On Fri, Apr 26, 2019 at 01:41:46PM -0700, Eric Biggers wrote: > Hello, > > This series adds xfstests which verify that encrypted contents and > filenames on ext4 and f2fs are actually correct, i.e. that the > encryption uses the correct algorithms, keys, IVs, and padding amounts. > The new tests work by creating encrypted files, unmounting the > filesystem, reading the ciphertext from disk using dd and debugfs or > dump.f2fs, and then comparing it against ciphertext computed > independently by a new test program that implements the same algorithms. > > These tests are important because: > > - The whole point of file encryption is that the files are actually > encrypted correctly on-disk. Except for generic/399, current xfstests > only tests the filesystem semantics, not the actual encryption. > generic/399 only tests for incompressibility of encrypted file > contents using one particular encryption setting, which isn't much. > > - fscrypt now supports 4 main combinations of encryption settings, > rather than 1 as it did originally. This may be doubled to 8 soon > (https://patchwork.kernel.org/patch/10908153/). We should test all > settings. And without tests, even if the initial implementation is > correct, breakage in one specific setting could go undetected. > > - Though Linux's crypto API has self-tests, these only test the > algorithms themselves, not how they are used, e.g. by fscrypt. > > Patch 1 is a cleanup patch. Patches 2-4 add the common helpers for > ciphertext verification tests. Patches 5-7 add the actual tests. > > These tests require e2fsprogs and f2fs-tools patches I recently sent out > to fix printing encrypted filenames. So, this series might not be > suitable for merging into mainline xfstests until those patches are > applied. Regardless, comments are appreciated. The needed patches are: > > debugfs: avoid ambiguity when printing filenames (https://marc.info/?l=linux-ext4&m=155596495624232&w=2) > f2fs-tools: improve filename printing (https://sourceforge.net/p/linux-f2fs/mailman/message/36648641/) > > This series can also be retrieved from git at > https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/xfstests-dev.git > branch "ciphertext-verification". > > I also have patches on top of this series which verify the ciphertext > produced from v2 encryption policies, which are proposed by my kernel > patch series "fscrypt: key management improvements" > (https://patchwork.kernel.org/cover/10908107/). v2 encryption policies > will use a different key derivation function, and thus their ciphertext > will be different. These additional patches can be found at branch > "fscrypt-key-mgmt-improvements" of my git repo above. But I've arranged > things such that this shorter series can potentially be applied earlier, > to test what's in the kernel now. > > Eric Biggers (7): > common/encrypt: introduce helpers for set_encpolicy and get_encpolicy > fscrypt-crypt-util: add utility for reproducing fscrypt encrypted data > common/encrypt: support requiring other encryption settings > common/encrypt: add helper for ciphertext verification tests > generic: verify ciphertext of v1 encryption policies with AES-256 > generic: verify ciphertext of v1 encryption policies with AES-128 > generic: verify ciphertext of v1 encryption policies with Adiantum > > .gitignore | 1 + > common/encrypt | 482 ++++++++++- > src/Makefile | 3 +- > src/fscrypt-crypt-util.c | 1645 ++++++++++++++++++++++++++++++++++++++ > tests/ext4/024 | 3 +- > tests/generic/395 | 28 +- > tests/generic/395.out | 2 +- > tests/generic/396 | 15 +- > tests/generic/397 | 3 +- > tests/generic/398 | 5 +- > tests/generic/399 | 3 +- > tests/generic/419 | 3 +- > tests/generic/421 | 3 +- > tests/generic/429 | 3 +- > tests/generic/435 | 3 +- > tests/generic/440 | 5 +- > tests/generic/700 | 41 + > tests/generic/700.out | 5 + > tests/generic/701 | 41 + > tests/generic/701.out | 5 + > tests/generic/702 | 43 + > tests/generic/702.out | 10 + > tests/generic/group | 3 + > 23 files changed, 2308 insertions(+), 47 deletions(-) > create mode 100644 src/fscrypt-crypt-util.c > create mode 100755 tests/generic/700 > create mode 100644 tests/generic/700.out > create mode 100755 tests/generic/701 > create mode 100644 tests/generic/701.out > create mode 100755 tests/generic/702 > create mode 100644 tests/generic/702.out > > -- > 2.21.0.593.g511ec345e18-goog > Any comments on this? FYI, the e2fsprogs patch that these tests need was applied. I'm still waiting for the f2fs-tools patch. - Eric
