Is there any maximum lenght of the passphrase in the hardrive encryption option on ubuntu (luks)?
LUKS is configured via
cryptsetup which has a compiled-in limitation of 512 characters for an interactive passphrase. In theory there is no limitation on the length of the passphrase as it is processed through a key derivation function.
$ crypsetup --help ... Default compiled-in key and passphrase parameters: Maximum keyfile size: 8192kB, Maximum interactive passphrase length 512 (characters) Default PBKDF2 iteration time for LUKS: 1000 (ms) Default compiled-in device cipher parameters: loop-AES: aes, Key 256 bits plain: aes-cbc-essiv:sha256, Key: 256 bits, Password hashing: ripemd160 LUKS1: aes-xts-plain64, Key: 256 bits, LUKS header hashing: sha1, RNG: /dev/urandom