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      1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      2  * All rights reserved.
      3  *
      4  * This package is an SSL implementation written
      5  * by Eric Young (eay (at) 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 (at) 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 (at) 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 (at) 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)
     65 extern "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  *   struct foo {
     78  *     int bar;
     79  *   };
     80  *
     81  *   DEFINE_STACK_OF(struct 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 comparision 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 comparision function. */
     93 typedef 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. */
     97 typedef 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   size_t 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 comparision function. */
    108   stack_cmp_func comp;
    109 } _STACK;
    110 
    111 
    112 #define STACK_OF(type) struct stack_st_##type
    113 
    114 #define DEFINE_STACK_OF(type) \
    115 STACK_OF(type) {\
    116   _STACK stack; \
    117 };
    118 
    119 #define DECLARE_STACK_OF(type) STACK_OF(type);
    120 
    121 /* The make_macros.sh script in this directory parses the following lines and
    122  * generates the stack_macros.h file that contains macros for the following
    123  * types of stacks:
    124  *
    125  * STACK_OF:ACCESS_DESCRIPTION
    126  * STACK_OF:ASN1_ADB_TABLE
    127  * STACK_OF:ASN1_GENERALSTRING
    128  * STACK_OF:ASN1_INTEGER
    129  * STACK_OF:ASN1_OBJECT
    130  * STACK_OF:ASN1_STRING_TABLE
    131  * STACK_OF:ASN1_TYPE
    132  * STACK_OF:ASN1_VALUE
    133  * STACK_OF:BIO
    134  * STACK_OF:BY_DIR_ENTRY
    135  * STACK_OF:BY_DIR_HASH
    136  * STACK_OF:CONF_VALUE
    137  * STACK_OF:CRYPTO_EX_DATA_FUNCS
    138  * STACK_OF:DIST_POINT
    139  * STACK_OF:GENERAL_NAME
    140  * STACK_OF:GENERAL_NAMES
    141  * STACK_OF:GENERAL_SUBTREE
    142  * STACK_OF:MIME_HEADER
    143  * STACK_OF:PKCS7_SIGNER_INFO
    144  * STACK_OF:PKCS7_RECIP_INFO
    145  * STACK_OF:POLICYINFO
    146  * STACK_OF:POLICYQUALINFO
    147  * STACK_OF:POLICY_MAPPING
    148  * STACK_OF:SRTP_PROTECTION_PROFILE
    149  * STACK_OF:SSL_COMP
    150  * STACK_OF:STACK_OF_X509_NAME_ENTRY
    151  * STACK_OF:SXNETID
    152  * STACK_OF:X509
    153  * STACK_OF:X509V3_EXT_METHOD
    154  * STACK_OF:X509_ALGOR
    155  * STACK_OF:X509_ATTRIBUTE
    156  * STACK_OF:X509_CRL
    157  * STACK_OF:X509_EXTENSION
    158  * STACK_OF:X509_INFO
    159  * STACK_OF:X509_LOOKUP
    160  * STACK_OF:X509_NAME
    161  * STACK_OF:X509_NAME_ENTRY
    162  * STACK_OF:X509_OBJECT
    163  * STACK_OF:X509_POLICY_DATA
    164  * STACK_OF:X509_POLICY_NODE
    165  * STACK_OF:X509_PURPOSE
    166  * STACK_OF:X509_REVOKED
    167  * STACK_OF:X509_TRUST
    168  * STACK_OF:X509_VERIFY_PARAM
    169  * STACK_OF:void
    170  *
    171  * We declare STACK_OF(SSL_CIPHER) differently; every SSL_CIPHER is const,
    172  * so the stack should return const pointers to retain type-checking.
    173  *
    174  * CONST_STACK_OF:SSL_CIPHER */
    175 
    176 
    177 /* Some stacks are special because, although we would like STACK_OF(char *),
    178  * that would actually be a stack of pointers to char*, but we just want to
    179  * point to the string directly. In this case we call them "special" and use
    180  * |DEFINE_SPECIAL_STACK_OF(type)| */
    181 #define DEFINE_SPECIAL_STACK_OF(type, inner)             \
    182   STACK_OF(type) { _STACK special_stack; };              \
    183   OPENSSL_COMPILE_ASSERT(sizeof(type) == sizeof(void *), \
    184                          special_stack_of_non_pointer_##type);
    185 
    186 typedef char *OPENSSL_STRING;
    187 
    188 DEFINE_SPECIAL_STACK_OF(OPENSSL_STRING, char)
    189 DEFINE_SPECIAL_STACK_OF(OPENSSL_BLOCK, uint8_t)
    190 
    191 /* The make_macros.sh script in this directory parses the following lines and
    192  * generates the stack_macros.h file that contains macros for the following
    193  * types of stacks:
    194  *
    195  * SPECIAL_STACK_OF:OPENSSL_STRING
    196  * SPECIAL_STACK_OF:OPENSSL_BLOCK */
    197 
    198 #define IN_STACK_H
    199 #include <openssl/stack_macros.h>
    200 #undef IN_STACK_H
    201 
    202 
    203 /* These are the raw stack functions, you shouldn't be using them. Rather you
    204  * should be using the type stack macros implemented above. */
    205 
    206 /* sk_new creates a new, empty stack with the given comparision function, which
    207  * may be zero. It returns the new stack or NULL on allocation failure. */
    208 OPENSSL_EXPORT _STACK *sk_new(stack_cmp_func comp);
    209 
    210 /* sk_new_null creates a new, empty stack. It returns the new stack or NULL on
    211  * allocation failure. */
    212 OPENSSL_EXPORT _STACK *sk_new_null(void);
    213 
    214 /* sk_num returns the number of elements in |s|. */
    215 OPENSSL_EXPORT size_t sk_num(const _STACK *sk);
    216 
    217 /* sk_zero resets |sk| to the empty state but does nothing to free the
    218  * individual elements themselves. */
    219 OPENSSL_EXPORT void sk_zero(_STACK *sk);
    220 
    221 /* sk_value returns the |i|th pointer in |sk|, or NULL if |i| is out of
    222  * range. */
    223 OPENSSL_EXPORT void *sk_value(const _STACK *sk, size_t i);
    224 
    225 /* sk_set sets the |i|th pointer in |sk| to |p| and returns |p|. If |i| is out
    226  * of range, it returns NULL. */
    227 OPENSSL_EXPORT void *sk_set(_STACK *sk, size_t i, void *p);
    228 
    229 /* sk_free frees the given stack and array of pointers, but does nothing to
    230  * free the individual elements. Also see |sk_pop_free|. */
    231 OPENSSL_EXPORT void sk_free(_STACK *sk);
    232 
    233 /* sk_pop_free calls |free_func| on each element in the stack and then frees
    234  * the stack itself. */
    235 OPENSSL_EXPORT void sk_pop_free(_STACK *sk, void (*free_func)(void *));
    236 
    237 /* sk_insert inserts |p| into the stack at index |where|, moving existing
    238  * elements if needed. It returns the length of the new stack, or zero on
    239  * error. */
    240 OPENSSL_EXPORT size_t sk_insert(_STACK *sk, void *p, size_t where);
    241 
    242 /* sk_delete removes the pointer at index |where|, moving other elements down
    243  * if needed. It returns the removed pointer, or NULL if |where| is out of
    244  * range. */
    245 OPENSSL_EXPORT void *sk_delete(_STACK *sk, size_t where);
    246 
    247 /* sk_delete_ptr removes, at most, one instance of |p| from the stack based on
    248  * pointer equality. If an instance of |p| is found then |p| is returned,
    249  * otherwise it returns NULL. */
    250 OPENSSL_EXPORT void *sk_delete_ptr(_STACK *sk, void *p);
    251 
    252 /* sk_find returns the first value in the stack equal to |p|. If a comparision
    253  * function has been set on the stack, then equality is defined by it and the
    254  * stack will be sorted if need be so that a binary search can be used.
    255  * Otherwise pointer equality is used. If a matching element is found, its
    256  * index is written to |*out_index| (if |out_index| is not NULL) and one is
    257  * returned. Otherwise zero is returned. */
    258 OPENSSL_EXPORT int sk_find(_STACK *sk, size_t *out_index, void *p);
    259 
    260 /* sk_shift removes and returns the first element in the stack, or returns NULL
    261  * if the stack is empty. */
    262 OPENSSL_EXPORT void *sk_shift(_STACK *sk);
    263 
    264 /* sk_push appends |p| to the stack and returns the length of the new stack, or
    265  * 0 on allocation failure. */
    266 OPENSSL_EXPORT size_t sk_push(_STACK *sk, void *p);
    267 
    268 /* sk_pop returns and removes the last element on the stack, or NULL if the
    269  * stack is empty. */
    270 OPENSSL_EXPORT void *sk_pop(_STACK *sk);
    271 
    272 /* sk_dup performs a shallow copy of a stack and returns the new stack, or NULL
    273  * on error. */
    274 OPENSSL_EXPORT _STACK *sk_dup(const _STACK *sk);
    275 
    276 /* sk_sort sorts the elements of |sk| into ascending order based on the
    277  * comparison function. The stack maintains a |sorted| flag and sorting an
    278  * already sorted stack is a no-op. */
    279 OPENSSL_EXPORT void sk_sort(_STACK *sk);
    280 
    281 /* sk_is_sorted returns one if |sk| is known to be sorted and zero
    282  * otherwise. */
    283 OPENSSL_EXPORT int sk_is_sorted(const _STACK *sk);
    284 
    285 /* sk_set_cmp_func sets the comparison function to be used by |sk| and returns
    286  * the previous one. */
    287 OPENSSL_EXPORT stack_cmp_func sk_set_cmp_func(_STACK *sk, stack_cmp_func comp);
    288 
    289 
    290 #if defined(__cplusplus)
    291 }  /* extern C */
    292 #endif
    293 
    294 #endif  /* OPENSSL_HEADER_STACK_H */
    295