pub fn parse_mfa_header(value: &str) -> Result<(String, String), MfaError>Expand description
Parse the x-amz-mfa header value, format: <serial> <code> where
code is a 6-digit ASCII numeric string. Whitespace runs of more than
one ASCII space between serial and code are rejected; trailing /
leading whitespace likewise. AWS itself accepts a single ASCII space
here — clients always emit exactly one — so we keep the parser strict
to surface caller bugs early.