Converting an existing user to SSO automatically will impose security issue: assume a hacker wants to access private projects of a built-in user, he can register a user with same name on SSO source, and login via SSO to take over the built-in user.

Instead, you may convert built-in user to SSO user by running below SQL on the database:

update o_User set o_password='external_managed', o_SSO_CONNECTOR = '<SSO_PROVIDER_NAME>', o_SSO_SUBJECT = '<SSO_SUBJECT_NAME>' where o_name='<LOGIN_NAME>';

Here:

• <SSO_PROVIDER_NAME> should be replaced by name of the SSO provider you defined in OneDev
• <SSO_SUBJECT_NAME> should be replaced by subject name returned from SSO provider. In GitHub it is the same as login name. For other SSO provider, you may login with a sample account and check the value
• <LOGIN_NAME> should be replaced with name of the account you want to convert from internal authenticated to SSO authenticated

Hey, you're totally right about the security concern. Thank you very much for providing that info on how to manually convert a user!