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: Tom Rini trini@konsulko.com --- v2: - Extracted the passwd checking functions (sha256 and non-sha256) into passwd_abort(). Resulting in an easier to read code with less #ifdef's.
common/autoboot.c | 90 +++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 74 insertions(+), 16 deletions(-)
diff --git a/common/autoboot.c b/common/autoboot.c index c27cc2c..def1612 100644 --- a/common/autoboot.c +++ b/common/autoboot.c @@ -12,6 +12,7 @@ #include <fdtdec.h> #include <menu.h> #include <post.h> +#include <u-boot/sha256.h>
DECLARE_GLOBAL_DATA_PTR;
@@ -26,15 +27,58 @@ DECLARE_GLOBAL_DATA_PTR; /* Stored value of bootdelay, used by autoboot_command() */ static int stored_bootdelay;
-/*************************************************************************** - * Watch for 'delay' seconds for autoboot stop or autoboot delay string. - * returns: 0 - no key string, allow autoboot 1 - got key string, abort - */ -# if defined(CONFIG_AUTOBOOT_KEYED) -static int abortboot_keyed(int bootdelay) +#if defined(CONFIG_AUTOBOOT_KEYED) +#if defined(CONFIG_AUTOBOOT_STOP_STR_SHA256) +static int passwd_abort(uint64_t etime) +{ + const char *sha_env_str = getenv("bootstopkeysha256"); + u8 sha_env[SHA256_SUM_LEN]; + u8 sha[SHA256_SUM_LEN]; + char presskey[MAX_DELAY_STOP_STR]; + u_int presskey_len = 0; + int i; + int abort = 0; + + if (sha_env_str == NULL) + sha_env_str = CONFIG_AUTOBOOT_STOP_STR_SHA256; + + /* + * Generate the binary value from the environment hash value + * so that we can compare this value with the computed hash + * from the user input + */ + for (i = 0; i < SHA256_SUM_LEN; i++) { + char chr[3]; + + strncpy(chr, &sha_env_str[i * 2], 2); + sha_env[i] = simple_strtoul(chr, NULL, 16); + } + + /* + * We don't know how long the stop-string is, so we need to + * generate the sha256 hash upon each input character and + * compare the value with the one saved in the environment + */ + do { + if (tstc()) { + presskey[presskey_len++] = getc(); + + /* Calculate sha256 upon each new char */ + sha256_csum_wd((unsigned char *)presskey, presskey_len, + sha, CHUNKSZ_SHA256); + + /* And check if sha matches saved value in env */ + if (memcmp(sha, sha_env, SHA256_SUM_LEN) == 0) + abort = 1; + } + } while (!abort && get_ticks() <= etime); + + return abort; +} +#else +static int passwd_abort(uint64_t etime) { int abort = 0; - uint64_t etime = endtick(bootdelay); struct { char *str; u_int len; @@ -52,15 +96,6 @@ 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 - printf(CONFIG_AUTOBOOT_PROMPT); -# endif - # ifdef CONFIG_AUTOBOOT_DELAY_STR if (delaykey[0].str == NULL) delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR; @@ -125,6 +160,29 @@ static int abortboot_keyed(int bootdelay) } } while (!abort && get_ticks() <= etime);
+ return abort; +} +#endif + +/*************************************************************************** + * Watch for 'delay' seconds for autoboot stop or autoboot delay string. + * returns: 0 - no key string, allow autoboot 1 - got key string, abort + */ +static int abortboot_keyed(int bootdelay) +{ + int abort; + uint64_t etime = endtick(bootdelay); + +#ifndef CONFIG_ZERO_BOOTDELAY_CHECK + if (bootdelay == 0) + return 0; +#endif + +# ifdef CONFIG_AUTOBOOT_PROMPT + printf(CONFIG_AUTOBOOT_PROMPT); +# endif + + abort = passwd_abort(etime); if (!abort) debug_bootkeys("key timeout\n");