libtpms/src/tpm_memory.c

/********************************************************************************/
/*                                                                              */
/*                           TPM Memory Allocation                              */
/*                           Written by Ken Goldman                             */
/*                     IBM Thomas J. Watson Research Center                     */
/*            $Id: tpm_memory.c 4609 2011-08-26 19:27:38Z kgoldman $            */
/*                                                                              */
/* (c) Copyright IBM Corporation 2006, 2010.					*/
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/********************************************************************************/

#include <stdio.h>
#include <stdlib.h>

#include "tpm_debug.h"
#include "tpm_error.h"

#include "tpm_memory.h"

/* TPM_Malloc() is a general purpose wrapper around malloc()
 */

TPM_RESULT TPM_Malloc(unsigned char **buffer, uint32_t size)
{
    TPM_RESULT          rc = 0;
    
    /* assertion test.  The coding style requires that all allocated pointers are initialized to
       NULL.  A non-NULL value indicates either a missing initialization or a pointer reuse (a
       memory leak). */
    if (rc == 0) {
        if (*buffer != NULL) {
            printf("TPM_Malloc: Error (fatal), *buffer %p should be NULL before malloc\n", *buffer);
            rc = TPM_FAIL;
        }
    }
    /* verify that the size is not "too large" */
    if (rc == 0) {
        if (size > TPM_ALLOC_MAX) {
            printf("TPM_Malloc: Error, size %u greater than maximum allowed\n", size);
            rc = TPM_SIZE;
        }       
    }
    /* verify that the size is not 0, this would be implementation defined and should never occur */
    if (rc == 0) {
        if (size == 0) {
            printf("TPM_Malloc: Error (fatal), size is zero\n");
            rc = TPM_FAIL;
        }       
    }
    if (rc == 0) {
        *buffer = malloc(size);
        if (*buffer == NULL) {
            printf("TPM_Malloc: Error allocating %u bytes\n", size);
            rc = TPM_SIZE;
        }
    }
    return rc;
}

/* TPM_Realloc() is a general purpose wrapper around realloc()
 */

TPM_RESULT TPM_Realloc(unsigned char **buffer,
                       uint32_t size)
{
    TPM_RESULT          rc = 0;
    unsigned char       *tmpptr = NULL;
    
    /* verify that the size is not "too large" */
    if (rc == 0) {
        if (size > TPM_ALLOC_MAX) {
            printf("TPM_Realloc: Error, size %u greater than maximum allowed\n", size);
            rc = TPM_SIZE;
        }       
    }
    if (rc == 0) {
        tmpptr = realloc(*buffer, size);
        if (tmpptr == NULL) {
            printf("TPM_Realloc: Error reallocating %u bytes\n", size);
            rc = TPM_SIZE;
        }
    }
    if (rc == 0) {
        *buffer = tmpptr;
    }
    return rc;
}

/* TPM_Free() is the companion to the TPM allocation functions.  It is not used internally.  The
   intent is for use by an application that links directly to a TPM and wants to free memory
   allocated by the TPM.

   It avoids a potential problem if the application uses a different allocation library, perhaps one
   that wraps the functions to detect overflows or memory leaks.
*/

void TPM_Free(unsigned char *buffer)
{
    free(buffer);
    return;
}