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, equality is defined by it, otherwise 167// pointer equality is used. If the stack is sorted, then a binary search is 168// used, otherwise a linear search is performed. If a matching element is found, 169// its index is written to 170// |*out_index| (if |out_index| is not NULL) and one is returned. Otherwise zero 171// is returned. 172// 173// Note this differs from OpenSSL. The type signature is slightly different, and 174// OpenSSL's sk_find will implicitly sort |sk| if it has a comparison function 175// defined. 176OPENSSL_EXPORT int sk_find(const _STACK *sk, size_t *out_index, void *p); 177 178// sk_shift removes and returns the first element in the stack, or returns NULL 179// if the stack is empty. 180OPENSSL_EXPORT void *sk_shift(_STACK *sk); 181 182// sk_push appends |p| to the stack and returns the length of the new stack, or 183// 0 on allocation failure. 184OPENSSL_EXPORT size_t sk_push(_STACK *sk, void *p); 185 186// sk_pop returns and removes the last element on the stack, or NULL if the 187// stack is empty. 188OPENSSL_EXPORT void *sk_pop(_STACK *sk); 189 190// sk_dup performs a shallow copy of a stack and returns the new stack, or NULL 191// on error. 192OPENSSL_EXPORT _STACK *sk_dup(const _STACK *sk); 193 194// sk_sort sorts the elements of |sk| into ascending order based on the 195// comparison function. The stack maintains a |sorted| flag and sorting an 196// already sorted stack is a no-op. 197OPENSSL_EXPORT void sk_sort(_STACK *sk); 198 199// sk_is_sorted returns one if |sk| is known to be sorted and zero 200// otherwise. 201OPENSSL_EXPORT int sk_is_sorted(const _STACK *sk); 202 203// sk_set_cmp_func sets the comparison function to be used by |sk| and returns 204// the previous one. 205OPENSSL_EXPORT stack_cmp_func sk_set_cmp_func(_STACK *sk, stack_cmp_func comp); 206 207// sk_deep_copy performs a copy of |sk| and of each of the non-NULL elements in 208// |sk| by using |copy_func|. If an error occurs, |free_func| is used to free 209// any copies already made and NULL is returned. 210OPENSSL_EXPORT _STACK *sk_deep_copy(const _STACK *sk, 211 void *(*copy_func)(void *), 212 void (*free_func)(void *)); 213 214 215// Defining stack types. 216// 217// This set of macros is used to emit the typed functions that act on a 218// |STACK_OF(T)|. 219 220#if !defined(BORINGSSL_NO_CXX) 221extern "C++" { 222namespace bssl { 223namespace internal { 224template <typename T> 225struct StackTraits {}; 226} 227} 228} 229 230#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const) \ 231 extern "C++" { \ 232 namespace bssl { \ 233 namespace internal { \ 234 template <> \ 235 struct StackTraits<STACK_OF(name)> { \ 236 static constexpr bool kIsStack = true; \ 237 using Type = type; \ 238 static constexpr bool kIsConst = is_const; \ 239 }; \ 240 } \ 241 } \ 242 } 243 244#else 245#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const) 246#endif 247 248// Stack functions must be tagged unused to support file-local stack types. 249// Clang's -Wunused-function only allows unused static inline functions if they 250// are defined in a header. 251 252#define BORINGSSL_DEFINE_STACK_OF_IMPL(name, ptrtype, constptrtype) \ 253 DECLARE_STACK_OF(name) \ 254 \ 255 typedef int (*stack_##name##_cmp_func)(constptrtype *a, constptrtype *b); \ 256 \ 257 static inline OPENSSL_UNUSED STACK_OF(name) * \ 258 sk_##name##_new(stack_##name##_cmp_func comp) { \ 259 return (STACK_OF(name) *)sk_new((stack_cmp_func)comp); \ 260 } \ 261 \ 262 static inline OPENSSL_UNUSED STACK_OF(name) *sk_##name##_new_null(void) { \ 263 return (STACK_OF(name) *)sk_new_null(); \ 264 } \ 265 \ 266 static inline OPENSSL_UNUSED size_t sk_##name##_num( \ 267 const STACK_OF(name) *sk) { \ 268 return sk_num((const _STACK *)sk); \ 269 } \ 270 \ 271 static inline OPENSSL_UNUSED void sk_##name##_zero(STACK_OF(name) *sk) { \ 272 sk_zero((_STACK *)sk); \ 273 } \ 274 \ 275 static inline OPENSSL_UNUSED ptrtype sk_##name##_value( \ 276 const STACK_OF(name) *sk, size_t i) { \ 277 return (ptrtype)sk_value((const _STACK *)sk, i); \ 278 } \ 279 \ 280 static inline OPENSSL_UNUSED ptrtype sk_##name##_set(STACK_OF(name) *sk, \ 281 size_t i, ptrtype p) { \ 282 return (ptrtype)sk_set((_STACK *)sk, i, (void *)p); \ 283 } \ 284 \ 285 static inline OPENSSL_UNUSED void sk_##name##_free(STACK_OF(name) *sk) { \ 286 sk_free((_STACK *)sk); \ 287 } \ 288 \ 289 static inline OPENSSL_UNUSED void sk_##name##_pop_free( \ 290 STACK_OF(name) *sk, void (*free_func)(ptrtype p)) { \ 291 sk_pop_free((_STACK *)sk, (void (*)(void *))free_func); \ 292 } \ 293 \ 294 static inline OPENSSL_UNUSED size_t sk_##name##_insert( \ 295 STACK_OF(name) *sk, ptrtype p, size_t where) { \ 296 return sk_insert((_STACK *)sk, (void *)p, where); \ 297 } \ 298 \ 299 static inline OPENSSL_UNUSED ptrtype sk_##name##_delete(STACK_OF(name) *sk, \ 300 size_t where) { \ 301 return (ptrtype)sk_delete((_STACK *)sk, where); \ 302 } \ 303 \ 304 static inline OPENSSL_UNUSED ptrtype sk_##name##_delete_ptr( \ 305 STACK_OF(name) *sk, ptrtype p) { \ 306 return (ptrtype)sk_delete_ptr((_STACK *)sk, (void *)p); \ 307 } \ 308 \ 309 static inline OPENSSL_UNUSED int sk_##name##_find( \ 310 const STACK_OF(name) *sk, size_t *out_index, ptrtype p) { \ 311 return sk_find((const _STACK *)sk, out_index, (void *)p); \ 312 } \ 313 \ 314 static inline OPENSSL_UNUSED ptrtype sk_##name##_shift(STACK_OF(name) *sk) { \ 315 return (ptrtype)sk_shift((_STACK *)sk); \ 316 } \ 317 \ 318 static inline OPENSSL_UNUSED size_t sk_##name##_push(STACK_OF(name) *sk, \ 319 ptrtype p) { \ 320 return sk_push((_STACK *)sk, (void *)p); \ 321 } \ 322 \ 323 static inline OPENSSL_UNUSED ptrtype sk_##name##_pop(STACK_OF(name) *sk) { \ 324 return (ptrtype)sk_pop((_STACK *)sk); \ 325 } \ 326 \ 327 static inline OPENSSL_UNUSED STACK_OF(name) * \ 328 sk_##name##_dup(const STACK_OF(name) *sk) { \ 329 return (STACK_OF(name) *)sk_dup((const _STACK *)sk); \ 330 } \ 331 \ 332 static inline OPENSSL_UNUSED void sk_##name##_sort(STACK_OF(name) *sk) { \ 333 sk_sort((_STACK *)sk); \ 334 } \ 335 \ 336 static inline OPENSSL_UNUSED int sk_##name##_is_sorted( \ 337 const STACK_OF(name) *sk) { \ 338 return sk_is_sorted((const _STACK *)sk); \ 339 } \ 340 \ 341 static inline OPENSSL_UNUSED stack_##name##_cmp_func \ 342 sk_##name##_set_cmp_func(STACK_OF(name) *sk, \ 343 stack_##name##_cmp_func comp) { \ 344 return (stack_##name##_cmp_func)sk_set_cmp_func((_STACK *)sk, \ 345 (stack_cmp_func)comp); \ 346 } \ 347 \ 348 static inline OPENSSL_UNUSED STACK_OF(name) * \ 349 sk_##name##_deep_copy(const STACK_OF(name) *sk, \ 350 ptrtype(*copy_func)(ptrtype), \ 351 void (*free_func)(ptrtype)) { \ 352 return (STACK_OF(name) *)sk_deep_copy((const _STACK *)sk, \ 353 (void *(*)(void *))copy_func, \ 354 (void (*)(void *))free_func); \ 355 } 356 357// DEFINE_STACK_OF defines |STACK_OF(type)| to be a stack whose elements are 358// |type| *. 359#define DEFINE_STACK_OF(type) \ 360 BORINGSSL_DEFINE_STACK_OF_IMPL(type, type *, const type *) \ 361 BORINGSSL_DEFINE_STACK_TRAITS(type, type, false) 362 363// DEFINE_CONST_STACK_OF defines |STACK_OF(type)| to be a stack whose elements 364// are const |type| *. 365#define DEFINE_CONST_STACK_OF(type) \ 366 BORINGSSL_DEFINE_STACK_OF_IMPL(type, const type *, const type *) \ 367 BORINGSSL_DEFINE_STACK_TRAITS(type, const type, true) 368 369// DEFINE_SPECIAL_STACK_OF defines |STACK_OF(type)| to be a stack whose elements 370// are |type|, where |type| must be a typedef for a pointer. 371#define DEFINE_SPECIAL_STACK_OF(type) \ 372 OPENSSL_COMPILE_ASSERT(sizeof(type) == sizeof(void *), \ 373 special_stack_of_non_pointer_##type); \ 374 BORINGSSL_DEFINE_STACK_OF_IMPL(type, type, const type) 375 376 377typedef char *OPENSSL_STRING; 378 379DEFINE_STACK_OF(void) 380DEFINE_SPECIAL_STACK_OF(OPENSSL_STRING) 381 382 383#if defined(__cplusplus) 384} // extern C 385#endif 386 387#if !defined(BORINGSSL_NO_CXX) 388extern "C++" { 389 390#include <type_traits> 391 392namespace bssl { 393 394namespace internal { 395 396// Stacks defined with |DEFINE_CONST_STACK_OF| are freed with |sk_free|. 397template <typename Stack> 398struct DeleterImpl< 399 Stack, typename std::enable_if<StackTraits<Stack>::kIsConst>::type> { 400 static void Free(Stack *sk) { sk_free(reinterpret_cast<_STACK *>(sk)); } 401}; 402 403// Stacks defined with |DEFINE_STACK_OF| are freed with |sk_pop_free| and the 404// corresponding type's deleter. 405template <typename Stack> 406struct DeleterImpl< 407 Stack, typename std::enable_if<!StackTraits<Stack>::kIsConst>::type> { 408 static void Free(Stack *sk) { 409 sk_pop_free( 410 reinterpret_cast<_STACK *>(sk), 411 reinterpret_cast<void (*)(void *)>( 412 DeleterImpl<typename StackTraits<Stack>::Type>::Free)); 413 } 414}; 415 416template <typename Stack> 417class StackIteratorImpl { 418 public: 419 using Type = typename StackTraits<Stack>::Type; 420 // Iterators must be default-constructable. 421 StackIteratorImpl() : sk_(nullptr), idx_(0) {} 422 StackIteratorImpl(const Stack *sk, size_t idx) : sk_(sk), idx_(idx) {} 423 424 bool operator==(StackIteratorImpl other) const { 425 return sk_ == other.sk_ && idx_ == other.idx_; 426 } 427 bool operator!=(StackIteratorImpl other) const { 428 return !(*this == other); 429 } 430 431 Type *operator*() const { 432 return reinterpret_cast<Type *>( 433 sk_value(reinterpret_cast<const _STACK *>(sk_), idx_)); 434 } 435 436 StackIteratorImpl &operator++(/* prefix */) { 437 idx_++; 438 return *this; 439 } 440 441 StackIteratorImpl operator++(int /* postfix */) { 442 StackIteratorImpl copy(*this); 443 ++(*this); 444 return copy; 445 } 446 447 private: 448 const Stack *sk_; 449 size_t idx_; 450}; 451 452template <typename Stack> 453using StackIterator = typename std::enable_if<StackTraits<Stack>::kIsStack, 454 StackIteratorImpl<Stack>>::type; 455 456} // namespace internal 457 458// PushToStack pushes |elem| to |sk|. It returns true on success and false on 459// allocation failure. 460template <typename Stack> 461static inline 462 typename std::enable_if<!internal::StackTraits<Stack>::kIsConst, bool>::type 463 PushToStack(Stack *sk, 464 UniquePtr<typename internal::StackTraits<Stack>::Type> elem) { 465 if (!sk_push(reinterpret_cast<_STACK *>(sk), elem.get())) { 466 return false; 467 } 468 // sk_push takes ownership on success. 469 elem.release(); 470 return true; 471} 472 473} // namespace bssl 474 475// Define begin() and end() for stack types so C++ range for loops work. 476template <typename Stack> 477static inline bssl::internal::StackIterator<Stack> begin(const Stack *sk) { 478 return bssl::internal::StackIterator<Stack>(sk, 0); 479} 480 481template <typename Stack> 482static inline bssl::internal::StackIterator<Stack> end(const Stack *sk) { 483 return bssl::internal::StackIterator<Stack>( 484 sk, sk_num(reinterpret_cast<const _STACK *>(sk))); 485} 486 487} // extern C++ 488#endif 489 490#endif // OPENSSL_HEADER_STACK_H 491