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|
/*
* Copyright 2019-2023 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
*/
#include <openssl/crypto.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include "internal/cryptlib.h"
#include "internal/refcount.h"
#include "internal/provider.h"
#include "internal/core.h"
#include "internal/numbers.h" /* includes SIZE_MAX */
#include "crypto/evp.h"
#include "evp_local.h"
static EVP_KEYEXCH *evp_keyexch_new(OSSL_PROVIDER *prov)
{
EVP_KEYEXCH *exchange = OPENSSL_zalloc(sizeof(EVP_KEYEXCH));
if (exchange == NULL)
return NULL;
if (!CRYPTO_NEW_REF(&exchange->refcnt, 1)) {
OPENSSL_free(exchange);
return NULL;
}
exchange->prov = prov;
ossl_provider_up_ref(prov);
return exchange;
}
static void *evp_keyexch_from_algorithm(int name_id,
const OSSL_ALGORITHM *algodef,
OSSL_PROVIDER *prov)
{
const OSSL_DISPATCH *fns = algodef->implementation;
EVP_KEYEXCH *exchange = NULL;
int fncnt = 0, sparamfncnt = 0, gparamfncnt = 0;
if ((exchange = evp_keyexch_new(prov)) == NULL) {
ERR_raise(ERR_LIB_EVP, ERR_R_EVP_LIB);
goto err;
}
exchange->name_id = name_id;
if ((exchange->type_name = ossl_algorithm_get1_first_name(algodef)) == NULL)
goto err;
exchange->description = algodef->algorithm_description;
for (; fns->function_id != 0; fns++) {
switch (fns->function_id) {
case OSSL_FUNC_KEYEXCH_NEWCTX:
if (exchange->newctx != NULL)
break;
exchange->newctx = OSSL_FUNC_keyexch_newctx(fns);
fncnt++;
break;
case OSSL_FUNC_KEYEXCH_INIT:
if (exchange->init != NULL)
break;
exchange->init = OSSL_FUNC_keyexch_init(fns);
fncnt++;
break;
case OSSL_FUNC_KEYEXCH_SET_PEER:
if (exchange->set_peer != NULL)
break;
exchange->set_peer = OSSL_FUNC_keyexch_set_peer(fns);
break;
case OSSL_FUNC_KEYEXCH_DERIVE:
if (exchange->derive != NULL)
break;
exchange->derive = OSSL_FUNC_keyexch_derive(fns);
fncnt++;
break;
case OSSL_FUNC_KEYEXCH_FREECTX:
if (exchange->freectx != NULL)
break;
exchange->freectx = OSSL_FUNC_keyexch_freectx(fns);
fncnt++;
break;
case OSSL_FUNC_KEYEXCH_DUPCTX:
if (exchange->dupctx != NULL)
break;
exchange->dupctx = OSSL_FUNC_keyexch_dupctx(fns);
break;
case OSSL_FUNC_KEYEXCH_GET_CTX_PARAMS:
if (exchange->get_ctx_params != NULL)
break;
exchange->get_ctx_params = OSSL_FUNC_keyexch_get_ctx_params(fns);
gparamfncnt++;
break;
case OSSL_FUNC_KEYEXCH_GETTABLE_CTX_PARAMS:
if (exchange->gettable_ctx_params != NULL)
break;
exchange->gettable_ctx_params
= OSSL_FUNC_keyexch_gettable_ctx_params(fns);
gparamfncnt++;
break;
case OSSL_FUNC_KEYEXCH_SET_CTX_PARAMS:
if (exchange->set_ctx_params != NULL)
break;
exchange->set_ctx_params = OSSL_FUNC_keyexch_set_ctx_params(fns);
sparamfncnt++;
break;
case OSSL_FUNC_KEYEXCH_SETTABLE_CTX_PARAMS:
if (exchange->settable_ctx_params != NULL)
break;
exchange->settable_ctx_params
= OSSL_FUNC_keyexch_settable_ctx_params(fns);
sparamfncnt++;
break;
}
}
if (fncnt != 4
|| (gparamfncnt != 0 && gparamfncnt != 2)
|| (sparamfncnt != 0 && sparamfncnt != 2)) {
/*
* In order to be a consistent set of functions we must have at least
* a complete set of "exchange" functions: init, derive, newctx,
* and freectx. The set_ctx_params and settable_ctx_params functions are
* optional, but if one of them is present then the other one must also
* be present. Same goes for get_ctx_params and gettable_ctx_params.
* The dupctx and set_peer functions are optional.
*/
ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS);
goto err;
}
return exchange;
err:
EVP_KEYEXCH_free(exchange);
return NULL;
}
void EVP_KEYEXCH_free(EVP_KEYEXCH *exchange)
{
int i;
if (exchange == NULL)
return;
CRYPTO_DOWN_REF(&exchange->refcnt, &i);
if (i > 0)
return;
OPENSSL_free(exchange->type_name);
ossl_provider_free(exchange->prov);
CRYPTO_FREE_REF(&exchange->refcnt);
OPENSSL_free(exchange);
}
int EVP_KEYEXCH_up_ref(EVP_KEYEXCH *exchange)
{
int ref = 0;
CRYPTO_UP_REF(&exchange->refcnt, &ref);
return 1;
}
OSSL_PROVIDER *EVP_KEYEXCH_get0_provider(const EVP_KEYEXCH *exchange)
{
return exchange->prov;
}
EVP_KEYEXCH *EVP_KEYEXCH_fetch(OSSL_LIB_CTX *ctx, const char *algorithm,
const char *properties)
{
return evp_generic_fetch(ctx, OSSL_OP_KEYEXCH, algorithm, properties,
evp_keyexch_from_algorithm,
(int (*)(void *))EVP_KEYEXCH_up_ref,
(void (*)(void *))EVP_KEYEXCH_free);
}
EVP_KEYEXCH *evp_keyexch_fetch_from_prov(OSSL_PROVIDER *prov,
const char *algorithm,
const char *properties)
{
return evp_generic_fetch_from_prov(prov, OSSL_OP_KEYEXCH,
algorithm, properties,
evp_keyexch_from_algorithm,
(int (*)(void *))EVP_KEYEXCH_up_ref,
(void (*)(void *))EVP_KEYEXCH_free);
}
int EVP_PKEY_derive_init(EVP_PKEY_CTX *ctx)
{
return EVP_PKEY_derive_init_ex(ctx, NULL);
}
int EVP_PKEY_derive_init_ex(EVP_PKEY_CTX *ctx, const OSSL_PARAM params[])
{
int ret;
void *provkey = NULL;
EVP_KEYEXCH *exchange = NULL;
EVP_KEYMGMT *tmp_keymgmt = NULL;
const OSSL_PROVIDER *tmp_prov = NULL;
const char *supported_exch = NULL;
int iter;
if (ctx == NULL) {
ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
return -2;
}
evp_pkey_ctx_free_old_ops(ctx);
ctx->operation = EVP_PKEY_OP_DERIVE;
ERR_set_mark();
if (evp_pkey_ctx_is_legacy(ctx))
goto legacy;
/*
* Some algorithms (e.g. legacy KDFs) don't have a pkey - so we create
* a blank one.
*/
if (ctx->pkey == NULL) {
EVP_PKEY *pkey = EVP_PKEY_new();
if (pkey == NULL
|| !EVP_PKEY_set_type_by_keymgmt(pkey, ctx->keymgmt)
|| (pkey->keydata = evp_keymgmt_newdata(ctx->keymgmt)) == NULL) {
ERR_clear_last_mark();
EVP_PKEY_free(pkey);
ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
goto err;
}
ctx->pkey = pkey;
}
/*
* Try to derive the supported exch from |ctx->keymgmt|.
*/
if (!ossl_assert(ctx->pkey->keymgmt == NULL
|| ctx->pkey->keymgmt == ctx->keymgmt)) {
ERR_clear_last_mark();
ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
goto err;
}
supported_exch = evp_keymgmt_util_query_operation_name(ctx->keymgmt,
OSSL_OP_KEYEXCH);
if (supported_exch == NULL) {
ERR_clear_last_mark();
ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
goto err;
}
/*
* We perform two iterations:
*
* 1. Do the normal exchange fetch, using the fetching data given by
* the EVP_PKEY_CTX.
* 2. Do the provider specific exchange fetch, from the same provider
* as |ctx->keymgmt|
*
* We then try to fetch the keymgmt from the same provider as the
* exchange, and try to export |ctx->pkey| to that keymgmt (when
* this keymgmt happens to be the same as |ctx->keymgmt|, the export
* is a no-op, but we call it anyway to not complicate the code even
* more).
* If the export call succeeds (returns a non-NULL provider key pointer),
* we're done and can perform the operation itself. If not, we perform
* the second iteration, or jump to legacy.
*/
for (iter = 1, provkey = NULL; iter < 3 && provkey == NULL; iter++) {
EVP_KEYMGMT *tmp_keymgmt_tofree = NULL;
/*
* If we're on the second iteration, free the results from the first.
* They are NULL on the first iteration, so no need to check what
* iteration we're on.
*/
EVP_KEYEXCH_free(exchange);
EVP_KEYMGMT_free(tmp_keymgmt);
switch (iter) {
case 1:
exchange =
EVP_KEYEXCH_fetch(ctx->libctx, supported_exch, ctx->propquery);
if (exchange != NULL)
tmp_prov = EVP_KEYEXCH_get0_provider(exchange);
break;
case 2:
tmp_prov = EVP_KEYMGMT_get0_provider(ctx->keymgmt);
exchange =
evp_keyexch_fetch_from_prov((OSSL_PROVIDER *)tmp_prov,
supported_exch, ctx->propquery);
if (exchange == NULL)
goto legacy;
break;
}
if (exchange == NULL)
continue;
/*
* Ensure that the key is provided, either natively, or as a cached
* export. We start by fetching the keymgmt with the same name as
* |ctx->keymgmt|, but from the provider of the exchange method, using
* the same property query as when fetching the exchange method.
* With the keymgmt we found (if we did), we try to export |ctx->pkey|
* to it (evp_pkey_export_to_provider() is smart enough to only actually
* export it if |tmp_keymgmt| is different from |ctx->pkey|'s keymgmt)
*/
tmp_keymgmt_tofree = tmp_keymgmt =
evp_keymgmt_fetch_from_prov((OSSL_PROVIDER *)tmp_prov,
EVP_KEYMGMT_get0_name(ctx->keymgmt),
ctx->propquery);
if (tmp_keymgmt != NULL)
provkey = evp_pkey_export_to_provider(ctx->pkey, ctx->libctx,
&tmp_keymgmt, ctx->propquery);
if (tmp_keymgmt == NULL)
EVP_KEYMGMT_free(tmp_keymgmt_tofree);
}
if (provkey == NULL) {
EVP_KEYEXCH_free(exchange);
goto legacy;
}
ERR_pop_to_mark();
/* No more legacy from here down to legacy: */
/* A Coverity false positive with up_ref/down_ref and free */
/* coverity[use_after_free] */
ctx->op.kex.exchange = exchange;
/* A Coverity false positive with up_ref/down_ref and free */
/* coverity[deref_arg] */
ctx->op.kex.algctx = exchange->newctx(ossl_provider_ctx(exchange->prov));
if (ctx->op.kex.algctx == NULL) {
/* The provider key can stay in the cache */
ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
goto err;
}
ret = exchange->init(ctx->op.kex.algctx, provkey, params);
EVP_KEYMGMT_free(tmp_keymgmt);
return ret ? 1 : 0;
err:
evp_pkey_ctx_free_old_ops(ctx);
ctx->operation = EVP_PKEY_OP_UNDEFINED;
EVP_KEYMGMT_free(tmp_keymgmt);
return 0;
legacy:
/*
* If we don't have the full support we need with provided methods,
* let's go see if legacy does.
*/
ERR_pop_to_mark();
#ifdef FIPS_MODULE
return 0;
#else
if (ctx->pmeth == NULL || ctx->pmeth->derive == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
return -2;
}
if (ctx->pmeth->derive_init == NULL)
return 1;
ret = ctx->pmeth->derive_init(ctx);
if (ret <= 0)
ctx->operation = EVP_PKEY_OP_UNDEFINED;
EVP_KEYMGMT_free(tmp_keymgmt);
return ret;
#endif
}
int EVP_PKEY_derive_set_peer_ex(EVP_PKEY_CTX *ctx, EVP_PKEY *peer,
int validate_peer)
{
int ret = 0, check;
void *provkey = NULL;
EVP_PKEY_CTX *check_ctx = NULL;
EVP_KEYMGMT *tmp_keymgmt = NULL, *tmp_keymgmt_tofree = NULL;
if (ctx == NULL) {
ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
return -1;
}
if (!EVP_PKEY_CTX_IS_DERIVE_OP(ctx) || ctx->op.kex.algctx == NULL)
goto legacy;
if (ctx->op.kex.exchange->set_peer == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
return -2;
}
if (validate_peer) {
check_ctx = EVP_PKEY_CTX_new_from_pkey(ctx->libctx, peer, ctx->propquery);
if (check_ctx == NULL)
return -1;
check = EVP_PKEY_public_check(check_ctx);
EVP_PKEY_CTX_free(check_ctx);
if (check <= 0)
return -1;
}
/*
* Ensure that the |peer| is provided, either natively, or as a cached
* export. We start by fetching the keymgmt with the same name as
* |ctx->keymgmt|, but from the provider of the exchange method, using
* the same property query as when fetching the exchange method.
* With the keymgmt we found (if we did), we try to export |peer|
* to it (evp_pkey_export_to_provider() is smart enough to only actually
* export it if |tmp_keymgmt| is different from |peer|'s keymgmt)
*/
tmp_keymgmt_tofree = tmp_keymgmt =
evp_keymgmt_fetch_from_prov((OSSL_PROVIDER *)
EVP_KEYEXCH_get0_provider(ctx->op.kex.exchange),
EVP_KEYMGMT_get0_name(ctx->keymgmt),
ctx->propquery);
if (tmp_keymgmt != NULL)
/* A Coverity issue with up_ref/down_ref and free */
/* coverity[pass_freed_arg] */
provkey = evp_pkey_export_to_provider(peer, ctx->libctx,
&tmp_keymgmt, ctx->propquery);
EVP_KEYMGMT_free(tmp_keymgmt_tofree);
/*
* If making the key provided wasn't possible, legacy may be able to pick
* it up
*/
if (provkey == NULL)
goto legacy;
return ctx->op.kex.exchange->set_peer(ctx->op.kex.algctx, provkey);
legacy:
#ifdef FIPS_MODULE
return ret;
#else
if (ctx->pmeth == NULL
|| !(ctx->pmeth->derive != NULL
|| ctx->pmeth->encrypt != NULL
|| ctx->pmeth->decrypt != NULL)
|| ctx->pmeth->ctrl == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
return -2;
}
if (ctx->operation != EVP_PKEY_OP_DERIVE
&& ctx->operation != EVP_PKEY_OP_ENCRYPT
&& ctx->operation != EVP_PKEY_OP_DECRYPT) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_INITIALIZED);
return -1;
}
ret = ctx->pmeth->ctrl(ctx, EVP_PKEY_CTRL_PEER_KEY, 0, peer);
if (ret <= 0)
return ret;
if (ret == 2)
return 1;
if (ctx->pkey == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_NO_KEY_SET);
return -1;
}
if (ctx->pkey->type != peer->type) {
ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);
return -1;
}
/*
* For clarity. The error is if parameters in peer are
* present (!missing) but don't match. EVP_PKEY_parameters_eq may return
* 1 (match), 0 (don't match) and -2 (comparison is not defined). -1
* (different key types) is impossible here because it is checked earlier.
* -2 is OK for us here, as well as 1, so we can check for 0 only.
*/
if (!EVP_PKEY_missing_parameters(peer) &&
!EVP_PKEY_parameters_eq(ctx->pkey, peer)) {
ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_PARAMETERS);
return -1;
}
EVP_PKEY_free(ctx->peerkey);
ctx->peerkey = peer;
ret = ctx->pmeth->ctrl(ctx, EVP_PKEY_CTRL_PEER_KEY, 1, peer);
if (ret <= 0) {
ctx->peerkey = NULL;
return ret;
}
EVP_PKEY_up_ref(peer);
return 1;
#endif
}
int EVP_PKEY_derive_set_peer(EVP_PKEY_CTX *ctx, EVP_PKEY *peer)
{
return EVP_PKEY_derive_set_peer_ex(ctx, peer, 1);
}
int EVP_PKEY_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *pkeylen)
{
int ret;
if (ctx == NULL || pkeylen == NULL) {
ERR_raise(ERR_LIB_EVP, ERR_R_PASSED_NULL_PARAMETER);
return -1;
}
if (!EVP_PKEY_CTX_IS_DERIVE_OP(ctx)) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_INITIALIZED);
return -1;
}
if (ctx->op.kex.algctx == NULL)
goto legacy;
ret = ctx->op.kex.exchange->derive(ctx->op.kex.algctx, key, pkeylen,
key != NULL ? *pkeylen : 0);
return ret;
legacy:
if (ctx->pmeth == NULL || ctx->pmeth->derive == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
return -2;
}
M_check_autoarg(ctx, key, pkeylen, EVP_F_EVP_PKEY_DERIVE)
return ctx->pmeth->derive(ctx, key, pkeylen);
}
int evp_keyexch_get_number(const EVP_KEYEXCH *keyexch)
{
return keyexch->name_id;
}
const char *EVP_KEYEXCH_get0_name(const EVP_KEYEXCH *keyexch)
{
return keyexch->type_name;
}
const char *EVP_KEYEXCH_get0_description(const EVP_KEYEXCH *keyexch)
{
return keyexch->description;
}
int EVP_KEYEXCH_is_a(const EVP_KEYEXCH *keyexch, const char *name)
{
return keyexch != NULL
&& evp_is_a(keyexch->prov, keyexch->name_id, NULL, name);
}
void EVP_KEYEXCH_do_all_provided(OSSL_LIB_CTX *libctx,
void (*fn)(EVP_KEYEXCH *keyexch, void *arg),
void *arg)
{
evp_generic_do_all(libctx, OSSL_OP_KEYEXCH,
(void (*)(void *, void *))fn, arg,
evp_keyexch_from_algorithm,
(int (*)(void *))EVP_KEYEXCH_up_ref,
(void (*)(void *))EVP_KEYEXCH_free);
}
int EVP_KEYEXCH_names_do_all(const EVP_KEYEXCH *keyexch,
void (*fn)(const char *name, void *data),
void *data)
{
if (keyexch->prov != NULL)
return evp_names_do_all(keyexch->prov, keyexch->name_id, fn, data);
return 1;
}
const OSSL_PARAM *EVP_KEYEXCH_gettable_ctx_params(const EVP_KEYEXCH *keyexch)
{
void *provctx;
if (keyexch == NULL || keyexch->gettable_ctx_params == NULL)
return NULL;
provctx = ossl_provider_ctx(EVP_KEYEXCH_get0_provider(keyexch));
return keyexch->gettable_ctx_params(NULL, provctx);
}
const OSSL_PARAM *EVP_KEYEXCH_settable_ctx_params(const EVP_KEYEXCH *keyexch)
{
void *provctx;
if (keyexch == NULL || keyexch->settable_ctx_params == NULL)
return NULL;
provctx = ossl_provider_ctx(EVP_KEYEXCH_get0_provider(keyexch));
return keyexch->settable_ctx_params(NULL, provctx);
}
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