Re: [edk2-devel] [PATCH] OvmfPkg/README: Document Secure Boot

Re: [edk2-devel] [PATCH] OvmfPkg/README: Document Secure Boot

[Joursoir]

+cc to maintainers

On Sat, 3 Jun 2023 01:44:40 +0400
"Joursoir" <chat@joursoir.net> wrote:

> Add the new section for Secure Boot.
> 
> Signed-off-by: Alexander Goncharov <chat@joursoir.net>
> ---
>  OvmfPkg/README | 36 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> diff --git a/OvmfPkg/README b/OvmfPkg/README
> index 0a408abf01..e106e19818 100644
> --- a/OvmfPkg/README
> +++ b/OvmfPkg/README
> @@ -120,6 +120,42 @@ $ OvmfPkg/build.sh -a X64 qemu -cdrom
> /path/to/disk-image.iso To build a 32-bit OVMF without debug messages
> using GCC 4.8: $ OvmfPkg/build.sh -a IA32 -b RELEASE -t GCC48
>  
> +=== Secure Boot ===
> +
> +Secure Boot is a security feature that ensures only trusted and
> digitally +signed software is allowed to run during the boot process.
> +
> +* In order to support Secure Boot, OVMF must be built with the
> +  "-D SECURE_BOOT_ENABLE" option.
> +
> +* By default, OVMF is not shipped with any SecureBoot keys installed.
> The user
> +  need to install them with "Secure Boot Configuration" utility in
> the firmware
> +  UI, or enroll the default UEFI keys using the
> OvmfPkg/EnrollDefaultKeys app. +
> +  For the EnrollDefaultKeys application, the hypervisor is expected
> to add a
> +  string entry to the "OEM Strings" (Type 11) SMBIOS table. The
> string should
> +  have the following format:
> +
> +    4e32566d-8e9e-4f52-81d3-5bb9715f9727:<Base64 X509 cert for PK and
> first KEK> +
> +  Such string can be generated with the following script, for
> example: +
> +    sed \
> +      -e 's/^-----BEGIN
> CERTIFICATE-----$/4e32566d-8e9e-4f52-81d3-5bb9715f9727:/' \
> +      -e '/^-----END CERTIFICATE-----$/d' \
> +      PkKek1.pem \
> +    | tr -d '\n' \
> +    > PkKek1.oemstr
> +
> +  - Using QEMU 5.2 or later, the SMBIOS type 11 field can be
> specified from a
> +    file:
> +
> +    -smbios type=11,path=PkKek1.oemstr \
> +
> +  - Using QEMU 5.1 or earlier, the string has to be passed as a
> value: +
> +    -smbios type=11,value="$(< PkKek1.oemstr)"
> +
>  === SMM support ===
>  
>  Requirements:

-- 
Joursoir

Re: [edk2-devel] [PATCH] OvmfPkg/README: Document Secure Boot

[Gerd Hoffmann]

On Fri, Jun 16, 2023 at 12:51:55AM +0400, Joursoir wrote:
> +cc to maintainers
> 
> On Sat, 3 Jun 2023 01:44:40 +0400
> "Joursoir" <chat@joursoir.net> wrote:
> 
> > Add the new section for Secure Boot.
> > 
> > Signed-off-by: Alexander Goncharov <chat@joursoir.net>
> > ---
> >  OvmfPkg/README | 36 ++++++++++++++++++++++++++++++++++++
> >  1 file changed, 36 insertions(+)
> > 
> > diff --git a/OvmfPkg/README b/OvmfPkg/README
> > index 0a408abf01..e106e19818 100644
> > --- a/OvmfPkg/README
> > +++ b/OvmfPkg/README
> > @@ -120,6 +120,42 @@ $ OvmfPkg/build.sh -a X64 qemu -cdrom
> > /path/to/disk-image.iso To build a 32-bit OVMF without debug messages
> > using GCC 4.8: $ OvmfPkg/build.sh -a IA32 -b RELEASE -t GCC48
> >  
> > +=== Secure Boot ===
> > +
> > +Secure Boot is a security feature that ensures only trusted and
> > digitally +signed software is allowed to run during the boot process.
> > +
> > +* In order to support Secure Boot, OVMF must be built with the
> > +  "-D SECURE_BOOT_ENABLE" option.

Also note that you need either a read-only varstore or SMM support,
otherwise it is trivial to bypass secure boot by writing directly to
flash varstore.

> > +* By default, OVMF is not shipped with any SecureBoot keys installed.
> > The user
> > +  need to install them with "Secure Boot Configuration" utility in
> > the firmware
> > +  UI, or enroll the default UEFI keys using the
> > OvmfPkg/EnrollDefaultKeys app. +

Alternatively use https://gitlab.com/kraxel/virt-firmware

take care,
  Gerd