1/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 2 * All rights reserved. 3 * 4 * This package is an SSL implementation written 5 * by Eric Young (eay@cryptsoft.com). 6 * The implementation was written so as to conform with Netscapes SSL. 7 * 8 * This library is free for commercial and non-commercial use as long as 9 * the following conditions are aheared to. The following conditions 10 * apply to all code found in this distribution, be it the RC4, RSA, 11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 12 * included with this distribution is covered by the same copyright terms 13 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 14 * 15 * Copyright remains Eric Young's, and as such any Copyright notices in 16 * the code are not to be removed. 17 * If this package is used in a product, Eric Young should be given attribution 18 * as the author of the parts of the library used. 19 * This can be in the form of a textual message at program startup or 20 * in documentation (online or textual) provided with the package. 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 3. All advertising materials mentioning features or use of this software 31 * must display the following acknowledgement: 32 * "This product includes cryptographic software written by 33 * Eric Young (eay@cryptsoft.com)" 34 * The word 'cryptographic' can be left out if the rouines from the library 35 * being used are not cryptographic related :-). 36 * 4. If you include any Windows specific code (or a derivative thereof) from 37 * the apps directory (application code) you must include an acknowledgement: 38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 * 52 * The licence and distribution terms for any publically available version or 53 * derivative of this code cannot be changed. i.e. this code cannot simply be 54 * copied and put under another distribution licence 55 * [including the GNU Public Licence.] */ 56 57#ifndef OPENSSL_HEADER_STACK_H 58#define OPENSSL_HEADER_STACK_H 59 60#include <openssl/base.h> 61 62#include <openssl/type_check.h> 63 64#if defined(__cplusplus) 65extern "C" { 66#endif 67 68 69// A stack, in OpenSSL, is an array of pointers. They are the most commonly 70// used collection object. 71// 72// This file defines macros for type safe use of the stack functions. A stack 73// of a specific type of object has type |STACK_OF(type)|. This can be defined 74// (once) with |DEFINE_STACK_OF(type)| and declared where needed with 75// |DECLARE_STACK_OF(type)|. For example: 76// 77// typedef struct foo_st { 78// int bar; 79// } FOO; 80// 81// DEFINE_STACK_OF(FOO); 82// 83// Although note that the stack will contain /pointers/ to |FOO|. 84// 85// A macro will be defined for each of the sk_* functions below. For 86// STACK_OF(FOO), the macros would be sk_FOO_new, sk_FOO_pop etc. 87 88 89// stack_cmp_func is a comparison function that returns a value < 0, 0 or > 0 90// if |*a| is less than, equal to or greater than |*b|, respectively. Note the 91// extra indirection - the function is given a pointer to a pointer to the 92// element. This differs from the usual qsort/bsearch comparison function. 93typedef int (*stack_cmp_func)(const void **a, const void **b); 94 95// stack_st contains an array of pointers. It is not designed to be used 96// directly, rather the wrapper macros should be used. 97typedef struct stack_st { 98 // num contains the number of valid pointers in |data|. 99 size_t num; 100 void **data; 101 // sorted is non-zero if the values pointed to by |data| are in ascending 102 // order, based on |comp|. 103 int sorted; 104 // num_alloc contains the number of pointers allocated in the buffer pointed 105 // to by |data|, which may be larger than |num|. 106 size_t num_alloc; 107 // comp is an optional comparison function. 108 stack_cmp_func comp; 109} _STACK; 110 111 112#define STACK_OF(type) struct stack_st_##type 113 114#define DECLARE_STACK_OF(type) STACK_OF(type); 115 116// These are the raw stack functions, you shouldn't be using them. Rather you 117// should be using the type stack macros implemented above. 118 119// sk_new creates a new, empty stack with the given comparison function, which 120// may be zero. It returns the new stack or NULL on allocation failure. 121OPENSSL_EXPORT _STACK *sk_new(stack_cmp_func comp); 122 123// sk_new_null creates a new, empty stack. It returns the new stack or NULL on 124// allocation failure. 125OPENSSL_EXPORT _STACK *sk_new_null(void); 126 127// sk_num returns the number of elements in |s|. 128OPENSSL_EXPORT size_t sk_num(const _STACK *sk); 129 130// sk_zero resets |sk| to the empty state but does nothing to free the 131// individual elements themselves. 132OPENSSL_EXPORT void sk_zero(_STACK *sk); 133 134// sk_value returns the |i|th pointer in |sk|, or NULL if |i| is out of 135// range. 136OPENSSL_EXPORT void *sk_value(const _STACK *sk, size_t i); 137 138// sk_set sets the |i|th pointer in |sk| to |p| and returns |p|. If |i| is out 139// of range, it returns NULL. 140OPENSSL_EXPORT void *sk_set(_STACK *sk, size_t i, void *p); 141 142// sk_free frees the given stack and array of pointers, but does nothing to 143// free the individual elements. Also see |sk_pop_free|. 144OPENSSL_EXPORT void sk_free(_STACK *sk); 145 146// sk_pop_free calls |free_func| on each element in the stack and then frees 147// the stack itself. 148OPENSSL_EXPORT void sk_pop_free(_STACK *sk, void (*free_func)(void *)); 149 150// sk_insert inserts |p| into the stack at index |where|, moving existing 151// elements if needed. It returns the length of the new stack, or zero on 152// error. 153OPENSSL_EXPORT size_t sk_insert(_STACK *sk, void *p, size_t where); 154 155// sk_delete removes the pointer at index |where|, moving other elements down 156// if needed. It returns the removed pointer, or NULL if |where| is out of 157// range. 158OPENSSL_EXPORT void *sk_delete(_STACK *sk, size_t where); 159 160// sk_delete_ptr removes, at most, one instance of |p| from the stack based on 161// pointer equality. If an instance of |p| is found then |p| is returned, 162// otherwise it returns NULL. 163OPENSSL_EXPORT void *sk_delete_ptr(_STACK *sk, void *p); 164 165// sk_find returns the first value in the stack equal to |p|. If a comparison 166// function has been set on the stack, then equality is defined by it and the 167// stack will be sorted if need be so that a binary search can be used. 168// Otherwise pointer equality is used. If a matching element is found, its 169// index is written to |*out_index| (if |out_index| is not NULL) and one is 170// returned. Otherwise zero is returned. 171OPENSSL_EXPORT int sk_find(_STACK *sk, size_t *out_index, void *p); 172 173// sk_shift removes and returns the first element in the stack, or returns NULL 174// if the stack is empty. 175OPENSSL_EXPORT void *sk_shift(_STACK *sk); 176 177// sk_push appends |p| to the stack and returns the length of the new stack, or 178// 0 on allocation failure. 179OPENSSL_EXPORT size_t sk_push(_STACK *sk, void *p); 180 181// sk_pop returns and removes the last element on the stack, or NULL if the 182// stack is empty. 183OPENSSL_EXPORT void *sk_pop(_STACK *sk); 184 185// sk_dup performs a shallow copy of a stack and returns the new stack, or NULL 186// on error. 187OPENSSL_EXPORT _STACK *sk_dup(const _STACK *sk); 188 189// sk_sort sorts the elements of |sk| into ascending order based on the 190// comparison function. The stack maintains a |sorted| flag and sorting an 191// already sorted stack is a no-op. 192OPENSSL_EXPORT void sk_sort(_STACK *sk); 193 194// sk_is_sorted returns one if |sk| is known to be sorted and zero 195// otherwise. 196OPENSSL_EXPORT int sk_is_sorted(const _STACK *sk); 197 198// sk_set_cmp_func sets the comparison function to be used by |sk| and returns 199// the previous one. 200OPENSSL_EXPORT stack_cmp_func sk_set_cmp_func(_STACK *sk, stack_cmp_func comp); 201 202// sk_deep_copy performs a copy of |sk| and of each of the non-NULL elements in 203// |sk| by using |copy_func|. If an error occurs, |free_func| is used to free 204// any copies already made and NULL is returned. 205OPENSSL_EXPORT _STACK *sk_deep_copy(const _STACK *sk, 206 void *(*copy_func)(void *), 207 void (*free_func)(void *)); 208 209 210// Defining stack types. 211// 212// This set of macros is used to emit the typed functions that act on a 213// |STACK_OF(T)|. 214 215#if !defined(BORINGSSL_NO_CXX) 216extern "C++" { 217namespace bssl { 218namespace internal { 219template <typename T> 220struct StackTraits {}; 221} 222} 223} 224 225#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const) \ 226 extern "C++" { \ 227 namespace bssl { \ 228 namespace internal { \ 229 template <> \ 230 struct StackTraits<STACK_OF(name)> { \ 231 static constexpr bool kIsStack = true; \ 232 using Type = type; \ 233 static constexpr bool kIsConst = is_const; \ 234 }; \ 235 } \ 236 } \ 237 } 238 239#else 240#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const) 241#endif 242 243// Stack functions must be tagged unused to support file-local stack types. 244// Clang's -Wunused-function only allows unused static inline functions if they 245// are defined in a header. 246 247#define BORINGSSL_DEFINE_STACK_OF_IMPL(name, ptrtype, constptrtype) \ 248 DECLARE_STACK_OF(name) \ 249 \ 250 typedef int (*stack_##name##_cmp_func)(constptrtype *a, constptrtype *b); \ 251 \ 252 static inline OPENSSL_UNUSED STACK_OF(name) * \ 253 sk_##name##_new(stack_##name##_cmp_func comp) { \ 254 return (STACK_OF(name) *)sk_new((stack_cmp_func)comp); \ 255 } \ 256 \ 257 static inline OPENSSL_UNUSED STACK_OF(name) *sk_##name##_new_null(void) { \ 258 return (STACK_OF(name) *)sk_new_null(); \ 259 } \ 260 \ 261 static inline OPENSSL_UNUSED size_t sk_##name##_num( \ 262 const STACK_OF(name) *sk) { \ 263 return sk_num((const _STACK *)sk); \ 264 } \ 265 \ 266 static inline OPENSSL_UNUSED void sk_##name##_zero(STACK_OF(name) *sk) { \ 267 sk_zero((_STACK *)sk); \ 268 } \ 269 \ 270 static inline OPENSSL_UNUSED ptrtype sk_##name##_value( \ 271 const STACK_OF(name) *sk, size_t i) { \ 272 return (ptrtype)sk_value((const _STACK *)sk, i); \ 273 } \ 274 \ 275 static inline OPENSSL_UNUSED ptrtype sk_##name##_set(STACK_OF(name) *sk, \ 276 size_t i, ptrtype p) { \ 277 return (ptrtype)sk_set((_STACK *)sk, i, (void *)p); \ 278 } \ 279 \ 280 static inline OPENSSL_UNUSED void sk_##name##_free(STACK_OF(name) *sk) { \ 281 sk_free((_STACK *)sk); \ 282 } \ 283 \ 284 static inline OPENSSL_UNUSED void sk_##name##_pop_free( \ 285 STACK_OF(name) *sk, void (*free_func)(ptrtype p)) { \ 286 sk_pop_free((_STACK *)sk, (void (*)(void *))free_func); \ 287 } \ 288 \ 289 static inline OPENSSL_UNUSED size_t sk_##name##_insert( \ 290 STACK_OF(name) *sk, ptrtype p, size_t where) { \ 291 return sk_insert((_STACK *)sk, (void *)p, where); \ 292 } \ 293 \ 294 static inline OPENSSL_UNUSED ptrtype sk_##name##_delete(STACK_OF(name) *sk, \ 295 size_t where) { \ 296 return (ptrtype)sk_delete((_STACK *)sk, where); \ 297 } \ 298 \ 299 static inline OPENSSL_UNUSED ptrtype sk_##name##_delete_ptr( \ 300 STACK_OF(name) *sk, ptrtype p) { \ 301 return (ptrtype)sk_delete_ptr((_STACK *)sk, (void *)p); \ 302 } \ 303 \ 304 static inline OPENSSL_UNUSED int sk_##name##_find( \ 305 STACK_OF(name) *sk, size_t *out_index, ptrtype p) { \ 306 return sk_find((_STACK *)sk, out_index, (void *)p); \ 307 } \ 308 \ 309 static inline OPENSSL_UNUSED ptrtype sk_##name##_shift(STACK_OF(name) *sk) { \ 310 return (ptrtype)sk_shift((_STACK *)sk); \ 311 } \ 312 \ 313 static inline OPENSSL_UNUSED size_t sk_##name##_push(STACK_OF(name) *sk, \ 314 ptrtype p) { \ 315 return sk_push((_STACK *)sk, (void *)p); \ 316 } \ 317 \ 318 static inline OPENSSL_UNUSED ptrtype sk_##name##_pop(STACK_OF(name) *sk) { \ 319 return (ptrtype)sk_pop((_STACK *)sk); \ 320 } \ 321 \ 322 static inline OPENSSL_UNUSED STACK_OF(name) * \ 323 sk_##name##_dup(const STACK_OF(name) *sk) { \ 324 return (STACK_OF(name) *)sk_dup((const _STACK *)sk); \ 325 } \ 326 \ 327 static inline OPENSSL_UNUSED void sk_##name##_sort(STACK_OF(name) *sk) { \ 328 sk_sort((_STACK *)sk); \ 329 } \ 330 \ 331 static inline OPENSSL_UNUSED int sk_##name##_is_sorted( \ 332 const STACK_OF(name) *sk) { \ 333 return sk_is_sorted((const _STACK *)sk); \ 334 } \ 335 \ 336 static inline OPENSSL_UNUSED stack_##name##_cmp_func \ 337 sk_##name##_set_cmp_func(STACK_OF(name) *sk, \ 338 stack_##name##_cmp_func comp) { \ 339 return (stack_##name##_cmp_func)sk_set_cmp_func((_STACK *)sk, \ 340 (stack_cmp_func)comp); \ 341 } \ 342 \ 343 static inline OPENSSL_UNUSED STACK_OF(name) * \ 344 sk_##name##_deep_copy(const STACK_OF(name) *sk, \ 345 ptrtype(*copy_func)(ptrtype), \ 346 void (*free_func)(ptrtype)) { \ 347 return (STACK_OF(name) *)sk_deep_copy((const _STACK *)sk, \ 348 (void *(*)(void *))copy_func, \ 349 (void (*)(void *))free_func); \ 350 } 351 352// DEFINE_STACK_OF defines |STACK_OF(type)| to be a stack whose elements are 353// |type| *. 354#define DEFINE_STACK_OF(type) \ 355 BORINGSSL_DEFINE_STACK_OF_IMPL(type, type *, const type *) \ 356 BORINGSSL_DEFINE_STACK_TRAITS(type, type, false) 357 358// DEFINE_CONST_STACK_OF defines |STACK_OF(type)| to be a stack whose elements 359// are const |type| *. 360#define DEFINE_CONST_STACK_OF(type) \ 361 BORINGSSL_DEFINE_STACK_OF_IMPL(type, const type *, const type *) \ 362 BORINGSSL_DEFINE_STACK_TRAITS(type, const type, true) 363 364// DEFINE_SPECIAL_STACK_OF defines |STACK_OF(type)| to be a stack whose elements 365// are |type|, where |type| must be a typedef for a pointer. 366#define DEFINE_SPECIAL_STACK_OF(type) \ 367 OPENSSL_COMPILE_ASSERT(sizeof(type) == sizeof(void *), \ 368 special_stack_of_non_pointer_##type); \ 369 BORINGSSL_DEFINE_STACK_OF_IMPL(type, type, const type) 370 371 372typedef char *OPENSSL_STRING; 373 374DEFINE_STACK_OF(void) 375DEFINE_SPECIAL_STACK_OF(OPENSSL_STRING) 376 377 378#if defined(__cplusplus) 379} // extern C 380#endif 381 382#if !defined(BORINGSSL_NO_CXX) 383extern "C++" { 384 385#include <type_traits> 386 387namespace bssl { 388 389namespace internal { 390 391// Stacks defined with |DEFINE_CONST_STACK_OF| are freed with |sk_free|. 392template <typename Stack> 393struct DeleterImpl< 394 Stack, typename std::enable_if<StackTraits<Stack>::kIsConst>::type> { 395 static void Free(Stack *sk) { sk_free(reinterpret_cast<_STACK *>(sk)); } 396}; 397 398// Stacks defined with |DEFINE_STACK_OF| are freed with |sk_pop_free| and the 399// corresponding type's deleter. 400template <typename Stack> 401struct DeleterImpl< 402 Stack, typename std::enable_if<!StackTraits<Stack>::kIsConst>::type> { 403 static void Free(Stack *sk) { 404 sk_pop_free( 405 reinterpret_cast<_STACK *>(sk), 406 reinterpret_cast<void (*)(void *)>( 407 DeleterImpl<typename StackTraits<Stack>::Type>::Free)); 408 } 409}; 410 411template <typename Stack> 412class StackIteratorImpl { 413 public: 414 using Type = typename StackTraits<Stack>::Type; 415 // Iterators must be default-constructable. 416 StackIteratorImpl() : sk_(nullptr), idx_(0) {} 417 StackIteratorImpl(const Stack *sk, size_t idx) : sk_(sk), idx_(idx) {} 418 419 bool operator==(StackIteratorImpl other) const { 420 return sk_ == other.sk_ && idx_ == other.idx_; 421 } 422 bool operator!=(StackIteratorImpl other) const { 423 return !(*this == other); 424 } 425 426 Type *operator*() const { 427 return reinterpret_cast<Type *>( 428 sk_value(reinterpret_cast<const _STACK *>(sk_), idx_)); 429 } 430 431 StackIteratorImpl &operator++(/* prefix */) { 432 idx_++; 433 return *this; 434 } 435 436 StackIteratorImpl operator++(int /* postfix */) { 437 StackIteratorImpl copy(*this); 438 ++(*this); 439 return copy; 440 } 441 442 private: 443 const Stack *sk_; 444 size_t idx_; 445}; 446 447template <typename Stack> 448using StackIterator = typename std::enable_if<StackTraits<Stack>::kIsStack, 449 StackIteratorImpl<Stack>>::type; 450 451} // namespace internal 452 453// PushToStack pushes |elem| to |sk|. It returns true on success and false on 454// allocation failure. 455template <typename Stack> 456static inline 457 typename std::enable_if<!internal::StackTraits<Stack>::kIsConst, bool>::type 458 PushToStack(Stack *sk, 459 UniquePtr<typename internal::StackTraits<Stack>::Type> elem) { 460 if (!sk_push(reinterpret_cast<_STACK *>(sk), elem.get())) { 461 return false; 462 } 463 // sk_push takes ownership on success. 464 elem.release(); 465 return true; 466} 467 468} // namespace bssl 469 470// Define begin() and end() for stack types so C++ range for loops work. 471template <typename Stack> 472static inline bssl::internal::StackIterator<Stack> begin(const Stack *sk) { 473 return bssl::internal::StackIterator<Stack>(sk, 0); 474} 475 476template <typename Stack> 477static inline bssl::internal::StackIterator<Stack> end(const Stack *sk) { 478 return bssl::internal::StackIterator<Stack>( 479 sk, sk_num(reinterpret_cast<const _STACK *>(sk))); 480} 481 482} // extern C++ 483#endif 484 485#endif // OPENSSL_HEADER_STACK_H 486