Heinrich, Do you have any comments? # not only on this issue, but also other issues that I pointed out # in the initial RFC.
On Fri, Apr 23, 2021 at 02:38:09PM +0530, Sughosh Ganu wrote: > Takahiro, > > On Fri, 23 Apr 2021 at 12:30, AKASHI Takahiro <[email protected]> > wrote: > > > Sughosh, > > > > On Fri, Apr 23, 2021 at 11:55:04AM +0530, Sughosh Ganu wrote: > > > Takahiro, > > > > > > On Fri, 23 Apr 2021 at 11:17, AKASHI Takahiro < > > [email protected]> > > > wrote: > > > > > > > Heinrich, > > > > > > > > I'm currently thinking of improving capsule authentication > > > > that Sughosh has made, particularly around mkeficapsule command: > > > > > > > > 1) Add a signing feature to the command > > > > This will allow us to create a *signed* capsule file solely > > > > with mkeficapsule. We will no longer rely on EDK2's script. > > > > 2) Delete "-K" and "-D" option > > > > Specifically, revert 322c813f4bec ("mkeficapsule: Add support > > > > for embedding public key in a dtb") > > > > As I said, this feature doesn't have anything to do with > > > > creating a capsule file. Above all, we can do the same thing > > > > with the existing commands (dtc and fdtoverlay). > > > > > > > > > > I would vote against this particular revert that you are suggesting. I > > have > > > already submitted a patchset which is under review[1], which is adding > > > support for embedding the key in the platform's dtb, using the above > > > functionality in mkeficapsule. > > > > That is why I insisted "(2) should be done in 2021.04" > > as we should stop it being merged immediately. > > > > > I don't see any reason why we should be > > > adding this logic in another utility, > > > > ? > > I never tried to add anything about this issue. Just remove. > > FYI, we can get the exact same result with: > > === pubkey.dts === > > /dts-v1/; > > /plugin/; > > > > &{/} { > > signature { > > capsule-key = /incbin/("CRT.esl"); > > }; > > }; > > === > > $ dtc -@ -I dts -O dtb -o pubkey.dtbo pubkey.dts > > $ fdtoverlay -i test.dtb -o test_pubkey.dtb -v pubkey.dtbo > > > > No "C" code needed here. You also re-invented the almost same function > > as fdt_overlay_apply() in mkeficapsule, and yet your function is > > incompatible with dtc/fdtoverlay commands in terms of overlay syntax. > > > > I have already confirmed the capsule file signed by my mkeficapsule > > + above dtb work perfectly with efi_capsule_authenticate() > > in my pytest with sandbox. > > > > And again, the feature has nothing to do with generating a capsule file. > > It is simply to perform fdt overlay which is already supported by standard > > commands. > > > > Those are the reasons why we should revert the patch. > > > > I am sure that the method you have shown above would work for embedding the > key into the dtb. But having the logic in mkeficapsule also does not hurt. > I would say that a patch should be reverted in the scenario that it causes > some regression and there is no easy or obvious fix available. This is > adding some logic to a host tool, and not breaking any existing > functionality. Also, this code being part of a host tool, there is no case > of it causing any increase to the u-boot size. If you think that there are > some bugs, or certain things can be improved in the code, I am open to > making changes and fixing stuff. But I am still of the opinion that a > revert in a host tool, and that too when it is not breaking any stuff is > not needed. Instead of fixing bugs, just remove it as it is not necessary. Regarding to your recent patch, use the command sequence I gave above. It's enough. You don't have to maintain the code that has nothing to do with capsule files. > > > > and cannot use the mkeficapsule > > > utility for embedding the public key in the platform's dtb. > > > > ? > > No need to use mkeficapsule any more. > > > > ? When did I say that. I said that there is no reason why mkeficapsule > utility cannot be used for embedding the public key in the platform's dtb. My previous reply gave you lots of reasons why we should remove the feature. I don't want to repeat them. -Takahiro Akashi > -sughosh > > > > > > -Takahiro Akashi > > > > > The > > > mkeficapsule utility can be extended to add the authentication > > information > > > that you plan to submit. > > > > > > -sughosh > > > > > > [1] - https://lists.denx.de/pipermail/u-boot/2021-April/447183.html > > > > > > > > > > 3) Add pytest for capsule authentication with sandbox > > > > > > > > Now I have done all of them above although some cleanup work is > > > > still needed. I think that (2) should be done in 2021.04. > > > > > > > > I plan to send patches for 1-3 (and maybe 5 and 7 below) if you agree. > > > > > > > > Other concerns: > > > > 4) Documentation > > > > Currently, "doc/board/emulation/qemu_capsule_update.rst" is > > > > the only document about the usage of UEFI capsule on U-Boot. > > > > Unfortunately, it contains some errors and more importantly, > > > > most of the content are generic, not qemu-specific. > > > > > > > > 5) Certificate (public key) in dtb > > > > That's fine, but again "board/emulation/common/qemu_capsule.c" > > > > is naturally generic. It should be available for other platforms > > > > with a new Kconfig option. > > > > > > > > # IMHO, I don't understand why the data in dtb needs be in > > > > efi-signature-list structure. A single key (cert) would be enough. > > > > > > > > 6) "capsule_authentication_enabled" > > > > I think that we have agreed with deleting this variable. > > > > But I don't see any patch. > > > > Moreover, capsule authentication must be enforced only > > > > if the attribute, IMAGE_ATTRIBUTE_AUTHENTICATION_REQUIRED, > > > > is set. But there is no code to check the flag. > > > > > > > > 7) Pytest is broken > > > > Due to your and Ilias' recent patches, existing pytests for > > > > secure boot as well as capsule update are now broken. > > > > I'm not sure why you have not yet noticed. > > > > Presumably, Travis CI now skips those tests? > > > > > > > > If I have some time in the future, I will address them. > > > > But Sughosh can do as well. > > > > > > > > -Takahiro Akashi > > > > > >
