On Fri, Nov 4, 2022 at 11:33 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > On Thu, Nov 03, 2022 at 11:01:12AM -0700, Evan Green wrote: > > In addition to the private key and public key, the TPM2_Create > > command may also return creation data, a creation hash, and a creation > > ticket. These fields allow the TPM to attest to the contents of a > > specified set of PCRs at the time the trusted key was created. Encrypted > > hibernation will use this to ensure that PCRs settable only by the > > kernel were set properly at the time of creation, indicating this is an > > authentic hibernate key. > > > > Encode these additional parameters into the ASN.1 created to represent > > the key blob. The new fields are made optional so that they don't bloat > > key blobs which don't need them, and to ensure interoperability with > > old blobs. > > > > Signed-off-by: Evan Green <evgreen@xxxxxxxxxxxx> > > There's a lot of open-coded math for the bounds checking. I didn't > immediately see any problems, but it'd be nice if there was a way to > hook a fuzzer up to this, or at least write some KUnit tests to check > boundary conditions explicitly. > > Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> Thank you! Yes, agreed about all the bounds checking. I could probably pull out the "check for src + 2 > end, then get_unaligned_be16()" into a helper function. Let me see if that makes things look better or ends up looking the same. -Evan
