keymgmt_lib.c
/*
* 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/core_names.h>
#include "internal/cryptlib.h"
#include "internal/nelem.h"
#include "crypto/evp.h"
#include "internal/core.h"
#include "internal/provider.h"
#include "evp_local.h"
/*
* match_type() checks if two EVP_KEYMGMT are matching key types. This
* function assumes that the caller has made all the necessary NULL checks.
*/
static int match_type(const EVP_KEYMGMT *keymgmt1, const EVP_KEYMGMT *keymgmt2)
{
const char *name2 = EVP_KEYMGMT_get0_name(keymgmt2);
return EVP_KEYMGMT_is_a(keymgmt1, name2);
}
int evp_keymgmt_util_try_import(const OSSL_PARAM params[], void *arg)
{
struct evp_keymgmt_util_try_import_data_st *data = arg;
int delete_on_error = 0;
/* Just in time creation of keydata */
if (data->keydata == NULL) {
if ((data->keydata = evp_keymgmt_newdata(data->keymgmt)) == NULL) {
ERR_raise(ERR_LIB_EVP, ERR_R_EVP_LIB);
return 0;
}
delete_on_error = 1;
}
/*
* It's fine if there was no data to transfer, we just end up with an
* empty destination key.
*/
if (params[0].key == NULL)
return 1;
if (evp_keymgmt_import(data->keymgmt, data->keydata, data->selection,
params))
return 1;
if (delete_on_error) {
evp_keymgmt_freedata(data->keymgmt, data->keydata);
data->keydata = NULL;
}
return 0;
}
int evp_keymgmt_util_assign_pkey(EVP_PKEY *pkey, EVP_KEYMGMT *keymgmt,
void *keydata)
{
if (pkey == NULL || keymgmt == NULL || keydata == NULL
|| !EVP_PKEY_set_type_by_keymgmt(pkey, keymgmt)) {
ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
return 0;
}
pkey->keydata = keydata;
evp_keymgmt_util_cache_keyinfo(pkey);
return 1;
}
EVP_PKEY *evp_keymgmt_util_make_pkey(EVP_KEYMGMT *keymgmt, void *keydata)
{
EVP_PKEY *pkey = NULL;
if (keymgmt == NULL
|| keydata == NULL
|| (pkey = EVP_PKEY_new()) == NULL
|| !evp_keymgmt_util_assign_pkey(pkey, keymgmt, keydata)) {
EVP_PKEY_free(pkey);
return NULL;
}
return pkey;
}
int evp_keymgmt_util_export(const EVP_PKEY *pk, int selection,
OSSL_CALLBACK *export_cb, void *export_cbarg)
{
if (pk == NULL || export_cb == NULL)
return 0;
return evp_keymgmt_export(pk->keymgmt, pk->keydata, selection,
export_cb, export_cbarg);
}
void *evp_keymgmt_util_export_to_provider(EVP_PKEY *pk, EVP_KEYMGMT *keymgmt,
int selection)
{
struct evp_keymgmt_util_try_import_data_st import_data;
OP_CACHE_ELEM *op;
/* Export to where? */
if (keymgmt == NULL)
return NULL;
/* If we have an unassigned key, give up */
if (pk->keydata == NULL)
return NULL;
/*
* If |keymgmt| matches the "origin" |keymgmt|, there is no more to do.
* The "origin" is determined by the |keymgmt| pointers being identical
* or when the provider and the name ID match. The latter case handles the
* situation where the fetch cache is flushed and a "new" key manager is
* created.
*/
if (pk->keymgmt == keymgmt
|| (pk->keymgmt->name_id == keymgmt->name_id
&& pk->keymgmt->prov == keymgmt->prov))
return pk->keydata;
if (!CRYPTO_THREAD_read_lock(pk->lock))
return NULL;
/*
* If the provider native "origin" hasn't changed since last time, we
* try to find our keymgmt in the operation cache. If it has changed
* and our keymgmt isn't found, we will clear the cache further down.
*/
if (pk->dirty_cnt == pk->dirty_cnt_copy) {
/* If this key is already exported to |keymgmt|, no more to do */
op = evp_keymgmt_util_find_operation_cache(pk, keymgmt, selection);
if (op != NULL && op->keymgmt != NULL) {
void *ret = op->keydata;
CRYPTO_THREAD_unlock(pk->lock);
return ret;
}
}
CRYPTO_THREAD_unlock(pk->lock);
/* If the "origin" |keymgmt| doesn't support exporting, give up */
if (pk->keymgmt->export == NULL)
return NULL;
/*
* Make sure that the type of the keymgmt to export to matches the type
* of the "origin"
*/
if (!ossl_assert(match_type(pk->keymgmt, keymgmt)))
return NULL;
/*
* We look at the already cached provider keys, and import from the
* first that supports it (i.e. use its export function), and export
* the imported data to the new provider.
*/
/* Setup for the export callback */
import_data.keydata = NULL; /* evp_keymgmt_util_try_import will create it */
import_data.keymgmt = keymgmt;
import_data.selection = selection;
/*
* The export function calls the callback (evp_keymgmt_util_try_import),
* which does the import for us. If successful, we're done.
*/
if (!evp_keymgmt_util_export(pk, selection,
&evp_keymgmt_util_try_import, &import_data))
/* If there was an error, bail out */
return NULL;
if (!CRYPTO_THREAD_write_lock(pk->lock)) {
evp_keymgmt_freedata(keymgmt, import_data.keydata);
return NULL;
}
/* Check to make sure some other thread didn't get there first */
op = evp_keymgmt_util_find_operation_cache(pk, keymgmt, selection);
if (op != NULL && op->keydata != NULL) {
void *ret = op->keydata;
CRYPTO_THREAD_unlock(pk->lock);
/*
* Another thread seemms to have already exported this so we abandon
* all the work we just did.
*/
evp_keymgmt_freedata(keymgmt, import_data.keydata);
return ret;
}
/*
* If the dirty counter changed since last time, then clear the
* operation cache. In that case, we know that |i| is zero.
*/
if (pk->dirty_cnt != pk->dirty_cnt_copy)
evp_keymgmt_util_clear_operation_cache(pk);
/* Add the new export to the operation cache */
if (!evp_keymgmt_util_cache_keydata(pk, keymgmt, import_data.keydata,
selection)) {
CRYPTO_THREAD_unlock(pk->lock);
evp_keymgmt_freedata(keymgmt, import_data.keydata);
return NULL;
}
/* Synchronize the dirty count */
pk->dirty_cnt_copy = pk->dirty_cnt;
CRYPTO_THREAD_unlock(pk->lock);
return import_data.keydata;
}
static void op_cache_free(OP_CACHE_ELEM *e)
{
evp_keymgmt_freedata(e->keymgmt, e->keydata);
EVP_KEYMGMT_free(e->keymgmt);
OPENSSL_free(e);
}
int evp_keymgmt_util_clear_operation_cache(EVP_PKEY *pk)
{
if (pk != NULL) {
sk_OP_CACHE_ELEM_pop_free(pk->operation_cache, op_cache_free);
pk->operation_cache = NULL;
}
return 1;
}
OP_CACHE_ELEM *evp_keymgmt_util_find_operation_cache(EVP_PKEY *pk,
EVP_KEYMGMT *keymgmt,
int selection)
{
int i, end = sk_OP_CACHE_ELEM_num(pk->operation_cache);
OP_CACHE_ELEM *p;
/*
* A comparison and sk_P_CACHE_ELEM_find() are avoided to not cause
* problems when we've only a read lock.
*/
for (i = 0; i < end; i++) {
p = sk_OP_CACHE_ELEM_value(pk->operation_cache, i);
if (keymgmt == p->keymgmt && (p->selection & selection) == selection)
return p;
}
return NULL;
}
int evp_keymgmt_util_cache_keydata(EVP_PKEY *pk, EVP_KEYMGMT *keymgmt,
void *keydata, int selection)
{
OP_CACHE_ELEM *p = NULL;
if (keydata != NULL) {
if (pk->operation_cache == NULL) {
pk->operation_cache = sk_OP_CACHE_ELEM_new_null();
if (pk->operation_cache == NULL)
return 0;
}
p = OPENSSL_malloc(sizeof(*p));
if (p == NULL)
return 0;
p->keydata = keydata;
p->keymgmt = keymgmt;
p->selection = selection;
if (!EVP_KEYMGMT_up_ref(keymgmt)) {
OPENSSL_free(p);
return 0;
}
if (!sk_OP_CACHE_ELEM_push(pk->operation_cache, p)) {
EVP_KEYMGMT_free(keymgmt);
OPENSSL_free(p);
return 0;
}
}
return 1;
}
void evp_keymgmt_util_cache_keyinfo(EVP_PKEY *pk)
{
/*
* Cache information about the provider "origin" key.
*
* This services functions like EVP_PKEY_get_size, EVP_PKEY_get_bits, etc
*/
if (pk->keydata != NULL) {
int bits = 0;
int security_bits = 0;
int size = 0;
OSSL_PARAM params[4];
params[0] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_BITS, &bits);
params[1] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_SECURITY_BITS,
&security_bits);
params[2] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_MAX_SIZE, &size);
params[3] = OSSL_PARAM_construct_end();
if (evp_keymgmt_get_params(pk->keymgmt, pk->keydata, params)) {
pk->cache.size = size;
pk->cache.bits = bits;
pk->cache.security_bits = security_bits;
}
}
}
void *evp_keymgmt_util_fromdata(EVP_PKEY *target, EVP_KEYMGMT *keymgmt,
int selection, const OSSL_PARAM params[])
{
void *keydata = NULL;
if ((keydata = evp_keymgmt_newdata(keymgmt)) == NULL
|| !evp_keymgmt_import(keymgmt, keydata, selection, params)
|| !evp_keymgmt_util_assign_pkey(target, keymgmt, keydata)) {
evp_keymgmt_freedata(keymgmt, keydata);
keydata = NULL;
}
return keydata;
}
int evp_keymgmt_util_has(EVP_PKEY *pk, int selection)
{
/* Check if key is even assigned */
if (pk->keymgmt == NULL)
return 0;
return evp_keymgmt_has(pk->keymgmt, pk->keydata, selection);
}
/*
* evp_keymgmt_util_match() doesn't just look at the provider side "origin",
* but also in the operation cache to see if there's any common keymgmt that
* supplies OP_keymgmt_match.
*
* evp_keymgmt_util_match() adheres to the return values that EVP_PKEY_eq()
* and EVP_PKEY_parameters_eq() return, i.e.:
*
* 1 same key
* 0 not same key
* -1 not same key type
* -2 unsupported operation
*/
int evp_keymgmt_util_match(EVP_PKEY *pk1, EVP_PKEY *pk2, int selection)
{
EVP_KEYMGMT *keymgmt1 = NULL, *keymgmt2 = NULL;
void *keydata1 = NULL, *keydata2 = NULL;
if (pk1 == NULL || pk2 == NULL) {
if (pk1 == NULL && pk2 == NULL)
return 1;
return 0;
}
keymgmt1 = pk1->keymgmt;
keydata1 = pk1->keydata;
keymgmt2 = pk2->keymgmt;
keydata2 = pk2->keydata;
if (keymgmt1 != keymgmt2) {
/*
* The condition for a successful cross export is that the
* keydata to be exported is NULL (typed, but otherwise empty
* EVP_PKEY), or that it was possible to export it with
* evp_keymgmt_util_export_to_provider().
*
* We use |ok| to determine if it's ok to cross export one way,
* but also to determine if we should attempt a cross export
* the other way. There's no point doing it both ways.
*/
int ok = 0;
/* Complex case, where the keymgmt differ */
if (keymgmt1 != NULL
&& keymgmt2 != NULL
&& !match_type(keymgmt1, keymgmt2)) {
ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);
return -1; /* Not the same type */
}
/*
* The key types are determined to match, so we try cross export,
* but only to keymgmt's that supply a matching function.
*/
if (keymgmt2 != NULL
&& keymgmt2->match != NULL) {
void *tmp_keydata = NULL;
ok = 1;
if (keydata1 != NULL) {
tmp_keydata =
evp_keymgmt_util_export_to_provider(pk1, keymgmt2,
selection);
ok = (tmp_keydata != NULL);
}
if (ok) {
keymgmt1 = keymgmt2;
keydata1 = tmp_keydata;
}
}
/*
* If we've successfully cross exported one way, there's no point
* doing it the other way, hence the |!ok| check.
*/
if (!ok
&& keymgmt1 != NULL
&& keymgmt1->match != NULL) {
void *tmp_keydata = NULL;
ok = 1;
if (keydata2 != NULL) {
tmp_keydata =
evp_keymgmt_util_export_to_provider(pk2, keymgmt1,
selection);
ok = (tmp_keydata != NULL);
}
if (ok) {
keymgmt2 = keymgmt1;
keydata2 = tmp_keydata;
}
}
}
/* If we still don't have matching keymgmt implementations, we give up */
if (keymgmt1 != keymgmt2)
return -2;
/* If both keydata are NULL, then they're the same key */
if (keydata1 == NULL && keydata2 == NULL)
return 1;
/* If only one of the keydata is NULL, then they're different keys */
if (keydata1 == NULL || keydata2 == NULL)
return 0;
/* If both keydata are non-NULL, we let the backend decide */
return evp_keymgmt_match(keymgmt1, keydata1, keydata2, selection);
}
int evp_keymgmt_util_copy(EVP_PKEY *to, EVP_PKEY *from, int selection)
{
/* Save copies of pointers we want to play with without affecting |to| */
EVP_KEYMGMT *to_keymgmt = to->keymgmt;
void *to_keydata = to->keydata, *alloc_keydata = NULL;
/* An unassigned key can't be copied */
if (from == NULL || from->keydata == NULL)
return 0;
/*
* If |to| is unassigned, ensure it gets the same KEYMGMT as |from|,
* Note that the final setting of KEYMGMT is done further down, with
* EVP_PKEY_set_type_by_keymgmt(); we don't want to do that prematurely.
*/
if (to_keymgmt == NULL)
to_keymgmt = from->keymgmt;
if (to_keymgmt == from->keymgmt && to_keymgmt->dup != NULL
&& to_keydata == NULL) {
to_keydata = alloc_keydata = evp_keymgmt_dup(to_keymgmt,
from->keydata,
selection);
if (to_keydata == NULL)
return 0;
} else if (match_type(to_keymgmt, from->keymgmt)) {
struct evp_keymgmt_util_try_import_data_st import_data;
import_data.keymgmt = to_keymgmt;
import_data.keydata = to_keydata;
import_data.selection = selection;
if (!evp_keymgmt_util_export(from, selection,
&evp_keymgmt_util_try_import,
&import_data))
return 0;
/*
* In case to_keydata was previously unallocated,
* evp_keymgmt_util_try_import() may have created it for us.
*/
if (to_keydata == NULL)
to_keydata = alloc_keydata = import_data.keydata;
} else {
ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);
return 0;
}
/*
* We only need to set the |to| type when its |keymgmt| isn't set.
* We can then just set its |keydata| to what we have, which might
* be exactly what it had when entering this function.
* This is a bit different from using evp_keymgmt_util_assign_pkey(),
* which isn't as careful with |to|'s original |keymgmt|, since it's
* meant to forcibly reassign an EVP_PKEY no matter what, which is
* why we don't use that one here.
*/
if (to->keymgmt == NULL
&& !EVP_PKEY_set_type_by_keymgmt(to, to_keymgmt)) {
evp_keymgmt_freedata(to_keymgmt, alloc_keydata);
return 0;
}
to->keydata = to_keydata;
evp_keymgmt_util_cache_keyinfo(to);
return 1;
}
void *evp_keymgmt_util_gen(EVP_PKEY *target, EVP_KEYMGMT *keymgmt,
void *genctx, OSSL_CALLBACK *cb, void *cbarg)
{
void *keydata = NULL;
if ((keydata = evp_keymgmt_gen(keymgmt, genctx, cb, cbarg)) == NULL
|| !evp_keymgmt_util_assign_pkey(target, keymgmt, keydata)) {
evp_keymgmt_freedata(keymgmt, keydata);
keydata = NULL;
}
return keydata;
}
/*
* Returns the same numbers as EVP_PKEY_get_default_digest_name()
* When the string from the EVP_KEYMGMT implementation is "", we use
* SN_undef, since that corresponds to what EVP_PKEY_get_default_nid()
* returns for no digest.
*/
int evp_keymgmt_util_get_deflt_digest_name(EVP_KEYMGMT *keymgmt,
void *keydata,
char *mdname, size_t mdname_sz)
{
OSSL_PARAM params[3];
char mddefault[100] = "";
char mdmandatory[100] = "";
char *result = NULL;
int rv = -2;
params[0] =
OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_DEFAULT_DIGEST,
mddefault, sizeof(mddefault));
params[1] =
OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_MANDATORY_DIGEST,
mdmandatory,
sizeof(mdmandatory));
params[2] = OSSL_PARAM_construct_end();
if (!evp_keymgmt_get_params(keymgmt, keydata, params))
return 0;
if (OSSL_PARAM_modified(params + 1)) {
if (params[1].return_size <= 1) /* Only a NUL byte */
result = SN_undef;
else
result = mdmandatory;
rv = 2;
} else if (OSSL_PARAM_modified(params)) {
if (params[0].return_size <= 1) /* Only a NUL byte */
result = SN_undef;
else
result = mddefault;
rv = 1;
}
if (rv > 0)
OPENSSL_strlcpy(mdname, result, mdname_sz);
return rv;
}
/*
* If |keymgmt| has the method function |query_operation_name|, use it to get
* the name of a supported operation identity. Otherwise, return the keytype,
* assuming that it works as a default operation name.
*/
const char *evp_keymgmt_util_query_operation_name(EVP_KEYMGMT *keymgmt,
int op_id)
{
const char *name = NULL;
if (keymgmt != NULL) {
if (keymgmt->query_operation_name != NULL)
name = keymgmt->query_operation_name(op_id);
if (name == NULL)
name = EVP_KEYMGMT_get0_name(keymgmt);
}
return name;
}
