I have a signup flow and it is working fine and it is multi-step: Contact details Verification Password And now the flow is, after completing all steps a new user will get created, if the user name already exists then in the last step I'm getting an error message that the user already exists. Now I need to change this flow. After entering the contact details(email), I want to check whether this user exists or not. If it exists then I need to show the error message that shows in the last step in the first step itself and block the journey from moving to the next step. To achieve this, what I did is: Created a TP that reads the user details using email and put that as a validation technical profile for the first step: And added to Following is the validation profile section: But it is not working as expected, I tried with an existing user after clicking next on the first step it moves the verification step without any error.

I find solution in another way as follows: After a Read Operation, the objectId claim is populated only if the user already exists. I have put Read with RaiseErrorIfClaimsPrincipalDoesNotExist = false and then I used ClaimTransformations and ValidationTechnicalProfiles to block the UserJourney if objectId != null. More specifically used " UserMessageIfClaimsTransformationStringsAreNotEqual "

I ran into the same issue, where I'm using display control for email verification as part of the sign up process. My good guess is that 'AAD-UserReadUsingEmailAddress' exists for SSPR and would only throw an error if the user doesn't exist. However I was able to resolve this by adding a write step after read, if the user is found with a precondition to see if my objectId claimExists and this will throw an error if the user exists and skips the write step if the user doesn't exist. It's lil hacky but works. Hope this helps!

How to check user exists in AD B2C, using custom policy?

Accepted answer

AB 156 Reputation points

2020-01-31T10:06:42.043+00:00

I find solution in another way as follows:

After a Read Operation, the objectId claim is populated only if the user already exists. I have put Read with RaiseErrorIfClaimsPrincipalDoesNotExist = false and then I used ClaimTransformations and ValidationTechnicalProfiles to block the UserJourney if objectId != null. More specifically
used "UserMessageIfClaimsTransformationStringsAreNotEqual"
Please sign in to rate this answer.

5 people found this answer helpful.
Juan M Solórzano I 6 Reputation points

2020-02-12T21:09:51.553+00:00

thank you for the information. Could you share you final code? Pls.

AB 156 Reputation points

2020-02-20T11:27:28.077+00:00

See the file attached.3231-policy.txt

AB 156 Reputation points

2020-02-20T11:28:56.127+00:00

@Juan M Solórzano I Please find the answer i have added. Please check the file attached.

Juan M Solórzano I 6 Reputation points

2020-02-20T16:16:43.087+00:00

Thks... I could solve the problem with you information. I only have one situacion, I need to stop the process when the email exist.
I attach my action code.

But the validation NOT stop in the "AAD-UserReadUsingEmailAddress-RaiseIfExists"- and run the other two TechnicalProfile. (GenerateOtp and SendGrid).

Do you know how can I stop the process when the TechnicalProfile AAD-UserReadUsingEmailAddress-RaiseIfExists return the InputParameter Id="stringComparison" in true?

AB 156 Reputation points

2020-02-20T18:32:53.387+00:00

Add precondition for your Validation technical profiles:

AB 156 Reputation points

2020-02-21T15:18:21.667+00:00

@Juan M Solórzano I Hope that helps

Juan M Solórzano I 6 Reputation points

2020-02-24T22:48:19.657+00:00

Thank you! I solved the situation with your help.

Sakhardande, Sudesh @ Dallas 1 Reputation point

2020-07-02T18:33:45.727+00:00

The attached policy worked for me. Thank you.

Naman Gupta02 1 Reputation point

2020-10-22T09:55:08.827+00:00

I guess you would be adding preconditions like this:-

<Preconditions> <Precondition Type="ClaimEquals" ExecuteActionsIf="false"> <Value>objectId</Value> <Value>NOTFOUND</Value> <Action>SkipThisValidationTechnicalProfile</Action> </Precondition> </Preconditions>

Sashikiran Rachakonda 21 Reputation points

2021-02-26T22:27:35.787+00:00

what the above does not do is stop the userJourney at the point of clicking the 'Send Verification Code' button below the email..wonder if there is a way to do the before the verification code email is sent out.

Sashikiran Rachakonda 21 Reputation points

2021-02-26T22:32:23.373+00:00

what the above accepted answer does not do is stop the userJourney at the point of clicking the 'Send Verification Code' button below the email..wonder if there is a way to do the before the verification code email is sent out.

Jeremy 136 Reputation points

2022-09-19T16:08:46.43+00:00

This works, except if you change the email and try again with an unused mail I continue to get the error message. I assume the objectId remains populated. How should we blank it when they attempt to reverify?

AB 156 Reputation points

2022-09-20T18:31:31.587+00:00

@Jeremy You can use an input claimtransformation in your initial step. Assign "NOTFOUND" to ObjectId, that will fix your problem, I guess.

Jeremy 136 Reputation points

2022-09-20T19:07:52.963+00:00

I tried blanking it on the input, but I think that doesn't work, because if it did find a match on the second round it blanks it.

So I ended up just always blanking it right after the assertion as a second output transformation. It seems to be working, but I'm not 100% confident yet.

<ClaimsTransformation Id="SetObjectIdToNull" TransformationMethod="NullClaim"> <OutputClaims> <OutputClaim ClaimTypeReferenceId="objectId" TransformationClaimType="claim_to_null" /> </OutputClaims> </ClaimsTransformation>

...

<OutputClaimsTransformations> <OutputClaimsTransformation ReferenceId="AssertObjectIdObjectIdNotFoundAreEqual" /> <OutputClaimsTransformation ReferenceId="SetObjectIdToNull" /> </OutputClaimsTransformations>

AB 156 Reputation points

2022-09-21T08:58:41.18+00:00

@Jeremy Ok, if it is working then it is working, why you are not confident? Output claim transformation will also work.

Supreeta Poojary 0 Reputation points

2023-05-22T07:21:58.56+00:00

@Juan M Solórzano I I have similar situation. Could you please share the code?
Sign in to comment

How to check user exists in AD B2C, using custom policy?

1 additional answer