unsigned int GetSystemSmBios()

in azure-protected-vm-secrets/System.cpp [53:113]

• 46 lines of code
• 10 McCabe index (conditional complexity)

unsigned int GetSystemSmBios(unsigned char **outUuid)
{
#ifndef PLATFORM_UNIX
    DWORD smbiosSize = 0;
    UINT actualSize = GetSystemFirmwareTable('RSMB', 0, NULL, smbiosSize);

    if (actualSize == 0)
    {
        return 0;
    }

    PUCHAR smbiosBuffer = (PUCHAR)malloc(actualSize);

    if (smbiosBuffer == NULL)
    {
        return 0;
    }

    smbiosSize = GetSystemFirmwareTable('RSMB', 0, smbiosBuffer, actualSize);
    RawSMBIOSData* smbiosData = (RawSMBIOSData*)smbiosBuffer;
    ULONG i = 0;
    SmBiosStructure* smBiosStructure = NULL;
    bool properTermination = false;

    do
    {
        properTermination = false;

        // Check that the buffer contains at least one whole structure header
        if (i + sizeof(SmBiosStructure) < smbiosData->Size)
        {
            if (smbiosData->SMBIOSTableData[i] == 1)
            {
                // Found structure that matches type
                smBiosStructure = (SmBiosStructure*)&smbiosData->SMBIOSTableData[i];
            }

            // Jump to the end of the structure header
            i += smbiosData->SMBIOSTableData[i + 1];

            // Look for a double-null (\0\0), which indicates the end of the structure
            while (i + 1 < smbiosData->Size)
            {
                if ((smbiosData->SMBIOSTableData[i] == 0) && (smbiosData->SMBIOSTableData[i + 1] == 0))
                {
                    properTermination = true;
                    i += 2;
                    break;
                }

                ++i;
            }
        }
    } while (properTermination && !smBiosStructure);

    *outUuid = ((SystemInfo*)smBiosStructure)->UUID;

    return 16;
#else
#endif
}