openssl/crypto/stack/stack.c

414 lines
10 KiB
C

/*
* Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (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 "internal/cryptlib.h"
#include "internal/numbers.h"
#include <openssl/stack.h>
#include <openssl/objects.h>
#include <errno.h>
#include <openssl/e_os2.h> /* For ossl_inline */
/*
* The initial number of nodes in the array.
*/
static const int min_nodes = 4;
static const int max_nodes = SIZE_MAX / sizeof(void *) < INT_MAX
? (int)(SIZE_MAX / sizeof(void *))
: INT_MAX;
struct stack_st {
int num;
const void **data;
int sorted;
int num_alloc;
OPENSSL_sk_compfunc comp;
};
OPENSSL_sk_compfunc OPENSSL_sk_set_cmp_func(OPENSSL_STACK *sk, OPENSSL_sk_compfunc c)
{
OPENSSL_sk_compfunc old = sk->comp;
if (sk->comp != c)
sk->sorted = 0;
sk->comp = c;
return old;
}
OPENSSL_STACK *OPENSSL_sk_dup(const OPENSSL_STACK *sk)
{
OPENSSL_STACK *ret;
if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL) {
CRYPTOerr(CRYPTO_F_OPENSSL_SK_DUP, ERR_R_MALLOC_FAILURE);
return NULL;
}
/* direct structure assignment */
*ret = *sk;
if (sk->num == 0) {
/* postpone |ret->data| allocation */
ret->data = NULL;
ret->num_alloc = 0;
return ret;
}
/* duplicate |sk->data| content */
if ((ret->data = OPENSSL_malloc(sizeof(*ret->data) * sk->num_alloc)) == NULL)
goto err;
memcpy(ret->data, sk->data, sizeof(void *) * sk->num);
return ret;
err:
OPENSSL_sk_free(ret);
return NULL;
}
OPENSSL_STACK *OPENSSL_sk_deep_copy(const OPENSSL_STACK *sk,
OPENSSL_sk_copyfunc copy_func,
OPENSSL_sk_freefunc free_func)
{
OPENSSL_STACK *ret;
int i;
if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL) {
CRYPTOerr(CRYPTO_F_OPENSSL_SK_DEEP_COPY, ERR_R_MALLOC_FAILURE);
return NULL;
}
/* direct structure assignment */
*ret = *sk;
if (sk->num == 0) {
/* postpone |ret| data allocation */
ret->data = NULL;
ret->num_alloc = 0;
return ret;
}
ret->num_alloc = sk->num > min_nodes ? sk->num : min_nodes;
ret->data = OPENSSL_zalloc(sizeof(*ret->data) * ret->num_alloc);
if (ret->data == NULL) {
OPENSSL_free(ret);
return NULL;
}
for (i = 0; i < ret->num; ++i) {
if (sk->data[i] == NULL)
continue;
if ((ret->data[i] = copy_func(sk->data[i])) == NULL) {
while (--i >= 0)
if (ret->data[i] != NULL)
free_func((void *)ret->data[i]);
OPENSSL_sk_free(ret);
return NULL;
}
}
return ret;
}
OPENSSL_STACK *OPENSSL_sk_new_null(void)
{
return OPENSSL_sk_new_reserve(NULL, 0);
}
OPENSSL_STACK *OPENSSL_sk_new(OPENSSL_sk_compfunc c)
{
return OPENSSL_sk_new_reserve(c, 0);
}
/*
* Calculate the array growth based on the target size.
*
* The growth fraction is a rational number and is defined by a numerator
* and a denominator. According to Andrew Koenig in his paper "Why Are
* Vectors Efficient?" from JOOP 11(5) 1998, this factor should be less
* than the golden ratio (1.618...).
*
* We use 3/2 = 1.5 for simplicity of calculation and overflow checking.
* Another option 8/5 = 1.6 allows for slightly faster growth, although safe
* computation is more difficult.
*
* The limit to avoid overflow is spot on. The modulo three correction term
* ensures that the limit is the largest number than can be expanded by the
* growth factor without exceeding the hard limit.
*
* Do not call it with |current| lower than 2, or it will infinitely loop.
*/
static ossl_inline int compute_growth(int target, int current)
{
const int limit = (max_nodes / 3) * 2 + (max_nodes % 3 ? 1 : 0);
while (current < target) {
/* Check to see if we're at the hard limit */
if (current >= max_nodes)
return 0;
/* Expand the size by a factor of 3/2 if it is within range */
current = current < limit ? current + current / 2 : max_nodes;
}
return current;
}
/* internal STACK storage allocation */
static int sk_reserve(OPENSSL_STACK *st, int n, int exact)
{
const void **tmpdata;
int num_alloc;
/* Check to see the reservation isn't exceeding the hard limit */
if (n > max_nodes - st->num)
return 0;
/* Figure out the new size */
num_alloc = st->num + n;
if (num_alloc < min_nodes)
num_alloc = min_nodes;
/* If |st->data| allocation was postponed */
if (st->data == NULL) {
/*
* At this point, |st->num_alloc| and |st->num| are 0;
* so |num_alloc| value is |n| or |min_nodes| if greater than |n|.
*/
if ((st->data = OPENSSL_zalloc(sizeof(void *) * num_alloc)) == NULL) {
CRYPTOerr(CRYPTO_F_SK_RESERVE, ERR_R_MALLOC_FAILURE);
return 0;
}
st->num_alloc = num_alloc;
return 1;
}
if (!exact) {
if (num_alloc <= st->num_alloc)
return 1;
num_alloc = compute_growth(num_alloc, st->num_alloc);
if (num_alloc == 0)
return 0;
} else if (num_alloc == st->num_alloc) {
return 1;
}
tmpdata = OPENSSL_realloc((void *)st->data, sizeof(void *) * num_alloc);
if (tmpdata == NULL)
return 0;
st->data = tmpdata;
st->num_alloc = num_alloc;
return 1;
}
OPENSSL_STACK *OPENSSL_sk_new_reserve(OPENSSL_sk_compfunc c, int n)
{
OPENSSL_STACK *st = OPENSSL_zalloc(sizeof(OPENSSL_STACK));
if (st == NULL)
return NULL;
st->comp = c;
if (n <= 0)
return st;
if (!sk_reserve(st, n, 1)) {
OPENSSL_sk_free(st);
return NULL;
}
return st;
}
int OPENSSL_sk_reserve(OPENSSL_STACK *st, int n)
{
if (st == NULL)
return 0;
if (n < 0)
return 1;
return sk_reserve(st, n, 1);
}
int OPENSSL_sk_insert(OPENSSL_STACK *st, const void *data, int loc)
{
if (st == NULL || st->num == max_nodes)
return 0;
if (!sk_reserve(st, 1, 0))
return 0;
if ((loc >= st->num) || (loc < 0)) {
st->data[st->num] = data;
} else {
memmove(&st->data[loc + 1], &st->data[loc],
sizeof(st->data[0]) * (st->num - loc));
st->data[loc] = data;
}
st->num++;
st->sorted = 0;
return st->num;
}
static ossl_inline void *internal_delete(OPENSSL_STACK *st, int loc)
{
const void *ret = st->data[loc];
if (loc != st->num - 1)
memmove(&st->data[loc], &st->data[loc + 1],
sizeof(st->data[0]) * (st->num - loc - 1));
st->num--;
return (void *)ret;
}
void *OPENSSL_sk_delete_ptr(OPENSSL_STACK *st, const void *p)
{
int i;
for (i = 0; i < st->num; i++)
if (st->data[i] == p)
return internal_delete(st, i);
return NULL;
}
void *OPENSSL_sk_delete(OPENSSL_STACK *st, int loc)
{
if (st == NULL || loc < 0 || loc >= st->num)
return NULL;
return internal_delete(st, loc);
}
static int internal_find(OPENSSL_STACK *st, const void *data,
int ret_val_options)
{
const void *r;
int i;
if (st == NULL || st->num == 0)
return -1;
if (st->comp == NULL) {
for (i = 0; i < st->num; i++)
if (st->data[i] == data)
return i;
return -1;
}
if (!st->sorted) {
if (st->num > 1)
qsort(st->data, st->num, sizeof(void *), st->comp);
st->sorted = 1; /* empty or single-element stack is considered sorted */
}
if (data == NULL)
return -1;
r = OBJ_bsearch_ex_(&data, st->data, st->num, sizeof(void *), st->comp,
ret_val_options);
return r == NULL ? -1 : (int)((const void **)r - st->data);
}
int OPENSSL_sk_find(OPENSSL_STACK *st, const void *data)
{
return internal_find(st, data, OBJ_BSEARCH_FIRST_VALUE_ON_MATCH);
}
int OPENSSL_sk_find_ex(OPENSSL_STACK *st, const void *data)
{
return internal_find(st, data, OBJ_BSEARCH_VALUE_ON_NOMATCH);
}
int OPENSSL_sk_push(OPENSSL_STACK *st, const void *data)
{
if (st == NULL)
return -1;
return OPENSSL_sk_insert(st, data, st->num);
}
int OPENSSL_sk_unshift(OPENSSL_STACK *st, const void *data)
{
return OPENSSL_sk_insert(st, data, 0);
}
void *OPENSSL_sk_shift(OPENSSL_STACK *st)
{
if (st == NULL || st->num == 0)
return NULL;
return internal_delete(st, 0);
}
void *OPENSSL_sk_pop(OPENSSL_STACK *st)
{
if (st == NULL || st->num == 0)
return NULL;
return internal_delete(st, st->num - 1);
}
void OPENSSL_sk_zero(OPENSSL_STACK *st)
{
if (st == NULL || st->num == 0)
return;
memset(st->data, 0, sizeof(*st->data) * st->num);
st->num = 0;
}
void OPENSSL_sk_pop_free(OPENSSL_STACK *st, OPENSSL_sk_freefunc func)
{
int i;
if (st == NULL)
return;
for (i = 0; i < st->num; i++)
if (st->data[i] != NULL)
func((char *)st->data[i]);
OPENSSL_sk_free(st);
}
void OPENSSL_sk_free(OPENSSL_STACK *st)
{
if (st == NULL)
return;
OPENSSL_free(st->data);
OPENSSL_free(st);
}
int OPENSSL_sk_num(const OPENSSL_STACK *st)
{
return st == NULL ? -1 : st->num;
}
void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)
{
if (st == NULL || i < 0 || i >= st->num)
return NULL;
return (void *)st->data[i];
}
void *OPENSSL_sk_set(OPENSSL_STACK *st, int i, const void *data)
{
if (st == NULL || i < 0 || i >= st->num)
return NULL;
st->data[i] = data;
st->sorted = 0;
return (void *)st->data[i];
}
void OPENSSL_sk_sort(OPENSSL_STACK *st)
{
if (st != NULL && !st->sorted && st->comp != NULL) {
if (st->num > 1)
qsort(st->data, st->num, sizeof(void *), st->comp);
st->sorted = 1; /* empty or single-element stack is considered sorted */
}
}
int OPENSSL_sk_is_sorted(const OPENSSL_STACK *st)
{
return st == NULL ? 1 : st->sorted;
}