how to reset MFA and get a new QR when using azure b2c, MFA with REST API - azure

Question

i've followed https://github.com/azure-ad-b2c/samples/tree/master/policies/custom-mfa-totp to build MFA in azure B2C and it's working fine. just one question, after user scanned the QR code and register their phone, if they want to use another phone or reset their MFA, how can they get the QR code agian?

Answer 1

Any type of account management should existing on a 'Profile Edit' policy. This sample does not include it. You would need to pull the components out of the TrustFrameworkExtensions.xml like the AppFactor-Register, AppFactor-Challenge, ect., technical profile and add to your new user journey for ProfileEdit - potentially created a whole new experience. Of course, adding a write technical profile back into the directory will be needed to 'update' any information that is stored.
Most of the components to achieve your scenario is already there with this sample - just create a new user journey called "ProfileEditwithQR" or something and copy the starter pack profileEdit user journey to your Extension file (if you haven't already done this) - then add the steps from this sample to it.
This will require you to have a minimum of 300 level knowledge on custom policies to put this together.

Answer 2

I created a policy which allows to re-create the QR code.
Prerequisites: You have been able to run this sample in you tenant.
Add this to the TrustFrameworkExtension.xml:
<UserJourney Id="EditQR" DefaultCpimIssuerTechnicalProfileReferenceId="JwtIssuer">
<OrchestrationSteps>
<OrchestrationStep Order="1" Type="ClaimsProviderSelection" ContentDefinitionReferenceId="api.idpselections">
<ClaimsProviderSelections>
<ClaimsProviderSelection TargetClaimsExchangeId="LocalAccountSigninEmailExchange" />
</ClaimsProviderSelections>
</OrchestrationStep>
<OrchestrationStep Order="2" Type="ClaimsExchange">
<ClaimsExchanges>
<ClaimsExchange Id="LocalAccountSigninEmailExchange" TechnicalProfileReferenceId="SelfAsserted-LocalAccountSignin-Email" />
</ClaimsExchanges>
</OrchestrationStep>
<OrchestrationStep Order="3" Type="ClaimsExchange">
<ClaimsExchanges>
<ClaimsExchange Id="AADUserReadWithObjectId" TechnicalProfileReferenceId="AAD-UserReadUsingObjectId" />
</ClaimsExchanges>
</OrchestrationStep>
<!-- Demo: The following orchestration step is alwasy executed.
It generates a verification app secret key for the user (none interactive step). -->
<OrchestrationStep Order="4" Type="ClaimsExchange">
<ClaimsExchanges>
<ClaimsExchange Id="AppFactorGenerateTotpWebHook" TechnicalProfileReferenceId="AppFactor-GenerateTotpWebHook" />
</ClaimsExchanges>
</OrchestrationStep>
<!-- Demo: The following orchestration step is alwasy executed.
It registers a verification app through QR code that mobile authentication app should scan. -->
<OrchestrationStep Order="5" Type="ClaimsExchange">
<ClaimsExchanges>
<ClaimsExchange Id="AppFactorRegisterExchange" TechnicalProfileReferenceId="AppFactor-Register" />
</ClaimsExchanges>
</OrchestrationStep>
<!-- Demo: The following orchestration step is always executed.
It updates the verification app time step matched for a given user in the Azure Active Directory.
An error is raised if the user does not exist. -->
<OrchestrationStep Order="6" Type="ClaimsExchange">
<ClaimsExchanges>
<ClaimsExchange Id="AADWriteUserAppCodeByObjectId" TechnicalProfileReferenceId="AAD-WriteUserAppCodeByObjectId" />
</ClaimsExchanges>
</OrchestrationStep>
<OrchestrationStep Order="7" Type="SendClaims" CpimIssuerTechnicalProfileReferenceId="JwtIssuer" />
</OrchestrationSteps>
<ClientDefinition ReferenceId="DefaultWeb" />
</UserJourney>
and this is the new user flow, I called it EditQR.xml:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<TrustFrameworkPolicy
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns="http://schemas.microsoft.com/online/cpim/schemas/2013/06"
PolicySchemaVersion="0.3.0.0"
TenantId="yourtenant.onmicrosoft.com"
PolicyId="B2C_1A_editQr"
PublicPolicyUri="http://yourtenant.onmicrosoft.com/B2C_1A_editQr">
<BasePolicy>
<TenantId>yourtenant.onmicrosoft.com</TenantId>
<PolicyId>B2C_1A_TrustFrameworkExtensions</PolicyId>
</BasePolicy>
<RelyingParty>
<DefaultUserJourney ReferenceId="EditQR" />
<UserJourneyBehaviors>
<ScriptExecution>Allow</ScriptExecution>
</UserJourneyBehaviors>
<TechnicalProfile Id="PolicyProfile">
<DisplayName>PolicyProfile</DisplayName>
<Protocol Name="OpenIdConnect" />
<OutputClaims>
<OutputClaim ClaimTypeReferenceId="objectId" PartnerClaimType="sub"/>
<OutputClaim ClaimTypeReferenceId="tenantId" AlwaysUseDefaultValue="true" DefaultValue="{Policy:TenantObjectId}" />
</OutputClaims>
<SubjectNamingInfo ClaimType="sub" />
</TechnicalProfile>
</RelyingParty>
</TrustFrameworkPolicy>
Test it using http://jwt.ms, you will be promted to login and then redirected to the QR page.
Cheers!