Spec Lite: Deprecate Checksum Computation




The glance ‘checksum’ image property contains an MD5 hash of image data. MD5 has not been considered secure for some time, and in order to comply with various security standards, an implementation of the MD5 algorithm may not be available on glance nodes.


Announce that Glance will no longer populate the ‘checksum’ on new images beginning with the Victoria release. Instead, operators should rely on the secure “multihash” feature that was introduced in Rocky. The ‘checksum’ property will remain on legacy images.




In Ussuri: release note. In Victoria: Remove the code that uses MD5. (This will affect primarily the glance_store drivers.)


We could check to see if the algorithm is available, and if it is, compute the MD5. But this seems pointless as the secure multihash is already being computed for all new images.

We could remove the ‘checksum’ entirely, but this would require a migration to the multihash. For at least some backends, this would mean downloading the image data for each legacy image to do the computation, which could take a very long time.


Deprecation and release note in Ussuri; removal in Victoria.