Re:

[Roberto Sassu]

On 5/24/2019 5:12 PM, Mimi Zohar wrote:
> On Mon, 2019-05-20 at 17:06 -0700, Prakhar Srivastava wrote:
> > A buffer(cmdline args) measured into ima cannot be appraised
> > without already being aware of the buffer contents.Since we
> > don't know what cmdline args will be passed (or need to validate
> > what was passed) it is not possible to appraise it.
> >
> > Since hashs are non reversible the raw buffer is needed to
> > recompute the hash.
> > To regenrate the hash of the buffer and appraise the same
> > the contents of the buffer need to be available.
> >
> > A new template field buf is added to the existing ima template
> > fields, which can be used to store/read the buffer itself.
> > Two new fields are added to the ima_event_data to carry the
> > buf and buf_len whenever necessary.
> >
> > Updated the process_buffer_measurement call to add the buf
> > to the ima_event_data.
> > process_buffer_measurement added in "Add a new ima hook
> > ima_kexec_cmdline to measure cmdline args"
> >
> > - Add a new template field 'buf' to be used to store/read
> > the buffer data.
> > - Added two new fields to ima_event_data to hold the buf and
> > buf_len [Suggested by Roberto]
> > -Updated process_buffer_meaurement to add the buffer to
> > ima_event_data
>
> This patch description can be written more concisely.
>
> Patch 1/3 in this series introduces measuring the kexec boot command
> line. ÂThis patch defines a new template field for storing the kexec
> boot command line in the measurement list in order for a remote
> attestation server to verify.
>
> 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. ÂThis patch description
> should include a shell command showing how to verify the digest based
> on the new field. ÂShould 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 '_'.

Roberto

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