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 SP800-108 KDF implementation into the crypto API. If this patch is accepted, another patch set will be published attempting to move the HKDF implementation from the crypto file system code base to the kernel crypto API. The KDF implementation is provided as service functions. Yet, the interface to the the provided KDF is modeled such, that additional KDF implementation can use the same API style. The goal is to allow the transformation from a service function into a crypto API template eventually. The KDF executes 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. Changes v3 to v4: * SP800-108 KDF kernel configuration parameter is not user selectable as suggested by Eric Biggers * update the error code path for the self test handling to mirror testmgr.c as suggested by Eric Biggers * further cleanup in kdf_alloc as suggested by Mat Martineau Changes v2 to v3: * port to kernel 5.16-rc1 * remove the HKDF patch to only leave the SP800-108 patch Stephan Mueller (4): crypto: Add key derivation self-test support code crypto: add SP800-108 counter key derivation function security: DH - remove dead code for zero padding security: DH - use KDF implementation from crypto API crypto/Kconfig | 4 + crypto/Makefile | 5 + crypto/kdf_sp800108.c | 153 +++++++++++++++++++++++++ include/crypto/internal/kdf_selftest.h | 71 ++++++++++++ include/crypto/kdf_sp800108.h | 61 ++++++++++ security/keys/Kconfig | 2 +- security/keys/dh.c | 130 ++++----------------- 7 files changed, 315 insertions(+), 111 deletions(-) create mode 100644 crypto/kdf_sp800108.c create mode 100644 include/crypto/internal/kdf_selftest.h create mode 100644 include/crypto/kdf_sp800108.h -- 2.33.1
