[PATCH v2 0/2] Fix module signing with PKCS#11 URIs

[PATCH v2 0/2] Fix module signing with PKCS#11 URIs

[Jan Luebbe]

Hi,

here are two patches to fix kernel module signing when using a key via
PKCS#11, including the case where the URI contains semicolons to
separate components.

Compared to v1, I've used the change suggested by Masahiro Yamada in the
first patch.

Jan Luebbe (2):
  certs: Fix build error when PKCS#11 URI contains semicolon
  kbuild: modinst: Fix build error when CONFIG_MODULE_SIG_KEY is a
    PKCS#11 URI

 certs/Makefile           | 4 ++--
 scripts/Makefile.modinst | 6 +++++-
 2 files changed, 7 insertions(+), 3 deletions(-)

-- 
2.30.2

[PATCH v2 1/2] certs: Fix build error when PKCS#11 URI contains semicolon

[Jan Luebbe]

When CONFIG_MODULE_SIG_KEY is PKCS#11 URI (pkcs11:*) and contains a
semicolon, signing_key.x509 fails to build:

  certs/extract-cert pkcs11:token=foo;object=bar;pin-value=1111 certs/signing_key.x509
  Usage: extract-cert <source> <dest>

Add quotes to the extract-cert argument to avoid splitting by the shell.

This approach was suggested by Masahiro Yamada <masahiroy@kernel.org>.

Fixes: 129ab0d2d9f3 ("kbuild: do not quote string values in include/config/auto.conf")
Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
---
 certs/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/certs/Makefile b/certs/Makefile
index 9486ed924731..799ad7b9e68a 100644
--- a/certs/Makefile
+++ b/certs/Makefile
@@ -23,8 +23,8 @@ $(obj)/blacklist_hash_list: $(CONFIG_SYSTEM_BLACKLIST_HASH_LIST) FORCE
 targets += blacklist_hash_list
 
 quiet_cmd_extract_certs  = CERT    $@
-      cmd_extract_certs  = $(obj)/extract-cert $(extract-cert-in) $@
-extract-cert-in = $(or $(filter-out $(obj)/extract-cert, $(real-prereqs)),"")
+      cmd_extract_certs  = $(obj)/extract-cert "$(extract-cert-in)" $@
+extract-cert-in = $(filter-out $(obj)/extract-cert, $(real-prereqs))
 
 $(obj)/system_certificates.o: $(obj)/x509_certificate_list
 
-- 
2.30.2

[PATCH v2 2/2] kbuild: modinst: Fix build error when CONFIG_MODULE_SIG_KEY is a PKCS#11 URI

[Jan Luebbe]

When CONFIG_MODULE_SIG_KEY is PKCS#11 URI (pkcs11:*), signing of modules
fails:

  scripts/sign-file sha256 /.../linux/pkcs11:token=foo;object=bar;pin-value=1111 certs/signing_key.x509 /.../kernel/crypto/tcrypt.ko
  Usage: scripts/sign-file [-dp] <hash algo> <key> <x509> <module> [<dest>]
         scripts/sign-file -s <raw sig> <hash algo> <x509> <module> [<dest>]

First, we need to avoid adding the $(srctree)/ prefix to the URL.

Second, since the kconfig string values no longer include quotes, we need to add
them again when passing a PKCS#11 URI to sign-file. This avoids
splitting by the shell if the URI contains semicolons.

Fixes: 4db9c2e3d055 ("kbuild: stop using config_filename in scripts/Makefile.modsign")
Fixes: 129ab0d2d9f3 ("kbuild: do not quote string values in include/config/auto.conf")
Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
---
 scripts/Makefile.modinst | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst
index 836391e5d209..4815a8e32227 100644
--- a/scripts/Makefile.modinst
+++ b/scripts/Makefile.modinst
@@ -66,9 +66,13 @@ endif
 # Don't stop modules_install even if we can't sign external modules.
 #
 ifeq ($(CONFIG_MODULE_SIG_ALL),y)
+ifeq ($(filter pkcs11:%, $(CONFIG_MODULE_SIG_KEY)),)
 sig-key := $(if $(wildcard $(CONFIG_MODULE_SIG_KEY)),,$(srctree)/)$(CONFIG_MODULE_SIG_KEY)
+else
+sig-key := $(CONFIG_MODULE_SIG_KEY)
+endif
 quiet_cmd_sign = SIGN    $@
-      cmd_sign = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(sig-key) certs/signing_key.x509 $@ \
+      cmd_sign = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) "$(sig-key)" certs/signing_key.x509 $@ \
                  $(if $(KBUILD_EXTMOD),|| true)
 else
 quiet_cmd_sign :=
-- 
2.30.2

Re: [PATCH v2 1/2] certs: Fix build error when PKCS#11 URI contains semicolon

[Masahiro Yamada]

On Tue, Jan 31, 2023 at 5:43 PM Jan Luebbe <jlu@pengutronix.de> wrote:
>
> When CONFIG_MODULE_SIG_KEY is PKCS#11 URI (pkcs11:*) and contains a
> semicolon, signing_key.x509 fails to build:
>
>   certs/extract-cert pkcs11:token=foo;object=bar;pin-value=1111 certs/signing_key.x509
>   Usage: extract-cert <source> <dest>
>
> Add quotes to the extract-cert argument to avoid splitting by the shell.
>
> This approach was suggested by Masahiro Yamada <masahiroy@kernel.org>.
>
> Fixes: 129ab0d2d9f3 ("kbuild: do not quote string values in include/config/auto.conf")
> Signed-off-by: Jan Luebbe <jlu@pengutronix.de>


Both applied to linux-kbuild/fixes.
Thanks.




> ---
>  certs/Makefile | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/certs/Makefile b/certs/Makefile
> index 9486ed924731..799ad7b9e68a 100644
> --- a/certs/Makefile
> +++ b/certs/Makefile
> @@ -23,8 +23,8 @@ $(obj)/blacklist_hash_list: $(CONFIG_SYSTEM_BLACKLIST_HASH_LIST) FORCE
>  targets += blacklist_hash_list
>
>  quiet_cmd_extract_certs  = CERT    $@
> -      cmd_extract_certs  = $(obj)/extract-cert $(extract-cert-in) $@
> -extract-cert-in = $(or $(filter-out $(obj)/extract-cert, $(real-prereqs)),"")
> +      cmd_extract_certs  = $(obj)/extract-cert "$(extract-cert-in)" $@
> +extract-cert-in = $(filter-out $(obj)/extract-cert, $(real-prereqs))
>
>  $(obj)/system_certificates.o: $(obj)/x509_certificate_list
>
> --
> 2.30.2
>


-- 
Best Regards
Masahiro Yamada