openssl/crypto/property/property_string.c
Pauli 3377f34fb8 property: add locking for the property string database
This previously relied on the caller locking the property store correctly.
This is no longer the case so the string database now requires locking.

Fixes #15866

Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15871)
2021-06-24 15:51:48 +10:00

247 lines
7.1 KiB
C

/*
* Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
* Copyright (c) 2019, Oracle and/or its affiliates. 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 <string.h>
#include <openssl/crypto.h>
#include <openssl/lhash.h>
#include "crypto/lhash.h"
#include "property_local.h"
/*
* Property strings are a consolidation of all strings seen by the property
* subsystem. There are two name spaces to keep property names separate from
* property values (numeric values are not expected to be cached however).
* They allow a rapid conversion from a string to a unique index and any
* subsequent string comparison can be done via an integer compare.
*
* This implementation uses OpenSSL's standard hash table. There are more
* space and time efficient algorithms if this becomes a bottleneck.
*/
typedef struct {
const char *s;
OSSL_PROPERTY_IDX idx;
char body[1];
} PROPERTY_STRING;
DEFINE_LHASH_OF(PROPERTY_STRING);
typedef LHASH_OF(PROPERTY_STRING) PROP_TABLE;
typedef struct {
CRYPTO_RWLOCK *lock;
PROP_TABLE *prop_names;
PROP_TABLE *prop_values;
OSSL_PROPERTY_IDX prop_name_idx;
OSSL_PROPERTY_IDX prop_value_idx;
} PROPERTY_STRING_DATA;
static unsigned long property_hash(const PROPERTY_STRING *a)
{
return OPENSSL_LH_strhash(a->s);
}
static int property_cmp(const PROPERTY_STRING *a, const PROPERTY_STRING *b)
{
return strcmp(a->s, b->s);
}
static void property_free(PROPERTY_STRING *ps)
{
OPENSSL_free(ps);
}
static void property_table_free(PROP_TABLE **pt)
{
PROP_TABLE *t = *pt;
if (t != NULL) {
lh_PROPERTY_STRING_doall(t, &property_free);
lh_PROPERTY_STRING_free(t);
*pt = NULL;
}
}
static void property_string_data_free(void *vpropdata)
{
PROPERTY_STRING_DATA *propdata = vpropdata;
if (propdata == NULL)
return;
CRYPTO_THREAD_lock_free(propdata->lock);
property_table_free(&propdata->prop_names);
property_table_free(&propdata->prop_values);
propdata->prop_name_idx = propdata->prop_value_idx = 0;
OPENSSL_free(propdata);
}
static void *property_string_data_new(OSSL_LIB_CTX *ctx) {
PROPERTY_STRING_DATA *propdata = OPENSSL_zalloc(sizeof(*propdata));
if (propdata == NULL)
return NULL;
propdata->lock = CRYPTO_THREAD_lock_new();
if (propdata->lock == NULL)
goto err;
propdata->prop_names = lh_PROPERTY_STRING_new(&property_hash,
&property_cmp);
if (propdata->prop_names == NULL)
goto err;
propdata->prop_values = lh_PROPERTY_STRING_new(&property_hash,
&property_cmp);
if (propdata->prop_values == NULL)
goto err;
return propdata;
err:
property_string_data_free(propdata);
return NULL;
}
static const OSSL_LIB_CTX_METHOD property_string_data_method = {
OSSL_LIB_CTX_METHOD_DEFAULT_PRIORITY,
property_string_data_new,
property_string_data_free,
};
static PROPERTY_STRING *new_property_string(const char *s,
OSSL_PROPERTY_IDX *pidx)
{
const size_t l = strlen(s);
PROPERTY_STRING *ps = OPENSSL_malloc(sizeof(*ps) + l);
if (ps != NULL) {
memcpy(ps->body, s, l + 1);
ps->s = ps->body;
ps->idx = ++*pidx;
if (ps->idx == 0) {
OPENSSL_free(ps);
return NULL;
}
}
return ps;
}
static OSSL_PROPERTY_IDX ossl_property_string(CRYPTO_RWLOCK *lock,
PROP_TABLE *t,
OSSL_PROPERTY_IDX *pidx,
const char *s)
{
PROPERTY_STRING p, *ps, *ps_new;
p.s = s;
if (!CRYPTO_THREAD_read_lock(lock)) {
ERR_raise(ERR_LIB_CRYPTO, ERR_R_UNABLE_TO_GET_READ_LOCK);
return 0;
}
ps = lh_PROPERTY_STRING_retrieve(t, &p);
if (ps == NULL && pidx != NULL) {
CRYPTO_THREAD_unlock(lock);
if (!CRYPTO_THREAD_write_lock(lock)) {
ERR_raise(ERR_LIB_CRYPTO, ERR_R_UNABLE_TO_GET_WRITE_LOCK);
return 0;
}
ps = lh_PROPERTY_STRING_retrieve(t, &p);
if (ps == NULL && (ps_new = new_property_string(s, pidx)) != NULL) {
lh_PROPERTY_STRING_insert(t, ps_new);
if (lh_PROPERTY_STRING_error(t)) {
property_free(ps_new);
CRYPTO_THREAD_unlock(lock);
return 0;
}
ps = ps_new;
}
}
CRYPTO_THREAD_unlock(lock);
return ps != NULL ? ps->idx : 0;
}
struct find_str_st {
const char *str;
OSSL_PROPERTY_IDX idx;
};
static void find_str_fn(PROPERTY_STRING *prop, void *vfindstr)
{
struct find_str_st *findstr = vfindstr;
if (prop->idx == findstr->idx)
findstr->str = prop->s;
}
static const char *ossl_property_str(int name, OSSL_LIB_CTX *ctx,
OSSL_PROPERTY_IDX idx)
{
struct find_str_st findstr;
PROPERTY_STRING_DATA *propdata
= ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_PROPERTY_STRING_INDEX,
&property_string_data_method);
if (propdata == NULL)
return NULL;
findstr.str = NULL;
findstr.idx = idx;
if (!CRYPTO_THREAD_read_lock(propdata->lock)) {
ERR_raise(ERR_LIB_CRYPTO, ERR_R_UNABLE_TO_GET_READ_LOCK);
return NULL;
}
lh_PROPERTY_STRING_doall_arg(name ? propdata->prop_names
: propdata->prop_values,
find_str_fn, &findstr);
CRYPTO_THREAD_unlock(propdata->lock);
return findstr.str;
}
OSSL_PROPERTY_IDX ossl_property_name(OSSL_LIB_CTX *ctx, const char *s,
int create)
{
PROPERTY_STRING_DATA *propdata
= ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_PROPERTY_STRING_INDEX,
&property_string_data_method);
if (propdata == NULL)
return 0;
return ossl_property_string(propdata->lock, propdata->prop_names,
create ? &propdata->prop_name_idx : NULL,
s);
}
const char *ossl_property_name_str(OSSL_LIB_CTX *ctx, OSSL_PROPERTY_IDX idx)
{
return ossl_property_str(1, ctx, idx);
}
OSSL_PROPERTY_IDX ossl_property_value(OSSL_LIB_CTX *ctx, const char *s,
int create)
{
PROPERTY_STRING_DATA *propdata
= ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_PROPERTY_STRING_INDEX,
&property_string_data_method);
if (propdata == NULL)
return 0;
return ossl_property_string(propdata->lock, propdata->prop_values,
create ? &propdata->prop_value_idx : NULL,
s);
}
const char *ossl_property_value_str(OSSL_LIB_CTX *ctx, OSSL_PROPERTY_IDX idx)
{
return ossl_property_str(0, ctx, idx);
}