openssl/include/crypto/ec.h
slontis 78c44b0594 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 <hlandau@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19068)
2022-09-23 09:24:47 +01:00

102 lines
4.3 KiB
C

/*
* Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/* Internal EC functions for other submodules: not for application use */
#ifndef OSSL_CRYPTO_EC_H
# define OSSL_CRYPTO_EC_H
# pragma once
# include <openssl/opensslconf.h>
# include <openssl/evp.h>
int ossl_ec_curve_name2nid(const char *name);
const char *ossl_ec_curve_nid2nist_int(int nid);
int ossl_ec_curve_nist2nid_int(const char *name);
int evp_pkey_ctx_set_ec_param_enc_prov(EVP_PKEY_CTX *ctx, int param_enc);
# ifndef OPENSSL_NO_EC
# include <openssl/core.h>
# include <openssl/ec.h>
# include "crypto/types.h"
/*-
* Computes the multiplicative inverse of x in the range
* [1,EC_GROUP::order), where EC_GROUP::order is the cardinality of the
* subgroup generated by the generator G:
*
* res := x^(-1) (mod EC_GROUP::order).
*
* This function expects the following two conditions to hold:
* - the EC_GROUP order is prime, and
* - x is included in the range [1, EC_GROUP::order).
*
* This function returns 1 on success, 0 on error.
*
* If the EC_GROUP order is even, this function explicitly returns 0 as
* an error.
* In case any of the two conditions stated above is not satisfied,
* the correctness of its output is not guaranteed, even if the return
* value could still be 1 (as primality testing and a conditional modular
* reduction round on the input can be omitted by the underlying
* implementations for better SCA properties on regular input values).
*/
__owur int ossl_ec_group_do_inverse_ord(const EC_GROUP *group, BIGNUM *res,
const BIGNUM *x, BN_CTX *ctx);
/*-
* ECDH Key Derivation Function as defined in ANSI X9.63
*/
int ossl_ecdh_kdf_X9_63(unsigned char *out, size_t outlen,
const unsigned char *Z, size_t Zlen,
const unsigned char *sinfo, size_t sinfolen,
const EVP_MD *md, OSSL_LIB_CTX *libctx,
const char *propq);
int ossl_ec_key_public_check(const EC_KEY *eckey, BN_CTX *ctx);
int ossl_ec_key_public_check_quick(const EC_KEY *eckey, BN_CTX *ctx);
int ossl_ec_key_private_check(const EC_KEY *eckey);
int ossl_ec_key_pairwise_check(const EC_KEY *eckey, BN_CTX *ctx);
OSSL_LIB_CTX *ossl_ec_key_get_libctx(const EC_KEY *eckey);
const char *ossl_ec_key_get0_propq(const EC_KEY *eckey);
void ossl_ec_key_set0_libctx(EC_KEY *key, OSSL_LIB_CTX *libctx);
/* Backend support */
int ossl_ec_group_todata(const EC_GROUP *group, OSSL_PARAM_BLD *tmpl,
OSSL_PARAM params[], OSSL_LIB_CTX *libctx,
const char *propq,
BN_CTX *bnctx, unsigned char **genbuf);
int ossl_ec_group_fromdata(EC_KEY *ec, const OSSL_PARAM params[]);
int ossl_ec_group_set_params(EC_GROUP *group, const OSSL_PARAM params[]);
int ossl_ec_key_fromdata(EC_KEY *ecx, const OSSL_PARAM params[],
int include_private);
int ossl_ec_key_otherparams_fromdata(EC_KEY *ec, const OSSL_PARAM params[]);
int ossl_ec_key_is_foreign(const EC_KEY *ec);
EC_KEY *ossl_ec_key_dup(const EC_KEY *key, int selection);
int ossl_x509_algor_is_sm2(const X509_ALGOR *palg);
EC_KEY *ossl_ec_key_param_from_x509_algor(const X509_ALGOR *palg,
OSSL_LIB_CTX *libctx,
const char *propq);
EC_KEY *ossl_ec_key_from_pkcs8(const PKCS8_PRIV_KEY_INFO *p8inf,
OSSL_LIB_CTX *libctx, const char *propq);
int ossl_ec_set_ecdh_cofactor_mode(EC_KEY *ec, int mode);
int ossl_ec_encoding_name2id(const char *name);
int ossl_ec_encoding_param2id(const OSSL_PARAM *p, int *id);
int ossl_ec_pt_format_name2id(const char *name);
int ossl_ec_pt_format_param2id(const OSSL_PARAM *p, int *id);
char *ossl_ec_pt_format_id2name(int id);
char *ossl_ec_check_group_type_id2name(int flags);
int ossl_ec_set_check_group_type_from_name(EC_KEY *ec, const char *name);
int ossl_ec_generate_key_dhkem(EC_KEY *eckey,
const unsigned char *ikm, size_t ikmlen);
# endif /* OPENSSL_NO_EC */
#endif