[U-Boot] [PATCH v2 4/4] autoboot.c: Add feature to stop autobooting via SHA256 encrypted password

["Andreas Bießmann" <andreas.devel@googlemail.com>]

Hi Stefan,

On 05/08/2015 09:52 AM, Stefan Roese wrote:
> This patch adds the feature to only stop the autobooting, and therefor
> boot into the U-Boot prompt, when the input string / password matches
> a values that is encypted via a SHA256 hash and saved in the environment.
> 
> This feature is enabled by defined these config options:
>      CONFIG_AUTOBOOT_KEYED
>      CONFIG_AUTOBOOT_STOP_STR_SHA256
> 
> Signed-off-by: Stefan Roese <sr@denx.de>
> Cc: Simon Glass <sjg@chromium.org>
> Cc: Magnus Lilja <lilja.magnus@gmail.com>
> ---
> v2:
> - AUTOBOOT_STOP_STR_SHA256 is a string and not bool
> - Add input key length check as suggested by Magnus
> - Add "constant-length" time compare function as suggested
>   by Magnus
> 
>  common/Kconfig    |  20 +++++++--
>  common/autoboot.c | 132 +++++++++++++++++++++++++++++++++++++++++++++---------
>  2 files changed, 128 insertions(+), 24 deletions(-)

[snip]

> @@ -42,7 +108,9 @@ static int abortboot_keyed(int bootdelay)
>  	}
>  	delaykey[] = {
>  		{ .str = getenv("bootdelaykey"),  .retry = 1 },
> +		{ .str = getenv("bootdelaykey2"), .retry = 1 },
>  		{ .str = getenv("bootstopkey"),   .retry = 0 },
> +		{ .str = getenv("bootstopkey2"),  .retry = 0 },
>  	};
>  
>  	char presskey[MAX_DELAY_STOP_STR];
> @@ -50,26 +118,21 @@ static int abortboot_keyed(int bootdelay)
>  	u_int presskey_max = 0;
>  	u_int i;
>  
> -#ifndef CONFIG_ZERO_BOOTDELAY_CHECK
> -	if (bootdelay == 0)
> -		return 0;
> -#endif
> -
> -#  ifdef CONFIG_AUTOBOOT_PROMPT
> -	/*
> -	 * CONFIG_AUTOBOOT_PROMPT includes the %d for all boards.
> -	 * To print the bootdelay value upon bootup.
> -	 */
> -	printf(CONFIG_AUTOBOOT_PROMPT, bootdelay);
> -#  endif
> -
>  #  ifdef CONFIG_AUTOBOOT_DELAY_STR
>  	if (delaykey[0].str == NULL)
>  		delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR;
>  #  endif
> -#  ifdef CONFIG_AUTOBOOT_STOP_STR
> +#  ifdef CONFIG_AUTOBOOT_DELAY_STR2
>  	if (delaykey[1].str == NULL)
> -		delaykey[1].str = CONFIG_AUTOBOOT_STOP_STR;
> +		delaykey[1].str = CONFIG_AUTOBOOT_DELAY_STR2;
> +#  endif
> +#  ifdef CONFIG_AUTOBOOT_STOP_STR
> +	if (delaykey[2].str == NULL)
> +		delaykey[2].str = CONFIG_AUTOBOOT_STOP_STR;
> +#  endif
> +#  ifdef CONFIG_AUTOBOOT_STOP_STR2
> +	if (delaykey[3].str == NULL)
> +		delaykey[3].str = CONFIG_AUTOBOOT_STOP_STR2;
>  #  endif
>  
>  	for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {

isn't this part removed before in 2/4 'autoboot.c: Remove
CONFIG_AUTOBOOT_STOP_STR2 and CONFIG_AUTOBOOT_DELAY_STR2'?

Andreas