// SPDX-License-Identifier: GPL-2.0+

  /*
   * (C) Copyright 2000
   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.

   */
  
  #include <common.h>

  #include <autoboot.h>

  #include <bootretry.h>

  #include <cli.h>

  #include <console.h>

  #include <env.h>

  #include <fdtdec.h>

  #include <hash.h>

  #include <memalign.h>

  #include <menu.h>
  #include <post.h>

  #include <u-boot/sha256.h>

  #include <bootcount.h>

  
  DECLARE_GLOBAL_DATA_PTR;
  
  #define MAX_DELAY_STOP_STR 32
  
  #ifndef DEBUG_BOOTKEYS
  #define DEBUG_BOOTKEYS 0
  #endif
  #define debug_bootkeys(fmt, args...)		\
  	debug_cond(DEBUG_BOOTKEYS, fmt, ##args)

  /* Stored value of bootdelay, used by autoboot_command() */
  static int stored_bootdelay;

  static int menukey;

  #ifdef CONFIG_AUTOBOOT_ENCRYPTION
  #define AUTOBOOT_STOP_STR_SHA256 CONFIG_AUTOBOOT_STOP_STR_SHA256
  #else
  #define AUTOBOOT_STOP_STR_SHA256 ""
  #endif

  #ifdef CONFIG_USE_AUTOBOOT_MENUKEY
  #define AUTOBOOT_MENUKEY CONFIG_USE_AUTOBOOT_MENUKEY
  #else
  #define AUTOBOOT_MENUKEY 0
  #endif

  /*
   * Use a "constant-length" time compare function for this
   * hash compare:
   *
   * https://crackstation.net/hashing-security.htm

   */

  static int slow_equals(u8 *a, u8 *b, int len)
  {
  	int diff = 0;
  	int i;
  
  	for (i = 0; i < len; i++)
  		diff |= a[i] ^ b[i];
  
  	return diff == 0;
  }

  /**
   * passwd_abort_sha256() - check for a hashed key sequence to abort booting
   *
   * This checks for the user entering a SHA256 hash within a given time.
   *
   * @etime: Timeout value ticks (stop when get_ticks() reachs this)
   * @return 0 if autoboot should continue, 1 if it should stop
   */

  static int passwd_abort_sha256(uint64_t etime)

  {

  	const char *sha_env_str = env_get("bootstopkeysha256");

  	u8 sha_env[SHA256_SUM_LEN];

  	u8 *sha;
  	char *presskey;

  	const char *algo_name = "sha256";
  	u_int presskey_len = 0;
  	int abort = 0;

  	int size = sizeof(sha);

  	int ret;
  
  	if (sha_env_str == NULL)

  		sha_env_str = 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
  	 */
  	ret = hash_parse_string(algo_name, sha_env_str, sha_env);
  	if (ret) {
  		printf("Hash %s not supported!
  ", algo_name);
  		return 0;
  	}

  	presskey = malloc_cache_aligned(MAX_DELAY_STOP_STR);
  	sha = malloc_cache_aligned(SHA256_SUM_LEN);
  	size = SHA256_SUM_LEN;

  	/*
  	 * 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()) {
  			/* Check for input string overflow */

  			if (presskey_len >= MAX_DELAY_STOP_STR) {
  				free(presskey);
  				free(sha);

  				return 0;

  			}

  
  			presskey[presskey_len++] = getc();
  
  			/* Calculate sha256 upon each new char */
  			hash_block(algo_name, (const void *)presskey,
  				   presskey_len, sha, &size);
  
  			/* And check if sha matches saved value in env */
  			if (slow_equals(sha, sha_env, SHA256_SUM_LEN))
  				abort = 1;
  		}
  	} while (!abort && get_ticks() <= etime);

  	free(presskey);
  	free(sha);

  	return abort;
  }

  /**
   * passwd_abort_key() - check for a key sequence to aborted booting
   *
   * This checks for the user entering a string within a given time.
   *
   * @etime: Timeout value ticks (stop when get_ticks() reachs this)
   * @return 0 if autoboot should continue, 1 if it should stop
   */

  static int passwd_abort_key(uint64_t etime)

  {
  	int abort = 0;

  	struct {
  		char *str;
  		u_int len;
  		int retry;
  	}
  	delaykey[] = {

  		{ .str = env_get("bootdelaykey"),  .retry = 1 },
  		{ .str = env_get("bootstopkey"),   .retry = 0 },

  	};
  
  	char presskey[MAX_DELAY_STOP_STR];
  	u_int presskey_len = 0;
  	u_int presskey_max = 0;
  	u_int i;

  #  ifdef CONFIG_AUTOBOOT_DELAY_STR
  	if (delaykey[0].str == NULL)
  		delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR;
  #  endif

  #  ifdef CONFIG_AUTOBOOT_STOP_STR

  	if (delaykey[1].str == NULL)
  		delaykey[1].str = CONFIG_AUTOBOOT_STOP_STR;

  #  endif
  
  	for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
  		delaykey[i].len = delaykey[i].str == NULL ?
  				    0 : strlen(delaykey[i].str);
  		delaykey[i].len = delaykey[i].len > MAX_DELAY_STOP_STR ?
  				    MAX_DELAY_STOP_STR : delaykey[i].len;
  
  		presskey_max = presskey_max > delaykey[i].len ?
  				    presskey_max : delaykey[i].len;
  
  		debug_bootkeys("%s key:<%s>
  ",
  			       delaykey[i].retry ? "delay" : "stop",
  			       delaykey[i].str ? delaykey[i].str : "NULL");
  	}
  
  	/* In order to keep up with incoming data, check timeout only
  	 * when catch up.
  	 */
  	do {
  		if (tstc()) {
  			if (presskey_len < presskey_max) {
  				presskey[presskey_len++] = getc();
  			} else {
  				for (i = 0; i < presskey_max - 1; i++)
  					presskey[i] = presskey[i + 1];
  
  				presskey[i] = getc();
  			}
  		}
  
  		for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
  			if (delaykey[i].len > 0 &&
  			    presskey_len >= delaykey[i].len &&
  				memcmp(presskey + presskey_len -
  					delaykey[i].len, delaykey[i].str,
  					delaykey[i].len) == 0) {
  					debug_bootkeys("got %skey
  ",
  						delaykey[i].retry ? "delay" :
  						"stop");

  				/* don't retry auto boot */
  				if (!delaykey[i].retry)
  					bootretry_dont_retry();

  				abort = 1;
  			}
  		}
  	} while (!abort && get_ticks() <= etime);

  	return abort;
  }

  
  /***************************************************************************
   * 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_key_sequence(int bootdelay)

  {
  	int abort;
  	uint64_t etime = endtick(bootdelay);

  #  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

  	if (IS_ENABLED(CONFIG_AUTOBOOT_ENCRYPTION))
  		abort = passwd_abort_sha256(etime);
  	else
  		abort = passwd_abort_key(etime);

  	if (!abort)
  		debug_bootkeys("key timeout
  ");

  	return abort;
  }

  static int abortboot_single_key(int bootdelay)

  {
  	int abort = 0;
  	unsigned long ts;

  	printf("Hit any key to stop autoboot: %2d ", bootdelay);

  	/*
  	 * Check if key already pressed

  	 */

  	if (tstc()) {	/* we got a key press	*/
  		(void) getc();  /* consume input	*/
  		puts("\b\b\b 0");
  		abort = 1;	/* don't auto boot	*/

  	}

  
  	while ((bootdelay > 0) && (!abort)) {
  		--bootdelay;
  		/* delay 1000 ms */
  		ts = get_timer(0);
  		do {
  			if (tstc()) {	/* we got a key press	*/

  				int key;

  				abort  = 1;	/* don't auto boot	*/
  				bootdelay = 0;	/* no more delay	*/

  				key = getc(); /* consume input	*/
  				if (IS_ENABLED(CONFIG_USE_AUTOBOOT_MENUKEY))
  					menukey = key;

  				break;
  			}
  			udelay(10000);
  		} while (!abort && get_timer(ts) < 1000);
  
  		printf("\b\b\b%2d ", bootdelay);
  	}
  
  	putc('
  ');

  	return abort;
  }

  
  static int abortboot(int bootdelay)
  {

  	int abort = 0;

  	if (bootdelay >= 0) {
  		if (IS_ENABLED(CONFIG_AUTOBOOT_KEYED))
  			abort = abortboot_key_sequence(bootdelay);
  		else
  			abort = abortboot_single_key(bootdelay);
  	}

  	if (IS_ENABLED(CONFIG_SILENT_CONSOLE) && abort)

  		gd->flags &= ~GD_FLG_SILENT;

  
  	return abort;

  }

  static void process_fdt_options(const void *blob)
  {

  #ifdef CONFIG_SYS_TEXT_BASE

  	ulong addr;
  
  	/* Add an env variable to point to a kernel payload, if available */
  	addr = fdtdec_get_config_int(gd->fdt_blob, "kernel-offset", 0);
  	if (addr)

  		env_set_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));

  
  	/* Add an env variable to point to a root disk, if available */
  	addr = fdtdec_get_config_int(gd->fdt_blob, "rootdisk-offset", 0);
  	if (addr)

  		env_set_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));

  #endif /* CONFIG_SYS_TEXT_BASE */

  }

  const char *bootdelay_process(void)

  {

  	char *s;
  	int bootdelay;

  
  	bootcount_inc();

  	s = env_get("bootdelay");

  	bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY;

  	if (IS_ENABLED(CONFIG_OF_CONTROL))
  		bootdelay = fdtdec_get_config_int(gd->fdt_blob, "bootdelay",
  						  bootdelay);

  
  	debug("### main_loop entered: bootdelay=%d
  
  ", bootdelay);

  	if (IS_ENABLED(CONFIG_AUTOBOOT_MENU_SHOW))
  		bootdelay = menu_show(bootdelay);

  	bootretry_init_cmd_timeout();

  
  #ifdef CONFIG_POST
  	if (gd->flags & GD_FLG_POSTFAIL) {

  		s = env_get("failbootcmd");

  	} else
  #endif /* CONFIG_POST */

  	if (bootcount_error())

  		s = env_get("altbootcmd");

  	else

  		s = env_get("bootcmd");

  	if (IS_ENABLED(CONFIG_OF_CONTROL))
  		process_fdt_options(gd->fdt_blob);

  	stored_bootdelay = bootdelay;

  	return s;
  }

  void autoboot_command(const char *s)
  {

  	debug("### main_loop: bootcmd=\"%s\"
  ", s ? s : "<UNDEFINED>");

  	if (stored_bootdelay != -1 && s && !abortboot(stored_bootdelay)) {

  		bool lock;
  		int prev;
  
  		lock = IS_ENABLED(CONFIG_AUTOBOOT_KEYED) &&
  			!IS_ENABLED(CONFIG_AUTOBOOT_KEYED_CTRLC);
  		if (lock)
  			prev = disable_ctrlc(1); /* disable Ctrl-C checking */

  
  		run_command_list(s, -1, 0);

  		if (lock)
  			disable_ctrlc(prev);	/* restore Ctrl-C checking */

  	}

  	if (IS_ENABLED(CONFIG_USE_AUTOBOOT_MENUKEY) &&
  	    menukey == AUTOBOOT_MENUKEY) {

  		s = env_get("menucmd");

  		if (s)
  			run_command_list(s, -1, 0);
  	}

  }