e98ad46475
Add an ioctl FS_IOC_GET_ENCRYPTION_NONCE which retrieves the nonce from an encrypted file or directory. The nonce is the 16-byte random value stored in the inode's encryption xattr. It is normally used together with the master key to derive the inode's actual encryption key. The nonces are needed by automated tests that verify the correctness of the ciphertext on-disk. Except for the IV_INO_LBLK_64 case, there's no way to replicate a file's ciphertext without knowing that file's nonce. The nonces aren't secret, and the existing ciphertext verification tests in xfstests retrieve them from disk using debugfs or dump.f2fs. But in environments that lack these debugging tools, getting the nonces by manually parsing the filesystem structure would be very hard. To make this important type of testing much easier, let's just add an ioctl that retrieves the nonce. Link: https://lore.kernel.org/r/20200314205052.93294-2-ebiggers@kernel.org Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com> |
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| asm-generic | ||
| drm | ||
| linux | ||
| misc | ||
| mtd | ||
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| scsi | ||
| sound | ||
| video | ||
| xen | ||
| Kbuild | ||