crypto/stack/stack.c

   1 /*
   2  * Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include "internal/numbers.h"
  13 #include "internal/safe_math.h"
  14 #include <openssl/stack.h>
  15 #include <errno.h>
  16 #include <openssl/e_os2.h>      /* For ossl_inline */
  17
  18 OSSL_SAFE_MATH_SIGNED(int, int)
  19
  20 /*
  21  * The initial number of nodes in the array.
  22  */
  23 static const int min_nodes = 4;
  24 static const int max_nodes = SIZE_MAX / sizeof(void *) < INT_MAX
  25     ? (int)(SIZE_MAX / sizeof(void *)) : INT_MAX;
  26
  27 struct stack_st {
  28     int num;
  29     const void **data;
  30     int sorted;
  31     int num_alloc;
  32     OPENSSL_sk_compfunc comp;
  33 };
  34
  35 OPENSSL_sk_compfunc OPENSSL_sk_set_cmp_func(OPENSSL_STACK *sk,
  36                                             OPENSSL_sk_compfunc c)
  37 {
  38     OPENSSL_sk_compfunc old = sk->comp;
  39
  40     if (sk->comp != c)
  41         sk->sorted = 0;
  42     sk->comp = c;
  43
  44     return old;
  45 }
  46
  47 OPENSSL_STACK *OPENSSL_sk_dup(const OPENSSL_STACK *sk)
  48 {
  49     OPENSSL_STACK *ret;
  50
  51     if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL)
  52         goto err;
  53
  54     if (sk == NULL) {
  55         ret->num = 0;
  56         ret->sorted = 0;
  57         ret->comp = NULL;
  58     } else {
  59         /* direct structure assignment */
  60         *ret = *sk;
  61     }
  62
  63     if (sk == NULL || sk->num == 0) {
  64         /* postpone |ret->data| allocation */
  65         ret->data = NULL;
  66         ret->num_alloc = 0;
  67         return ret;
  68     }
  69
  70     /* duplicate |sk->data| content */
  71     ret->data = OPENSSL_malloc(sizeof(*ret->data) * sk->num_alloc);
  72     if (ret->data == NULL)
  73         goto err;
  74     memcpy(ret->data, sk->data, sizeof(void *) * sk->num);
  75     return ret;
  76
  77  err:
  78     OPENSSL_sk_free(ret);
  79     return NULL;
  80 }
  81
  82 OPENSSL_STACK *OPENSSL_sk_deep_copy(const OPENSSL_STACK *sk,
  83                                     OPENSSL_sk_copyfunc copy_func,
  84                                     OPENSSL_sk_freefunc free_func)
  85 {
  86     OPENSSL_STACK *ret;
  87     int i;
  88
  89     if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL)
  90         goto err;
  91
  92     if (sk == NULL) {
  93         ret->num = 0;
  94         ret->sorted = 0;
  95         ret->comp = NULL;
  96     } else {
  97         /* direct structure assignment */
  98         *ret = *sk;
  99     }
 100
 101     if (sk == NULL || sk->num == 0) {
 102         /* postpone |ret| data allocation */
 103         ret->data = NULL;
 104         ret->num_alloc = 0;
 105         return ret;
 106     }
 107
 108     ret->num_alloc = sk->num > min_nodes ? sk->num : min_nodes;
 109     ret->data = OPENSSL_zalloc(sizeof(*ret->data) * ret->num_alloc);
 110     if (ret->data == NULL)
 111         goto err;
 112
 113     for (i = 0; i < ret->num; ++i) {
 114         if (sk->data[i] == NULL)
 115             continue;
 116         if ((ret->data[i] = copy_func(sk->data[i])) == NULL) {
 117             while (--i >= 0)
 118                 if (ret->data[i] != NULL)
 119                     free_func((void *)ret->data[i]);
 120             goto err;
 121         }
 122     }
 123     return ret;
 124
 125  err:
 126     OPENSSL_sk_free(ret);
 127     return NULL;
 128 }
 129
 130 OPENSSL_STACK *OPENSSL_sk_new_null(void)
 131 {
 132     return OPENSSL_sk_new_reserve(NULL, 0);
 133 }
 134
 135 OPENSSL_STACK *OPENSSL_sk_new(OPENSSL_sk_compfunc c)
 136 {
 137     return OPENSSL_sk_new_reserve(c, 0);
 138 }
 139
 140 /*
 141  * Calculate the array growth based on the target size.
 142  *
 143  * The growth factor is a rational number and is defined by a numerator
 144  * and a denominator.  According to Andrew Koenig in his paper "Why Are
 145  * Vectors Efficient?" from JOOP 11(5) 1998, this factor should be less
 146  * than the golden ratio (1.618...).
 147  *
 148  * Considering only the Fibonacci ratios less than the golden ratio, the
 149  * number of steps from the minimum allocation to integer overflow is:
 150  *      factor  decimal    growths
 151  *       3/2     1.5          51
 152  *       8/5     1.6          45
 153  *      21/13    1.615...     44
 154  *
 155  * All larger factors have the same number of growths.
 156  *
 157  * 3/2 and 8/5 have nice power of two shifts, so seem like a good choice.
 158  */
 159 static ossl_inline int compute_growth(int target, int current)
 160 {
 161     int err = 0;
 162
 163     while (current < target) {
 164         if (current >= max_nodes)
 165             return 0;
 166
 167         current = safe_muldiv_int(current, 8, 5, &err);
 168         if (err != 0)
 169             return 0;
 170         if (current >= max_nodes)
 171             current = max_nodes;
 172     }
 173     return current;
 174 }
 175
 176 /* internal STACK storage allocation */
 177 static int sk_reserve(OPENSSL_STACK *st, int n, int exact)
 178 {
 179     const void **tmpdata;
 180     int num_alloc;
 181
 182     /* Check to see the reservation isn't exceeding the hard limit */
 183     if (n > max_nodes - st->num) {
 184         ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_TOO_MANY_RECORDS);
 185         return 0;
 186     }
 187
 188     /* Figure out the new size */
 189     num_alloc = st->num + n;
 190     if (num_alloc < min_nodes)
 191         num_alloc = min_nodes;
 192
 193     /* If |st->data| allocation was postponed */
 194     if (st->data == NULL) {
 195         /*
 196          * At this point, |st->num_alloc| and |st->num| are 0;
 197          * so |num_alloc| value is |n| or |min_nodes| if greater than |n|.
 198          */
 199         if ((st->data = OPENSSL_zalloc(sizeof(void *) * num_alloc)) == NULL)
 200             return 0;
 201         st->num_alloc = num_alloc;
 202         return 1;
 203     }
 204
 205     if (!exact) {
 206         if (num_alloc <= st->num_alloc)
 207             return 1;
 208         num_alloc = compute_growth(num_alloc, st->num_alloc);
 209         if (num_alloc == 0) {
 210             ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_TOO_MANY_RECORDS);
 211             return 0;
 212         }
 213     } else if (num_alloc == st->num_alloc) {
 214         return 1;
 215     }
 216
 217     tmpdata = OPENSSL_realloc((void *)st->data, sizeof(void *) * num_alloc);
 218     if (tmpdata == NULL)
 219         return 0;
 220
 221     st->data = tmpdata;
 222     st->num_alloc = num_alloc;
 223     return 1;
 224 }
 225
 226 OPENSSL_STACK *OPENSSL_sk_new_reserve(OPENSSL_sk_compfunc c, int n)
 227 {
 228     OPENSSL_STACK *st = OPENSSL_zalloc(sizeof(OPENSSL_STACK));
 229
 230     if (st == NULL)
 231         return NULL;
 232
 233     st->comp = c;
 234
 235     if (n <= 0)
 236         return st;
 237
 238     if (!sk_reserve(st, n, 1)) {
 239         OPENSSL_sk_free(st);
 240         return NULL;
 241     }
 242
 243     return st;
 244 }
 245
 246 int OPENSSL_sk_reserve(OPENSSL_STACK *st, int n)
 247 {
 248     if (st == NULL) {
 249         ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_NULL_PARAMETER);
 250         return 0;
 251     }
 252
 253     if (n < 0)
 254         return 1;
 255     return sk_reserve(st, n, 1);
 256 }
 257
 258 int OPENSSL_sk_insert(OPENSSL_STACK *st, const void *data, int loc)
 259 {
 260     if (st == NULL) {
 261         ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_NULL_PARAMETER);
 262         return 0;
 263     }
 264     if (st->num == max_nodes) {
 265         ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_TOO_MANY_RECORDS);
 266         return 0;
 267     }
 268
 269     if (!sk_reserve(st, 1, 0))
 270         return 0;
 271
 272     if ((loc >= st->num) || (loc < 0)) {
 273         st->data[st->num] = data;
 274     } else {
 275         memmove(&st->data[loc + 1], &st->data[loc],
 276                 sizeof(st->data[0]) * (st->num - loc));
 277         st->data[loc] = data;
 278     }
 279     st->num++;
 280     st->sorted = 0;
 281     return st->num;
 282 }
 283
 284 static ossl_inline void *internal_delete(OPENSSL_STACK *st, int loc)
 285 {
 286     const void *ret = st->data[loc];
 287
 288     if (loc != st->num - 1)
 289         memmove(&st->data[loc], &st->data[loc + 1],
 290                 sizeof(st->data[0]) * (st->num - loc - 1));
 291     st->num--;
 292
 293     return (void *)ret;
 294 }
 295
 296 void *OPENSSL_sk_delete_ptr(OPENSSL_STACK *st, const void *p)
 297 {
 298     int i;
 299
 300     if (st == NULL)
 301         return NULL;
 302
 303     for (i = 0; i < st->num; i++)
 304         if (st->data[i] == p)
 305             return internal_delete(st, i);
 306     return NULL;
 307 }
 308
 309 void *OPENSSL_sk_delete(OPENSSL_STACK *st, int loc)
 310 {
 311     if (st == NULL || loc < 0 || loc >= st->num)
 312         return NULL;
 313
 314     return internal_delete(st, loc);
 315 }
 316
 317 static int internal_find(OPENSSL_STACK *st, const void *data,
 318                          int ret_val_options, int *pnum_matched)
 319 {
 320     const void *r;
 321     int i, count = 0;
 322     int *pnum = pnum_matched;
 323
 324     if (st == NULL || st->num == 0)
 325         return -1;
 326
 327     if (pnum == NULL)
 328         pnum = &count;
 329
 330     if (st->comp == NULL) {
 331         for (i = 0; i < st->num; i++)
 332             if (st->data[i] == data) {
 333                 *pnum = 1;
 334                 return i;
 335             }
 336         *pnum = 0;
 337         return -1;
 338     }
 339
 340     if (data == NULL)
 341         return -1;
 342
 343     if (!st->sorted) {
 344         int res = -1;
 345
 346         for (i = 0; i < st->num; i++)
 347             if (st->comp(&data, st->data + i) == 0) {
 348                 if (res == -1)
 349                     res = i;
 350                 ++*pnum;
 351                 /* Check if only one result is wanted and exit if so */
 352                 if (pnum_matched == NULL)
 353                     return i;
 354             }
 355         if (res == -1)
 356             *pnum = 0;
 357         return res;
 358     }
 359
 360     if (pnum_matched != NULL)
 361         ret_val_options |= OSSL_BSEARCH_FIRST_VALUE_ON_MATCH;
 362     r = ossl_bsearch(&data, st->data, st->num, sizeof(void *), st->comp,
 363                      ret_val_options);
 364
 365     if (pnum_matched != NULL) {
 366         *pnum = 0;
 367         if (r != NULL) {
 368             const void **p = (const void **)r;
 369
 370             while (p < st->data + st->num) {
 371                 if (st->comp(&data, p) != 0)
 372                     break;
 373                 ++*pnum;
 374                 ++p;
 375             }
 376         }
 377     }
 378
 379     return r == NULL ? -1 : (int)((const void **)r - st->data);
 380 }
 381
 382 int OPENSSL_sk_find(OPENSSL_STACK *st, const void *data)
 383 {
 384     return internal_find(st, data, OSSL_BSEARCH_FIRST_VALUE_ON_MATCH, NULL);
 385 }
 386
 387 int OPENSSL_sk_find_ex(OPENSSL_STACK *st, const void *data)
 388 {
 389     return internal_find(st, data, OSSL_BSEARCH_VALUE_ON_NOMATCH, NULL);
 390 }
 391
 392 int OPENSSL_sk_find_all(OPENSSL_STACK *st, const void *data, int *pnum)
 393 {
 394     return internal_find(st, data, OSSL_BSEARCH_FIRST_VALUE_ON_MATCH, pnum);
 395 }
 396
 397 int OPENSSL_sk_push(OPENSSL_STACK *st, const void *data)
 398 {
 399     if (st == NULL)
 400         return -1;
 401     return OPENSSL_sk_insert(st, data, st->num);
 402 }
 403
 404 int OPENSSL_sk_unshift(OPENSSL_STACK *st, const void *data)
 405 {
 406     return OPENSSL_sk_insert(st, data, 0);
 407 }
 408
 409 void *OPENSSL_sk_shift(OPENSSL_STACK *st)
 410 {
 411     if (st == NULL || st->num == 0)
 412         return NULL;
 413     return internal_delete(st, 0);
 414 }
 415
 416 void *OPENSSL_sk_pop(OPENSSL_STACK *st)
 417 {
 418     if (st == NULL || st->num == 0)
 419         return NULL;
 420     return internal_delete(st, st->num - 1);
 421 }
 422
 423 void OPENSSL_sk_zero(OPENSSL_STACK *st)
 424 {
 425     if (st == NULL || st->num == 0)
 426         return;
 427     memset(st->data, 0, sizeof(*st->data) * st->num);
 428     st->num = 0;
 429 }
 430
 431 void OPENSSL_sk_pop_free(OPENSSL_STACK *st, OPENSSL_sk_freefunc func)
 432 {
 433     int i;
 434
 435     if (st == NULL)
 436         return;
 437     for (i = 0; i < st->num; i++)
 438         if (st->data[i] != NULL)
 439             func((char *)st->data[i]);
 440     OPENSSL_sk_free(st);
 441 }
 442
 443 void OPENSSL_sk_free(OPENSSL_STACK *st)
 444 {
 445     if (st == NULL)
 446         return;
 447     OPENSSL_free(st->data);
 448     OPENSSL_free(st);
 449 }
 450
 451 int OPENSSL_sk_num(const OPENSSL_STACK *st)
 452 {
 453     return st == NULL ? -1 : st->num;
 454 }
 455
 456 void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)
 457 {
 458     if (st == NULL || i < 0 || i >= st->num)
 459         return NULL;
 460     return (void *)st->data[i];
 461 }
 462
 463 void *OPENSSL_sk_set(OPENSSL_STACK *st, int i, const void *data)
 464 {
 465     if (st == NULL) {
 466         ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_NULL_PARAMETER);
 467         return NULL;
 468     }
 469     if (i < 0 || i >= st->num) {
 470         ERR_raise_data(ERR_LIB_CRYPTO, ERR_R_PASSED_INVALID_ARGUMENT,
 471                        "i=%d", i);
 472         return NULL;
 473     }
 474     st->data[i] = data;
 475     st->sorted = 0;
 476     return (void *)st->data[i];
 477 }
 478
 479 void OPENSSL_sk_sort(OPENSSL_STACK *st)
 480 {
 481     if (st != NULL && !st->sorted && st->comp != NULL) {
 482         if (st->num > 1)
 483             qsort(st->data, st->num, sizeof(void *), st->comp);
 484         st->sorted = 1; /* empty or single-element stack is considered sorted */
 485     }
 486 }
 487
 488 int OPENSSL_sk_is_sorted(const OPENSSL_STACK *st)
 489 {
 490     return st == NULL ? 1 : st->sorted;
 491 }