Function sodalite::sign_attached_open

pub fn sign_attached_open(m: &mut [u8],
                          sm: &[u8],
                          pk: &SignPublicKey)
                          -> Result<usize, ()>

verify an attached signature

@m must have the same length as @sm.

If verification failed, returns Err(()). Otherwise, returns the number of bytes in message & copies the message into @m

Panics:

• If m.len() != sm.len()