1 /* Copyright (c) 2016, Google Inc.
2  *
3  * Permission to use, copy, modify, and/or distribute this software for any
4  * purpose with or without fee is hereby granted, provided that the above
5  * copyright notice and this permission notice appear in all copies.
6  *
7  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14 
15 #ifndef OPENSSL_HEADER_POOL_H
16 #define OPENSSL_HEADER_POOL_H
17 
18 #include <openssl/base.h>
19 
20 #include <openssl/stack.h>
21 
22 #if defined(__cplusplus)
23 extern "C" {
24 #endif
25 
26 
27 // Buffers and buffer pools.
28 //
29 // |CRYPTO_BUFFER|s are simply reference-counted blobs. A |CRYPTO_BUFFER_POOL|
30 // is an intern table for |CRYPTO_BUFFER|s. This allows for a single copy of a
31 // given blob to be kept in memory and referenced from multiple places.
32 
33 
34 DEFINE_STACK_OF(CRYPTO_BUFFER)
35 
36 // CRYPTO_BUFFER_POOL_new returns a freshly allocated |CRYPTO_BUFFER_POOL| or
37 // NULL on error.
38 OPENSSL_EXPORT CRYPTO_BUFFER_POOL* CRYPTO_BUFFER_POOL_new(void);
39 
40 // CRYPTO_BUFFER_POOL_free frees |pool|, which must be empty.
41 OPENSSL_EXPORT void CRYPTO_BUFFER_POOL_free(CRYPTO_BUFFER_POOL *pool);
42 
43 // CRYPTO_BUFFER_new returns a |CRYPTO_BUFFER| containing a copy of |data|, or
44 // else NULL on error. If |pool| is not NULL then the returned value may be a
45 // reference to a previously existing |CRYPTO_BUFFER| that contained the same
46 // data. Otherwise, the returned, fresh |CRYPTO_BUFFER| will be added to the
47 // pool.
48 OPENSSL_EXPORT CRYPTO_BUFFER *CRYPTO_BUFFER_new(const uint8_t *data, size_t len,
49                                                 CRYPTO_BUFFER_POOL *pool);
50 
51 // CRYPTO_BUFFER_alloc creates an unpooled |CRYPTO_BUFFER| of the given size and
52 // writes the underlying data pointer to |*out_data|. It returns NULL on error.
53 //
54 // After calling this function, |len| bytes of contents must be written to
55 // |out_data| before passing the returned pointer to any other BoringSSL
56 // functions. Once initialized, the |CRYPTO_BUFFER| should be treated as
57 // immutable.
58 OPENSSL_EXPORT CRYPTO_BUFFER *CRYPTO_BUFFER_alloc(uint8_t **out_data,
59                                                   size_t len);
60 
61 // CRYPTO_BUFFER_new_from_CBS acts the same as |CRYPTO_BUFFER_new|.
62 OPENSSL_EXPORT CRYPTO_BUFFER *CRYPTO_BUFFER_new_from_CBS(
63     CBS *cbs, CRYPTO_BUFFER_POOL *pool);
64 
65 // CRYPTO_BUFFER_free decrements the reference count of |buf|. If there are no
66 // other references, or if the only remaining reference is from a pool, then
67 // |buf| will be freed.
68 OPENSSL_EXPORT void CRYPTO_BUFFER_free(CRYPTO_BUFFER *buf);
69 
70 // CRYPTO_BUFFER_up_ref increments the reference count of |buf| and returns
71 // one.
72 OPENSSL_EXPORT int CRYPTO_BUFFER_up_ref(CRYPTO_BUFFER *buf);
73 
74 // CRYPTO_BUFFER_data returns a pointer to the data contained in |buf|.
75 OPENSSL_EXPORT const uint8_t *CRYPTO_BUFFER_data(const CRYPTO_BUFFER *buf);
76 
77 // CRYPTO_BUFFER_len returns the length, in bytes, of the data contained in
78 // |buf|.
79 OPENSSL_EXPORT size_t CRYPTO_BUFFER_len(const CRYPTO_BUFFER *buf);
80 
81 // CRYPTO_BUFFER_init_CBS initialises |out| to point at the data from |buf|.
82 OPENSSL_EXPORT void CRYPTO_BUFFER_init_CBS(const CRYPTO_BUFFER *buf, CBS *out);
83 
84 
85 #if defined(__cplusplus)
86 }  // extern C
87 
88 extern "C++" {
89 
90 BSSL_NAMESPACE_BEGIN
91 
92 BORINGSSL_MAKE_DELETER(CRYPTO_BUFFER_POOL, CRYPTO_BUFFER_POOL_free)
93 BORINGSSL_MAKE_DELETER(CRYPTO_BUFFER, CRYPTO_BUFFER_free)
94 BORINGSSL_MAKE_UP_REF(CRYPTO_BUFFER, CRYPTO_BUFFER_up_ref)
95 
96 BSSL_NAMESPACE_END
97 
98 }  // extern C++
99 
100 #endif
101 
102 #endif  // OPENSSL_HEADER_POOL_H
103