6 OPENSSL_malloc, OPENSSL_zalloc, OPENSSL_realloc, OPENSSL_free,
7 OPENSSL_clear_realloc, OPENSSL_clear_free, OPENSSL_cleanse,
8 CRYPTO_malloc, CRYPTO_zalloc, CRYPTO_realloc, CRYPTO_free,
9 OPENSSL_strdup, OPENSSL_strndup,
10 OPENSSL_memdup, OPENSSL_strlcpy, OPENSSL_strlcat,
11 OPENSSL_hexstr2buf, OPENSSL_buf2hexstr, OPENSSL_hexchar2int,
12 CRYPTO_strdup, CRYPTO_strndup,
13 OPENSSL_mem_debug_push, OPENSSL_mem_debug_pop,
14 CRYPTO_mem_debug_push, CRYPTO_mem_debug_pop,
15 CRYPTO_clear_realloc, CRYPTO_clear_free,
16 CRYPTO_get_mem_functions, CRYPTO_set_mem_functions,
17 CRYPTO_get_alloc_counts,
18 CRYPTO_set_mem_debug, CRYPTO_mem_ctrl,
19 CRYPTO_mem_leaks, CRYPTO_mem_leaks_fp, CRYPTO_mem_leaks_cb,
20 OPENSSL_MALLOC_FAILURES,
22 - Memory allocation functions
26 #include <openssl/crypto.h>
28 int OPENSSL_malloc_init(void)
30 void *OPENSSL_malloc(size_t num)
31 void *OPENSSL_zalloc(size_t num)
32 void *OPENSSL_realloc(void *addr, size_t num)
33 void OPENSSL_free(void *addr)
34 char *OPENSSL_strdup(const char *str)
35 char *OPENSSL_strndup(const char *str, size_t s)
36 size_t OPENSSL_strlcat(char *dst, const char *src, size_t size);
37 size_t OPENSSL_strlcpy(char *dst, const char *src, size_t size);
38 void *OPENSSL_memdup(void *data, size_t s)
39 void *OPENSSL_clear_realloc(void *p, size_t old_len, size_t num)
40 void OPENSSL_clear_free(void *str, size_t num)
41 void OPENSSL_cleanse(void *ptr, size_t len);
43 unsigned char *OPENSSL_hexstr2buf(const char *str, long *len);
44 char *OPENSSL_buf2hexstr(const unsigned char *buffer, long len);
45 int OPENSSL_hexchar2int(unsigned char c);
47 void *CRYPTO_malloc(size_t num, const char *file, int line)
48 void *CRYPTO_zalloc(size_t num, const char *file, int line)
49 void *CRYPTO_realloc(void *p, size_t num, const char *file, int line)
50 void CRYPTO_free(void *str, const char *, int)
51 char *CRYPTO_strdup(const char *p, const char *file, int line)
52 char *CRYPTO_strndup(const char *p, size_t num, const char *file, int line)
53 void *CRYPTO_clear_realloc(void *p, size_t old_len, size_t num,
54 const char *file, int line)
55 void CRYPTO_clear_free(void *str, size_t num, const char *, int)
57 void CRYPTO_get_mem_functions(
58 void *(**m)(size_t, const char *, int),
59 void *(**r)(void *, size_t, const char *, int),
60 void (**f)(void *, const char *, int))
61 int CRYPTO_set_mem_functions(
62 void *(*m)(size_t, const char *, int),
63 void *(*r)(void *, size_t, const char *, int),
64 void (*f)(void *, const char *, int))
66 void CRYPTO_get_alloc_counts(int *m, int *r, int *f)
68 int CRYPTO_set_mem_debug(int onoff)
70 env OPENSSL_MALLOC_FAILURES=... <application>
71 env OPENSSL_MALLOC_FD=... <application>
73 int CRYPTO_mem_ctrl(int mode);
75 int CRYPTO_mem_leaks(BIO *b);
76 int CRYPTO_mem_leaks_fp(FILE *fp);
77 int CRYPTO_mem_leaks_cb(int (*cb)(const char *str, size_t len, void *u),
82 int OPENSSL_mem_debug_push(const char *info)
83 int OPENSSL_mem_debug_pop(void);
84 int CRYPTO_mem_debug_push(const char *info, const char *file, int line);
85 int CRYPTO_mem_debug_pop(void);
89 OpenSSL memory allocation is handled by the B<OPENSSL_xxx> API. These are
90 generally macro's that add the standard C B<__FILE__> and B<__LINE__>
91 parameters and call a lower-level B<CRYPTO_xxx> API.
92 Some functions do not add those parameters, but exist for consistency.
94 OPENSSL_malloc_init() does nothing and does not need to be called. It is
95 included for compatibility with older versions of OpenSSL.
97 OPENSSL_malloc(), OPENSSL_realloc(), and OPENSSL_free() are like the
98 C malloc(), realloc(), and free() functions.
99 OPENSSL_zalloc() calls memset() to zero the memory before returning.
101 OPENSSL_clear_realloc() and OPENSSL_clear_free() should be used
102 when the buffer at B<addr> holds sensitive information.
103 The old buffer is filled with zero's by calling OPENSSL_cleanse()
104 before ultimately calling OPENSSL_free().
106 OPENSSL_cleanse() fills B<ptr> of size B<len> with a string of 0's.
107 Use OPENSSL_cleanse() with care if the memory is a mapping of a file.
108 If the storage controller uses write compression, then its possible
109 that sensitive tail bytes will survive zeroization because the block of
110 zeros will be compressed. If the storage controller uses wear leveling,
111 then the old sensitive data will not be overwritten; rather, a block of
112 0's will be written at a new physical location.
114 OPENSSL_strdup(), OPENSSL_strndup() and OPENSSL_memdup() are like the
115 equivalent C functions, except that memory is allocated by calling the
116 OPENSSL_malloc() and should be released by calling OPENSSL_free().
119 OPENSSL_strlcat() and OPENSSL_strnlen() are equivalents of the common C
120 library functions and are provided for portability.
122 OPENSSL_hexstr2buf() parses B<str> as a hex string and returns a
123 pointer to the parsed value. The memory is allocated by calling
124 OPENSSL_malloc() and should be released by calling OPENSSL_free().
125 If B<len> is not NULL, it is filled in with the output length.
126 Colons between two-character hex "bytes" are ignored.
127 An odd number of hex digits is an error.
129 OPENSSL_buf2hexstr() takes the specified buffer and length, and returns
130 a hex string for value, or NULL on error.
131 B<Buffer> cannot be NULL; if B<len> is 0 an empty string is returned.
133 OPENSSL_hexchar2int() converts a character to the hexadecimal equivalent,
134 or returns -1 on error.
136 If no allocations have been done, it is possible to "swap out" the default
137 implementations for OPENSSL_malloc(), OPENSSL_realloc and OPENSSL_free()
138 and replace them with alternate versions (hooks).
139 CRYPTO_get_mem_functions() function fills in the given arguments with the
140 function pointers for the current implementations.
141 With CRYPTO_set_mem_functions(), you can specify a different set of functions.
142 If any of B<m>, B<r>, or B<f> are NULL, then the function is not changed.
144 The default implementation can include some debugging capability (if enabled
146 This adds some overhead by keeping a list of all memory allocations, and
147 removes items from the list when they are free'd.
148 This is most useful for identifying memory leaks.
149 CRYPTO_set_mem_debug() turns this tracking on and off. In order to have
150 any effect, is must be called before any of the allocation functions
151 (e.g., CRYPTO_malloc()) are called, and is therefore normally one of the
152 first lines of main() in an application.
153 CRYPTO_mem_ctrl() provides fine-grained control of memory leak tracking.
154 To enable tracking call CRYPTO_mem_ctrl() with a B<mode> argument of
155 the B<CRYPTO_MEM_CHECK_ON>.
156 To disable tracking call CRYPTO_mem_ctrl() with a B<mode> argument of
157 the B<CRYPTO_MEM_CHECK_OFF>.
159 At the end of the program, calling CRYPTO_mem_leaks() or
160 CRYPTO_mem_leaks_fp() will report all "leaked" memory, writing it
161 to the specified BIO B<b> or FILE B<fp>. These functions return 1 if
162 there are no leaks, 0 if there are leaks and -1 if an error occurred.
164 CRYPTO_mem_leaks_cb() does the same as CRYPTO_mem_leaks(), but instead
165 of writing to a given BIO, the callback function is called for each
166 output string with the string, length, and userdata B<u> as the callback
169 If the library is built with the C<crypto-mdebug> option, then one
170 function, CRYPTO_get_alloc_counts(), and two additional environment
171 variables, B<OPENSSL_MALLOC_FAILURES> and B<OPENSSL_MALLOC_FD>,
174 The function CRYPTO_get_alloc_counts() fills in the number of times
175 each of CRYPTO_malloc(), CRYPTO_realloc(), and CRYPTO_free() have been
176 called, into the values pointed to by B<mcount>, B<rcount>, and B<fcount>,
177 respectively. If a pointer is NULL, then the corresponding count is not stored.
180 B<OPENSSL_MALLOC_FAILURES> controls how often allocations should fail.
181 It is a set of fields separated by semicolons, which each field is a count
182 (defaulting to zero) and an optional atsign and percentage (defaulting
183 to 100). If the count is zero, then it lasts forever. For example,
184 C<100;@25> or C<100@0;0@25> means the first 100 allocations pass, then all
185 other allocations (until the program exits or crashes) have a 25% chance of
188 If the variable B<OPENSSL_MALLOC_FD> is parsed as a positive integer, then
189 it is taken as an open file descriptor, and a record of all allocations is
190 written to that descriptor. If an allocation will fail, and the platform
191 supports it, then a backtrace will be written to the descriptor. This can
192 be useful because a malloc may fail but not be checked, and problems will
193 only occur later. The following example in classic shell syntax shows how
194 to use this (will not work on all platforms):
196 OPENSSL_MALLOC_FAILURES='200;@10'
197 export OPENSSL_MALLOC_FAILURES
199 export OPENSSL_MALLOC_FD
200 ...app invocation... 3>/tmp/log$$
202 OPENSSL_mem_debug_push(), OPENSSL_mem_debug_pop(),
203 CRYPTO_mem_debug_push(), and CRYPTO_mem_debug_pop()
204 have been deprecated and replaced with functions that only return zero.
208 OPENSSL_malloc_init(), OPENSSL_free(), OPENSSL_clear_free()
209 CRYPTO_free(), CRYPTO_clear_free() and CRYPTO_get_mem_functions()
212 CRYPTO_mem_leaks(), CRYPTO_mem_leaks_fp() and CRYPTO_mem_leaks_cb() return 1 if
213 there are no leaks, 0 if there are leaks and -1 if an error occurred.
215 OPENSSL_malloc(), OPENSSL_zalloc(), OPENSSL_realloc(),
216 OPENSSL_clear_realloc(),
217 CRYPTO_malloc(), CRYPTO_zalloc(), CRYPTO_realloc(),
218 CRYPTO_clear_realloc(),
219 OPENSSL_buf2hexstr(), OPENSSL_hexstr2buf(),
220 OPENSSL_strdup(), and OPENSSL_strndup()
221 return a pointer to allocated memory or NULL on error.
223 CRYPTO_set_mem_functions() and CRYPTO_set_mem_debug()
224 return 1 on success or 0 on failure (almost
225 always because allocations have already happened).
227 CRYPTO_mem_ctrl() returns -1 if an error occurred, otherwise the
228 previous value of the mode.
232 While it's permitted to swap out only a few and not all the functions
233 with CRYPTO_set_mem_functions(), it's recommended to swap them all out
234 at once, especially if OpenSSL was built with the
235 configuration option> C<crypto-mdebug>.
239 OPENSSL_mem_debug_push(), OPENSSL_mem_debug_pop(),
240 CRYPTO_mem_debug_push(), and CRYPTO_mem_debug_pop()
241 were deprecated in OpenSSL 3.0.
246 Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
248 Licensed under the Apache License 2.0 (the "License"). You may not use
249 this file except in compliance with the License. You can obtain a copy
250 in the file LICENSE in the source distribution or at
251 L<https://www.openssl.org/source/license.html>.