Removed RegDeleteTreeA usage in storage_winuser

src/platform/storage_winuser.c

@@ -348,5 +348,116 @@ CxPlatStorageClear(
     _In_ CXPLAT_STORAGE* Storage
     )
 {
-    return HRESULT_FROM_WIN32(RegDeleteTreeA(Storage->RegKey, NULL));
-}
+    QUIC_STATUS Status = QUIC_STATUS_SUCCESS;
+    DWORD Error = NO_ERROR;
+    DWORD AllocatedLength = 255;
+    PSTR ValueName = NULL;
+
+    ValueName = CXPLAT_ALLOC_PAGED(AllocatedLength, QUIC_POOL_PLATFORM_TMP_ALLOC);
+    if (ValueName == NULL) {
+        Status = QUIC_STATUS_OUT_OF_MEMORY;
+        QuicTraceEvent(
+            AllocFailure,
+            "Allocation of '%s' failed. (%llu bytes)",
+            "RegEnumValueA ValueName",
+            AllocatedLength);
+        goto Exit;
+    }
+
+    //
+    // Iterate through all values and delete them
+    // We always use index 0 because deletion shifts the remaining values
+    //
+    while (TRUE) {
+        DWORD NameLength = AllocatedLength;
+        Error =
+            RegEnumValueA(
+                Storage->RegKey,
+                0, // Always use index 0 since we delete as we go
+                ValueName,
+                &NameLength,
+                NULL,   // Reserved
+                NULL,   // Type
+                NULL,   // Data
+                NULL);  // DataLength
+
+        while (Error == ERROR_MORE_DATA && AllocatedLength < 32767) {
+            //
+            // Reallocate buffer only if current buffer is too small
+            //
+            CXPLAT_DBG_ASSERT(ValueName != NULL);
+
+            CXPLAT_FREE(ValueName, QUIC_POOL_PLATFORM_TMP_ALLOC);
+
+            AllocatedLength *= 2; // The API doesn't tell us the needed length; just double it.
+            if (AllocatedLength > 32767) {
+                //
+                // The registry API interprets this value as a SHORT, so
+                // values larger than 32,767 will cause it to overflow and
+                // return ERROR_MORE_DATA. So limit allocation to this length.
+                //
+                AllocatedLength = 32767;
+            }
+
+            ValueName = CXPLAT_ALLOC_PAGED(AllocatedLength, QUIC_POOL_PLATFORM_TMP_ALLOC);
+            if (ValueName == NULL) {
+                Status = QUIC_STATUS_OUT_OF_MEMORY;
+                QuicTraceEvent(
+                    AllocFailure,
+                    "Allocation of '%s' failed. (%llu bytes)",
+                    "RegEnumValueA ValueName (realloc)",
+                    AllocatedLength);
+                goto Exit;
+            }
+
+            NameLength = AllocatedLength;
+
+            //
+            // Get the value name
+            //
+            Error =
+                RegEnumValueA(
+                    Storage->RegKey,
+                    0, // Always use index 0 since we delete as we go
+                    ValueName,
+                    &NameLength,
+                    NULL,   // Reserved
+                    NULL,   // Type
+                    NULL,   // Data
+                    NULL);  // DataLength
+        }
+
+        if (Error == ERROR_NO_MORE_ITEMS) {
+            Status = QUIC_STATUS_SUCCESS;
+            break;
+        } else if (Error != NO_ERROR) {
+            Status = HRESULT_FROM_WIN32(Error);
+            QuicTraceEvent(
+                LibraryErrorStatus,
+                "[ lib] ERROR, %u, %s.",
+                Status,
+                "RegEnumValueA failed");
+            goto Exit;
+        }
+
+        //
+        // Delete this value
+        //
+        Status = RegDeleteValueA(Storage->RegKey, ValueName);
+        if (QUIC_FAILED(Status)) {
+            QuicTraceEvent(
+                LibraryErrorStatus,
+                "[ lib] ERROR, %u, %s.",
+                Status,
+                "ZwDeleteValueKey failed");
+            goto Exit;
+        }
+    }
+
+Exit:
+    if (ValueName != NULL) {
+        CXPLAT_FREE(ValueName, QUIC_POOL_PLATFORM_TMP_ALLOC);
+    }
+
+    return Status;
+}