openssl/crypto/evp/evp_fetch.c
Richard Levitte 3d96a51c09 Add internal function evp_generic_do_all()
This function is used to traverse all algorithm implementations for a
given operation type, and execute the given function for each of them.

For each algorithm implementation, a method is created and passed to
the given function, and then freed after that function's return.  If
the caller wishes to keep the method for longer, they must call the
appropriate up_ref function on the method, and they must also make
sure to free the passed methods at some point.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9356)
2019-07-23 06:34:09 +02:00

276 lines
8.8 KiB
C

/*
* Copyright 2019 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 <stddef.h>
#include <openssl/ossl_typ.h>
#include <openssl/evp.h>
#include <openssl/core.h>
#include "internal/cryptlib.h"
#include "internal/thread_once.h"
#include "internal/property.h"
#include "internal/core.h"
#include "internal/namemap.h"
#include "internal/evp_int.h" /* evp_locl.h needs it */
#include "evp_locl.h"
static void default_method_store_free(void *vstore)
{
ossl_method_store_free(vstore);
}
static void *default_method_store_new(OPENSSL_CTX *ctx)
{
return ossl_method_store_new(ctx);
}
static const OPENSSL_CTX_METHOD default_method_store_method = {
default_method_store_new,
default_method_store_free,
};
/* Data to be passed through ossl_method_construct() */
struct method_data_st {
OPENSSL_CTX *libctx;
const char *name;
OSSL_METHOD_CONSTRUCT_METHOD *mcm;
void *(*method_from_dispatch)(const char *, const OSSL_DISPATCH *,
OSSL_PROVIDER *);
int (*refcnt_up_method)(void *method);
void (*destruct_method)(void *method);
};
/*
* Generic routines to fetch / create EVP methods with ossl_method_construct()
*/
static void *alloc_tmp_method_store(OPENSSL_CTX *ctx)
{
return ossl_method_store_new(ctx);
}
static void dealloc_tmp_method_store(void *store)
{
if (store != NULL)
ossl_method_store_free(store);
}
static OSSL_METHOD_STORE *get_default_method_store(OPENSSL_CTX *libctx)
{
return openssl_ctx_get_data(libctx, OPENSSL_CTX_DEFAULT_METHOD_STORE_INDEX,
&default_method_store_method);
}
/*
* To identity the method in the method store, we mix the name identity
* with the operation identity, with the assumption that we don't have
* more than 2^24 names or more than 2^8 operation types.
*
* The resulting identity is a 32-bit integer, composed like this:
*
* +---------24 bits--------+-8 bits-+
* | name identity | op id |
* +------------------------+--------+
*/
static uint32_t method_id(unsigned int operation_id, unsigned int name_id)
{
if (!ossl_assert(name_id < (1 << 24) || operation_id < (1 << 8))
|| !ossl_assert(name_id > 0 && operation_id > 0))
return 0;
return ((name_id << 8) & 0xFFFFFF00) | (operation_id & 0x000000FF);
}
static void *get_method_from_store(OPENSSL_CTX *libctx, void *store,
int operation_id, const char *name,
const char *propquery, void *data)
{
struct method_data_st *methdata = data;
void *method = NULL;
OSSL_NAMEMAP *namemap;
int nameid;
uint32_t methid;
if (store == NULL
&& (store = get_default_method_store(libctx)) == NULL)
return NULL;
if ((namemap = ossl_namemap_stored(libctx)) == NULL
|| (nameid = ossl_namemap_name2num(namemap, name)) == 0
|| (methid = method_id(operation_id, nameid)) == 0)
return NULL;
(void)ossl_method_store_fetch(store, methid, propquery, &method);
if (method != NULL
&& !methdata->refcnt_up_method(method)) {
method = NULL;
}
return method;
}
static int put_method_in_store(OPENSSL_CTX *libctx, void *store,
void *method, int operation_id,
const char *name, const char *propdef,
void *data)
{
struct method_data_st *methdata = data;
OSSL_NAMEMAP *namemap;
int nameid;
uint32_t methid;
if ((namemap = ossl_namemap_stored(methdata->libctx)) == NULL
|| (nameid = ossl_namemap_add(namemap, 0, name)) == 0
|| (methid = method_id(operation_id, nameid)) == 0)
return 0;
if (store == NULL
&& (store = get_default_method_store(libctx)) == NULL)
return 0;
if (methdata->refcnt_up_method(method)
&& ossl_method_store_add(store, methid, propdef, method,
methdata->destruct_method))
return 1;
return 0;
}
static void *construct_method(const char *name, const OSSL_DISPATCH *fns,
OSSL_PROVIDER *prov, void *data)
{
struct method_data_st *methdata = data;
return methdata->method_from_dispatch(name, fns, prov);
}
static void destruct_method(void *method, void *data)
{
struct method_data_st *methdata = data;
methdata->destruct_method(method);
}
void *evp_generic_fetch(OPENSSL_CTX *libctx, int operation_id,
const char *name, const char *properties,
void *(*new_method)(const char *name,
const OSSL_DISPATCH *fns,
OSSL_PROVIDER *prov),
int (*up_ref_method)(void *),
void (*free_method)(void *))
{
OSSL_METHOD_STORE *store = get_default_method_store(libctx);
OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
int nameid = 0;
uint32_t methid = 0;
void *method = NULL;
if (store == NULL || namemap == NULL)
return NULL;
/*
* If there's ever an operation_id == 0 passed, we have an internal
* programming error.
*/
if (!ossl_assert(operation_id > 0))
return NULL;
/*
* method_id returns 0 if we have too many operations (more than
* about 2^8) or too many names (more than about 2^24). In that
* case, we can't create any new method.
*/
if ((nameid = ossl_namemap_name2num(namemap, name)) != 0
&& (methid = method_id(operation_id, nameid)) == 0)
return NULL;
if (nameid == 0
|| !ossl_method_store_cache_get(store, methid, properties,
&method)) {
OSSL_METHOD_CONSTRUCT_METHOD mcm = {
alloc_tmp_method_store,
dealloc_tmp_method_store,
get_method_from_store,
put_method_in_store,
construct_method,
destruct_method
};
struct method_data_st mcmdata;
mcmdata.mcm = &mcm;
mcmdata.libctx = libctx;
mcmdata.name = name;
mcmdata.method_from_dispatch = new_method;
mcmdata.destruct_method = free_method;
mcmdata.refcnt_up_method = up_ref_method;
mcmdata.destruct_method = free_method;
if ((method = ossl_method_construct(libctx, operation_id, name,
properties, 0 /* !force_cache */,
&mcm, &mcmdata)) != NULL) {
/*
* If construction did create a method for us, we know that
* there is a correct nameid and methodid, since those have
* already been calculated in get_method_from_store() and
* put_method_in_store() above.
*/
nameid = ossl_namemap_name2num(namemap, name);
methid = method_id(operation_id, nameid);
ossl_method_store_cache_set(store, methid, properties, method);
}
} else {
up_ref_method(method);
}
return method;
}
int EVP_set_default_properties(OPENSSL_CTX *libctx, const char *propq)
{
OSSL_METHOD_STORE *store = get_default_method_store(libctx);
if (store != NULL)
return ossl_method_store_set_global_properties(store, propq);
EVPerr(EVP_F_EVP_SET_DEFAULT_PROPERTIES, ERR_R_INTERNAL_ERROR);
return 0;
}
struct do_all_data_st {
void (*user_fn)(void *method, void *arg);
void *user_arg;
void *(*new_method)(const char *name, const OSSL_DISPATCH *fns,
OSSL_PROVIDER *prov);
void (*free_method)(void *);
};
static void do_one(OSSL_PROVIDER *provider, const OSSL_ALGORITHM *algo,
int no_store, void *vdata)
{
struct do_all_data_st *data = vdata;
void *method = data->new_method(algo->algorithm_name,
algo->implementation, provider);
if (method != NULL) {
data->user_fn(method, data->user_arg);
data->free_method(method);
}
}
void evp_generic_do_all(OPENSSL_CTX *libctx, int operation_id,
void (*user_fn)(void *method, void *arg),
void *user_arg,
void *(*new_method)(const char *name,
const OSSL_DISPATCH *fns,
OSSL_PROVIDER *prov),
void (*free_method)(void *))
{
struct do_all_data_st data;
data.new_method = new_method;
data.free_method = free_method;
data.user_fn = user_fn;
data.user_arg = user_arg;
ossl_algorithm_do_all(libctx, operation_id, NULL, do_one, &data);
}