XChaChaPoly1305AuthenticationData
internal data class XChaChaPoly1305AuthenticationData(val passphrase: String, val salt: <Error class: unknown class>, val additionalData: <Error class: unknown class> = ubyteArrayOf(), val hashOpsLimit: <Error class: unknown class> = HASH_OPS_LIMIT, val hashMemLimit: Int = HASH_MEM_LIMIT)
Parameters
passphrase
the password created by the user when encrypting
salt
the random bytes to spice things up, can be created with XChaChaPoly1305AuthenticationData.newSalt.
additionalData
extra data that can be used and can be validated together with the encrypted data.
It is optional and an empty array can be used, if no extra plaintext data needs to be validated.
For the purposes of backup, we can use a hash of the non-encrypted bytes of the file as additional data. This way, if these bytes were tempered with, the decryption will also fail. The idea is to do not trust any fruit from the poisoned tree.