My understanding is that in general under current law a US citizen cannot be held in contempt or put in prison indefinitely for failing to disclose a password.

My understanding is that in general under current law a US citizen cannot be held in contempt or put in prison indefinitely for failing to disclose a password. The 5th ammendment protection there is not entirely void, but it can be void under certain specific circumstances (such as the "foregone conclusion doctrine", where LE can prove that specific illicit content both exists, and can be decrypted, by the accused).