Re: [XENBUS PATCH 1/2] Add RegistryQueryQwordValue

[Owen Smith <owen.smith@xxxxxxxxx>]

Reviewed-by: Owen Smith <owen.smith@xxxxxxxxx>

On Wed, Aug 13, 2025 at 2:32 PM Tu Dinh <ngoc-tu.dinh@xxxxxxxxxx> wrote:

Signed-off-by: Tu Dinh <ngoc-tu.dinh@xxxxxxxxxx>
---
 src/common/registry.c | 70 +++++++++++++++++++++++++++++++++++++++++++
 src/common/registry.h |  7 +++++
 2 files changed, 77 insertions(+)

diff --git a/src/common/registry.c b/src/common/registry.c
index 7965233..1f7a73c 100644
--- a/src/common/registry.c
+++ b/src/common/registry.c
@@ -853,6 +853,76 @@ fail1:
     return status;
 }

+NTSTATUS
+RegistryQueryQwordValue(
+    _In_ HANDLE                     Key,
+    _In_ PSTR                       Name,
+    _Out_ PULONGLONG                Value
+    )
+{
+    ANSI_STRING                     Ansi;
+    UNICODE_STRING                  Unicode;
+    PKEY_VALUE_PARTIAL_INFORMATION  Partial;
+    ULONG                           Size;
+    NTSTATUS                        status;
+
+    RtlInitAnsiString(&Ansi, Name);
+
+    status = RtlAnsiStringToUnicodeString(&Unicode, &Ansi, TRUE);
+    if (!NT_SUCCESS(status))
+        goto fail1;
+
+    status = ZwQueryValueKey(Key,
+                             &Unicode,
+                             KeyValuePartialInformation,
+                             NULL,
+                             0,
+                             &Size);
+    if (!NT_SUCCESS(status) &&
+        status != STATUS_BUFFER_OVERFLOW &&
+        status != STATUS_BUFFER_TOO_SMALL)
+        goto fail2;
+
+    Partial = __RegistryAllocate(Size);
+
+    status = STATUS_NO_MEMORY;
+    if (Partial == NULL)
+        goto fail3;
+
+    status = ZwQueryValueKey(Key,
+                             &Unicode,
+                             KeyValuePartialInformation,
+                             Partial,
+                             Size,
+                             &Size);
+    if (!NT_SUCCESS(status))
+        goto fail4;
+
+    status = STATUS_INVALID_PARAMETER;
+    if (Partial->Type != REG_QWORD ||
+        Partial->DataLength != sizeof (ULONGLONG))
+        goto fail5;
+
+    *Value = *(PULONGLONG)Partial->Data;
+
+    __RegistryFree(Partial);
+
+    RtlFreeUnicodeString(&Unicode);
+
+    return STATUS_SUCCESS;
+
+fail5:
+fail4:
+    __RegistryFree(Partial);
+
+fail3:
+fail2:
+    RtlFreeUnicodeString(&Unicode);
+
+fail1:
+    return status;
+}
+
 NTSTATUS
 RegistryUpdateDwordValue(
     _In_ HANDLE                     Key,
diff --git a/src/common/registry.h b/src/common/registry.h
index e70a6ed..26bc0c6 100644
--- a/src/common/registry.h
+++ b/src/common/registry.h
@@ -142,6 +142,13 @@ RegistryQueryDwordValue(
     _Out_ PULONG        Value
     );

+extern NTSTATUS
+RegistryQueryQwordValue(
+    _In_ HANDLE         Key,
+    _In_ PSTR           Name,
+    _Out_ PULONGLONG    Value
+    );
+
 extern NTSTATUS
 RegistryUpdateDwordValue(
     _In_ HANDLE         Key,
--
2.50.1.windows.1



Ngoc Tu Dinh | Vates XCP-ng Developer

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