u-boot/common/main.c

/*
 * (C) Copyright 2000
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/* #define	DEBUG	*/

#include <common.h>
#include <autoboot.h>
#include <cli.h>
#include <console.h>
#include <version.h>

#ifdef CONFIG_NM_LOGIN
#include <fs.h>
#include <u-boot/md5.h>
#include <malloc.h>
#include <crypt.h>

/* Set defaults for passwd file location */
#ifndef CONFIG_NM_LOGIN_PART
#define CONFIG_NM_LOGIN_PART	"1:3"
#endif
#ifndef CONFIG_NM_LOGIN_PASSWD
#define CONFIG_NM_LOGIN_PASSWD	"/root/boot/bootpass"
#endif

#endif

DECLARE_GLOBAL_DATA_PTR;

/*
 * Board-specific Platform code can reimplement show_boot_progress () if needed
 */
__weak void show_boot_progress(int val) {}


#ifdef CONFIG_NM_LOGIN
/****************************************************************************
 *  check if ubootpwd exists in data partition and perform a login,
 *  otherwise continue booting
 */
int login (void)
{
	#define MAX_TRIES_ENTER 4096
	#define PASSWORD_LEN 256

	char stored_pw_hash[PASSWORD_LEN];
	char password[PASSWORD_LEN];
	int res, i, tries;
	int legacy_md5 = 0;
	loff_t actread;
	char c;

	puts("\nautoboot has been stopped, press 'e' to enter: ");

	for (i=0; i<=MAX_TRIES_ENTER; i++) {
		c = getc();
		if (c == 'e' || c == '\n') {
			puts("e");
			break;
		}

		/* Enter condition not given -> restart */
		if (i == MAX_TRIES_ENTER) 
			return 0;
	}
	puts("\n");

	/* Try to get password hash file */
	memset(stored_pw_hash, 0x0, sizeof(stored_pw_hash));
	if (fs_set_blk_dev("mmc", CONFIG_NM_LOGIN_PART, FS_TYPE_EXT) != 0) {
		puts("Error, can not set blk device\n");
		return 1;
	}

	res = fs_read(CONFIG_NM_LOGIN_PASSWD, (ulong)stored_pw_hash, 0, sizeof(stored_pw_hash), &actread);
	if ((res != 0) || (actread <= 0)) {
		/* no file or hash found -> allow login w/o password */
		puts("Login succeeded\n\n");
		return 1;
	} else if (actread == 16) {
		legacy_md5 = 1;
	}

	for (tries = 1; ; tries++) {
		puts("\nEnter password: ");

		/* TODO: no backspace ? */
		/* TODO: rename buf to something more useful */
		/* TODO: print a dot or blind? */
		password[0] = 0;
		for (i=0; i<PASSWORD_LEN; i++) {
			password[i] = getc();
			if (password[i] == '\r' || password[i] == '\n') {
				password[i] = 0;
				break;
			}
		}
		password[PASSWORD_LEN-1] = 0;

		if (strlen(password) > 0) {
			puts("\n");
			if (legacy_md5) {
				/* MD5 - legacy */
				char entered[32];	/* TODO: Why 32, MD5 algo uses only 16 bytes */

				md5((unsigned char *)password, strlen(password), (unsigned char *)entered);
				if (memcmp(stored_pw_hash, entered, 16) == 0) {
					break;
				}
			}
			else {
				/* SHA256 */
				char *cp = sha_crypt(password, stored_pw_hash);	/* TODO: Salt = PW? */
				res = memcmp(cp, stored_pw_hash, actread);
				free(cp);
				if (res == 0)
					break;
			}

			/* TODO: exponentional delay */
			puts("Login incorrect\n");
			if (tries == 3) {
				return 0;
			}
		}

		/* TODO: remove password from memory !!!!! */
		memset(password, 0, sizeof(password));
	}

	/* succeeded */
	puts("Login succeeded\n\n");

	return 1;
}

#endif /* CONIFG_NM_LOGIN */

/****************************************************************************/

static void run_preboot_environment_command(void)
{
#ifdef CONFIG_PREBOOT
	char *p;

	p = getenv("preboot");
	if (p != NULL) {
# ifdef CONFIG_AUTOBOOT_KEYED
		int prev = disable_ctrlc(1);	/* disable Control C checking */
# endif

		run_command_list(p, -1, 0);

# ifdef CONFIG_AUTOBOOT_KEYED
		disable_ctrlc(prev);	/* restore Control C checking */
# endif
	}
#endif /* CONFIG_PREBOOT */
}

/* We come here after U-Boot is initialised and ready to process commands */
void main_loop(void)
{
	const char *s;

	bootstage_mark_name(BOOTSTAGE_ID_MAIN_LOOP, "main_loop");

#ifdef CONFIG_VERSION_VARIABLE
	setenv("ver", version_string);  /* set version variable */
#endif /* CONFIG_VERSION_VARIABLE */

	cli_init();

	run_preboot_environment_command();

#if defined(CONFIG_UPDATE_TFTP)
	update_tftp(0UL, NULL, NULL);
#endif /* CONFIG_UPDATE_TFTP */

	s = bootdelay_process();
	if (cli_process_fdt(&s))
		cli_secure_boot_cmd(s);

	autoboot_command(s);

#ifdef CONFIG_NM_LOGIN
	if (!login()) {
		puts ("Login failed, resetting...\n");
		do_reset (NULL, 0, 0, NULL);
	}
#endif

	cli_loop();
	panic("No CLI available");
}