[Bug] B2C API token validation reports invalid issuer

[mrochon]

Which version of Microsoft Identity Web are you using?
Note that to get help, you need to run the latest version.

1.12.0

Where is the issue?

• Web app
  • Sign-in users
  • Sign-in users and call web APIs
• Web API
  • [X ] Protected web APIs (validating tokens)
  • Protected web APIs (validating scopes)
  • Protected web APIs call downstream web APIs
• Token cache serialization
  • In-memory caches
  • Session caches
  • Distributed caches
• Other (please describe)

Is this a new or an existing app?
Sample app in development.

Repro

1. Token to API obtained from B2C includes issuer: https://mrochonb2cprod.b2clogin.com/cf6c572c-c72e-4f31-bd0b-75623d040495/v2.0/
2. Fiddlr shows that the API is obtaining .well-known metadata with the same issuer
3. App errors with: Microsoft.IdentityModel.Tokens.SecurityTokenInvalidIssuerException: IDW10303: Issuer: 'https://mrochonb2cprod.b2clogin.com/cf6c572c-c72e-4f31-bd0b-75623d040495/v2.0/', does not match any of the valid issuers provided for this application. Microsoft.IdentityModel.Tokens.SecurityTokenInvalidIssuerException: IDW10303: Issuer: 'https://mrochonb2cprod.b2clogin.com/cf6c572c-c72e-4f31-bd0b-75623d040495/v2.0/', does not match any of the valid issuers provided for this application.

  "B2C": {
    "Instance": "https://login.microsoftonline.com/tfp/",
    //"Instance": "https://mrochonb2cprod.onmicrosoft.com",
    "TenantId": "cf6c572c-c72e-4f31-bd0b-75623d040495",
    "Domain": "mrochonb2cprod.onmicrosoft.com",
    "ClientId": "5e976aba-65ee-4185-8fdc-d317f7c34959",
    "RedirectUri": "https://b2crestapis",
    "SignUpSignInPolicyId": "B2C_1_BasicSUSI"
  }

Expected behavior
Issuer should be accepted as valid

Actual behavior
Error: Microsoft.IdentityModel.Tokens.SecurityTokenInvalidIssuerException: IDW10303: Issuer: 'https://mrochonb2cprod.b2clogin.com/cf6c572c-c72e-4f31-bd0b-75623d040495/v2.0/', does not match any of the valid issuers provided for this application.

Possible solution
Will experiment with TokenValidationParameters as per some other bugs mentioned here.

Additional context / logs / screenshots
Add any other context about the problem here, such as logs and screenshots.

[jmprieur]

@mrochon : would you mind trying the following configuration:

"Instance": "https://mrochonb2cprod.b2clogin.com",

[mrochon]

Yes, that worked. No errors. Thanks.

[jmprieur]

Thanks for confirming, @mrochon