512 lines
15 KiB
C
512 lines
15 KiB
C
/*
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* Copyright 2019-2023 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the Apache License 2.0 (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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/*
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* DH low level APIs are deprecated for public use, but still ok for
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* internal use.
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*/
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#include "internal/deprecated.h"
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#include <string.h>
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#include <openssl/crypto.h>
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#include <openssl/core_dispatch.h>
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#include <openssl/core_names.h>
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#include <openssl/dh.h>
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#include <openssl/err.h>
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#include <openssl/proverr.h>
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#include <openssl/params.h>
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#include "prov/providercommon.h"
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#include "prov/implementations.h"
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#include "prov/provider_ctx.h"
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#include "prov/securitycheck.h"
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#include "crypto/dh.h"
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static OSSL_FUNC_keyexch_newctx_fn dh_newctx;
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static OSSL_FUNC_keyexch_init_fn dh_init;
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static OSSL_FUNC_keyexch_set_peer_fn dh_set_peer;
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static OSSL_FUNC_keyexch_derive_fn dh_derive;
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static OSSL_FUNC_keyexch_freectx_fn dh_freectx;
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static OSSL_FUNC_keyexch_dupctx_fn dh_dupctx;
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static OSSL_FUNC_keyexch_set_ctx_params_fn dh_set_ctx_params;
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static OSSL_FUNC_keyexch_settable_ctx_params_fn dh_settable_ctx_params;
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static OSSL_FUNC_keyexch_get_ctx_params_fn dh_get_ctx_params;
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static OSSL_FUNC_keyexch_gettable_ctx_params_fn dh_gettable_ctx_params;
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/*
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* This type is only really used to handle some legacy related functionality.
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* If you need to use other KDF's (such as SSKDF) just use PROV_DH_KDF_NONE
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* here and then create and run a KDF after the key is derived.
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* Note that X942 has 2 variants of key derivation:
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* (1) DH_KDF_X9_42_ASN1 - which contains an ANS1 encoded object that has
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* the counter embedded in it.
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* (2) DH_KDF_X941_CONCAT - which is the same as ECDH_X963_KDF (which can be
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* done by creating a "X963KDF".
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*/
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enum kdf_type {
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PROV_DH_KDF_NONE = 0,
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PROV_DH_KDF_X9_42_ASN1
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};
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/*
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* What's passed as an actual key is defined by the KEYMGMT interface.
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* We happen to know that our KEYMGMT simply passes DH structures, so
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* we use that here too.
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*/
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typedef struct {
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OSSL_LIB_CTX *libctx;
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DH *dh;
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DH *dhpeer;
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unsigned int pad : 1;
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/* DH KDF */
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/* KDF (if any) to use for DH */
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enum kdf_type kdf_type;
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/* Message digest to use for key derivation */
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EVP_MD *kdf_md;
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/* User key material */
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unsigned char *kdf_ukm;
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size_t kdf_ukmlen;
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/* KDF output length */
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size_t kdf_outlen;
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char *kdf_cekalg;
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} PROV_DH_CTX;
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static void *dh_newctx(void *provctx)
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{
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PROV_DH_CTX *pdhctx;
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if (!ossl_prov_is_running())
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return NULL;
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pdhctx = OPENSSL_zalloc(sizeof(PROV_DH_CTX));
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if (pdhctx == NULL)
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return NULL;
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pdhctx->libctx = PROV_LIBCTX_OF(provctx);
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pdhctx->kdf_type = PROV_DH_KDF_NONE;
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return pdhctx;
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}
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static int dh_init(void *vpdhctx, void *vdh, const OSSL_PARAM params[])
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{
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PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
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if (!ossl_prov_is_running()
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|| pdhctx == NULL
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|| vdh == NULL
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|| !DH_up_ref(vdh))
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return 0;
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DH_free(pdhctx->dh);
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pdhctx->dh = vdh;
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pdhctx->kdf_type = PROV_DH_KDF_NONE;
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return dh_set_ctx_params(pdhctx, params)
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&& ossl_dh_check_key(pdhctx->libctx, vdh);
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}
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/* The 2 parties must share the same domain parameters */
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static int dh_match_params(DH *priv, DH *peer)
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{
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int ret;
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FFC_PARAMS *dhparams_priv = ossl_dh_get0_params(priv);
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FFC_PARAMS *dhparams_peer = ossl_dh_get0_params(peer);
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ret = dhparams_priv != NULL
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&& dhparams_peer != NULL
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&& ossl_ffc_params_cmp(dhparams_priv, dhparams_peer, 1);
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if (!ret)
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ERR_raise(ERR_LIB_PROV, PROV_R_MISMATCHING_DOMAIN_PARAMETERS);
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return ret;
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}
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static int dh_set_peer(void *vpdhctx, void *vdh)
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{
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PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
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if (!ossl_prov_is_running()
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|| pdhctx == NULL
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|| vdh == NULL
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|| !dh_match_params(vdh, pdhctx->dh)
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|| !DH_up_ref(vdh))
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return 0;
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DH_free(pdhctx->dhpeer);
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pdhctx->dhpeer = vdh;
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return 1;
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}
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static int dh_plain_derive(void *vpdhctx,
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unsigned char *secret, size_t *secretlen,
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size_t outlen, unsigned int pad)
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{
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PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
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int ret;
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size_t dhsize;
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const BIGNUM *pub_key = NULL;
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if (pdhctx->dh == NULL || pdhctx->dhpeer == NULL) {
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ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY);
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return 0;
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}
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dhsize = (size_t)DH_size(pdhctx->dh);
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if (secret == NULL) {
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*secretlen = dhsize;
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return 1;
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}
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if (outlen < dhsize) {
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ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
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return 0;
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}
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DH_get0_key(pdhctx->dhpeer, &pub_key, NULL);
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if (pad)
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ret = DH_compute_key_padded(secret, pub_key, pdhctx->dh);
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else
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ret = DH_compute_key(secret, pub_key, pdhctx->dh);
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if (ret <= 0)
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return 0;
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*secretlen = ret;
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return 1;
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}
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static int dh_X9_42_kdf_derive(void *vpdhctx, unsigned char *secret,
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size_t *secretlen, size_t outlen)
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{
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PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
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unsigned char *stmp = NULL;
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size_t stmplen;
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int ret = 0;
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if (secret == NULL) {
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*secretlen = pdhctx->kdf_outlen;
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return 1;
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}
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if (pdhctx->kdf_outlen > outlen) {
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ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
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return 0;
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}
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if (!dh_plain_derive(pdhctx, NULL, &stmplen, 0, 1))
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return 0;
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if ((stmp = OPENSSL_secure_malloc(stmplen)) == NULL)
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return 0;
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if (!dh_plain_derive(pdhctx, stmp, &stmplen, stmplen, 1))
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goto err;
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/* Do KDF stuff */
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if (pdhctx->kdf_type == PROV_DH_KDF_X9_42_ASN1) {
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if (!ossl_dh_kdf_X9_42_asn1(secret, pdhctx->kdf_outlen,
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stmp, stmplen,
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pdhctx->kdf_cekalg,
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pdhctx->kdf_ukm,
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pdhctx->kdf_ukmlen,
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pdhctx->kdf_md,
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pdhctx->libctx, NULL))
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goto err;
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}
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*secretlen = pdhctx->kdf_outlen;
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ret = 1;
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err:
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OPENSSL_secure_clear_free(stmp, stmplen);
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return ret;
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}
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static int dh_derive(void *vpdhctx, unsigned char *secret,
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size_t *psecretlen, size_t outlen)
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{
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PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
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if (!ossl_prov_is_running())
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return 0;
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switch (pdhctx->kdf_type) {
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case PROV_DH_KDF_NONE:
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return dh_plain_derive(pdhctx, secret, psecretlen, outlen,
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pdhctx->pad);
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case PROV_DH_KDF_X9_42_ASN1:
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return dh_X9_42_kdf_derive(pdhctx, secret, psecretlen, outlen);
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default:
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break;
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}
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return 0;
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}
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static void dh_freectx(void *vpdhctx)
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{
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PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
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OPENSSL_free(pdhctx->kdf_cekalg);
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DH_free(pdhctx->dh);
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DH_free(pdhctx->dhpeer);
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EVP_MD_free(pdhctx->kdf_md);
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OPENSSL_clear_free(pdhctx->kdf_ukm, pdhctx->kdf_ukmlen);
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OPENSSL_free(pdhctx);
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}
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static void *dh_dupctx(void *vpdhctx)
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{
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PROV_DH_CTX *srcctx = (PROV_DH_CTX *)vpdhctx;
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PROV_DH_CTX *dstctx;
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if (!ossl_prov_is_running())
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return NULL;
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dstctx = OPENSSL_zalloc(sizeof(*srcctx));
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if (dstctx == NULL)
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return NULL;
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*dstctx = *srcctx;
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dstctx->dh = NULL;
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dstctx->dhpeer = NULL;
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dstctx->kdf_md = NULL;
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dstctx->kdf_ukm = NULL;
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dstctx->kdf_cekalg = NULL;
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if (srcctx->dh != NULL && !DH_up_ref(srcctx->dh))
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goto err;
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else
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dstctx->dh = srcctx->dh;
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if (srcctx->dhpeer != NULL && !DH_up_ref(srcctx->dhpeer))
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goto err;
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else
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dstctx->dhpeer = srcctx->dhpeer;
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if (srcctx->kdf_md != NULL && !EVP_MD_up_ref(srcctx->kdf_md))
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goto err;
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else
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dstctx->kdf_md = srcctx->kdf_md;
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/* Duplicate UKM data if present */
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if (srcctx->kdf_ukm != NULL && srcctx->kdf_ukmlen > 0) {
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dstctx->kdf_ukm = OPENSSL_memdup(srcctx->kdf_ukm,
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srcctx->kdf_ukmlen);
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if (dstctx->kdf_ukm == NULL)
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goto err;
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}
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if (srcctx->kdf_cekalg != NULL) {
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dstctx->kdf_cekalg = OPENSSL_strdup(srcctx->kdf_cekalg);
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if (dstctx->kdf_cekalg == NULL)
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goto err;
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}
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return dstctx;
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err:
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dh_freectx(dstctx);
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return NULL;
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}
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static int dh_set_ctx_params(void *vpdhctx, const OSSL_PARAM params[])
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{
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PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
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const OSSL_PARAM *p;
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unsigned int pad;
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char name[80] = { '\0' }; /* should be big enough */
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char *str = NULL;
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if (pdhctx == NULL)
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return 0;
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if (params == NULL)
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return 1;
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p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_TYPE);
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if (p != NULL) {
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str = name;
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if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(name)))
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return 0;
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if (name[0] == '\0')
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pdhctx->kdf_type = PROV_DH_KDF_NONE;
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else if (strcmp(name, OSSL_KDF_NAME_X942KDF_ASN1) == 0)
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pdhctx->kdf_type = PROV_DH_KDF_X9_42_ASN1;
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else
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return 0;
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}
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p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_DIGEST);
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if (p != NULL) {
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char mdprops[80] = { '\0' }; /* should be big enough */
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str = name;
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if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(name)))
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return 0;
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str = mdprops;
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p = OSSL_PARAM_locate_const(params,
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OSSL_EXCHANGE_PARAM_KDF_DIGEST_PROPS);
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if (p != NULL) {
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if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdprops)))
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return 0;
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}
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EVP_MD_free(pdhctx->kdf_md);
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pdhctx->kdf_md = EVP_MD_fetch(pdhctx->libctx, name, mdprops);
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if (pdhctx->kdf_md == NULL)
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return 0;
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if (!ossl_digest_is_allowed(pdhctx->libctx, pdhctx->kdf_md)) {
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EVP_MD_free(pdhctx->kdf_md);
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pdhctx->kdf_md = NULL;
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return 0;
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}
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}
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p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_OUTLEN);
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if (p != NULL) {
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size_t outlen;
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if (!OSSL_PARAM_get_size_t(p, &outlen))
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return 0;
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pdhctx->kdf_outlen = outlen;
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}
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p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_UKM);
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if (p != NULL) {
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void *tmp_ukm = NULL;
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size_t tmp_ukmlen;
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OPENSSL_free(pdhctx->kdf_ukm);
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pdhctx->kdf_ukm = NULL;
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pdhctx->kdf_ukmlen = 0;
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/* ukm is an optional field so it can be NULL */
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if (p->data != NULL && p->data_size != 0) {
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if (!OSSL_PARAM_get_octet_string(p, &tmp_ukm, 0, &tmp_ukmlen))
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return 0;
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pdhctx->kdf_ukm = tmp_ukm;
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pdhctx->kdf_ukmlen = tmp_ukmlen;
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}
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}
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p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_PAD);
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if (p != NULL) {
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if (!OSSL_PARAM_get_uint(p, &pad))
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return 0;
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pdhctx->pad = pad ? 1 : 0;
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}
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p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_CEK_ALG);
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if (p != NULL) {
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str = name;
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OPENSSL_free(pdhctx->kdf_cekalg);
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pdhctx->kdf_cekalg = NULL;
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if (p->data != NULL && p->data_size != 0) {
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if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(name)))
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return 0;
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pdhctx->kdf_cekalg = OPENSSL_strdup(name);
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if (pdhctx->kdf_cekalg == NULL)
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return 0;
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}
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}
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return 1;
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}
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static const OSSL_PARAM known_settable_ctx_params[] = {
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OSSL_PARAM_int(OSSL_EXCHANGE_PARAM_PAD, NULL),
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OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_TYPE, NULL, 0),
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OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_DIGEST, NULL, 0),
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OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_DIGEST_PROPS, NULL, 0),
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OSSL_PARAM_size_t(OSSL_EXCHANGE_PARAM_KDF_OUTLEN, NULL),
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OSSL_PARAM_octet_string(OSSL_EXCHANGE_PARAM_KDF_UKM, NULL, 0),
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OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CEK_ALG, NULL, 0),
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OSSL_PARAM_END
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};
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static const OSSL_PARAM *dh_settable_ctx_params(ossl_unused void *vpdhctx,
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ossl_unused void *provctx)
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{
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return known_settable_ctx_params;
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}
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static const OSSL_PARAM known_gettable_ctx_params[] = {
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OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_TYPE, NULL, 0),
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OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_DIGEST, NULL, 0),
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OSSL_PARAM_size_t(OSSL_EXCHANGE_PARAM_KDF_OUTLEN, NULL),
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OSSL_PARAM_DEFN(OSSL_EXCHANGE_PARAM_KDF_UKM, OSSL_PARAM_OCTET_PTR,
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NULL, 0),
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OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CEK_ALG, NULL, 0),
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OSSL_PARAM_END
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};
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static const OSSL_PARAM *dh_gettable_ctx_params(ossl_unused void *vpdhctx,
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ossl_unused void *provctx)
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{
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return known_gettable_ctx_params;
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}
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static int dh_get_ctx_params(void *vpdhctx, OSSL_PARAM params[])
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{
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PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx;
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OSSL_PARAM *p;
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if (pdhctx == NULL)
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return 0;
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p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_TYPE);
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if (p != NULL) {
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const char *kdf_type = NULL;
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switch (pdhctx->kdf_type) {
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case PROV_DH_KDF_NONE:
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kdf_type = "";
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break;
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case PROV_DH_KDF_X9_42_ASN1:
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kdf_type = OSSL_KDF_NAME_X942KDF_ASN1;
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break;
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default:
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return 0;
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}
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if (!OSSL_PARAM_set_utf8_string(p, kdf_type))
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return 0;
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}
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p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_DIGEST);
|
|
if (p != NULL
|
|
&& !OSSL_PARAM_set_utf8_string(p, pdhctx->kdf_md == NULL
|
|
? ""
|
|
: EVP_MD_get0_name(pdhctx->kdf_md))) {
|
|
return 0;
|
|
}
|
|
|
|
p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_OUTLEN);
|
|
if (p != NULL && !OSSL_PARAM_set_size_t(p, pdhctx->kdf_outlen))
|
|
return 0;
|
|
|
|
p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_UKM);
|
|
if (p != NULL
|
|
&& !OSSL_PARAM_set_octet_ptr(p, pdhctx->kdf_ukm, pdhctx->kdf_ukmlen))
|
|
return 0;
|
|
|
|
p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_CEK_ALG);
|
|
if (p != NULL
|
|
&& !OSSL_PARAM_set_utf8_string(p, pdhctx->kdf_cekalg == NULL
|
|
? "" : pdhctx->kdf_cekalg))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
const OSSL_DISPATCH ossl_dh_keyexch_functions[] = {
|
|
{ OSSL_FUNC_KEYEXCH_NEWCTX, (void (*)(void))dh_newctx },
|
|
{ OSSL_FUNC_KEYEXCH_INIT, (void (*)(void))dh_init },
|
|
{ OSSL_FUNC_KEYEXCH_DERIVE, (void (*)(void))dh_derive },
|
|
{ OSSL_FUNC_KEYEXCH_SET_PEER, (void (*)(void))dh_set_peer },
|
|
{ OSSL_FUNC_KEYEXCH_FREECTX, (void (*)(void))dh_freectx },
|
|
{ OSSL_FUNC_KEYEXCH_DUPCTX, (void (*)(void))dh_dupctx },
|
|
{ OSSL_FUNC_KEYEXCH_SET_CTX_PARAMS, (void (*)(void))dh_set_ctx_params },
|
|
{ OSSL_FUNC_KEYEXCH_SETTABLE_CTX_PARAMS,
|
|
(void (*)(void))dh_settable_ctx_params },
|
|
{ OSSL_FUNC_KEYEXCH_GET_CTX_PARAMS, (void (*)(void))dh_get_ctx_params },
|
|
{ OSSL_FUNC_KEYEXCH_GETTABLE_CTX_PARAMS,
|
|
(void (*)(void))dh_gettable_ctx_params },
|
|
OSSL_DISPATCH_END
|
|
};
|