Re: Re:

Mimi Zohar
2019-05-24T18:09:55Z

> >> As mentioned, the first patch description should include a shell
> >> command for verifying the digest in the kexec boot command line
> >> measurement list record against /proc/cmdline.  This patch description
> >> should include a shell command showing how to verify the digest based
> >> on the new field.  Should the new field in the ascii measurement list
> >> be displayed as a string, not hex?
> >
> > We should define a new type. If the type is DATA_FMT_STRING, spaces are
> > replaced with '_'.
>
> Or better. Leave it as hex, otherwise there would be a parsing problem
> if there are spaces in the data for a field.

After making a few changes, the measurement list contains the
following kexec-cmdline data:

10 edc32d1e3a5ba7272280a395b6fb56a5ef7c78c3 ima-buf
sha256:4f43b7db850e
88c49dfeffd4b1eb4f021d78033dfb05b07e45eec8d0b45275
kexec-cmdline
726f6f
743d2f6465762f7364613420726f2072642e6c756b732e757569643d6c756b73
2d6637
3633643737632d653236622d343431642d613734652d62363633636334643832
656120
696d615f706f6c6963793d7463627c61707072616973655f746362

There's probably a better shell command, but the following works to
verify the digest locally against the /proc/cmdline:

$ echo -n -e `cat /proc/cmdline | sed 's/^.*root=/root=/'` | sha256sum
4f43b7db850e88c49dfeffd4b1eb4f021d78033dfb05b07e45eec8d0b4527f65 -

If we leave the "buf" field as ascii-hex, what would the shell command
look like when verifying the digest based on the "buf" field?

Mimi