ReadonlychallengeChallenge module identifier.
ReadonlyretryRetry limit, including the initial attempt.
ReadonlytimeTime limit, in milliseconds.
Process selection or continuation of the challenge.
ProtectedstartValidate a new request, create State object, and deliver PIN to client if applicable.
CHALLENGE request packet.
Challenge context, which contains the certificate request.
State to continue the challenge, or ServerChallengeResponse to fail the challenge.
The "email" challenge where client receives a pin code via email.