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. 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
