common/checkoverflow.c

//**********************************************************************;
// Copyright (c) 2015, 2016 Intel Corporation
// All rights reserved.
//
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#include <sapi/tpm20.h>
#include "sysapi_util.h"


TSS2_RC CheckOverflow( UINT8 *buffer, UINT32 bufferSize, UINT8 *nextData, UINT32 size )
{
    TSS2_RC rval = TSS2_RC_SUCCESS;
    INT64 usedSize;

    usedSize = (INT64)(nextData - buffer) - 1 + size;
    if( usedSize > (INT64)bufferSize )
    {
        rval = TSS2_SYS_RC_INSUFFICIENT_CONTEXT;
    }

    return( rval );
}
/**
 * The buffer and nextData parameters track the front of the output command
 * buffer and the next location where data is to be written in said buffer
 * respectively. In the marshal_* functions depend on these two pointers
 * being in a relatively sane order. Specifically neither should be NULL,
 * and buffer must be less than nextData.
 */
TSS2_RC CheckDataPointers( UINT8 *buffer, UINT8 **nextData )
{
    if( buffer == NULL || nextData == NULL || *nextData == NULL \
        || *nextData < buffer )
    {
        return TSS2_SYS_RC_BAD_REFERENCE;
    }

    return TSS2_RC_SUCCESS;
}