memory.h

Functions

	Name
void *	wolfSSL_Malloc(size_t size, void * heap, int type) This function is similar to malloc(), but calls the memory allocation function which wolfSSL has been configured to use. By default, wolfSSL uses malloc(). This can be changed using the wolfSSL memory abstraction layer _ see wolfSSL_SetAllocators(). Note wolfSSL_Malloc is not called directly by wolfSSL, but instead called by macro XMALLOC. For the default build only the size argument exists. If using WOLFSSL_STATIC_MEMORY build then heap and type arguments are included.
void	wolfSSL_Free(void * ptr, void * heap, int type) This function is similar to free(), but calls the memory free function which wolfSSL has been configured to use. By default, wolfSSL uses free(). This can be changed using the wolfSSL memory abstraction layer _ see wolfSSL_SetAllocators(). Note wolfSSL_Free is not called directly by wolfSSL, but instead called by macro XFREE. For the default build only the ptr argument exists. If using WOLFSSL_STATIC_MEMORY build then heap and type arguments are included.
void *	wolfSSL_Realloc(void * ptr, size_t size, void * heap, int type) This function is similar to realloc(), but calls the memory re_allocation function which wolfSSL has been configured to use. By default, wolfSSL uses realloc(). This can be changed using the wolfSSL memory abstraction layer _ see wolfSSL_SetAllocators(). Note wolfSSL_Realloc is not called directly by wolfSSL, but instead called by macro XREALLOC. For the default build only the size argument exists. If using WOLFSSL_STATIC_MEMORY build then heap and type arguments are included.
int	wolfSSL_SetAllocators(wolfSSL_Malloc_cb , wolfSSL_Free_cb , wolfSSL_Realloc_cb ) This function registers the allocation functions used by wolfSSL. By default, if the system supports it, malloc/free and realloc are used. Using this function allows the user at runtime to install their own memory handlers.
int	wolfSSL_StaticBufferSz(byte * buffer, word32 sz, int flag) This function is available when static memory feature is used (–enable_staticmemory). It gives the optimum buffer size for memory “buckets”. This allows for a way to compute buffer size so that no extra unused memory is left at the end after it has been partitioned. The returned value, if positive, is the computed buffer size to use.
int	wolfSSL_MemoryPaddingSz(void ) This function is available when static memory feature is used (–enable_staticmemory). It gives the size of padding needed for each partition of memory. This padding size will be the size needed to contain a memory management structure along with any extra for memory alignment.
int	wolfSSL_CTX_load_static_memory(WOLFSSL_CTX * ctx, wolfSSL_method_func method, unsigned char * buf, unsigned int sz, int flag, int max) This function is used to set aside static memory for a CTX. Memory set aside is then used for the CTX’s lifetime and for any SSL objects created from the CTX. By passing in a NULL ctx pointer and a wolfSSL_method_func function the creation of the CTX itself will also use static memory. wolfSSL_method_func has the function signature of WOLFSSL_METHOD (wolfSSL_method_func)(void heap);. Passing in 0 for max makes it behave as if not set and no max concurrent use restrictions is in place. The flag value passed in determines how the memory is used and behavior while operating. Available flags are the following.
int	wolfSSL_CTX_is_static_memory(WOLFSSL_CTX * ctx, WOLFSSL_MEM_STATS * mem_stats) This function does not change any of the connections behavior and is used only for gathering information about the static memory usage.
int	wolfSSL_is_static_memory(WOLFSSL * ssl, WOLFSSL_MEM_CONN_STATS * mem_stats) wolfSSL_is_static_memory is used to gather information about a SSL’s static memory usage. The return value indicates if static memory is being used and WOLFSSL_MEM_CONN_STATS will be filled out if and only if the flag WOLFMEM_TRACK_STATS was passed to the parent CTX when loading in static memory.
int	wc_LoadStaticMemory(WOLFSSL_HEAP_HINT * hint, unsigned char * buf, unsigned int sz, int flag, int max) This function is used to set aside static memory for wolfCrypt use. Memory can be used by passing the created heap hint into functions. An example of this is when calling wc_InitRng_ex. The flag value passed in determines how the memory is used and behavior while operating, in general wolfCrypt operations will use memory from a WOLFMEM_GENERAL pool. Available flags are the following.

Functions Documentation

function wolfSSL_Malloc

void * wolfSSL_Malloc(
    size_t size,
    void * heap,
    int type
)

This function is similar to malloc(), but calls the memory allocation function which wolfSSL has been configured to use. By default, wolfSSL uses malloc(). This can be changed using the wolfSSL memory abstraction layer - see wolfSSL_SetAllocators(). Note wolfSSL_Malloc is not called directly by wolfSSL, but instead called by macro XMALLOC. For the default build only the size argument exists. If using WOLFSSL_STATIC_MEMORY build then heap and type arguments are included.

Parameters:

• size size, in bytes, of the memory to allocate
• heap heap hint to use for memory. Can be NULL
• type dynamic type (see DYNAMIC_TYPE_ list in types.h)

See:

• wolfSSL_Free
• wolfSSL_Realloc
• wolfSSL_SetAllocators
• XMALLOC
• XFREE
• XREALLOC

Return:

• pointer If successful, this function returns a pointer to allocated memory.
• error If there is an error, NULL will be returned.

Example

int* tenInts = (int*)wolfSSL_Malloc(sizeof(int)*10);

function wolfSSL_Free

void wolfSSL_Free(
    void * ptr,
    void * heap,
    int type
)

This function is similar to free(), but calls the memory free function which wolfSSL has been configured to use. By default, wolfSSL uses free(). This can be changed using the wolfSSL memory abstraction layer - see wolfSSL_SetAllocators(). Note wolfSSL_Free is not called directly by wolfSSL, but instead called by macro XFREE. For the default build only the ptr argument exists. If using WOLFSSL_STATIC_MEMORY build then heap and type arguments are included.

Parameters:

• ptr pointer to the memory to be freed.
• heap heap hint to use for memory. Can be NULL
• type dynamic type (see DYNAMIC_TYPE_ list in types.h)

See:

• wolfSSL_Alloc
• wolfSSL_Realloc
• wolfSSL_SetAllocators
• XMALLOC
• XFREE
• XREALLOC

Return: none No returns.

Example

int* tenInts = (int*)wolfSSL_Malloc(sizeof(int)*10);
// process data as desired
...
if(tenInts) {
    wolfSSL_Free(tenInts);
}

function wolfSSL_Realloc

void * wolfSSL_Realloc(
    void * ptr,
    size_t size,
    void * heap,
    int type
)

This function is similar to realloc(), but calls the memory re-allocation function which wolfSSL has been configured to use. By default, wolfSSL uses realloc(). This can be changed using the wolfSSL memory abstraction layer - see wolfSSL_SetAllocators(). Note wolfSSL_Realloc is not called directly by wolfSSL, but instead called by macro XREALLOC. For the default build only the size argument exists. If using WOLFSSL_STATIC_MEMORY build then heap and type arguments are included.

Parameters:

• ptr pointer to the previously-allocated memory, to be reallocated.
• size number of bytes to allocate.
• heap heap hint to use for memory. Can be NULL
• type dynamic type (see DYNAMIC_TYPE_ list in types.h)

See:

• wolfSSL_Free
• wolfSSL_Malloc
• wolfSSL_SetAllocators
• XMALLOC
• XFREE
• XREALLOC

Return:

• pointer If successful, this function returns a pointer to re-allocated memory. This may be the same pointer as ptr, or a new pointer location.
• Null If there is an error, NULL will be returned.

Example

int* tenInts = (int*)wolfSSL_Malloc(sizeof(int)*10);
int* twentyInts = (int*)wolfSSL_Realloc(tenInts, sizeof(int)*20);

function wolfSSL_SetAllocators

int wolfSSL_SetAllocators(
    wolfSSL_Malloc_cb ,
    wolfSSL_Free_cb ,
    wolfSSL_Realloc_cb 
)

This function registers the allocation functions used by wolfSSL. By default, if the system supports it, malloc/free and realloc are used. Using this function allows the user at runtime to install their own memory handlers.

Parameters:

• malloc_function memory allocation function for wolfSSL to use. Function signature must match wolfSSL_Malloc_cb prototype, above.
• free_function memory free function for wolfSSL to use. Function signature must match wolfSSL_Free_cb prototype, above.
• realloc_function memory re-allocation function for wolfSSL to use. Function signature must match wolfSSL_Realloc_cb prototype, above.

See: none

Return:

• Success If successful this function will return 0.
• BAD_FUNC_ARG is the error that will be returned if a function pointer is not provided.

Example

static void* MyMalloc(size_t size)
{
    // custom malloc function
}

static void MyFree(void* ptr)
{
    // custom free function
}

static void* MyRealloc(void* ptr, size_t size)
{
    // custom realloc function
}

// Register custom memory functions with wolfSSL
int ret = wolfSSL_SetAllocators(MyMalloc, MyFree, MyRealloc);
if (ret != 0) {
    // failed to set memory functions
}

function wolfSSL_StaticBufferSz

int wolfSSL_StaticBufferSz(
    byte * buffer,
    word32 sz,
    int flag
)

This function is available when static memory feature is used (–enable-staticmemory). It gives the optimum buffer size for memory “buckets”. This allows for a way to compute buffer size so that no extra unused memory is left at the end after it has been partitioned. The returned value, if positive, is the computed buffer size to use.

Parameters:

• buffer pointer to buffer
• size size of buffer
• type desired type of memory ie WOLFMEM_GENERAL or WOLFMEM_IO_POOL

See:

• wolfSSL_Malloc
• wolfSSL_Free

Return:

• Success On successfully completing buffer size calculations a positive value is returned. This returned value is for optimum buffer size.
• Failure All negative values are considered to be error cases.

Example

byte buffer[1000];
word32 size = sizeof(buffer);
int optimum;
optimum = wolfSSL_StaticBufferSz(buffer, size, WOLFMEM_GENERAL);
if (optimum < 0) { //handle error case }
printf(“The optimum buffer size to make use of all memory is %d\n”,
optimum);
...

function wolfSSL_MemoryPaddingSz

int wolfSSL_MemoryPaddingSz(
    void 
)

This function is available when static memory feature is used (–enable-staticmemory). It gives the size of padding needed for each partition of memory. This padding size will be the size needed to contain a memory management structure along with any extra for memory alignment.

Parameters:

• none No parameters.

See:

• wolfSSL_Malloc
• wolfSSL_Free

Return:

• On successfully memory padding calculation the return value will be a positive value
• All negative values are considered error cases.

Example

int padding;
padding = wolfSSL_MemoryPaddingSz();
if (padding < 0) { //handle error case }
printf(“The padding size needed for each \”bucket\” of memory is %d\n”,
padding);
// calculation of buffer for IO POOL size is number of buckets
// times (padding + WOLFMEM_IO_SZ)
...

function wolfSSL_CTX_load_static_memory

int wolfSSL_CTX_load_static_memory(
    WOLFSSL_CTX ** ctx,
    wolfSSL_method_func method,
    unsigned char * buf,
    unsigned int sz,
    int flag,
    int max
)

This function is used to set aside static memory for a CTX. Memory set aside is then used for the CTX’s lifetime and for any SSL objects created from the CTX. By passing in a NULL ctx pointer and a wolfSSL_method_func function the creation of the CTX itself will also use static memory. wolfSSL_method_func has the function signature of WOLFSSL_METHOD* (wolfSSL_method_func)(void heap);. Passing in 0 for max makes it behave as if not set and no max concurrent use restrictions is in place. The flag value passed in determines how the memory is used and behavior while operating. Available flags are the following.

Parameters:

• ctx address of pointer to a WOLFSSL_CTX structure.
• method function to create protocol. (should be NULL if ctx is not also NULL)
• buf memory to use for all operations.
• sz size of memory buffer being passed in.
• flag type of memory.
• max max concurrent operations.

See:

• wolfSSL_CTX_new
• wolfSSL_CTX_is_static_memory
• wolfSSL_is_static_memory

Return:

• If successful, SSL_SUCCESS will be returned.
• All unsuccessful return values will be less than 0 or equal to SSL_FAILURE.

0 - default general memory

WOLFMEM_IO_POOL - used for input/output buffer when sending receiving messages. Overrides general memory, so all memory in buffer passed in is used for IO. WOLFMEM_IO_FIXED - same as WOLFMEM_IO_POOL but each SSL now keeps two buffers to themselves for their lifetime. WOLFMEM_TRACK_STATS - each SSL keeps track of memory stats while running.

Example

WOLFSSL_CTX* ctx;
WOLFSSL* ssl;
int ret;
unsigned char memory[MAX];
int memorySz = MAX;
unsigned char IO[MAX];
int IOSz = MAX;
int flag = WOLFMEM_IO_FIXED | WOLFMEM_TRACK_STATS;
...
// create ctx also using static memory, start with general memory to use
ctx = NULL:
ret = wolfSSL_CTX_load_static_memory(&ctx, wolfSSLv23_server_method_ex, memory, memorySz, 0,
MAX_CONCURRENT_HANDSHAKES);
if (ret != SSL_SUCCESS) {
// handle error case
}
// load in memory for use with IO
ret = wolfSSL_CTX_load_static_memory(&ctx, NULL, IO, IOSz, flag, MAX_CONCURRENT_IO);
if (ret != SSL_SUCCESS) {
// handle error case
}
...

function wolfSSL_CTX_is_static_memory

int wolfSSL_CTX_is_static_memory(
    WOLFSSL_CTX * ctx,
    WOLFSSL_MEM_STATS * mem_stats
)

This function does not change any of the connections behavior and is used only for gathering information about the static memory usage.

Parameters:

• ctx a pointer to a WOLFSSL_CTX structure, created using wolfSSL_CTX_new().
• mem_stats structure to hold information about staic memory usage.

See:

• wolfSSL_CTX_new
• wolfSSL_CTX_load_static_memory
• wolfSSL_is_static_memory

Return:

• A value of 1 is returned if using static memory for the CTX is true.
• 0 is returned if not using static memory.

Example

WOLFSSL_CTX* ctx;
int ret;
WOLFSSL_MEM_STATS mem_stats;
...
//get information about static memory with CTX

ret = wolfSSL_CTX_is_static_memory(ctx, &mem_stats);

if (ret == 1) {
    // handle case of is using static memory
    // print out or inspect elements of mem_stats
}

if (ret == 0) {
    //handle case of ctx not using static memory
}
...

function wolfSSL_is_static_memory

int wolfSSL_is_static_memory(
    WOLFSSL * ssl,
    WOLFSSL_MEM_CONN_STATS * mem_stats
)

wolfSSL_is_static_memory is used to gather information about a SSL’s static memory usage. The return value indicates if static memory is being used and WOLFSSL_MEM_CONN_STATS will be filled out if and only if the flag WOLFMEM_TRACK_STATS was passed to the parent CTX when loading in static memory.

Parameters:

• ssl a pointer to a WOLFSSL structure, created using wolfSSL_new().
• mem_stats structure to contain static memory usage

See:

• wolfSSL_new
• wolfSSL_CTX_is_static_memory

Return:

• A value of 1 is returned if using static memory for the CTX is true.
• 0 is returned if not using static memory.

Example

WOLFSSL* ssl;
int ret;
WOLFSSL_MEM_CONN_STATS mem_stats;

...

ret = wolfSSL_is_static_memory(ssl, mem_stats);

if (ret == 1) {
    // handle case when is static memory
    // investigate elements in mem_stats if WOLFMEM_TRACK_STATS flag
}
...

function wc_LoadStaticMemory

int wc_LoadStaticMemory(
    WOLFSSL_HEAP_HINT * hint,
    unsigned char * buf,
    unsigned int sz,
    int flag,
    int max
)

This function is used to set aside static memory for wolfCrypt use. Memory can be used by passing the created heap hint into functions. An example of this is when calling wc_InitRng_ex. The flag value passed in determines how the memory is used and behavior while operating, in general wolfCrypt operations will use memory from a WOLFMEM_GENERAL pool. Available flags are the following.

Parameters:

• hint WOLFSSL_HEAP_HINT structure to use
• buf memory to use for all operations.
• sz size of memory buffer being passed in.
• flag type of memory.
• max max concurrent operations (handshakes, IO).

See: none

Return:

• If successful, 0 will be returned.
• All unsuccessful return values will be less than 0.

WOLFMEM_GENERAL - default general memory

WOLFMEM_IO_POOL - used for input/output buffer when sending receiving messages. Overrides general memory, so all memory in buffer passed in is used for IO. WOLFMEM_IO_FIXED - same as WOLFMEM_IO_POOL but each SSL now keeps two buffers to themselves for their lifetime. WOLFMEM_TRACK_STATS - each SSL keeps track of memory stats while running

Example

WOLFSSL_HEAP_HINT hint;
int ret;
unsigned char memory[MAX];
int memorySz = MAX;
int flag = WOLFMEM_GENERAL | WOLFMEM_TRACK_STATS;
...

// load in memory for use

ret = wc_LoadStaticMemory(&hint, memory, memorySz, flag, 0);
if (ret != SSL_SUCCESS) {
    // handle error case
}
...

ret = wc_InitRng_ex(&rng, hint, 0);

// check ret value

Source code

void* wolfSSL_Malloc(size_t size, void* heap, int type);

void  wolfSSL_Free(void *ptr, void* heap, int type);

void* wolfSSL_Realloc(void *ptr, size_t size, void* heap, int type);

int wolfSSL_SetAllocators(wolfSSL_Malloc_cb,
                                      wolfSSL_Free_cb,
                                      wolfSSL_Realloc_cb);

int wolfSSL_StaticBufferSz(byte* buffer, word32 sz, int flag);

int wolfSSL_MemoryPaddingSz(void);

int wolfSSL_CTX_load_static_memory(WOLFSSL_CTX** ctx, wolfSSL_method_func method,
        unsigned char* buf, unsigned int sz, int flag, int max);

int wolfSSL_CTX_is_static_memory(WOLFSSL_CTX* ctx, WOLFSSL_MEM_STATS* mem_stats);

int wolfSSL_is_static_memory(WOLFSSL* ssl, WOLFSSL_MEM_CONN_STATS* mem_stats);

int wc_LoadStaticMemory(WOLFSSL_HEAP_HINT* hint, unsigned char* buf, unsigned int sz,
                int flag, int max);

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Updated on 2024-11-22 at 01:12:39 +0000