Viewing file:  kem.c (15.04 KB) -rw-r--r--
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/*
* Copyright 2020-2021 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
*/
#include <stdio.h>
#include <stdlib.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include "internal/cryptlib.h"
#include "internal/provider.h"
#include "internal/core.h"
#include "crypto/evp.h"
#include "evp_local.h"
static int evp_kem_init(EVP_PKEY_CTX *ctx, int operation,
const OSSL_PARAM params[])
{
int ret = 0;
EVP_KEM *kem = NULL;
EVP_KEYMGMT *tmp_keymgmt = NULL;
const OSSL_PROVIDER *tmp_prov = NULL;
void *provkey = NULL;
const char *supported_kem = NULL;
int iter;
if (ctx == NULL || ctx->keytype == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
return 0;
}
evp_pkey_ctx_free_old_ops(ctx);
ctx->operation = operation;
if (ctx->pkey == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_NO_KEY_SET);
goto err;
}
/*
* Try to derive the supported kem from |ctx->keymgmt|.
*/
if (!ossl_assert(ctx->pkey->keymgmt == NULL
|| ctx->pkey->keymgmt == ctx->keymgmt)) {
ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
goto err;
}
supported_kem = evp_keymgmt_util_query_operation_name(ctx->keymgmt,
OSSL_OP_KEM);
if (supported_kem == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
goto err;
}
/*
* Because we cleared out old ops, we shouldn't need to worry about
* checking if kem is already there.
* We perform two iterations:
*
* 1. Do the normal kem fetch, using the fetching data given by
* the EVP_PKEY_CTX.
* 2. Do the provider specific kem fetch, from the same provider
* as |ctx->keymgmt|
*
* We then try to fetch the keymgmt from the same provider as the
* kem, 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_KEM_free(kem);
EVP_KEYMGMT_free(tmp_keymgmt);
switch (iter) {
case 1:
kem = EVP_KEM_fetch(ctx->libctx, supported_kem, ctx->propquery);
if (kem != NULL)
tmp_prov = EVP_KEM_get0_provider(kem);
break;
case 2:
tmp_prov = EVP_KEYMGMT_get0_provider(ctx->keymgmt);
kem = evp_kem_fetch_from_prov((OSSL_PROVIDER *)tmp_prov,
supported_kem, ctx->propquery);
if (kem == NULL) {
ERR_raise(ERR_LIB_EVP,
EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
ret = -2;
goto err;
}
}
if (kem == 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->pkey|, but from the provider of the kem method, using the
* same property query as when fetching the kem 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_KEM_free(kem);
ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
goto err;
}
ctx->op.encap.kem = kem;
ctx->op.encap.algctx = kem->newctx(ossl_provider_ctx(kem->prov));
if (ctx->op.encap.algctx == NULL) {
/* The provider key can stay in the cache */
ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
goto err;
}
switch (operation) {
case EVP_PKEY_OP_ENCAPSULATE:
if (kem->encapsulate_init == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
ret = -2;
goto err;
}
ret = kem->encapsulate_init(ctx->op.encap.algctx, provkey, params);
break;
case EVP_PKEY_OP_DECAPSULATE:
if (kem->decapsulate_init == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
ret = -2;
goto err;
}
ret = kem->decapsulate_init(ctx->op.encap.algctx, provkey, params);
break;
default:
ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
goto err;
}
EVP_KEYMGMT_free(tmp_keymgmt);
tmp_keymgmt = NULL;
if (ret > 0)
return 1;
err:
if (ret <= 0) {
evp_pkey_ctx_free_old_ops(ctx);
ctx->operation = EVP_PKEY_OP_UNDEFINED;
}
EVP_KEYMGMT_free(tmp_keymgmt);
return ret;
}
int EVP_PKEY_encapsulate_init(EVP_PKEY_CTX *ctx, const OSSL_PARAM params[])
{
return evp_kem_init(ctx, EVP_PKEY_OP_ENCAPSULATE, params);
}
int EVP_PKEY_encapsulate(EVP_PKEY_CTX *ctx,
unsigned char *out, size_t *outlen,
unsigned char *secret, size_t *secretlen)
{
if (ctx == NULL)
return 0;
if (ctx->operation != EVP_PKEY_OP_ENCAPSULATE) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_INITIALIZED);
return -1;
}
if (ctx->op.encap.algctx == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
return -2;
}
if (out != NULL && secret == NULL)
return 0;
return ctx->op.encap.kem->encapsulate(ctx->op.encap.algctx,
out, outlen, secret, secretlen);
}
int EVP_PKEY_decapsulate_init(EVP_PKEY_CTX *ctx, const OSSL_PARAM params[])
{
return evp_kem_init(ctx, EVP_PKEY_OP_DECAPSULATE, params);
}
int EVP_PKEY_decapsulate(EVP_PKEY_CTX *ctx,
unsigned char *secret, size_t *secretlen,
const unsigned char *in, size_t inlen)
{
if (ctx == NULL
|| (in == NULL || inlen == 0)
|| (secret == NULL && secretlen == NULL))
return 0;
if (ctx->operation != EVP_PKEY_OP_DECAPSULATE) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_INITIALIZED);
return -1;
}
if (ctx->op.encap.algctx == NULL) {
ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
return -2;
}
return ctx->op.encap.kem->decapsulate(ctx->op.encap.algctx,
secret, secretlen, in, inlen);
}
static EVP_KEM *evp_kem_new(OSSL_PROVIDER *prov)
{
EVP_KEM *kem = OPENSSL_zalloc(sizeof(EVP_KEM));
if (kem == NULL) {
ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
return NULL;
}
kem->lock = CRYPTO_THREAD_lock_new();
if (kem->lock == NULL) {
ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
OPENSSL_free(kem);
return NULL;
}
kem->prov = prov;
ossl_provider_up_ref(prov);
kem->refcnt = 1;
return kem;
}
static void *evp_kem_from_algorithm(int name_id, const OSSL_ALGORITHM *algodef,
OSSL_PROVIDER *prov)
{
const OSSL_DISPATCH *fns = algodef->implementation;
EVP_KEM *kem = NULL;
int ctxfncnt = 0, encfncnt = 0, decfncnt = 0;
int gparamfncnt = 0, sparamfncnt = 0;
if ((kem = evp_kem_new(prov)) == NULL) {
ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
goto err;
}
kem->name_id = name_id;
if ((kem->type_name = ossl_algorithm_get1_first_name(algodef)) == NULL)
goto err;
kem->description = algodef->algorithm_description;
for (; fns->function_id != 0; fns++) {
switch (fns->function_id) {
case OSSL_FUNC_KEM_NEWCTX:
if (kem->newctx != NULL)
break;
kem->newctx = OSSL_FUNC_kem_newctx(fns);
ctxfncnt++;
break;
case OSSL_FUNC_KEM_ENCAPSULATE_INIT:
if (kem->encapsulate_init != NULL)
break;
kem->encapsulate_init = OSSL_FUNC_kem_encapsulate_init(fns);
encfncnt++;
break;
case OSSL_FUNC_KEM_ENCAPSULATE:
if (kem->encapsulate != NULL)
break;
kem->encapsulate = OSSL_FUNC_kem_encapsulate(fns);
encfncnt++;
break;
case OSSL_FUNC_KEM_DECAPSULATE_INIT:
if (kem->decapsulate_init != NULL)
break;
kem->decapsulate_init = OSSL_FUNC_kem_decapsulate_init(fns);
decfncnt++;
break;
case OSSL_FUNC_KEM_DECAPSULATE:
if (kem->decapsulate != NULL)
break;
kem->decapsulate = OSSL_FUNC_kem_decapsulate(fns);
decfncnt++;
break;
case OSSL_FUNC_KEM_FREECTX:
if (kem->freectx != NULL)
break;
kem->freectx = OSSL_FUNC_kem_freectx(fns);
ctxfncnt++;
break;
case OSSL_FUNC_KEM_DUPCTX:
if (kem->dupctx != NULL)
break;
kem->dupctx = OSSL_FUNC_kem_dupctx(fns);
break;
case OSSL_FUNC_KEM_GET_CTX_PARAMS:
if (kem->get_ctx_params != NULL)
break;
kem->get_ctx_params
= OSSL_FUNC_kem_get_ctx_params(fns);
gparamfncnt++;
break;
case OSSL_FUNC_KEM_GETTABLE_CTX_PARAMS:
if (kem->gettable_ctx_params != NULL)
break;
kem->gettable_ctx_params
= OSSL_FUNC_kem_gettable_ctx_params(fns);
gparamfncnt++;
break;
case OSSL_FUNC_KEM_SET_CTX_PARAMS:
if (kem->set_ctx_params != NULL)
break;
kem->set_ctx_params
= OSSL_FUNC_kem_set_ctx_params(fns);
sparamfncnt++;
break;
case OSSL_FUNC_KEM_SETTABLE_CTX_PARAMS:
if (kem->settable_ctx_params != NULL)
break;
kem->settable_ctx_params
= OSSL_FUNC_kem_settable_ctx_params(fns);
sparamfncnt++;
break;
}
}
if (ctxfncnt != 2
|| (encfncnt != 0 && encfncnt != 2)
|| (decfncnt != 0 && decfncnt != 2)
|| (encfncnt != 2 && decfncnt != 2)
|| (gparamfncnt != 0 && gparamfncnt != 2)
|| (sparamfncnt != 0 && sparamfncnt != 2)) {
/*
* In order to be a consistent set of functions we must have at least
* a set of context functions (newctx and freectx) as well as a pair of
* "kem" functions: (encapsulate_init, encapsulate) or
* (decapsulate_init, decapsulate). set_ctx_params and settable_ctx_params are
* optional, but if one of them is present then the other one must also
* be present. The same applies to get_ctx_params and
* gettable_ctx_params. The dupctx function is optional.
*/
ERR_raise(ERR_LIB_EVP, EVP_R_INVALID_PROVIDER_FUNCTIONS);
goto err;
}
return kem;
err:
EVP_KEM_free(kem);
return NULL;
}
void EVP_KEM_free(EVP_KEM *kem)
{
int i;
if (kem == NULL)
return;
CRYPTO_DOWN_REF(&kem->refcnt, &i, kem->lock);
if (i > 0)
return;
OPENSSL_free(kem->type_name);
ossl_provider_free(kem->prov);
CRYPTO_THREAD_lock_free(kem->lock);
OPENSSL_free(kem);
}
int EVP_KEM_up_ref(EVP_KEM *kem)
{
int ref = 0;
CRYPTO_UP_REF(&kem->refcnt, &ref, kem->lock);
return 1;
}
OSSL_PROVIDER *EVP_KEM_get0_provider(const EVP_KEM *kem)
{
return kem->prov;
}
EVP_KEM *EVP_KEM_fetch(OSSL_LIB_CTX *ctx, const char *algorithm,
const char *properties)
{
return evp_generic_fetch(ctx, OSSL_OP_KEM, algorithm, properties,
evp_kem_from_algorithm,
(int (*)(void *))EVP_KEM_up_ref,
(void (*)(void *))EVP_KEM_free);
}
EVP_KEM *evp_kem_fetch_from_prov(OSSL_PROVIDER *prov, const char *algorithm,
const char *properties)
{
return evp_generic_fetch_from_prov(prov, OSSL_OP_KEM, algorithm, properties,
evp_kem_from_algorithm,
(int (*)(void *))EVP_KEM_up_ref,
(void (*)(void *))EVP_KEM_free);
}
int EVP_KEM_is_a(const EVP_KEM *kem, const char *name)
{
return kem != NULL && evp_is_a(kem->prov, kem->name_id, NULL, name);
}
int evp_kem_get_number(const EVP_KEM *kem)
{
return kem->name_id;
}
const char *EVP_KEM_get0_name(const EVP_KEM *kem)
{
return kem->type_name;
}
const char *EVP_KEM_get0_description(const EVP_KEM *kem)
{
return kem->description;
}
void EVP_KEM_do_all_provided(OSSL_LIB_CTX *libctx,
void (*fn)(EVP_KEM *kem, void *arg),
void *arg)
{
evp_generic_do_all(libctx, OSSL_OP_KEM, (void (*)(void *, void *))fn, arg,
evp_kem_from_algorithm,
(int (*)(void *))EVP_KEM_up_ref,
(void (*)(void *))EVP_KEM_free);
}
int EVP_KEM_names_do_all(const EVP_KEM *kem,
void (*fn)(const char *name, void *data),
void *data)
{
if (kem->prov != NULL)
return evp_names_do_all(kem->prov, kem->name_id, fn, data);
return 1;
}
const OSSL_PARAM *EVP_KEM_gettable_ctx_params(const EVP_KEM *kem)
{
void *provctx;
if (kem == NULL || kem->gettable_ctx_params == NULL)
return NULL;
provctx = ossl_provider_ctx(EVP_KEM_get0_provider(kem));
return kem->gettable_ctx_params(NULL, provctx);
}
const OSSL_PARAM *EVP_KEM_settable_ctx_params(const EVP_KEM *kem)
{
void *provctx;
if (kem == NULL || kem->settable_ctx_params == NULL)
return NULL;
provctx = ossl_provider_ctx(EVP_KEM_get0_provider(kem));
return kem->settable_ctx_params(NULL, provctx);
}
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