[PATCH master] ARM: i.MX8M: HABv4: make barebox SHA256 embedding POSIX-shell compatible

[PATCH master] ARM: i.MX8M: HABv4: make barebox SHA256 embedding POSIX-shell compatible

[Ahmad Fatoum]

C-Style printf "\xHH" is not supported by a POSIX shell,
while printf "\oOOO" is. As we use printf "\xHH" for converting the
textual output of sha256sum into binary, systems using dash as shell
will end up embedding literal \xHH characters in the output resulting in
an ubootable barebox when CONFIG_PBL_VERIFY_PIGGY=y:

  !hash mismatch, refusing to decompress

Fix this by using octal escape sequences instead.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 images/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/images/Makefile b/images/Makefile
index c79f1a272e9c..7a8bb94fe0df 100644
--- a/images/Makefile
+++ b/images/Makefile
@@ -113,7 +113,8 @@ $(obj)/piggy.o: $(obj)/barebox.z FORCE
 $(obj)/sha_sum.o: $(obj)/barebox.sha.bin FORCE
 
 quiet_cmd_sha256bin ?= SHA-BIN $@
-      cmd_sha256bin ?= printf "$(shell awk '{printf $$1}' < $(obj)/barebox.sum | sed -e 's/../\\x&/g' )" > $@
+      cmd_sha256bin = printf "$(shell sed 's/ .*$$//;s/../0x&\n/g;s/\n$$//' $(obj)/barebox.sum | \
+			while read -r byte; do printf '\%o' $$byte; done)" > $@
 
 quiet_cmd_sha256sum ?= SHA     $@
       cmd_sha256sum ?= sha256sum $(obj)/barebox.z > $@
-- 
2.30.2

Re: [PATCH master] ARM: i.MX8M: HABv4: make barebox SHA256 embedding POSIX-shell compatible

[Rouven Czerwinski]

On Mon, 2022-08-15 at 08:38 +0200, Ahmad Fatoum wrote:
> C-Style printf "\xHH" is not supported by a POSIX shell,
> while printf "\oOOO" is. As we use printf "\xHH" for converting the
> textual output of sha256sum into binary, systems using dash as shell
> will end up embedding literal \xHH characters in the output resulting in
> an ubootable barebox when CONFIG_PBL_VERIFY_PIGGY=y:
> 
>   !hash mismatch, refusing to decompress
> 
> Fix this by using octal escape sequences instead.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

Reviewed-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>

> ---
>  images/Makefile | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/images/Makefile b/images/Makefile
> index c79f1a272e9c..7a8bb94fe0df 100644
> --- a/images/Makefile
> +++ b/images/Makefile
> @@ -113,7 +113,8 @@ $(obj)/piggy.o: $(obj)/barebox.z FORCE
>  $(obj)/sha_sum.o: $(obj)/barebox.sha.bin FORCE
>  
>  quiet_cmd_sha256bin ?= SHA-BIN $@
> -      cmd_sha256bin ?= printf "$(shell awk '{printf $$1}' < $(obj)/barebox.sum | sed -e 's/../\\x&/g' )" > $@
> +      cmd_sha256bin = printf "$(shell sed 's/ .*$$//;s/../0x&\n/g;s/\n$$//' $(obj)/barebox.sum | \
> +			while read -r byte; do printf '\%o' $$byte; done)" > $@
>  
>  quiet_cmd_sha256sum ?= SHA     $@
>        cmd_sha256sum ?= sha256sum $(obj)/barebox.z > $@

Best regards,
Rouven

Re: [PATCH master] ARM: i.MX8M: HABv4: make barebox SHA256 embedding POSIX-shell compatible

[Sascha Hauer]

On Mon, Aug 15, 2022 at 08:38:53AM +0200, Ahmad Fatoum wrote:
> C-Style printf "\xHH" is not supported by a POSIX shell,
> while printf "\oOOO" is. As we use printf "\xHH" for converting the
> textual output of sha256sum into binary, systems using dash as shell
> will end up embedding literal \xHH characters in the output resulting in
> an ubootable barebox when CONFIG_PBL_VERIFY_PIGGY=y:
> 
>   !hash mismatch, refusing to decompress
> 
> Fix this by using octal escape sequences instead.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  images/Makefile | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Applied, thanks

Sascha

> 
> diff --git a/images/Makefile b/images/Makefile
> index c79f1a272e9c..7a8bb94fe0df 100644
> --- a/images/Makefile
> +++ b/images/Makefile
> @@ -113,7 +113,8 @@ $(obj)/piggy.o: $(obj)/barebox.z FORCE
>  $(obj)/sha_sum.o: $(obj)/barebox.sha.bin FORCE
>  
>  quiet_cmd_sha256bin ?= SHA-BIN $@
> -      cmd_sha256bin ?= printf "$(shell awk '{printf $$1}' < $(obj)/barebox.sum | sed -e 's/../\\x&/g' )" > $@
> +      cmd_sha256bin = printf "$(shell sed 's/ .*$$//;s/../0x&\n/g;s/\n$$//' $(obj)/barebox.sum | \
> +			while read -r byte; do printf '\%o' $$byte; done)" > $@
>  
>  quiet_cmd_sha256sum ?= SHA     $@
>        cmd_sha256sum ?= sha256sum $(obj)/barebox.z > $@
> -- 
> 2.30.2
> 
> 
> 

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