Function message_decrypt_signal 

pub async fn message_decrypt_signal<R: Rng + CryptoRng>(
    ciphertext: &SignalMessage,
    remote_address: &ProtocolAddress,
    local_address: &ProtocolAddress,
    session_store: &mut dyn SessionStore,
    identity_store: &mut dyn IdentityKeyStore,
    csprng: &mut R,
) -> Result<Vec<u8>>

Decrypt a SignalMessage from remote_address.

Tries all sessions in the session record. Checks identity key trust after decryption.