Azure B2C - Sign-in with non-English email addresses - azure

Question

We are using a custom sign-up/sign-in policy with Azure B2C and are having trouble trying to sign-in with foreign language email addresses.
We have followed the Microsoft tutorials and have used the custom starter XML files here.
We initially found that we couldn't even SIGN-UP with a foreign language email address (such as 伊伊伊伊伊伊伊#伊伊伊.伊伊伊) but we noticed that there was some regex in the TrustFrameworkBase.xml starter file that we could manipulate:
<ClaimType Id="email">
<DisplayName>Email Address</DisplayName>
<DataType>string</DataType>
<DefaultPartnerClaimTypes>
<Protocol Name="OpenIdConnect" PartnerClaimType="email" />
</DefaultPartnerClaimTypes>
<UserHelpText>Email address that can be used to contact you.</UserHelpText>
<UserInputType>TextBox</UserInputType>
<Restriction>
<Pattern RegularExpression="^[a-zA-Z0-9.!#$%&'^_`{}~-]+#[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$" HelpText="Please enter a valid email address." />
</Restriction>
</ClaimType>
So we changed the regular expression and we could sign-up!
But then, when we tried to sign-IN with the account we just signed-up with we got a message saying "Please enter a valid email address".
I've tried this with a vanilla sign-up/sign-in policy out-the-box and I get the same thing. There's a regex pattern attribute on the HTML text box that looks like:
<input type="email" id="logonIdentifier" name="Username or email address" pattern="^[a-zA-Z0-9.!#$%&’'*+/=?^_`{|}~-]+#[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$" placeholder="Email Address" value="" tabindex="1">
that prevents sign-in.
If I go in and remove this pattern regex I can actually sign-in, so I know it CAN work. I just need to remove this pattern attribute.
I must be missing something. Can anyone tell me what I need to configure to be able to sign-in with such an email address?

Answer 1

The email regex pattern for signIn is not pulled from "pattern" attribute in ClaimType from policy. That's why you are observing this behavior.
What you can do is by adding a language setting in technical profile metadata like following.
<TechnicalProfile Id="SelfAsserted-LocalAccountSignin-Email">
<Metadata>
...
<Item Key="language.email_pattern">{desired_pattern}</Item>
</Metadata>
….
</TechnicalProfile>