[5/6] imagehlp: Recalculate PE checksum after file modification

[Alexandre Julliard]

Owen Rudge <orudge at codeweavers.com> writes:

> +static BOOL IMAGEHLP_RecalculateChecksum(HANDLE handle)
> +{
> +    IMAGE_DOS_HEADER dos_hdr;
> +    IMAGE_NT_HEADERS nt_hdr;
> +    HANDLE hMapping;
> +    LPVOID BaseAddress;
> +    DWORD FileLength, count, HeaderSum, CheckSum = 0;
> +    BOOL r;
> +
> +    TRACE("handle %p\n", handle);
> +
> +    /* read the DOS header */
> +    count = SetFilePointer(handle, 0, NULL, FILE_BEGIN);
> +
> +    if (count == INVALID_SET_FILE_POINTER)
> +        return FALSE;
> +
> +    count = 0;
> +
> +    r = ReadFile(handle, &dos_hdr, sizeof dos_hdr, &count, NULL);
> +
> +    if (!r)
> +        return FALSE;
> +
> +    if (count != sizeof dos_hdr)
> +        return FALSE;
> +
> +    /* verify magic number of 'MZ' */
> +    if (dos_hdr.e_magic != 0x5A4D)
> +        return FALSE;
> +
> +    /* read the PE header */
> +    count = SetFilePointer(handle, dos_hdr.e_lfanew, NULL, FILE_BEGIN);
> +
> +    if (count == INVALID_SET_FILE_POINTER)
> +        return FALSE;
> +
> +    count = 0;
> +    r = ReadFile(handle, &nt_hdr, sizeof nt_hdr, &count, NULL);
> +
> +    if (!r)
> +        return FALSE;
> +
> +    if (count != sizeof nt_hdr)
> +        return FALSE;
> +
> +    /* verify NT signature */
> +    if (nt_hdr.Signature != IMAGE_NT_SIGNATURE)
> +        return FALSE;

Please write a helper for this, we don't need 3 implementations of the
same thing.

-- 
Alexandre Julliard
julliard at winehq.org