After allocating memory for a wchar_t* parameter and copying a string into the buffer, when returning from the function the buffer can not be read. Per the debugger:
machineName 0xcccccccccccccccc wchar_t *
given the following code
wchar_t *machineName;
EXPECT_TRUE(c_GetMachineName(machineName));

file test.cpp
…

#include "sysCertStore.h"
TEST(sysCertStoreC, c_GetMachineName)
{
    wchar_t *machineName;
    EXPECT_TRUE(c_GetMachineName(machineName));
    setlocale(LC_ALL, "");
    printf("%ls", machineName);
    free(machineName);
}

file sysCertStore.h
…

#ifdef __cplusplus
    extern "C" 
    {  
        // only need to export C interface if
        // used by C++ source code
    BOOL c_GetMachineName(wchar_t* machineName);
    };
#endif

file sysCertStore.cpp
…

BOOL c_GetMachineName(wchar_t* machineName) {
  wchar_t Name[MAX_COMPUTERNAME_LENGTH + 1];
  int i = 0;


  LPWSTR infoBuf = new wchar_t[MAX_COMPUTERNAME_LENGTH + 1];  // = {''};
  DWORD bufCharCount = MAX_COMPUTERNAME_LENGTH + 1;
  memset(Name, 0, MAX_COMPUTERNAME_LENGTH + 1);
  if (GetComputerNameW(infoBuf, &bufCharCount)) 
  {
    for (i = 0; i < MAX_COMPUTERNAME_LENGTH + 1; i++) 
    {
      Name[i] = infoBuf[i];
    }
    delete[] infoBuf;
    INT strln= wcslen(Name)+1;
    machineName = (wchar_t*)malloc(strln * sizeof(wchar_t));  // new wchar_t[strln];
    wcscpy_s(machineName, strln, Name);
    return TRUE;
  } else 
  {
    wcscpy_s(Name,7+1, L"Unknown");
    return FALSE;
  }
  return FALSE;
 }

I’m expecting the test to print the machine name and free the memory of the allocated string/buffer, allocated in the c_GetMachineName function.

TEST(sysCertStoreC, c_GetMachineName)
{
    wchar_t *machineName;
    EXPECT_TRUE(c_GetMachineName(machineName));
    setlocale(LC_ALL, "");
    printf("%ls", machineName);
    free(machineName);
}