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_free_func is a function that frees an element in a stack. Note its
90// actual type is void (*)(T *) for some T. Low-level |sk_*| functions will be
91// passed a type-specific wrapper to call it correctly.
92typedef void (*stack_free_func)(void *ptr);
93
94// stack_copy_func is a function that copies an element in a stack. Note its
95// actual type is T *(*)(T *) for some T. Low-level |sk_*| functions will be
96// passed a type-specific wrapper to call it correctly.
97typedef void *(*stack_copy_func)(void *ptr);
98
99// stack_cmp_func is a comparison function that returns a value < 0, 0 or > 0
100// if |*a| is less than, equal to or greater than |*b|, respectively. Note the
101// extra indirection - the function is given a pointer to a pointer to the
102// element. This differs from the usual qsort/bsearch comparison function.
103//
104// Note its actual type is int (*)(const T **, const T **). Low-level |sk_*|
105// functions will be passed a type-specific wrapper to call it correctly.
106typedef int (*stack_cmp_func)(const void **a, const void **b);
107
108// stack_st contains an array of pointers. It is not designed to be used
109// directly, rather the wrapper macros should be used.
110typedef struct stack_st {
111 // num contains the number of valid pointers in |data|.
112 size_t num;
113 void **data;
114 // sorted is non-zero if the values pointed to by |data| are in ascending
115 // order, based on |comp|.
116 int sorted;
117 // num_alloc contains the number of pointers allocated in the buffer pointed
118 // to by |data|, which may be larger than |num|.
119 size_t num_alloc;
120 // comp is an optional comparison function.
121 stack_cmp_func comp;
122} _STACK;
123
124
125#define STACK_OF(type) struct stack_st_##type
126
127#define DECLARE_STACK_OF(type) STACK_OF(type);
128
129// These are the raw stack functions, you shouldn't be using them. Rather you
130// should be using the type stack macros implemented above.
131
132// sk_new creates a new, empty stack with the given comparison function, which
133// may be zero. It returns the new stack or NULL on allocation failure.
134OPENSSL_EXPORT _STACK *sk_new(stack_cmp_func comp);
135
136// sk_new_null creates a new, empty stack. It returns the new stack or NULL on
137// allocation failure.
138OPENSSL_EXPORT _STACK *sk_new_null(void);
139
140// sk_num returns the number of elements in |s|.
141OPENSSL_EXPORT size_t sk_num(const _STACK *sk);
142
143// sk_zero resets |sk| to the empty state but does nothing to free the
144// individual elements themselves.
145OPENSSL_EXPORT void sk_zero(_STACK *sk);
146
147// sk_value returns the |i|th pointer in |sk|, or NULL if |i| is out of
148// range.
149OPENSSL_EXPORT void *sk_value(const _STACK *sk, size_t i);
150
151// sk_set sets the |i|th pointer in |sk| to |p| and returns |p|. If |i| is out
152// of range, it returns NULL.
153OPENSSL_EXPORT void *sk_set(_STACK *sk, size_t i, void *p);
154
155// sk_free frees the given stack and array of pointers, but does nothing to
156// free the individual elements. Also see |sk_pop_free_ex|.
157OPENSSL_EXPORT void sk_free(_STACK *sk);
158
159// sk_pop_free_ex calls |free_func| on each element in the stack and then frees
160// the stack itself. Note this corresponds to |sk_FOO_pop_free|. It is named
161// |sk_pop_free_ex| as a workaround for existing code calling an older version
162// of |sk_pop_free|.
163OPENSSL_EXPORT void sk_pop_free_ex(_STACK *sk,
164 void (*call_free_func)(stack_free_func,
165 void *),
166 stack_free_func free_func);
167
168// sk_insert inserts |p| into the stack at index |where|, moving existing
169// elements if needed. It returns the length of the new stack, or zero on
170// error.
171OPENSSL_EXPORT size_t sk_insert(_STACK *sk, void *p, size_t where);
172
173// sk_delete removes the pointer at index |where|, moving other elements down
174// if needed. It returns the removed pointer, or NULL if |where| is out of
175// range.
176OPENSSL_EXPORT void *sk_delete(_STACK *sk, size_t where);
177
178// sk_delete_ptr removes, at most, one instance of |p| from the stack based on
179// pointer equality. If an instance of |p| is found then |p| is returned,
180// otherwise it returns NULL.
181OPENSSL_EXPORT void *sk_delete_ptr(_STACK *sk, const void *p);
182
183// sk_find returns the first value in the stack equal to |p|. If a comparison
184// function has been set on the stack, equality is defined by it, otherwise
185// pointer equality is used. If the stack is sorted, then a binary search is
186// used, otherwise a linear search is performed. If a matching element is found,
187// its index is written to
188// |*out_index| (if |out_index| is not NULL) and one is returned. Otherwise zero
189// is returned.
190//
191// Note this differs from OpenSSL. The type signature is slightly different, and
192// OpenSSL's sk_find will implicitly sort |sk| if it has a comparison function
193// defined.
194OPENSSL_EXPORT int sk_find(const _STACK *sk, size_t *out_index, const void *p,
195 int (*call_cmp_func)(stack_cmp_func, const void **,
196 const void **));
197
198// sk_shift removes and returns the first element in the stack, or returns NULL
199// if the stack is empty.
200OPENSSL_EXPORT void *sk_shift(_STACK *sk);
201
202// sk_push appends |p| to the stack and returns the length of the new stack, or
203// 0 on allocation failure.
204OPENSSL_EXPORT size_t sk_push(_STACK *sk, void *p);
205
206// sk_pop returns and removes the last element on the stack, or NULL if the
207// stack is empty.
208OPENSSL_EXPORT void *sk_pop(_STACK *sk);
209
210// sk_dup performs a shallow copy of a stack and returns the new stack, or NULL
211// on error.
212OPENSSL_EXPORT _STACK *sk_dup(const _STACK *sk);
213
214// sk_sort sorts the elements of |sk| into ascending order based on the
215// comparison function. The stack maintains a |sorted| flag and sorting an
216// already sorted stack is a no-op.
217OPENSSL_EXPORT void sk_sort(_STACK *sk);
218
219// sk_is_sorted returns one if |sk| is known to be sorted and zero
220// otherwise.
221OPENSSL_EXPORT int sk_is_sorted(const _STACK *sk);
222
223// sk_set_cmp_func sets the comparison function to be used by |sk| and returns
224// the previous one.
225OPENSSL_EXPORT stack_cmp_func sk_set_cmp_func(_STACK *sk, stack_cmp_func comp);
226
227// sk_deep_copy performs a copy of |sk| and of each of the non-NULL elements in
228// |sk| by using |copy_func|. If an error occurs, |free_func| is used to free
229// any copies already made and NULL is returned.
230OPENSSL_EXPORT _STACK *sk_deep_copy(
231 const _STACK *sk, void *(*call_copy_func)(stack_copy_func, void *),
232 stack_copy_func copy_func, void (*call_free_func)(stack_free_func, void *),
233 stack_free_func free_func);
234
235
236// Deprecated functions.
237
238// sk_pop_free behaves like |sk_pop_free_ex| but performs an invalid function
239// pointer cast. It exists because some existing callers called |sk_pop_free|
240// directly.
241//
242// TODO(davidben): Migrate callers to bssl::UniquePtr and remove this.
243OPENSSL_EXPORT void sk_pop_free(_STACK *sk, stack_free_func free_func);
244
245
246// Defining stack types.
247//
248// This set of macros is used to emit the typed functions that act on a
249// |STACK_OF(T)|.
250
251#if !defined(BORINGSSL_NO_CXX)
252extern "C++" {
253BSSL_NAMESPACE_BEGIN
254namespace internal {
255template <typename T>
256struct StackTraits {};
257}
258BSSL_NAMESPACE_END
259}
260
261#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const) \
262 extern "C++" { \
263 BSSL_NAMESPACE_BEGIN \
264 namespace internal { \
265 template <> \
266 struct StackTraits<STACK_OF(name)> { \
267 static constexpr bool kIsStack = true; \
268 using Type = type; \
269 static constexpr bool kIsConst = is_const; \
270 }; \
271 } \
272 BSSL_NAMESPACE_END \
273 }
274
275#else
276#define BORINGSSL_DEFINE_STACK_TRAITS(name, type, is_const)
277#endif
278
279#define BORINGSSL_DEFINE_STACK_OF_IMPL(name, ptrtype, constptrtype) \
280 DECLARE_STACK_OF(name) \
281 \
282 typedef void (*stack_##name##_free_func)(ptrtype); \
283 typedef ptrtype (*stack_##name##_copy_func)(ptrtype); \
284 typedef int (*stack_##name##_cmp_func)(constptrtype *a, constptrtype *b); \
285 \
286 OPENSSL_INLINE void sk_##name##_call_free_func(stack_free_func free_func, \
287 void *ptr) { \
288 ((stack_##name##_free_func)free_func)((ptrtype)ptr); \
289 } \
290 \
291 OPENSSL_INLINE void *sk_##name##_call_copy_func(stack_copy_func copy_func, \
292 void *ptr) { \
293 return (void *)((stack_##name##_copy_func)copy_func)((ptrtype)ptr); \
294 } \
295 \
296 OPENSSL_INLINE int sk_##name##_call_cmp_func( \
297 stack_cmp_func cmp_func, const void **a, const void **b) { \
298 constptrtype a_ptr = (constptrtype)*a; \
299 constptrtype b_ptr = (constptrtype)*b; \
300 return ((stack_##name##_cmp_func)cmp_func)(&a_ptr, &b_ptr); \
301 } \
302 \
303 OPENSSL_INLINE STACK_OF(name) * \
304 sk_##name##_new(stack_##name##_cmp_func comp) { \
305 return (STACK_OF(name) *)sk_new((stack_cmp_func)comp); \
306 } \
307 \
308 OPENSSL_INLINE STACK_OF(name) *sk_##name##_new_null(void) { \
309 return (STACK_OF(name) *)sk_new_null(); \
310 } \
311 \
312 OPENSSL_INLINE size_t sk_##name##_num(const STACK_OF(name) *sk) { \
313 return sk_num((const _STACK *)sk); \
314 } \
315 \
316 OPENSSL_INLINE void sk_##name##_zero(STACK_OF(name) *sk) { \
317 sk_zero((_STACK *)sk); \
318 } \
319 \
320 OPENSSL_INLINE ptrtype sk_##name##_value(const STACK_OF(name) *sk, \
321 size_t i) { \
322 return (ptrtype)sk_value((const _STACK *)sk, i); \
323 } \
324 \
325 OPENSSL_INLINE ptrtype sk_##name##_set(STACK_OF(name) *sk, size_t i, \
326 ptrtype p) { \
327 return (ptrtype)sk_set((_STACK *)sk, i, (void *)p); \
328 } \
329 \
330 OPENSSL_INLINE void sk_##name##_free(STACK_OF(name) * sk) { \
331 sk_free((_STACK *)sk); \
332 } \
333 \
334 OPENSSL_INLINE void sk_##name##_pop_free( \
335 STACK_OF(name) * sk, stack_##name##_free_func free_func) { \
336 sk_pop_free_ex((_STACK *)sk, sk_##name##_call_free_func, \
337 (stack_free_func)free_func); \
338 } \
339 \
340 OPENSSL_INLINE size_t sk_##name##_insert(STACK_OF(name) *sk, ptrtype p, \
341 size_t where) { \
342 return sk_insert((_STACK *)sk, (void *)p, where); \
343 } \
344 \
345 OPENSSL_INLINE ptrtype sk_##name##_delete(STACK_OF(name) *sk, \
346 size_t where) { \
347 return (ptrtype)sk_delete((_STACK *)sk, where); \
348 } \
349 \
350 OPENSSL_INLINE ptrtype sk_##name##_delete_ptr(STACK_OF(name) *sk, \
351 constptrtype p) { \
352 return (ptrtype)sk_delete_ptr((_STACK *)sk, (const void *)p); \
353 } \
354 \
355 OPENSSL_INLINE int sk_##name##_find(const STACK_OF(name) *sk, \
356 size_t * out_index, constptrtype p) { \
357 return sk_find((const _STACK *)sk, out_index, (const void *)p, \
358 sk_##name##_call_cmp_func); \
359 } \
360 \
361 OPENSSL_INLINE ptrtype sk_##name##_shift(STACK_OF(name) *sk) { \
362 return (ptrtype)sk_shift((_STACK *)sk); \
363 } \
364 \
365 OPENSSL_INLINE size_t sk_##name##_push(STACK_OF(name) *sk, ptrtype p) { \
366 return sk_push((_STACK *)sk, (void *)p); \
367 } \
368 \
369 OPENSSL_INLINE ptrtype sk_##name##_pop(STACK_OF(name) *sk) { \
370 return (ptrtype)sk_pop((_STACK *)sk); \
371 } \
372 \
373 OPENSSL_INLINE STACK_OF(name) * sk_##name##_dup(const STACK_OF(name) *sk) { \
374 return (STACK_OF(name) *)sk_dup((const _STACK *)sk); \
375 } \
376 \
377 OPENSSL_INLINE void sk_##name##_sort(STACK_OF(name) *sk) { \
378 sk_sort((_STACK *)sk); \
379 } \
380 \
381 OPENSSL_INLINE int sk_##name##_is_sorted(const STACK_OF(name) *sk) { \
382 return sk_is_sorted((const _STACK *)sk); \
383 } \
384 \
385 OPENSSL_INLINE stack_##name##_cmp_func sk_##name##_set_cmp_func( \
386 STACK_OF(name) *sk, stack_##name##_cmp_func comp) { \
387 return (stack_##name##_cmp_func)sk_set_cmp_func((_STACK *)sk, \
388 (stack_cmp_func)comp); \
389 } \
390 \
391 OPENSSL_INLINE STACK_OF(name) * \
392 sk_##name##_deep_copy(const STACK_OF(name) *sk, \
393 ptrtype(*copy_func)(ptrtype), \
394 void (*free_func)(ptrtype)) { \
395 return (STACK_OF(name) *)sk_deep_copy( \
396 (const _STACK *)sk, sk_##name##_call_copy_func, \
397 (stack_copy_func)copy_func, sk_##name##_call_free_func, \
398 (stack_free_func)free_func); \
399 }
400
401// DEFINE_NAMED_STACK_OF defines |STACK_OF(name)| to be a stack whose elements
402// are |type| *.
403#define DEFINE_NAMED_STACK_OF(name, type) \
404 BORINGSSL_DEFINE_STACK_OF_IMPL(name, type *, const type *) \
405 BORINGSSL_DEFINE_STACK_TRAITS(name, type, false)
406
407// DEFINE_STACK_OF defines |STACK_OF(type)| to be a stack whose elements are
408// |type| *.
409#define DEFINE_STACK_OF(type) DEFINE_NAMED_STACK_OF(type, type)
410
411// DEFINE_CONST_STACK_OF defines |STACK_OF(type)| to be a stack whose elements
412// are const |type| *.
413#define DEFINE_CONST_STACK_OF(type) \
414 BORINGSSL_DEFINE_STACK_OF_IMPL(type, const type *, const type *) \
415 BORINGSSL_DEFINE_STACK_TRAITS(type, const type, true)
416
417// DEFINE_SPECIAL_STACK_OF defines |STACK_OF(type)| to be a stack whose elements
418// are |type|, where |type| must be a typedef for a pointer.
419#define DEFINE_SPECIAL_STACK_OF(type) \
420 OPENSSL_STATIC_ASSERT(sizeof(type) == sizeof(void *), \
421 #type " is not a pointer"); \
422 BORINGSSL_DEFINE_STACK_OF_IMPL(type, type, const type)
423
424
425typedef char *OPENSSL_STRING;
426
427DEFINE_STACK_OF(void)
428DEFINE_SPECIAL_STACK_OF(OPENSSL_STRING)
429
430
431#if defined(__cplusplus)
432} // extern C
433#endif
434
435#if !defined(BORINGSSL_NO_CXX)
436extern "C++" {
437
438#include <type_traits>
439
440BSSL_NAMESPACE_BEGIN
441
442namespace internal {
443
444// Stacks defined with |DEFINE_CONST_STACK_OF| are freed with |sk_free|.
445template <typename Stack>
446struct DeleterImpl<
447 Stack, typename std::enable_if<StackTraits<Stack>::kIsConst>::type> {
448 static void Free(Stack *sk) { sk_free(reinterpret_cast<_STACK *>(sk)); }
449};
450
451// Stacks defined with |DEFINE_STACK_OF| are freed with |sk_pop_free| and the
452// corresponding type's deleter.
453template <typename Stack>
454struct DeleterImpl<
455 Stack, typename std::enable_if<!StackTraits<Stack>::kIsConst>::type> {
456 static void Free(Stack *sk) {
457 // sk_FOO_pop_free is defined by macros and bound by name, so we cannot
458 // access it from C++ here.
459 using Type = typename StackTraits<Stack>::Type;
460 sk_pop_free_ex(reinterpret_cast<_STACK *>(sk),
461 [](stack_free_func /* unused */, void *ptr) {
462 DeleterImpl<Type>::Free(reinterpret_cast<Type *>(ptr));
463 },
464 nullptr);
465 }
466};
467
468template <typename Stack>
469class StackIteratorImpl {
470 public:
471 using Type = typename StackTraits<Stack>::Type;
472 // Iterators must be default-constructable.
473 StackIteratorImpl() : sk_(nullptr), idx_(0) {}
474 StackIteratorImpl(const Stack *sk, size_t idx) : sk_(sk), idx_(idx) {}
475
476 bool operator==(StackIteratorImpl other) const {
477 return sk_ == other.sk_ && idx_ == other.idx_;
478 }
479 bool operator!=(StackIteratorImpl other) const {
480 return !(*this == other);
481 }
482
483 Type *operator*() const {
484 return reinterpret_cast<Type *>(
485 sk_value(reinterpret_cast<const _STACK *>(sk_), idx_));
486 }
487
488 StackIteratorImpl &operator++(/* prefix */) {
489 idx_++;
490 return *this;
491 }
492
493 StackIteratorImpl operator++(int /* postfix */) {
494 StackIteratorImpl copy(*this);
495 ++(*this);
496 return copy;
497 }
498
499 private:
500 const Stack *sk_;
501 size_t idx_;
502};
503
504template <typename Stack>
505using StackIterator = typename std::enable_if<StackTraits<Stack>::kIsStack,
506 StackIteratorImpl<Stack>>::type;
507
508} // namespace internal
509
510// PushToStack pushes |elem| to |sk|. It returns true on success and false on
511// allocation failure.
512template <typename Stack>
513inline
514 typename std::enable_if<!internal::StackTraits<Stack>::kIsConst, bool>::type
515 PushToStack(Stack *sk,
516 UniquePtr<typename internal::StackTraits<Stack>::Type> elem) {
517 if (!sk_push(reinterpret_cast<_STACK *>(sk), elem.get())) {
518 return false;
519 }
520 // sk_push takes ownership on success.
521 elem.release();
522 return true;
523}
524
525BSSL_NAMESPACE_END
526
527// Define begin() and end() for stack types so C++ range for loops work.
528template <typename Stack>
529inline bssl::internal::StackIterator<Stack> begin(const Stack *sk) {
530 return bssl::internal::StackIterator<Stack>(sk, 0);
531}
532
533template <typename Stack>
534inline bssl::internal::StackIterator<Stack> end(const Stack *sk) {
535 return bssl::internal::StackIterator<Stack>(
536 sk, sk_num(reinterpret_cast<const _STACK *>(sk)));
537}
538
539} // extern C++
540#endif
541
542#endif // OPENSSL_HEADER_STACK_H
543