Using exiftool on a .CR2 photo converted to DNG, the following tags can be seen in the printout.

AS_SHOT_NEUTRAL
Raw Data Unique ID

However, when unpacking an image captured from the same camera (Canon 7D), I cannot find that data in the libRaw.imgdata structure, despite reading through the sub-structure data several times when in debug mode. I have found almost everything else needed.

I also scanned the documentation.

Any help wold be welcomed.

Thanks. Great library.