From 78c44b05945be07eae86f0164b9b777e2de2295b Mon Sep 17 00:00:00 2001 From: slontis Date: Fri, 26 Aug 2022 11:54:35 +1000 Subject: Add HPKE DHKEM provider support for EC, X25519 and X448. The code is derived from @sftcd's work in PR #17172. This PR puts the DHKEM algorithms into the provider layer as KEM algorithms for EC and ECX. This PR only implements the DHKEM component of HPKE as specified in RFC 9180. crypto/hpke/hpke_util.c has been added for fuctions that will be shared between DHKEM and HPKE. API's for EVP_PKEY_auth_encapsulate_init() and EVP_PKEY_auth_decapsulate_init() have been added to support authenticated encapsulation. auth_init() functions were chosen rather that a EVP_PKEY_KEM_set_auth() interface to support future algorithms that could possibly need different init functions. Internal code has been refactored, so that it can be shared between the DHKEM and other systems. Since DHKEM operates on low level keys it needs to be able to do low level ECDH and ECXDH calls without converting the keys back into EVP_PKEY/EVP_PKEY_CTX form. See ossl_ecx_compute_key(), ossl_ec_public_from_private() DHKEM requires API's to derive a key using a seed (IKM). This did not sit well inside the DHKEM itself as dispatch functions. This functionality fits better inside the EC and ECX keymanagers keygen, since they are just variations of keygen where the private key is generated in a different manner. This should mainly be used for testing purposes. See ossl_ec_generate_key_dhkem(). It supports this by allowing a settable param to be passed to keygen (See OSSL_PKEY_PARAM_DHKEM_IKM). The keygen calls code within ec and ecx dhkem implementation to handle this. See ossl_ecx_dhkem_derive_private() and ossl_ec_dhkem_derive_private(). These 2 functions are also used by the EC/ECX DHKEM implementations to generate the sender ephemeral keys. Reviewed-by: Hugo Landau Reviewed-by: Matt Caswell (Merged from https://github.com/openssl/openssl/pull/19068) --- providers/implementations/kem/build.info | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'providers/implementations/kem/build.info') diff --git a/providers/implementations/kem/build.info b/providers/implementations/kem/build.info index dbb1b7d750..6addb9b2c7 100644 --- a/providers/implementations/kem/build.info +++ b/providers/implementations/kem/build.info @@ -2,5 +2,10 @@ # switch each to the Legacy provider when needed. $RSA_KEM_GOAL=../../libdefault.a ../../libfips.a +$EC_KEM_GOAL=../../libdefault.a SOURCE[$RSA_KEM_GOAL]=rsa_kem.c + +IF[{- !$disabled{ec} -}] + SOURCE[$EC_KEM_GOAL]=ecx_kem.c kem_util.c ec_kem.c +ENDIF -- cgit v1.2.1