Returns the length of the sealed data on success, or FALSE on error. If successful
the sealed data is returned in
sealed_data, and the envelope keys in env_keys.
openssl_seal() seals (encrypts)
data by using RC4 with a
randomly generated secret key. The key is encrypted with each
of the public keys associated with the identifiers in pub_key_ids and each encrypted
key is returned in
env_keys. This means that one can send sealed data
to multiple recipients (provided one has obtained their
public keys). Each recipient must receive both the sealed
data and the envelope key that was encrypted with the
recipient's public key.
See also openssl_open().