mirror of https://github.com/openssl/openssl.git
				
				
				
			
		
			
				
	
	
		
			208 lines
		
	
	
		
			8.6 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
			
		
		
	
	
			208 lines
		
	
	
		
			8.6 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
| =pod
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| 
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| =head1 NAME
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| 
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| OPENSSL_malloc_init,
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| OPENSSL_malloc, OPENSSL_zalloc, OPENSSL_realloc, OPENSSL_free,
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| OPENSSL_clear_realloc, OPENSSL_clear_free, OPENSSL_cleanse,
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| CRYPTO_malloc, CRYPTO_zalloc, CRYPTO_realloc, CRYPTO_free,
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| OPENSSL_strdup, OPENSSL_strndup,
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| OPENSSL_memdup, OPENSSL_strlcpy, OPENSSL_strlcat,
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| CRYPTO_strdup, CRYPTO_strndup,
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| OPENSSL_mem_debug_push, OPENSSL_mem_debug_pop,
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| CRYPTO_mem_debug_push, CRYPTO_mem_debug_pop,
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| CRYPTO_clear_realloc, CRYPTO_clear_free,
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| CRYPTO_malloc_fn, CRYPTO_realloc_fn, CRYPTO_free_fn,
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| CRYPTO_get_mem_functions, CRYPTO_set_mem_functions,
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| CRYPTO_get_alloc_counts,
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| CRYPTO_set_mem_debug, CRYPTO_mem_ctrl,
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| CRYPTO_mem_leaks, CRYPTO_mem_leaks_fp, CRYPTO_mem_leaks_cb,
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| OPENSSL_MALLOC_FAILURES,
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| OPENSSL_MALLOC_FD
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| - Memory allocation functions
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| 
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| =head1 SYNOPSIS
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| 
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|  #include <openssl/crypto.h>
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| 
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|  int OPENSSL_malloc_init(void);
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| 
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|  void *OPENSSL_malloc(size_t num);
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|  void *OPENSSL_zalloc(size_t num);
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|  void *OPENSSL_realloc(void *addr, size_t num);
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|  void OPENSSL_free(void *addr);
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|  char *OPENSSL_strdup(const char *str);
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|  char *OPENSSL_strndup(const char *str, size_t s);
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|  size_t OPENSSL_strlcat(char *dst, const char *src, size_t size);
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|  size_t OPENSSL_strlcpy(char *dst, const char *src, size_t size);
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|  void *OPENSSL_memdup(void *data, size_t s);
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|  void *OPENSSL_clear_realloc(void *p, size_t old_len, size_t num);
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|  void OPENSSL_clear_free(void *str, size_t num);
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|  void OPENSSL_cleanse(void *ptr, size_t len);
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| 
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|  void *CRYPTO_malloc(size_t num, const char *file, int line);
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|  void *CRYPTO_zalloc(size_t num, const char *file, int line);
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|  void *CRYPTO_realloc(void *p, size_t num, const char *file, int line);
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|  void CRYPTO_free(void *str, const char *, int);
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|  char *CRYPTO_strdup(const char *p, const char *file, int line);
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|  char *CRYPTO_strndup(const char *p, size_t num, const char *file, int line);
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|  void *CRYPTO_clear_realloc(void *p, size_t old_len, size_t num,
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|                             const char *file, int line);
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|  void CRYPTO_clear_free(void *str, size_t num, const char *, int);
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| 
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|  typedef void *(*CRYPTO_malloc_fn)(size_t num, const char *file, int line);
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|  typedef void *(*CRYPTO_realloc_fn)(void *addr, size_t num, const char *file,
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|                                     int line);
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|  typedef void (*CRYPTO_free_fn)(void *addr, const char *file, int line);
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|  void CRYPTO_get_mem_functions(CRYPTO_malloc_fn *malloc_fn,
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|                                CRYPTO_realloc_fn *realloc_fn,
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|                                CRYPTO_free_fn *free_fn);
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|  int CRYPTO_set_mem_functions(CRYPTO_malloc_fn malloc_fn,
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|                               CRYPTO_realloc_fn realloc_fn,
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|                               CRYPTO_free_fn free_fn);
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| 
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|  void CRYPTO_get_alloc_counts(int *mcount, int *rcount, int *fcount);
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| 
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|  env OPENSSL_MALLOC_FAILURES=... <application>
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|  env OPENSSL_MALLOC_FD=... <application>
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| 
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| Deprecated since OpenSSL 3.0.0, can be hidden entirely by defining
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| B<OPENSSL_API_COMPAT> with a suitable version value, see
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| L<openssl_user_macros(7)>:
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| 
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|  int CRYPTO_mem_leaks(BIO *b);
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|  int CRYPTO_mem_leaks_fp(FILE *fp);
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|  int CRYPTO_mem_leaks_cb(int (*cb)(const char *str, size_t len, void *u),
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|                          void *u);
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| 
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|  int CRYPTO_set_mem_debug(int onoff);
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|  int CRYPTO_mem_ctrl(int mode);
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|  int OPENSSL_mem_debug_push(const char *info);
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|  int OPENSSL_mem_debug_pop(void);
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|  int CRYPTO_mem_debug_push(const char *info, const char *file, int line);
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|  int CRYPTO_mem_debug_pop(void);
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| 
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| =head1 DESCRIPTION
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| 
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| OpenSSL memory allocation is handled by the B<OPENSSL_xxx> API. These are
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| generally macro's that add the standard C B<__FILE__> and B<__LINE__>
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| parameters and call a lower-level B<CRYPTO_xxx> API.
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| Some functions do not add those parameters, but exist for consistency.
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| 
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| OPENSSL_malloc_init() does nothing and does not need to be called. It is
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| included for compatibility with older versions of OpenSSL.
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| 
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| OPENSSL_malloc(), OPENSSL_realloc(), and OPENSSL_free() are like the
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| C malloc(), realloc(), and free() functions.
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| OPENSSL_zalloc() calls memset() to zero the memory before returning.
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| 
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| OPENSSL_clear_realloc() and OPENSSL_clear_free() should be used
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| when the buffer at B<addr> holds sensitive information.
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| The old buffer is filled with zero's by calling OPENSSL_cleanse()
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| before ultimately calling OPENSSL_free().
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| 
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| OPENSSL_cleanse() fills B<ptr> of size B<len> with a string of 0's.
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| Use OPENSSL_cleanse() with care if the memory is a mapping of a file.
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| If the storage controller uses write compression, then it's possible
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| that sensitive tail bytes will survive zeroization because the block of
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| zeros will be compressed. If the storage controller uses wear leveling,
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| then the old sensitive data will not be overwritten; rather, a block of
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| 0's will be written at a new physical location.
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| 
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| OPENSSL_strdup(), OPENSSL_strndup() and OPENSSL_memdup() are like the
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| equivalent C functions, except that memory is allocated by calling the
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| OPENSSL_malloc() and should be released by calling OPENSSL_free().
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| 
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| OPENSSL_strlcpy(),
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| OPENSSL_strlcat() and OPENSSL_strnlen() are equivalents of the common C
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| library functions and are provided for portability.
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| 
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| If no allocations have been done, it is possible to "swap out" the default
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| implementations for OPENSSL_malloc(), OPENSSL_realloc() and OPENSSL_free()
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| and replace them with alternate versions.
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| CRYPTO_get_mem_functions() function fills in the given arguments with the
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| function pointers for the current implementations.
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| With CRYPTO_set_mem_functions(), you can specify a different set of functions.
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| If any of B<malloc_fn>, B<realloc_fn>, or B<free_fn> are NULL, then
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| the function is not changed.
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| While it's permitted to swap out only a few and not all the functions
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| with CRYPTO_set_mem_functions(), it's recommended to swap them all out
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| at once.
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| 
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| If the library is built with the C<crypto-mdebug> option, then one
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| function, CRYPTO_get_alloc_counts(), and two additional environment
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| variables, B<OPENSSL_MALLOC_FAILURES> and B<OPENSSL_MALLOC_FD>,
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| are available.
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| 
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| The function CRYPTO_get_alloc_counts() fills in the number of times
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| each of CRYPTO_malloc(), CRYPTO_realloc(), and CRYPTO_free() have been
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| called, into the values pointed to by B<mcount>, B<rcount>, and B<fcount>,
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| respectively.  If a pointer is NULL, then the corresponding count is not stored.
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| 
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| The variable
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| B<OPENSSL_MALLOC_FAILURES> controls how often allocations should fail.
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| It is a set of fields separated by semicolons, which each field is a count
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| (defaulting to zero) and an optional atsign and percentage (defaulting
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| to 100).  If the count is zero, then it lasts forever.  For example,
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| C<100;@25> or C<100@0;0@25> means the first 100 allocations pass, then all
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| other allocations (until the program exits or crashes) have a 25% chance of
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| failing.
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| 
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| If the variable B<OPENSSL_MALLOC_FD> is parsed as a positive integer, then
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| it is taken as an open file descriptor, and a record of all allocations is
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| written to that descriptor.  If an allocation will fail, and the platform
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| supports it, then a backtrace will be written to the descriptor.  This can
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| be useful because a malloc may fail but not be checked, and problems will
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| only occur later.  The following example in classic shell syntax shows how
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| to use this (will not work on all platforms):
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| 
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|   OPENSSL_MALLOC_FAILURES='200;@10'
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|   export OPENSSL_MALLOC_FAILURES
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|   OPENSSL_MALLOC_FD=3
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|   export OPENSSL_MALLOC_FD
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|   ...app invocation... 3>/tmp/log$$
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| 
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| =head1 RETURN VALUES
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| 
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| OPENSSL_malloc_init(), OPENSSL_free(), OPENSSL_clear_free()
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| CRYPTO_free(), CRYPTO_clear_free() and CRYPTO_get_mem_functions()
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| return no value.
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| 
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| OPENSSL_malloc(), OPENSSL_zalloc(), OPENSSL_realloc(),
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| OPENSSL_clear_realloc(),
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| CRYPTO_malloc(), CRYPTO_zalloc(), CRYPTO_realloc(),
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| CRYPTO_clear_realloc(),
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| OPENSSL_strdup(), and OPENSSL_strndup()
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| return a pointer to allocated memory or NULL on error.
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| 
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| CRYPTO_set_mem_functions() returns 1 on success or 0 on failure (almost
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| always because allocations have already happened).
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| 
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| CRYPTO_mem_leaks(), CRYPTO_mem_leaks_fp(), CRYPTO_mem_leaks_cb(),
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| CRYPTO_set_mem_debug(), and CRYPTO_mem_ctrl() are deprecated and return -1.
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| OPENSSL_mem_debug_push(), OPENSSL_mem_debug_pop(),
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| CRYPTO_mem_debug_push(), and CRYPTO_mem_debug_pop()
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| are deprecated and return 0.
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| 
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| =head1 HISTORY
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| 
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| OPENSSL_mem_debug_push(), OPENSSL_mem_debug_pop(),
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| CRYPTO_mem_debug_push(), CRYPTO_mem_debug_pop(),
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| CRYPTO_mem_leaks(), CRYPTO_mem_leaks_fp(),
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| CRYPTO_mem_leaks_cb(), CRYPTO_set_mem_debug(), CRYPTO_mem_ctrl()
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| were deprecated in OpenSSL 3.0.
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| The memory-leak checking has been deprecated in OpenSSL 3.0 in favor of
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| clang's memory and leak sanitizer.
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| 
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| 
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| =head1 COPYRIGHT
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| 
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| Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
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| 
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| Licensed under the Apache License 2.0 (the "License").  You may not use
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| this file except in compliance with the License.  You can obtain a copy
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| in the file LICENSE in the source distribution or at
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| L<https://www.openssl.org/source/license.html>.
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| 
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| =cut
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