On Sun, 24 Jan 2021 at 15:10, Stephan Müller <smueller@xxxxxxxxxx> wrote: > > Hi, > > The key derviation functions are considered to be a cryptographic > operation. As cryptographic operations are provided via the kernel > crypto API, this patch set consolidates the KDF implementations into the > crypto API. > > The KDF implementations are provided as service functions. Yet, the > interface to the two provided KDFs are identical with the goal to allow > them to be transformed into a crypto API template eventually. > Why? There are typically two reasons to use the crypto API abstractions: - the algorithm is not known at compile time, so we need the runtime dispatch that the crypto API implements, - the algorithm may be implemented by a h/w accelerator which is discovered at runtime via the driver stack In other cases, a library API is much more suitable, even in the case where we may provide arch-specific accelerated implementations of such an algorithm. > The KDFs execute a power-on self test with test vectors from commonly > known sources. > > Tbe SP800-108 KDF implementation is used to replace the implementation > in the keys subsystem. The implementation was verified using the > keyutils command line test code provided in > tests/keyctl/dh_compute/valid. All tests show that the expected values > are calculated with the new code. > > The HKDF addition is used to replace the implementation in the filesystem > crypto extension. This code was tested by using an EXT4 encrypted file > system that was created and contains files written to by the current > implementation. Using the new implementation a successful read of the > existing files was possible and new files / directories were created > and read successfully. These newly added file system objects could be > successfully read using the current code. Yet if there is a test suite > to validate whether the invokcation of the HKDF calculates the same > result as the existing implementation, I would be happy to validate > the implementation accordingly. > > Changes v2: > > * change HKDF function names > * change HKDF/SP800-108 KDF extract / seed function prototype > * ensure clearing of memory of destination buffer in KDF implementation > if KDF operation fails > * security DH: split the removal of dead code into separate patch > > Stephan Mueller (7): > crypto: Add key derivation self-test support code > crypto: add SP800-108 counter key derivation function > crypto: add RFC5869 HKDF > security: DH - remove dead code for zero padding > security: DH - use KDF implementation from crypto API > fs: use HKDF implementation from kernel crypto API > fs: HKDF - remove duplicate memory clearing > > crypto/Kconfig | 14 ++ > crypto/Makefile | 6 + > crypto/hkdf.c | 199 +++++++++++++++++++++++++ > crypto/kdf_sp800108.c | 149 ++++++++++++++++++ > fs/crypto/Kconfig | 2 +- > fs/crypto/hkdf.c | 103 +++---------- > include/crypto/hkdf.h | 48 ++++++ > include/crypto/internal/kdf_selftest.h | 71 +++++++++ > include/crypto/kdf_sp800108.h | 61 ++++++++ > security/keys/Kconfig | 2 +- > security/keys/dh.c | 118 ++------------- > 11 files changed, 586 insertions(+), 187 deletions(-) > create mode 100644 crypto/hkdf.c > create mode 100644 crypto/kdf_sp800108.c > create mode 100644 include/crypto/hkdf.h > create mode 100644 include/crypto/internal/kdf_selftest.h > create mode 100644 include/crypto/kdf_sp800108.h > > -- > 2.26.2 > > > >
