Ecryptfs does not provide a helpful error when it fails to find a passphrase in the user's kernel keyring when mounting an encrypted directory.
The solution is to show an error that says, "Failed to perform eCryptfs mount, stored passphrase not found: [-32]"
The error reported by ecryptfs is the following, in system log:
mount.ecryptfs: Failed to perform eCryptfs mount: [-32]
in console output:
mount: mount(2) failed: No such file or directory
Error mounting eCryptfs: [-1] Operation not permitted
Below is the console output:
eric@skylab:~$ sudo ./mount.sh
Unable to find a list of options to parse, defaulting to interactive mount
Passphrase:
Select cipher:
1) aes: blocksize = 16; min keysize = 16; max keysize = 32
2) blowfish: blocksize = 8; min keysize = 16; max keysize = 56
3) des3_ede: blocksize = 8; min keysize = 24; max keysize = 24
4) twofish: blocksize = 16; min keysize = 16; max keysize = 32
5) cast6: blocksize = 16; min keysize = 16; max keysize = 32
6) cast5: blocksize = 8; min keysize = 5; max keysize = 16
Selection [aes]:
Select key bytes:
1) 16
2) 32
3) 24
Selection [16]:
Enable plaintext passthrough (y/n) [n]:
Enable filename encryption (y/n) [n]: y
Filename Encryption Key (FNEK) Signature [d395309aaad4de06]: be877764c5918621
Unable to find a list of options to parse, defaulting to interactive mount
Attempting to mount with the following options:
ecryptfs_unlink_sigs
ecryptfs_fnek_sig=be877764c5918621
ecryptfs_key_bytes=16
ecryptfs_cipher=aes
ecryptfs_sig=d395309aaad4de06
mount: mount(2) failed: No such file or directory
Error mounting eCryptfs: [-1] Operation not permitted
Check your system logs; visit <http://ecryptfs.org/support.html>