   • Originally I dont want to use model.AuthMethod, but use "5G_AKA" to compare directly.
     
     • But there are some flaws.
       
     • Also below has some other palce using this model format, to compare with the reutrn value from this UDM function.
       
       
   • So I decide to change the format in AuthSubs, then I don't need to do some change if the model is used in the part after.
     

1. After the resync part is OK, compiler say that we didnt use the parameters k, op, opc.
   
   
   
   • So comment out them at here.
     
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     • But it will be another problem, because the k declared in if/else will only be seen recognized in if/else.
       
       
   • So we still need to define them at begining, and need to change := to =, then the errHex and errMil need to be defined too.
     • Like here, after uncomment out the parameters defining and change := to =.
       
     • Comfirm te return formats of these function.
       
       
     • We can see the err returned by them are type error.
       
     • So the declaration is like this.
       
       
       
       

1. Add variables.
   
   
2. 
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3. 
   • The same as previous problem.
   • There are some return inlcuding Detail, some doesnt include, so I print out both cause and detail.
     
4. 
   • It assign status code but parameter rep has been commented out.
     
     • The rep is declared as http.Response
       
     • So I go to see the format of status code in this package(net/http).
       
     • About the int32 function : Link
   • Then I want to know the status code value when error happens, so I change the K in webconsole, and add printing lines in original free5gc.
     
     V
     
     • Here you can see the Forbidden status code is 403.
       
   • And if you check all error return, you can find that their status are all http.StatusForbidden, so change the parameter to 403(int) directly.
     • Confirm that the format of problemDetails.Status is int32, so that the value 403 can be assigned directly.
       
       
5. 
   • In the function definition, the returned variable number need to change.
     
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6. 
   
   • Add variables.
     
     

1. 
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2. 
   • Because I commented out here before.
     
     • But now I think it can be reserved before, because updateAuthenticationInfo.ServingNetworkName is received from func SendUEAuthenticationAuthenticateRequest and it write the SN name here.
       
     • Because it has value, I think we can just store it but not do any authorization.
   • So uncomment out it, and assign it to responseBody and authInfoReq.
     
3. 
   • No need to add &.
     
     V
4. 
   • It is also resulted from the format of err, because of the changing from API to function calling.
     
   • Because there is no API passing between func SendUEAuthenticationAuthenticateRequest and func UeAuthPostRequestProcedure, the received err has already been &models.ProblemDetails, we don't need to extract the problem from err, use err directly(err is address so don't add & before it).
     

• Derive Kseaf but not used.
  
• I think it will not be used so just comment out this part.
  

• The explanation of ChatGPT.
  

var client *mongo.Client
var err error

client, err = mongo.Connect(context.TODO(), options.Client().ApplyURI("mongodb://localhost:27017"))
if err != nil {
    log.Fatal(err)
}

// 檢查連接
err = client.Ping(context.TODO(), nil)
if err != nil {
    log.Fatal(err)
}

• It seems that I didn't set a client for MongoDB connection, go to see the line that error tells to me.
  
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  • As you can see, the client is also created in the same file which is called by UDR function, and in this func SetMongoDB it will build the connection with DB.
  • Terry build the connection by himself, you can see the process -> Link
  • And then I'm wondering where the original Free5GC do thhis action -> Link
• So I copy the connection building process from UDR to AMF in init.go.
  • The passing parameters in called function can be find in factory.
    
    
  • And the parameters creating sequence is like below.
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    • I don't know how it fill the mongo name and url from config.yaml to here, but it is confirmed that this two parameters are set in yaml file.
      
      
  • So we can direcly input these value to set the connection.
    
    
    

• For logs' sources.
  
  
• I have comfirmed that the setting in free5gc-ue.yaml and webconsole are no problem.
• Then I think maybe the searching keywords have problem, so I printing out supi.
  
  
  • As you can see, the collname is matched with the display on mongodb-compass, one hyphen(-, or you can say dash) is missing in ueId.
    
  • So modify here.
    
    V

• For logs' sources, it is right after the getDataFromDB, so data is got, but the transfer is not successful.
  
• The explanation from ChatGPT.
  
  
  
  
• So I think we can change the format of which will recieve number into float64 directly.
  
  
  • And this is also why Terry has some float64 in his structure.
    
  • I also check that these EncryptionAlgorithm and EncryptionKey will not be used in parts after, so this change will not cause error.

• I need to reconstruct the URI if I want to have a successful call to AUSF, but it is useless for the 2nd modification, because the client including ausfUri will be commented out after changing to function calling.
• But I want to test whether my change on 1st is OK for UE access, so I will just assign the locationURI manually even if it will be commented out.
  
  • self is declared here.
    
    V find in original ausf file
    
    V
    
    V
    
    V
    
  • And factory.AusfAuthResUriPrefix is here.
    
  • It seems that printing out them in original free5gc is faster
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    • 
      
• So they are all string format, can direcly add them together.
  

• After compiling OK, it turns out other errors related to AUSF context.
  
  
• It will be too much if I keep modify the AUSF context, so I decide to do 2nd modification directly, and ignore AUSF related part.

• 
  
  • This problem is that originally the variables in string format are declared together, about the explanation -> Link.
    
    
• So just give them the format.
  
  

1. I think that is becaues logger.DataRepoLog.Errorf needs string to print, but the format of err is error, original print function use logger.DataRepoLog.Error.
   
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2. 
   
   
   • Change the return format declaration.
     
     V
     
   • It causes other problem.
     
     • Just print problemDetails itself.
       
       
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3. 
   
   • Remove the redudent &.
     
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• In the process above, I was doubting that maybe the cause is from the modification in ue_authentication.go, the missing in some parameter resulit in the rejection of UE.
• And I ask Terry that whether the commenting out of Kseaf generating affects it or not, the answar is YES.
  • But I didnt know which part in security mode will use Kseaf, because I need to know where to put Kseaf value instead of AUSF context if I recover the generating process.
  • And Terry say that I can put into AMF context, becausee the security mode is working in AMF, and will access the parameter in AMF context.

• We need to use hex.EncodeToString().

• My method is put Kseaf into responseBody, so we need to change its format.
  • Check the format on model repo.
    
    
  • Then put it above this function, change the responseBody declaration, and add Kseaf declaration in structure.
    
  • And assign Kseaf to it after generating.
    
• And the error in above screenshot is about the format of variables in structure.
  • For first one you can find the difined source on repo
    
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  • For second one.
    
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• The problem is caused by the format in structure, which is not matched with the use below.
• Here I can change two places, in struc or in the use below, I choose to modify in struc directly, it is successful so I didnt try to change the second place.
  • 
  • The original variables are set as remarks commented out behind the sentence.

• This form is correct one.
  

1. 
   • It is caused by the return variable declaration.
     
2. 
   • It is in func SendUEAuthenticationAuthenticateRequest, to put the received Kseaf into ue context which is passed from func AuthenticaionProcedure to here.
   • Dont need to add models.
     
   • After Kseaf is assigned, we need to put the other value into the original passing format, so declar a new variable using model's format and assign the value one by one.
3. 

• So I find another place where call Kseaf in UE context for using, and add logger in three places to see whether the Kseaf exists or not.
  • In func SendUEAuthenticationAuthenticateRequest.
    
  • In func AuthenticationProcedure
    
  • The results of these two all have the value of Kseaf.
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    • 
  • In func HandleAuthenticationResponse
    
  • But the third place doesnt have.
    • 
• Then when you go to :
  
  V
  func SendAuth5gAkaConfirmRequest
  
  V
  func HandleAuth5gAkaComfirmRequestProcedure
  
• You can see if the authentication confirm is successful, it will get Kseaf from susf context, but I have commented out it and give it null value, because I thought Kseaf would not ne used.
  • So I comment out here to prevent the null value cover the original value.
    

• Comment out AUSF selecting part.
  

• There is no UE data in 5GC, so add them on webconsole, the SUCI will be from imsi-…3~7.

• Only one UE will successfully build the PDU session.
• And you can see some Synch failure for 4 UEs
  
  
  
  
• Other four will have a confirmation failed
  
  
  • Find that the XresStar comparison is not successful, not the same with res*.

• So I think the problem is that I use global variable for setting Xres*, then every UE's Xres* will be the same.
  • Here you can check the result that tests with 2 UEs.
    
  • And if you scroll up, you can see the final XresStar stored in the global variable is from imsi-…0003, so the imsi-…0004 will not pass the 5G-AKA confirmation.
    

• hex.DecodeString() has two return, but encode only one, so dont mess up them.

V

• Instead of hex.encodestring()
  

• Put the if/else of map in the most ouside place.
  

• Because there is no supi transformation in func UeAuthPostRequestProcedure
  
• So here change supi to ConfirmationDataResponseID which is suci, use supci to find in map.
  
  V
  

• In the VM of free5gc, need to set these network rules.

sudo sysctl -w net.ipv4.ip_forward=1
sudo iptables -t nat -A POSTROUTING -o ens18 -j MASQUERADE
sudo iptables -A FORWARD -p tcp -m tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1400
sudo systemctl stop ufw
sudo iptables -I FORWARD 1 -j ACCEPT